Articles containing the keyword 'vegetation'

Dry mass and nutrient (N, P, K, Ca, Mg, B) contents of field layer vegetation and a combination of bottom layer vegetation and litter (referred to as bottom/litter layer in the text) were studied one year before and three years after fertilization (NPK and PK) on a drained low-shrub pine bog in eastern Finland. The results of an earlier study on the tree layer were combined with those of this study in order to estimate the changes caused by fertilization in the total plant biomass and litter. Before fertilization the average dry mass of the field and bottom/litter layers was 8,400 kg ha^-1 and 7,650 kg ha^-1, respectively. The above-ground parts accounted for 25% of the total field layer biomass. The dry mass of the field and bottom/litter layers together was < 20% of the dry mass accumulated in the total plant biomass and litter. The corresponding figures for N, P, K, Ca, Mg and B were 44%, 38%, 30%, 38%, 31% and 17%, respectively. Fertilization did not significantly affect the dry mass of either the field layer vegetation or the bottom/litter layer. 33% of the applied P was accumulated in the total plant biomass and litter on the PK-fertilized plots, and 25% on the NPK-fertilized plots. For the other elements, the proportions on the PK-fertilized plots were K 31%, Ca 6%, Mg 11% and B 13%. On the NPK-fertilized plots, the corresponding figures were N 62%, K 32%, Ca 6%, Mg 9% and B 13%. Except for B and K, the accumulation of fertilizer nutrients in the understorey vegetation and litter was of the same magnitude or greater than the uptake by the tree layer.

• Finér, E-mail: lf@mm.unknown
• Nieminen, E-mail: mn@mm.unknown

An equilibrium model driven by climatic parameters, the Siberian Vegetation Model, was used to estimate changes in the phytomass of Siberian vegetation under climate change scenarios (CO₂ doubling) from four general circulation models (GCM's) of the atmosphere. Ecosystems were classified using a three-dimensional climatic ordination of growing degree days (above a 5 °C threshold), Budyko's dryness index (based on radiation balance and annual precipitation), and Conrad's continentality index. Phytomass density was estimated using published data of Bazilevich covering all vegetation zones in Siberia. Under current climate, total phytomass of Siberia is estimated to be 74.1 ± 2.0 Pg (petagram = 1,015 g). Note that this estimate is based on the current forested percentage in each vegetation class compiled from forest inventory data.

Moderate warming associated with the GISS (Goddard Institute for Space Studies) and OSU (Oregon State Univ.) projections resulted in a 23–26 % increase in phytomass (to 91.3 ± 2.1 Pg and 93.6 ± 2.4 Pg, respectively), primarily due to an increase in the productive Southern Taiga and Sub-taiga classes. Greater warming associated with the GFDL (General Fluid Dynamics Laboratory) and UKMO (United Kingdom Meteorological Office) projections resulted in a small 3–7 % increase in phytomass (to 76.6 ± 1.3 Pg and 79.6 ± 1.2 Pg, respectively). A major component of predicted change using GFDL and UKMO is the introduction of a vast Temperate Forest-Steppe class covering nearly 40% of the area of Siberia, at the expense of Taiga; with current climate, this vegetation class is nearly non-existent in Siberia. In addition, Sub-boreal Forest-Steppe phytomass double with all GCM predictions. In all four climate change scenarios, the predicted phytomass stock of all colder, northern classes is reduced considerably (viz., Tundra, Fore Tundra, northern Taiga, and Middle Taiga). Phytomass in Sub-taiga increases greatly with all scenarios, from a doubling with GFDL to quadrupling with OSU and GISS. Overall, phytomass of the Taiga biome (Northern, Middle, Southern and Sub-taiga) increased 15% in the moderate OSU and GISS scenarios and decreased by a third in the warmer UKMO and GFDL projections. In addition, a sensitivity analysis found that the percentage of a vegetation class that is forested is a major factor determining phytomass distribution. From 25 to 50% more phytomass is predicted under climate change if the forested proportion corresponding to potential rather than current vegetation is assumed.

• Monserud, E-mail: rm@mm.unknown
• Denissenko, E-mail: od@mm.unknown
• Kolchugina, E-mail: tk@mm.unknown
• Tchebakova, E-mail: nt@mm.unknown

Fresh and herb-rich upland forest sites in the north-western part of the central boreal vegetation zone in Finland were studied with respect to vegetation structure and vegetation-environment relationships (soil, stand characteristics). Two fresh heath vegetation data sets, one from the northern boreal zone and the other from the central boreal zone, were compared with the data of this study using multivariate methods.

The variation in heath forest vegetation within the climatically uniform area was mainly determined by the fertility of the soil (primarily Ca and Mg) and the stage of stand development. N, P and K content of the humus layer varied little between the vegetation classes. Fertile site types occurred, in general, on coarse-textured soils than infertile site types, may be due to the fact that the sample plots were located in various bedrock and glacial till areas, i.e. to sampling effects.

The place of the vegetational units of the study area in the Finnish forest site type system is discussed. The vegetation of the area has features in common with the northern boreal zone as well as the southern part of the central boreal vegetation zone. The results lend some support to the occurrence of a northern Myrtillus type or at least that intermediate form of fresh and herb-rich mineral soil sites commonly occur in the studied area. It is argued that the older name Dryopteris-Myrtillus type is more suitable than Geranium-Oxalis-Myrtillus type for herb-rich heath sites in the study area.

• Lehtelä, E-mail: ml@mm.unknown
• Hotanen, E-mail: jh@mm.unknown
• Sepponen, E-mail: ps@mm.unknown

The effects of wood ash and PK fertilization on natural regeneration and sowing of Scots pine (Pinus sylvestris L.) were studied in field experiments on nitrogen-poor (N_tot 0.87–1.26%) peat substrates. The study material was derived from three drained, nutrient-poor pine mires (64°52’ N, 25°08’ E) at Muhos, near Oulu, Finland. The experimental fields were laid out in 1985 as a split-split-plot design including the following treatments; mounding, natural regeneration and sowing and fertilization; PK (400 kg ha^-1) and wood ash (5,000 kg ha^-1). The seedlings were inventoried in circles in July–August 1991.

Changes in the vegetation were small and there were no statistical differences due to the fertilization treatments in the ground vegetation. PK or ash fertilization did not cause vegetation changes harmful to Scots pine regeneration on nitrogen-poor peatlands. Both sowing and fertilization significantly increased the number of pine seedlings, but not their height. Wood ash increased seedling number more than PK fertilizer. The number of seedlings varied from 7,963 (control) to 42,781 ha^-1 (mounding + sowing + ash). The seedling number was adequate for successful regeneration even on non-mounded, non-fertilized naturally regenerated plots.

The number of birch seedlings varied more than that of pine (370–25,927 ha-¹). Mounding especially increased the number of birches. The difference between PK fertiliser and ash was less pronounced than that for pine. In addition, to the field studies the effects of ash and PK fertilizer on the germination of Scots pine seeds was studied in a greenhouse experiment. Soaking in ash solutions strongly reduced seed germination, while the PK solution was less harmful.

• Silfverberg, E-mail: ks@mm.unknown

Forest ecosystems may accumulate large amounts of nitrogen in the biomass and in the soil organic matter. However, there is increasing concern that deposition of inorganic nitrogen compounds from the atmosphere will lead to nitrogen saturation; excess nitrogen input does not increase production. The aim of this study was to determine the long-term changes caused by nitrogen input on accumulation of nitrogen in forest soils and in ground vegetation.

The fertilization experiments used in this study were established during 1958–1962. They were situated on 36- to 63-year-old Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) stands of different levels of fertility. The experiments received nitrogen fertilization 5–7 times over a 30-year period, and the total input of nitrogen was 596–926 kg/ha.

Nitrogen input increased the amount of organic matter in the humus layer and the nitrogen concentration in the organic matter. Furthermore, the total amount of nutrients (N, P, K, Ca and Mg) bound by the humus layer increased due to the increase in the amount of organic matter. However, nitrogen input decreased the biomass of ground vegetation. The nitrogen concentration of the plant material on the nitrogen-fertilized plots was higher than on the control plots, but the amount of nutrients bound by ground vegetation decreased owing to the drastic decrease in the biomass of mosses. Ground vegetation does not have the potential to accumulate nitrogen, because vegetation is dominated by slow-growing mosses and dwarf shrubs which do not benefit from nitrogen input.

• Mäkipää, E-mail: rm@mm.unknown

Abundant snowfalls and thick snow cover influence forest ecology mainly in two ways. Snow loading increases the number of damaged stems, which increases the amount of decay in stems, in its turn important for many animals. Second, the ground remains unfrozen under the snow cover, which is of crucial importance for many perennial species of ground vegetation. These winter phenomena also have influenced the early Finnish culture as man in his everyday life in the wilderness was in close contact with nature. In this paper, ecological interactions between snow conditions, forest flora, fauna and early culture are discussed mainly with reference to the province of Uusimaa in Southern Finland.

• Solantie, E-mail: rs@mm.unknown

Coniferous and non-coniferous fine root and rhizome production was measured after one growing season using the ingrowth bag method in Scots pine (Pinus sylvestris L.) stands differing in ages from 7 to 105 years in Southern Finland. Total fine-root production decreased from the 7-year to 20-year-old stands, and then increased slightly in the 85- to 105-year-old stands. Most of the total fine-root biomass in the youngest age groups came from non-conifer species, whereas most of the total fine-root biomass in the three older age groups came from conifer species. The maximum coniferous fine-root production was found to occur at crown closure in the 11- to 13-year-old stands. Rhizome production was the lowest and highest in the 20- and 85- to 105-year-old stands, respectively. The increase in rhizome production in the 85- to 105-year-old stands was associated with an abundant understory cover of Vaccinium myrtillus and V. vitis-idaea and an increase in light penetration. The ingrowth bag method was found to be useful in assessing the relative fine-root production among species-group and successional stages of Scots pine stands.

The PDF includes an abstract in Finnish.

• Messier, E-mail: cm@mm.unknown
• Puttonen, E-mail: pp@mm.unknown

Different methods of sowing and planting of Norway spruce (Picea abies (L.) H. Karst.) were compared on fertile sites in North Karelia (62°20’N, 29°35’E, 85–120 m a.s.l.). The planting material were 4-year-old bare-rooted transplants, 2-year-old bare-rooted seedlings, and 2-year-old containerized seedlings raised in plastic greenhouse. The sowing methods were band sowing and shelter sowing. Ground vegetation was controlled during the first growing season mechanically or chemically, or the control was omitted totally.

Planting of spruce gave better results than sowing. After eight growing seasons there were sowed seedlings left in 30% of the sowing pots. The average height of them was 35 cm. Seedling survival was best with large bare-rooted transplants (91%). Survival of containerized seedlings was 79% and of small bare-rooted transplants 71%. The average height of large bare-rooted transplants was 131 cm, of containerized seedlings 86 cm and small bare-rooted seedlings 68 cm.

Sowing is not an advisable method for regeneration of spruce due to the small survival rate and slow initial development when ground vegetation is controlled only once. Also 2-year-old seedlings gave a satisfactory result in regeneration. Seedlings raised in greenhouse were more sensitive to frost damage than seedlings grown on open ground.

The PDF includes an abstract in English.

• Kolström, E-mail: tk@mm.unknown

Scots pine (Pinus sylvestris L.) living root biomass (ø≤ 10 mm) was 640 g/m² on the studied low-shrub pine bog before fertilization, and that of the ground vegetation almost the same. The total root necromass was 23% of the biomass of living roots. The length of the pine roots was 2,440 m/m². The biomass of living roots and root necromass were mostly located in the top 20 cm layer of the soil. The ø < 1 mm pine root fraction accounted for almost 90% of the pine root length; in contrast, over 50% of the biomass was in the 1–10 mm thick root biomass, pine root length and PK (MgB) fertilization did not affect total living root biomass, pine root length, nor the root necromass during the three-year observation period.

The PDF includes an abstract in Finnish.

• Finér, E-mail: lf@mm.unknown

Differences in vegetation cover estimation by field biologists of the 8th National Forest Inventory in Finland were tested. Eleven observers estimated the canopy coverages of six forests taxa in 25 sample plots, located in one stand. The experiment was arranged after the field work. The coverage of Vaccinium vitis-idaea and the ground layer appeared to be the most difficult to estimate. The mean of the highest estimator was about double that of the lowest one. The least abundant species and the sample plots with the smallest coverages had the largest estimation errors. The most important compositional gradient of the data was natural, even though the test was made in a homogenous area. However, the effect of the observer could be recognized. The differences between observers could be caused by the differences both in visual estimation level and in placing the sampling frame. The results suggest that tests should always be made when several observers are used in vegetation surveys. If calibration is used, it should be made separately for each species.

The PDF includes an abstract in Finnish.

• Tonteri, E-mail: tt@mm.unknown

The study uses the methodology of ecological field theory to model the effect of Scots pine (Pinus sylvestris L.) seed trees on the density of tree seedlings and other plants in the field layer. The seed trees had a clear effect on the expected value of the amount and distribution of the ground vegetation. The vicinity of seed trees had an adverse effect on the growth of grasses, herbs and seedlings, while mosses were most abundant near the trees. Models based on the ecological field approach were derived to describe the effect of seed trees on the ground vegetation.

The PDF includes an abstract in Finnish.

• Kuuluvainen, E-mail: tk@mm.unknown
• Pukkala, E-mail: tp@mm.unknown

Different sampling methods (the percentage cover scale, the graphical method, two-point quadrat methods, the five-, nine- and twelve-class cover scales, and the biomass harvesting) were used in estimating abundance of ground vegetation in clear-cut areas and on an abandoned field in Southern and Central Finland. The results are examined with the help of DCA ordinations. In addition, the species numbers and diversity indices obtained by different sampling methods are compared.

There were no large differences in DCA configurations between the sampling methods. According to all the sampling methods, a complex soil fertility-moisture gradient (a forest site type) was interpreted as the main ordination gradient in the vegetation data for clear-cut areas. However, different sampling methods did not give similar estimates of species numbers and diversity indices.

The PDF includes a summary in Finnish.

• Jukola-Sulonen, E-mail: ej@mm.unknown
• Salemaa, E-mail: ms@mm.unknown

A field data set representing boreal forest-floor vegetation in Southern Finland was analysed using a simultaneous equation model. Some physical and chemical characteristics of the soil and some structural characteristics of the tree stand were treated as predictors in such a way that the tree stand factor was specified to be dependent on the soil variables. Alpha diversity, measured as the total number of species per plot, was treated as a criterion variable.

The model explains 60% of variance in the alpha diversity indicating markedly strong relationships with the site characteristics. Alpha diversity appears to increase with increases in site fertility characteristics. On the other hand, measured characteristics of the tree stand indicate no significant independent effects on the alpha diversity.

The PDF includes a summary in Finnish.

• Kuusipalo, E-mail: jk@mm.unknown

The Lauhavuori area is barren, consisting of sandstone and granite bedrock covered by coarse moraine and sand. The woodlands are dominated by Scots pine (Pinus sylvestris L.) and Calluna. The top of the hill, rising 230 metres above the sea level, is more fertile, as it was never covered by the ancient Baltic Sea. Numerous springs and spring brooks are bordered by herb-rich Norway spruce (Picea abies (L.) H. Karst.) woodlands and swamps. Although most of the peatlands are oligotrophic, several mesotrophic peatland plants occur, some southern, giving the peatlands a rather northerly character.

The study area is 8 by 12 km. According to the vegetation analysis, 310 species were identified, 208 of which were native to the area and 102 immigrants. The native species can be separated from the immigrants because the area is largely undisturbed.

The PDF includes a summary in English.

• Suominen, E-mail: js@mm.unknown
• Varkki, E-mail: av@mm.unknown

Vegetation data collected from a random sample of mature forest stands representing mesic upland forest sites in Southern Finland were analysed and classified using two-way indicator species analysis (TWINSPAN). The variation of some characteristics of the tree stand and soil fertility between the produced vegetation units were analysed statistically.

Both the species list and the sample list arranged by TWINSPAN reflects the overall site fertility considerably well. The results are in agreement with the main division of mesic forest sites in the Finnish forest site type classification: vegetation units which can be assigned to the Oxalis-Myrtillus site type are clearly separated from the remaining units, and the overall site fertility indicates a statistically significant difference. The within-type variation in the vegetation composition in the Oxalis-Myrtillus site type reflects the variation in site fertility, whereas the within-type variation in the Myrtillus site type is mainly caused by the tree stand factor.

The PDF includes a summary in Finnish.

• Kuusipalo, E-mail: jk@mm.unknown

The tolerance of disturbance of the ground and field layer vegetation in a moderately fertile Norway spruce (Picea abies (L.) H. Karst.) on Oxalis-Myrtillus type forest in Southern Finland was studied. One of the sites, a summer cottage yard had been raked regularly during the last 25 years. The structure of the vegetation was quite different compared to the other sample site situated in a virgin forest. The phytomass and percentual coverage of the vegetation was remarkable lower in the raked habitat. Tall mosses, Pleuroxium schreberi and Hylocomnium splendens had especially disappeared. Most grass shrubs had also deteriorated. Only Deschampsia flexuosa was quite tolerant to raking. The phytomass of the dwarf shrubs was lower in the raked area but their relative production was higher. Three different kinds strategies of species were described: species of virgin shaded forest, species of meadow-like forest floor and species which tolerate or benefit from disturbance. The raked habitat had a higher species diversity than the virgin area. Nitrogen and carbon contents were lower in the soil of the raked area.

The PDF includes a summary in Finnish.

• Lindholm, E-mail: tl@mm.unknown
• Nummelin, E-mail: mn@mm.unknown

The study deals with the distribution of above-ground biomass of Vaccinium myrtillus L. along the vegetation continuum segregated by using phytosociological classification method composite clustering. The qualitative characteristics of forest sites corresponding to different vegetational clusters were defined on the basis of indirect gradient analysis of vegetation data and description of tree stand properties in stands in 160 sample areas in Southern Finland.

Six vegetation types differing from each other mainly in abundance of the most constant and dominant plant species were formed. Sample areas with rich grass-herb vegetation, as well as sample areas representing comparatively dry, barren site type were clearly separated from other groups of sample areas. Stand characteristics, particularly the proportional distribution of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) seems to be another important factor affecting the vegetation composition.

The lowest biomass values of blueberry were connected with herb-rich vegetation and shady spruce-dominated stands. Comparatively low values were connected to also other spruce-dominated sample areas. Pine-dominant or mixed pine-spruce stands the biomass values were significantly higher. Even if the site quality is essentially equal, the abundance relationships between Vaccinium myrtillus and other components of the ground vegetation may vary in wide ranges and cause difficulties in practical site classification.

The PDF includes a summary in English.

• Kuusipalo, E-mail: jk@mm.unknown

A mature Scots pine (Pinus sylvestris L.) stand growing on a site of the Vaccinium type in Southern Finland was fertilized with nitrogen-rich NPK fertilizer at a level of 150 kg pure nitrogen per hectare. The sample plots were also irrigated during four growing seasons. The total amount of irrigation during this period was 1,200 mm. Fertilization alone increased the coverage of grasses and dwarf shrubs. The culmination of the increase occurred during the second growing season after the start of the treatment. The rapid effect of irrigation on the coverage of ground vegetation was not so strong as that of fertilization. It was concluded on the basis of the developed growth model that the coverage of dwarf shrubs, especially Calluna vulgaris, was, however, increased with the fertilization treatment for a prolonged period. Fertilization and irrigation had no visible effect on the coverage of lichens and mosses.

The PDF includes a summary in Finnish.

• Mälkönen, E-mail: em@mm.unknown
• Aro-Heinilä, E-mail: va@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

Monitoring of heavy metal accumulation in plants has been used to reflect the deposition of heavy metals in terrestrial ecosystems. In some cases, the accumulation rates in plants are linearly correlated to deposition measured as bulk precipitation collected in funnel samplers. It is uncertain, however, how large the contribution due to adsorption/impaction of small particles is to this relationship. The need for design of enlightening experiments on deposition rates in different vegetation types and their relation to immission and bulk precipitation data is discussed.

• Johnsen, E-mail: ij@mm.unknown

Radial growth of Scots pine (Pinus sylvestris L.) was investigated in seven camping areas located in Southern Finland. Radial growth reduction of 20–40% were found. The magnitude of this reduction was related to the amount of damage in the trees, and the age of the trees. A loss of humus, exposure of the roots and soil compaction were associated with the use of area but not related to the reduction in growth.

The PDF includes a summary in Finnish.

• Nylund, E-mail: ln@mm.unknown
• Haapanen, E-mail: ah@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Nylund, E-mail: mn@mm.unknown

The ground cover vegetation and tree growth at several camping sites in Southern Finland were investigated. The deterioration of ground vegetation appeared to be unavoidable in these areas, and only a few grass species were tolerant to heavy trampling. Only moderate deterioration was, however, detected when the trampling level was lower than 10,000–15,000 user days. On the other hand, the ground cover was completely destroyed when the trampling level exceeded 100,000 user days. A considerable decrease in radial growth appeared to be associated with destruction of the ground vegetation. The decrease was abrupt and was found to continue throughout the whole period of use. After ten years’ use the growth in the trampled areas was 35% lower than that that of the untrampled areas. A further decrease in radial growth is expected in the future. 

The PDF includes a summary in Finnish. 

• Nylund, E-mail: mn@mm.unknown
• Haapanen, E-mail: ah@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Nylund, E-mail: ln@mm.unknown

The aim of the paper was to investigate the recreational potential of successional stand based on the suitability of the stands for different recreational activities and the trampling tolerance of ground cover. The relationship between selected recreational activities and the volume of the stands under study has been determined. These functions have been utilized in determining the potential of the successional stand for different recreational activities. Combining this information with trampling tolerance gave criteria for determining the recreational potential of a stand. The results emphasize the importance of varying the distribution of development stages in a recreational area and in its management.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown

The distribution of the dry matter and nutrients in Scots pine (Pinus sylvestris L.) tree stock growing on a Vaccinium type site, ground vegetation, and humus were determined in the study. The greatest part of the dry matter in the tree was found in the stemwood. The living branches, roots, bark, needles and dead branches decreasing order of magnitude made up the rest of the biomass. The trees contained over 90%, the field layer vegetation 3% and the bottom layer vegetation 2% of the dry matter in the tree stand. The tree stock contained 86–95% of the total amount nutrients in the stand. The field layer vegetation contained less nutrients than the bottom layer vegetation. Nitrogen, however, was an exception, the amount being approximately the same in both vegetation layers. 

The PDF includes a summary in English.

• Lehtonen, E-mail: il@mm.unknown

The structural matter production of selected plant species of a ground cover community was determined in relation to light available for photosynthesis. The resulting functions were applied in a situation where the light reaching the ground cover was controlled by the dynamics of the tree crown strata, and the occurrence of different plant species at different stages of succession was determined on the basis of their production of structural matter in actual light conditions. The possible strategies involved in adaptation to a successional environment have been discussed.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Kauppi, E-mail: pk@mm.unknown
• Väisänen, E-mail: ev@mm.unknown

A quantitative method for determining the annual growth level of plant species has been presented. In particular, attention was paid to the dependence of the growth level on the amount of light available for photosynthesis. A mathematical model for the dependence of structural matter production on photosynthetic production has been presented for some plant species.

The study is based on the assumption that the total amount of annual net photosynthesis plays a role of primary importance in determining the relationship between photosynthetic production and structural matter production. The basic environmental factors determining the photosynthetic rate are light and temperature, if the water and nutrient supply is adequate. The dependence of photosynthetic rate on light and temperature was determined by monitoring the CO₂ uptake rate of natural plant populations between the photosynthetic levels of different plant populations with an infrared gas analyser.

The PDF includes a summary in Finnish.

• Väisänen, E-mail: ev@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

The aim of the present study was to investigate the trampling tolerance of forest ground cover of the Calluna, Vaccinium and Myrtillus type sites. Positive correlation was found between the site fertility and trampling tolerance of plant communities. Annual trampling at level of about 16,000 visits per hectare decreased the biomass of the ground cover to almost half of the original amount, and annual trampling of about 160,000 visits per hectare completely destroyed the forest ground cover irrespective of site fertility. Comparisons made between herb and grass dominated forest ground cover showed that herb and grass cover is in the long run the best alternative for the management of ground cover in intensively used recreation areas.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown

The paper deals with variation in the nitrogen, phosphorus, potassium, calcium and magnesium content of vegetation and soil of young Scots pine (Pinus sylvestris L.) stand of Vaccinium site type situated in Central Finland. The material consists of sequential samples representing soil, ground vegetation and trees taken during summer 1974.

The amount of soluble nutrients in the humus layer decreased in June when maximum growth of trees and dwarf shrubs occurred. The nutrient content of this layer subsequently began to increase towards the end of the growing period.

The variation in the nutrient content of the bottom and ground layers followed a similar pattern. Nitrogen content increases at the beginning of the summer. After this phase it started to decrease and reached its lowest values by the end of growing period. Phosphorus and potassium content increased throughout the growing period.

The nutrient content of the needles and wood were positively correlated with tree height and negatively with the age of material. The highest values for the nutrient content were for new cells.

The PDF includes a summary in English.

• Lehtonen, E-mail: il@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Westman, E-mail: cw@mm.unknown

The area of Koilliskaira, situated in the eastern part of Finnish Lapland, is a popular venue for hikers. The present work examines the change of vegetation around 35 refuge huts in the area. The indigenous vegetation was found to conform to the various heath forest types common to forests in Lapland and continental subalpine mountain birch forest types, principally dry or fairly dry heath forest.

According to the study, the change in vegetation showed a clear positive correlation with the number of summer visitors. The dwarf shrubs and lichens were the most susceptible to trampling, and the grasses the least so. Both resilient and susceptible species were to be found among the mosses. The incoming hemerophilous flora was seen to consist principally of species known to accompany Lappish settlement in the area, and only occasional cases of alien species were noted.

The PDF includes a summary in English.

• Hoogesteger, E-mail: mh@mm.unknown

The study deals with the relationship between biomass and coverage in ground vegetation of Vaccinium and Calluna forest types. The results show that the biomass of the field layer on both forest types can predict satisfactorily in both coverage values of some the most important species and groups of species. Their total height per plot was used as independent variables. The explaining power of the models constructed for Vaccinium type increased to approximately 57% and for the Calluna type to approximately 74% of the total variation in the amount of dry matter. When the biomass of the bottom layer was predicted using the same kind of variables, the explaining power for the Vaccinium type increased to approximately 35% of the total variation and for the Calluna type approximately 53% of the total variation in the amounts of dry matter. The models for field layer of both Vaccinium and Calluna types were quite well suited for describing the test material. In the case of the bottom layer, the constructed models were not suitable for describing the test material.

The PDF includes a summary in English.

• Kellomäki, E-mail: sk@mm.unknown

The significance of water budget in June and July for forest and peatland vegetation, and consequent effects on fauna, climate and agriculture has been studied.

In June, the difference between evaporation and precipitation is greater than it is later in the summer. North of the line zero difference of evaporation and precipitation, coinciding with a line of sharp change in forest vegetation, the uppermost part of podsol remains wet throughout the summer. During July, the line of zero difference moves from north to south over the greater part of Finland, run-off being minute and podsol at the driest in this month. This line, indicating the length of the period with evaporation greater than precipitation and causing a sharp change in forest vegetation, in frequency of peatlands, amount of growing stock productive capacity of forests etc. This line is significant also for cultivation: because of the lower evaporation north of this line, night temperature below the freezing point often appear in summer.

The PDF includes a summary in English.

• Solantie, E-mail: rs@mm.unknown

The possibilities of using results of coverage analyses for estimating the dry matter content of the ground vegetation has been examined in this study. The material covers 150 sample areas, 400 m² large, which represent ground vegetation of Myrtillus type in the final succession stage. When the material was subjected to linear regression analysis, the amount of dry matter in the field and ground layer has been used as dependant variables and the results of the coverage analysis as the independent variable.

The study shows that it is possible to predict satisfactorily the dry matter content of the ground vegetation by grouping the coverage, according to the coverage weight, into parts of equal size and the using them as independent explaining variables. In particular, the value of the prediction equation for the dry matter content of the field layer could be improved by using the height and density characteristics of the vegetation as explaining variables in addition to the coverage figures. Thus, slightly over 80% of the total variation of the dry matter content of the field layer could be predicted. In the case of the ground layer vegetation, the explaining power rose slightly above 70%.

The PDF includes a summary in English.

• Kellomäki, E-mail: sk@mm.unknown

The paper deals with the relationships between macronutrients, ground vegetation and tree crop on a drained peatland area in Central Finland. The former herb-rich spruce swamp was drained in 1930s. The Norway spruce (Picea abies (L.) H. Karst.) stand was established by planting under a nurse crop of birch, which was removed later.

There was a negative correlation between the thickness of the peat layer and the volume and mean height of the growing stock. This was found to depend on the negative correlation prevailing between the potassium content of the topmost peat layer and the thickness of the peat cover. The deficiency of potassium is clearly discernible as deficiency symptoms in the needles, the intensity of which showed a strong correlation with the stand characteristics studied. Among the nutrient characteristics of the topmost peat layer, total potassium and the N/K and P/K ratios showed the closest correlation with the stand characteristics. The communities into which the ground vegetation was divided differed from each other with regard to the calcium content of the peat substrate.

The PDF includes a summary in English.

• Mannerkoski, E-mail: hm@mm.unknown

The study deals with the trampling tolerance of forest vegetation in a Myrtillus type closed forest of Norway spruce (Picea abies (L.) H. Karst.), based on the effects of simulated trampling on the coverage and biomass on the field and between layers of the vegetation. The reliability of the results from the simulated trampling was tested by comparing them with those obtained from real trampling.

According to the results, the trampling tolerance of the bottom layers is greater than that of the field layer. The trampling tolerance of different species varies, so that grasses and dwarf shrubs have a higher tolerance capacity than herbs. Even light trampling of short duration caused noticeable changes in the coverage and biomass of the ground vegetation. Despite certain deficiencies, the simulated trampling gave parallel results of those obtained for real trampling.

The PDF includes a summary in English.

• Kellomäki, E-mail: sk@mm.unknown

The Sinivuori Nature Park, located in the northeast part of the county of Häme in Southern Finland represents the rare fertile forest lands in the country, and belong partly to the so-called centre of herb‐rich forests of Häme. Sinivuori is one of the smallest nature reserves in Finland (64 ha). The detailed vegetation analysis was performed in 1969, supplemented by earlier and later observations. The area was divided into 69 one-hectare squares for the study of the flora and vegetation.

The most common rock in the park is mica schist. The pH of the soil is relatively high, in average 6.6. Thermal-time sum is 1,100–1,200. The vegetation differs to a large extent from the surrounding areas. 169 vascular plants were found in the area, some of which very rare in the area. The paper lists the plants and their abundance in the area, and the vegetation is described by the forest types. Distribution maps are presented for the species.

The PDF includes a summary in German.

• Rutanen, E-mail: kr@mm.unknown

Clone stands of bracken fern (Pteridium aquilinum (L.) Kuhn.) wood small reed (Calamagrostis epigeios L.) and lily-of-the-valley (Convallaria majalis L.) are often partly split into two by the road, but often encountered also unilaterally on the roadside in the shape of a semicircle. The unilateral stands can be at times 20–30 m wide and they are sometimes solitary stands of the species. A method to define the age of the solitary stands of six plant species including bracken, wood small reed and lily-of-the-valley was developed in a series of earlier studies.

These stands can be used to define the time the road was built. Clones that are bound by the road unilaterally are younger than the road. If there are several unilateral clones and they are of different sizes, the road is older than the largest clone. When the road is skirted bilaterally only by clones divided by the road, it is younger than the smallest clone. When there are by the road side both unilaterally delimited clones and clones split by the road, the age of the road comes in the range of time determined by the age difference between the largest unilateral and smallest bilateral clone.

The PDF includes a summary in English.

• Oinonen, E-mail: eo@mm.unknown

The paper is a review on the topics of Symposium on forest types and forest ecosystems, held in connection to the IX internal botanical congress in Montreal in August 1959, the chairman of which was Ilmari Hustich. The article includes 18 preparatory papers that were distributed among the participants of the symposium. The common theme of the papers was the question of finding common platform for the different schools of forest types and forest ecosystems. In addition to the papers, the article includes a summary of the proceedings and discussions of the symposium.

The following papers were presented in the symposium:

Aichinger, E. Können wir eine gemeinsame Platform für die verscheidenen Schulen in der Waldtypenklassifikationen finden?

Arnborg, T. Can we find a common platform for the different schools of forest type classifications?

Dansereau, P. A combined structural and floristic approach to the definition of forest ecosystems.

Daubenmire, R. Some major problems in vegetation classification

Ellenberg, H. Können wir eine gemeinsame Platform für die verscheidenen Schulen in der Waldtypenklassifikationen finden?

Hills, G.A. Comparison of forest ecosystems (vegetation and soil) in different climatic zones

Kalela, A. Classification of the vegetation, especially of the forest, with particular reference to regional problems

Krajina, V.J. Can we find a common platform for the different schools of forest type classifications?

Kühler, A.W. Mapping tropical forest vegetation

Linteau, A. Y. a-t-il. Un terrain d’entente possible entre les différentes écoles au sujet de la classification de types forestiers?

Medvecka-Kornaś, A. Some problems of forest climaxes in Poland

Ovington, J.D. The ecosystem concept as aid to forest classification

Puri, G.S. The concept of climax in forest botany as applied in India

Rowe, J.S. Can we find a common platform for the different schools of forest type classifications?

Scamoni, A. Können wir eine gemeinsame Grundlage für die verscheidenen Schulen in der Waldtypenklassifikationen finden?

Sukachev, V.N. The correlation between the concept ’forest ecosystem’ and ’forest biogeocoenise’ and their importance for the classification of forests

Webb, L.J. A new attempt to classify Australian rain forest

• Heikurainen, E-mail: –
• Finnish Society of Forest Science, E-mail: –

There are about 155,000 ha of fen-like pine swamps (eutrophic pine bogs) in Finland, major part of which are situated in Northern Finland. In the classification system for drainability of peatlands, this type of peatlands had been placed in the first class. The study presents a new evaluation for the peatland type, based on vegetation and tree growth.

According to a previous study, the vegetation of fen-like pine swamps can be characterised by distinctive plant communities that seem to reflect the fertility and high pH of the underlying soil. In this study, the fen-like pine swamps were divided in two subtypes based on the vegetation: proper fen-like pine swamps and fen-like pine swamps with ericaceous shrubs. Both have distinctive vegetation, which is described in the article. The distribution of the subtypes seems to be different: fen-like pine swamps with ericaceous shrubs are more common in eastern parts of Northern Finland. The two subtypes could be divided in different drainability classes according to tree growth, proper fen-like pine swamps belonging to class 1 and fen-like pine swamps with ericaceous shrubs to class 4.

The article includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown

The 4.4 km² sized area of Rokua is a sandy ridge situated in the transitional zone between Central and Northern Finland. It has been suggested to become a new national park due to its, in the area unique landscape and geological characteristics.

The vegetation of the area has been little studied. A vegetation analysis was performed in 1945, 1947 and 1949. Due to low nutrients in the sandy soil, the number of species is relatively low, including 236 vascular plants. The climate is continental. Lichen covering of soil in the Scots pine (Pinus sylvestris L.) dominated forests is mostly intact compared to the more northern areas, because grazing of reindeer has been little. Fellings have increased in the surrounding areas of the planned national park. The article includes a detailed description of vegetation and flora in the area.

The article includes a summary in German.

• Jalas, E-mail: jj@mm.unknown

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes a field experiment on the use of herbicides to prevent growth of ground vegetation in cutting areas before sowing. The study suggests that the chemicals used in the experiment were not effective enough to prevent growth of ground vegetation in the more fertile lands, but were effective in poorer lands. However, the treatment affected also growth of tree seedlings.

• Paavola, E-mail: ep@mm.unknown

Growth capacity of peatlands after draining depends largely on quality of the surface peat. The future growth capacity can be determined with considerable accuracy by the vegetation of the peatland. The aim of this study was to draw guidelines to identify the fertility of a peatland and its potential for draining based on its vegetation.

Certain species and plant associations were identified to describe the fertility of different peatland types. Brown mosses indicate an abundant nutrient content of the site, certain herbs moderately abundant nutrient content, sedges (Carex sp.) moderate nutrient content, shrubs poor nutrient content and vegetation indicating an oligotrophic peatland indicates excessively poor nutrient content. The article includes detailed descriptions of the vegetation of different peatland types.

Supplementary features, such as thin peat, flooded parts or abundance of Spangnum fuscum can be used as additional indications to determine the drainability of the site. The article describes an identification tool to determine the drainability of a peatland based on vegetation and the supplementary features of the peatland.

The article includes a summary in English.

• Huikari, E-mail: oh@mm.unknown

The aim of the study was to develop an determination method to define vegetation type of fen-like pine swamps, which are combinations of two peatland types, quagmire and pine swamp. Typical for this peatland type is that the vegetation is very heterogenous. Patches of different types of plant communities are found within a small area, but in a large scale, there are only few main types of plant communities. The commonly used way to use sample plots to study tree stands suit poorly to determine the type of this kind of heterogenous ground vegetation. The article compares strip survey and circular plot survey, of which circular plot survey is determined to be less time consuming. The article describes a way to choose the locations of sample points to achieve most correct areas for different plant communities.

The article includes an abstract in German.

• Heikurainen, E-mail: lh@mm.unknown

A vegetation survey was conducted in the Pisavaara national park in Northern Finland in 1946 and 1947. The national park (49,9 km2) includes southern half of the Pisavaara hills. The rock is quartzite. The most common vegetation type is dry upland forest type, but also fresh mineral soil sites are typical for the area.

The most common forest type, Empetrum-Myrtillus type coveres almost as much of the area as all the other forest types combined. The article describes in detail the vegetation of all forest types and gives a complete list of all plant species found in the survey. Total of 291 vascular plants was found, 242 of which were native to the area. In addition, 49 anthropochores had spread to the area when the forest ranger’s cottage was built. Number of species growing in the northern edge of their natural range is. Southern species can be found in the southern slopes of the hill.

The article includes an abstract in German.

• Teivainen, E-mail: lt@mm.unknown

The article is based on the writer’s visits in the area in 1933 and 1939. Pyhätunturi national park was established in 1938. The fell of Pyhätunturi rises up to 540 meters above the sea level, and 357 meters above the surrounding area. The soil is predominantly stony, and the rock is quartzite. The climate is continental with low rainfall. This results in a barren area, where array of plant species is limited with the exception of few gorges with fertile river valleys. The forests have remained mostly in natural state.

Vegetation is arranged in three zones: forested area, subalpine fell birch area and alpine bare top of the fell. Scots pine (Pinus sylvestris L.) forms timberline more often than Norway spruce (Picea abies (L.) H. Karst.). Coniferous forests rise up to 365 meters on the northern slopes and up to about 385 on the southern slopes of the fell. It is followed by fell birch zone (Betula tortuosa, now Betula pubescens subsp. Czerepanovii) up to about 450-475 meters on the eastern and northern slopes, and 475-490 meters on the western slopes. The most common forest site type is Empetrum-Myrtillus site type. Herb-rich spruce swamps along the rivers have highest diversity of species. The article describes the plant species found in forests, peatlands, fell birch zone and top of the fell in detail. In all 162 different vascular plant species and 16 non-indigenous species were found in the area.

The article includes an abstract in German.

• Kalliola, E-mail: rk@mm.unknown

Finland has a long tradition of grazing cattle in the forests and common land. There are also reports of degradation of forests by grazing already in 1600th century. The aim of the survey was to study which positive and negative effects grazing has in forests.

The study concludes that grazing has caused considerable economic losses through damages to forests. In addition, woodland pastures cannot give the yields required in modern animal husbandry. The quality of woodland pastures have decreased after the woodlands used in slash and burn culture have become wooded.

Grazing has also some positive effects to forests. It increases the diversity of vegetation in the woodland pastures and spreads species to new areas. This is supported by the lists of species found in different woodland pastures. Cattle destroy large grasses like Calamagrostis, which may avail growth of tree seedlings in the pastures. Grazing can also prepare the site for tree seedlings. On the other hand, prolonged grazing destroys tree seedlings and prevents regeneration.

The article includes a German summary.

• Lampimäki, E-mail: tl@mm.unknown

The aim of the study was to follow development of vegetation in dry upland forest sites after forest fire. The sample sites were situated in the counties of Muonio, Kolari, Sodankylä, Pelkosenniemi, Savukoski, Kemijärvi and Salla, in the northernmost Finland.
The growth of plant communities can arise either from the vegetation and seeds that survived the fire, or from seeds that spread from the surrounding areas. The development of vegetation in the burned areas was unexpectedly independent of the surrounding areas, which indicates that role of the seeds from the outside of the burned ares is small. The occurence of different species of lichens, moss, scale moss and vascular plants in the burned areas are described in detail. The development of vegetation was strongly dependent on the forest site type. The thin humus layer of Cladina site type burns usually evenly, and also the vegetation develops more evenly than in the more fresh site types. Vegetation typical for burned areas was fully developed within 10-15 years, and after 25 years it began to resemble the vegetation of Cladina site type forests. The ground vegetation of Calluna type burned area was more patchy. It developed quicker than in Cladina type. Absense of lichens made it seem more fertile than is usual for Calluna type. The humus layer of Empetrum-Myrtillus site type burned unevenly, and if the area was lightly burned, the vegetation recovered quickly. The vegetation was often patchy.
The PDF includes a summary in German.

• Sarvas, E-mail: rs@mm.unknown

A vegetation analysis was performed in Muhkuri experimental area of the Forest Research Institute. The area is located in southwest Finland near city of Turku. The dominant tree species of the area is oak (Quercus robur L.) which can be found in all the area. Common woody species are also aspen (Populus tremula L.), mountain ash (Sorbus aucuparia L.), hazel (Corylus avellana L.), juniper (Juniperus communis L.) and mountain currant (Ribes alpinum L.). A total of 198 vascular plants were found in the area, 34 of which were common in most parts of the area. Typical vegetation of different parts of the area is described. Finally, a list of all plant species is presented in the article.

The PDF includes a summary in German.

• Auer, E-mail: aa@mm.unknown

Vegetation inventory was made to study plant species growing in herb-rich forest in northern Pirkkala-Tyrvää area in Southern Finland. The area belongs to a district that is rich in grass-herb forests, where the bedrock is calciferous. Six herb-rich forest site types were identified in the area. The species composition in the herb-rich forests was compared to those in Turku in southwest Finland, and in Ladogda Karelia in Eastern Finland.  The main characteristics of the plant associations were similar, but there were a few species that are common in Pirkkala-Tyrvää area that are rare in the other areas, and vice versa. The district rich in grass-herb forests of Pirkkala may extend more westwards than it has been assessed earlier. Finally, the article lists the plant species found in the herb-rich forests in the area and defines their distribution and abundance.

The PDF includes a summary in German.

• Mäkelä, E-mail: tm@mm.unknown

Typical for the area of Längälmävesi, in Satakunta in Southern Finland, are densely populated fertile lowland areas near the waterways and poorer sparcely populated upland areas. The changes in fertility of the land influence the vegetation, and has directed where the population has settled. A vegetation survey was made using specific plant species as indication to fertility. A detailed description of the species composition and distribution of the plant species indicative for fertile land is presented in the article.

Analyzing the fertility only based on the plant species indicative for rich soils underestimates the proportion of fertile lands. Farmlands, on the other hand, have been cleared also on less fertile soils, which would give an overestimate of the fertile lands. A map of fertile lands was drawn based on both vegetation and location of the fields. The changes in fertility influenced also bird species observed in the area.

The PDF includes a summary in German.

• Cajander, E-mail: oc@mm.unknown

The article contains three presentations given about forest type classification at the University of Tarto in Estonia. The article has an introduction, a part about the meaning of the natural classification of forest sites and up to now conducted studies on site classification. The second part presents the characteristics of plant communities and the forest types, and practical and theoretical meaning of forest types.

Classifying the forest sites is important in practical forestry, because the forest growth and forest valuation are dependent on the productivity of the soil. The classification of the sites for forest management purposes needs to result in classes that are easily distinguished in the forest. This then leads to forest management that best fits to a certain forest site. 

• Cajander, E-mail: ac@mm.unknown

The article describes the geography and vegetation of Pummanginniemi area in Petsamo (now a Russian municipality of Pechenga; in 1926 the area was part of Finland in north-east Lapland), which has been suggested to become a natural park. Geologically it represented the only paleozoic area in Finland, constituting of layered rocks, mostly of slates and sandstones. The cape Pummanginniemi is situated on the cost of the Arctic Ocean, and it is known for its rich birdlife. Towards the inland, there is a plateau the vegetation of which is alpine. The area is situated above the mountain birch zone.

• Häyrén, E-mail: eh@mm.unknown

The purpose of this study is to clarify the forest types in pure coniferous stands in Åland in Finland, to study them in a biological light and account for the production of the stands on respective sites. The flora of the forest types in Åland has been described in an earlier study, but as the plant associations have not been described it has often been difficult to determine the correct types in field work. Sample plots were chosen in coniferous forests with maximum 20% of other species. The vegetation analysis was limited to determine composition of species, projected coverage and the frequency of species. In addition, cubic volume and growth of the growing stock was calculated for the stands.

The results of the study showed that site type and fertility correspond to each other nearly without exception only on normal moraines, if only the ground vegetation is used as a criterion for the type. The general occurense of soils of different qualities makes it necessary to determine, besides forest type, other characteristics in the stands, preferably the dominant height. The total production of coniferous forests with great probability is smaller in Åland than in mainland Finland. The results can be applied also to Åboland’s archipelago, where the milieu of the coniferous forests is similar.

The PDF includes a summary in English.

• Högnäs, E-mail: bh@mm.unknown

The aim of the study is to find out 1) whether and how the original moor type can be found out based on vegetation regardless the phase of drainage; 2) whether the different phases of draining can be distinguished based on the vegetation; and 3) is it possible to classify the well drained moors into vegetation types that would reflect the productive capacity of the land.

The data consists of samples collected from ditched areas. There are 11 moor types from two climatic ditching zones. The results show that the original moor type can be determined based on vegetation, the phase of drainage can be determined under some limitations, and the classification for productivity can be done for practical purposes.    

The PDF contains a summary in Finnish. 

• Sarasto, E-mail: js@mm.unknown

Especially in experimantal ecological research it is used small sample plots that are inventoried consequently. The paper describes a method for establishing small sample plots, developed by the writer in 1956. In the method, the central point of the sample plot is marked with an iron skewer, and the marking of the area to be inventoried was accomplished with a circular frame that is movable. The frame was fitted to the skewer with an aperture that indicated the central point. The area of the frame was relatively small, 0,25 m². The sample plots were arbitarily placed at intervals from one another.

The PDF includes a summary in Finnish.

• Yli-Vakkuri, E-mail: py@mm.unknown

Prescribed burning has been used to treat the mineral soil sites, but the method has been little used in drained peatlands. The course and methods of prescribed burning in drained peatlands, and the effect of burning on sprouting of broadleaved trees, growth of ground vegetation and regeneration of Scots pine (Pinus sylvestris L.) by sowing was studied in drained pine bogs in Southern Finland. The top layer of the peat was mostly Sphagnum peat. The material included a prescribed burned 12 ha drained peatland area in Tuomarniemi district, in addition to which ten previously burned areas were investigated.

The burning had succeeded mostly well, but also unsuccessfully burned sites were observed. Estinguishing of the fire was easy, and no peat fires occurred. The fire burned only the logging residue, ground vegetation and the dry top layer of the peat. The roots of brushwood and grasses survived in the peat that insulated the top layer from the heat. For instance, the abundance of cloudberry (Rubus chamaemorus L.) increased after the fire. Similarly, burning did not affect sprouting of the stumps of downy birch (Betula pubescens Ehrh.). It cannot thus be used as a method to restrict the growth of coppice in regenerated areas. The seeds of Scots pine germinated well on the burned surface. 46% of the seeds developed to seedlings on sphagnum-shrub vegetation and 16% in feathermoss-shrub vegetation.

The PDF includes a summary in German.

• Yli-Vakkuri, E-mail: py@mm.unknown

According to studies following the development of vegetation of drained peatlands, it seems that they have transformed to a relatively stable plant communities during the succession. In earlier studies it was assumed that after drainage a mire type would develop to a corresponding forest site. This investigation studies what kinds of plant communities are formed during succession of different mire types on peatlands drained for forestry in the southern half of Finland. Understorey vegetation was studied in 18 sample plots established by Forest Research Institute on drained peatlands. In addition, sample plots were studied on peatlands in natural state.

The results suggest that understorey vegetation on peatlands drained for forestry have developed into plant communities, the most advanced of which are the so-called dry plant communities. They represent transformed site types, which are the following: drained peatlands with upland herb-rich vegetation, drained peatlands with upland grass-herb vegetation, drained peatlands with upland Myrtillus site type vegetation, drained peatlands with upland Vaccinium site type vegetation, and drained peatlands with upland Calluna site type vegetation. Drained peatlands with upland Cladonia site type vegetation seem to be a temporary type caused by incomplete drainage. The transition between Myrtillus and Vaccinium dominated dry plant communities is not clear, but especially the pure Vaccinium vitis-ideae communities justify its place as an independent plant community. The dry drwarf shrub plant communities are also stable.

The PDF includes a summary in German.

• Sarasto, E-mail: js@mm.unknown

The article presents the results of the studies about the horizontal root systems of pine. The results have been obtained with the method developed by the author.

The size of the root system varies very strongly during the growing period. The amount of roots is at the smallest in the spring, increasing then rapidly and peaking at the end of July. After that the amount of roots decreases again against the winter to the same size than in the spring. The differences are due the changes in the amount of the smallest roots. There seem to be no big differences in the amount of roots between stand of different ages.

After the thinning there is a drop in the amount of roots on the stand level, but after two growing periods then standing trees have taken over the unused land. However after selection felling the less vital trees are not capable of utilizing the vacant resource as effectively.     

The PDF contains a summary in Finnish. 

• Kalela, E-mail: ek@mm.unknown

The southern border of occurrence of high moors is only known for western Finland. In other parts of southern Finland the high moors are bordered with Karelian mixed moor type. The article presents observations on high moor alike moors in middle Finland. The characteristics of these high moors are described and compared with other moor types in the area.

Morphological and hydrographicalas well as vegetation related characters are presented. The most important character of the moors increasingly occurring when moving from south the north is decrease in convexity of the moor. In western part of the country clarity of raises, in eastern part of the country the abundance of large dwarf shrubs are also typical. Climatic differences between west Finland and east Finland seem to cause the differences.   

Results indicate that the climatic reasons, meaning the more continental climate in eastern part of the country, is the reason that there are fewer high moors in eastern Finland than in western Finland. The areas with tendency for developing as high moors develop themselves as drier forest high moors. It is reasonable to limit the north border of occurrence of proper high moors further south than what has been done.

The PDF contains a summary in Finnish. 

• Paasio, E-mail: ip@mm.unknown

The article presents the characteristics of different vegetation areas (meadows and peatlands) by their distinctive vegetation. The study area is by the Barents Sea and is the northernmost part of continental European Russia. Different sites are classified by plant communities and/or vegetation units.

The article continues on the second PDF-file. 

• Kalela, E-mail: ak@mm.unknown

Ground vegetation can be used to determine the fertility of the peatlands. This information is needed when deciding if a peatland is suitable for drainage. The spruce and pine swamp types of Finland have been well established. The aim of the study was to develop further the peatland type classification for treeless bogs in Finland, presented in earlier studies. The treeless bogs consist of diversity of small patches of different vegetation that blend into complexes. Consequently, classification that is based on defining bog complexes makes it easier to determine a peatland type for a larger peatland area. A system describing peatland complexes for treeless bogs is presented with detailed description of the vegetation. The study identifies nine different peatland complex types for treeless bogs.

The PDF includes a summary in German.

• Paasio, E-mail: ip@mm.unknown

The data has been collected from an old natural meadow in Sortavala, Karelia (on that time it was part of Finland). The vegetation on that meadow was very homogenous. All plants of the selected species (Trollius europaeus; Ranunculus auricomus; R. acer; Potentilla erecta; Alchemilla vulgaris; Geum rivale; Prunella vulgaris; Chrysanthemum leucanthemum; Polygonum viviparum) were collected from the sample plots with their roots. The seedlings were then ordered into age classes, and the shortest possible time before inflorescence was determined. To find out the germination time sowing trials were conducted.

The seedlings are very abundant in the youngest age classes and then the amount of plant individuals sinks quickly. The reasons for dying are e.g. insufficient amount of nutrients available and the lack of winter hardiness.   

The PDF contains a summary in Finnish.  

• Linkola, E-mail: kl@mm.unknown

The article presents the studies about the vegetation communes on moisture soils in northern Finland. The studies are part of another study about calcium carbonate content of the soil as a factor influencing the vegetation.

The PDF contains a summary in Finnish.  

• Pesola, E-mail: vp@mm.unknown

The study is based on the measurements and observations made during summers 1927-1929 and 1932 on South- and West-Finnish high moors. The article aims to give an overview on the vegetation if the Finnish high moors. The study seeks to answer following questions: to what extent and what kind of characters of other moor types are present in high moors, to what extent occur the characteristics of high moors outside the high moor area, and what are the typical characteristics of high moors?

The article describes the different types of raised bogs and the plant topographic characters. The high moors in different parts of Finland differ from each other with their characteristics and vegetation that they are classified in three groups: high moors in south-west Finland, high moors of northern part of Satakunta-province, and high moors south-east Finland.    

The PDF contains a summary in Finnish.

• Paasio, E-mail: ip@mm.unknown

Half-deciduous woodlands are the combination of deciduous forests and heath forests from their vegetation. The article describes three half-deciduous forest types from the commune of Hager, 40 kilometers south form Tallinn.

The occurrence of half-deciduous forests depends on the soil conditions, especially on lime content of the soil, when the occurrence of other forest types is more a question of climate. They are important as an original site for many continental plant species.   

The PDF contains a summary in Finnish. 

• Linkola, E-mail: kl@mm.unknown

The article summarizes the observations about forest types from different parts of Estonia. The chosen examples represent the normal forest where age class division is natural and the species composition has not been altered through felling or grazing. These are mainly found in the areas of earlier manors of the nobility. The samples are only from mineral soils. Vegetation analysis and middle-European height-over-age-survey were made.

Because of the great share of herb-rich-forest the forest type classification for Estonia is complex. There are many types that have not been described earlier.

The study describes the characteristics and the vegetation types of the heath forests, fresh forests, half-herb-rich-forests and herb-rich-forests.        

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

• Linkola, E-mail: kl@mm.unknown

To be able to exactly describe the similarities and differences of vegetation in certain areas, classifying the vegetation only in communities or formations is not enough. Therefore more classes are needed. The classification according the horizontal layers is based on the heights of plants and their relations to each other. Every population in one community has own area of height which extends to horizontal direction.

In comparison with populations the vegetation horizons create a biologically validated comparison of different vegetation groups and their parts. Defining the populations and vegetation horizons creates a division and systematization of plant communities on an ecological basis.       

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.

• Kujala, E-mail: vk@mm.unknown

The paper describes plant species characteristic for ash (Fraxinus exelsior L.) forests in Denmark, and compares the vegetation to beech (Fagus ssp.) forests, the dominating tree species in Danish forests, which have notably simpler ground vegetation. The writer concludes that ground vegetation can be divided into distinct types. Beech grows in several types of soil differing in their fertility (bonitet). The writer has divided the different soil types by their flora (tilstandstyper). The flora is influenced by three factors: climate, fertility of the soil and soil moisture. The paper defines the types of vegetation which describe fertility of the sites (bonitet), and discusses how age, silvicultural condition and tree species affect the vegetation.

• Bornebusch, E-mail: cb@mm.unknown

The forest sites have typically been classified by two principles, either as stand quality classes or as locality (site) classes. This article describes the principles of Finnish forest site types (forest quality classes) which are based on classification of localities according to their forest plant associations. All the stands that belong to the same forest site type are characterized by a distinct, more or less identical plant species composition. The forest site types are independent of the tree species. The forest site types in a larger area are relatively numerous, but can be grouped according to their normal form. The Finnish forests are separated to dry moss forest class, the moist moss-forest forest class and grass-herb forest class. The different forest site types belonging to the classes are described in detail. Growth of the trees is different for the different forest site types, but varies little within a same site type. The forest site types suit therefore well for the purposes of forest mensuration and for yield tables. The forest site types reflect also the properties of the soil.

• Cajander, E-mail: ac@mm.unknown

The forest sites have typically been classified by two principles, either as stand quality classes or as locality (site) classes. This article describes the principles of Finnish forest site types (forest quality classes) which are based on classification of localities according to their forest plant associations. All the stands that belong to the same forest site type are characterized by a distinct, more or less identical plant species composition. The forest site types are independent of the tree species. The forest site types in a larger area are relatively numerous, but can be grouped according to their normal form. The Finnish forests are separated to dry moss forest class, the moist moss-forest forest class and grass-herb forest class. The different forest site types belonging to the classes are described in detail. Growth of the trees is different for the different forest site types, but varies little within a same site type. The forest site types suit therefore well for the purposes of forest mensuration and for yield tables. The forest site types reflect also the properties of the soil.

• Cajander, E-mail: ac@mm.unknown

The article begins on the page 91/122 of the PDF file.

The data has been collected during summer 1867. It examines the moos and lichen species in for regions of Lapland: spruce region, pine region, birch region and fjeld region. The division of the regions is related to the climatic and biological conditions of areas, the first mentioned being the most southern and still suitable e.g. for many grasses. Respective regions have been presented with their general characters and list of species. Finally the findings of different regions are compared.   

• Norrlin, E-mail: jn@mm.unknown

The article begins on the page 82/122 of the PDF file.

The article is a travel report of the author’s travel from Helsinki to north of Finland. Alongside the description of the travel arrangements, it contains observations about the vegetation of the destinations they visited. The observations are divided into section of “spruce region”, “pine region” and “fjeld region”. 

• Norrlin, E-mail: jn@mm.unknown

The article begins on the page 27/122 of the PDF file.

The first part of the text deals with a general presentation of the geographical, biological and cultural conditions of the studied areas. The second part presents the characteristics of vegetation classified according the forest types, with lists of species. Forested areas, open lands and swampy areas are dealt with separately. The Saoneshje peninsula is presented separately.

The third part of the text discusses the similarities of the natural conditions between studied area and respective part of Finland. The vegetation and amount of species is clearly more diverse in studied area than in parts of middle-Finland. The study shows that in respect to vegetation Onega-Karelia cannot be seen as a part of the same region than Finland.  

• Norrlin, E-mail: jn@mm.unknown

The article begins on the page 8/122 of the PDF file.

Data for this paper have been collected during years between 1859 and 1862 in the communes of Asikkala, Hollola, Padasjoki, Lammi and Koski. 

The first part of the text deals with a general presentation of the geographical, biological and cultural conditions of the studied areas. The second part presents the vegetation according their habitats; they are classified by the degree of moisture. The last is further classified as forested areas or open lands. The examination concentrates on phanerogams (seed plants).   

The characteristics of vegetation of forests, open lands and paludified places (swampy or swamp forming places) are presented with the most influential characters and lists of species.   

• Norrlin, E-mail: jn@mm.unknown

The paper deals with the ground vegetation of the barren coniferous forests of Åland Islands and seeks to describe its special vegetation characters with general features. The study is based on data collected during summers from 1918-1922 on Åland Islands.  Work presents the forest types of Åland Islands classified according Cajander (1909) with their typical species.

The Ålandian coniferous forests seem to have a low number of species. This is because they are mostly old and closed, and have been developing for a long time without human induced disturbances from outside. Some changes have occurred due to forest fires. There is very few traces of non-native species in the forests. If some are found, they have not been able to regenerate or distribute widely.   

• Palmgren, E-mail: ap@mm.unknown

The article describes the Ålandian vegetation of most typical habitats with greatest detail. The primary goal of the paper is to find out which deciduous species are native in the Åland Islands and hence can be seen as indicator plants for the living conditions. In addition to determining the native species of the Åland Islands, the study seeks to determine the human influence to the vegetation systems: which species are original, which have been introduced by agricultural activities, and how has the human activity influenced the abundance of the species.

• Palmgren, E-mail: ap@mm.unknown

The article is based on the work “Metsänhoidon perusteet I” [The fundamentals of Forest management I] by the author (1919 in Finnish). The different processes of the soil and the vegetation are dependent on the climatic conditions, but also affect each other. The article presents the climatic zones of the earth and their most important characteristics in regard of cultivation of (to respective zone) exotic trees species and agriculture. 

• Cajander, E-mail: ac@mm.unknown

The article statistically studies the vegetation patterns in different forest types.  

467 sample plots with area varying from one fourth of a hectare to one eighth, even one tenth of a hectare were collected. There are different amount of sample plots representing every forest type. The sample plots are located in 58 communes in southern parts of Finland, reaching from the Gulf of Finland up to Oulujärvi –see in northern Ostrobothnia. The vegetation was examined from rectangle shaped study plots in even structured and even-aged stands with one primary tree species.

The results are shown in tables for every forest type. The amount of species is at highest in the most nutritious forest types, and decreases with the shift to more infertile types. However, some species occur in all forest types, and some only or mostly on more barren types. The occurrence and abundance of most plant species does not seem to depend on the tree species of the stand, but there are some exceptions to this.

The possible shortcomings of the research method are discussed. The importance of systematic studying of the sample plots with a method of survey lines is emphasized.  

• Ilvessalo, E-mail: yi@mm.unknown

The article presents definitions for central concepts that are commonly used in the research of plant topography. The discipline has close connections to defining and classifying forest types.

The concepts defined involve concrete and abstract concepts linked to vegetation conditions and to habitat. 

• Cajander, E-mail: ac@mm.unknown

The article contains tree lectures given in the meeting of the Geographical Society in Finland on February 25^th 1921.  The titles of the lectures are I Forest types in general, II Forest types as a basis for new growth and yield tables in Finland, and III Other research on forest types.  

The first lecture is a follow-up of the Cajander’s 1909 published article on forest types. It deepens the theory on forest types. The classification into forest types represents primarily different plant communities of ground cover. The types are named after the characteristic plant species, indicator plants, however, many other species appear in different abundance.

The second lecture represents the research proceedings of mensuration of forest stands of different types to compile yield tables for pine.  The forest types differ from each other distinctly on their growing preconditions, but inside one class the variation of the growing conditions is so small, that the classification can be used for yield tables, determining the basis of taxation and for classification of forest based on height over age.

The third lecture is a summary of other studies about forest type classification.  They confirm the results presented in earlier lectures. 

• Cajander, E-mail: ac@mm.unknown
• Ilvessalo, E-mail: yi@mm.unknown

• Kujala, E-mail: vk@mm.unknown

The forest site classification system used in Finland is based on ground vegetation rather than the wood production capacity. A. K. Cajander has presented a detailed classification of different forest site classes in different parts of the country. This study focuses on the forest site types of Northern Finland, which are less well defined. The article presents detailed vegetation analysis and lists of plant species in different forest site types in Northern Finland. In contrast to southern parts of Finland, both the natural Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst) stands are uneven-aged in the north. The forests are also relatively thin. There is a marked difference in height of trees between the richest and poorest sites, but the dominant trees of the same site type were of similar height both in the north and south part of the study area. The differences in the height of dominant trees seem to be smaller than in Southern Finland. Also, in windy areas prone to snow damage, climate conditions can affect tree growth more than the forest site type. In more sheltered areas forest site type determines forest growth.

The PDF includes a summary in German.

• Lakari, E-mail: ol@mm.unknown

The article presents a survey on distribution of fertile lands, soil types and site classes in Savo and Karelia in the central and eastern parts of Finland. The survey was based both in existing publications and statistics, a line survey, and visual observations during field trips. The site quality classification is based on the vegetation and occurrence of indicator plant species. The article lists distribution of indicator species in different forest site types on maps of the area. In addition, a review of history of land use and agriculture give indications of the location of the fertile lands in the area. A map of the forest site types in different parts of the area illustrate the data collected from the different sources.

The PDF includes a summary in German.

• Lukkala, E-mail: ol@mm.unknown

The data has been collected in spruce forests in mountainous areas of Germany: Fichtelgebirge and Böhmerwald in Bavaria, Erzgebirge in Saxonia. The studied characteristics of the stand were: growth of the trees in height and diameter, and the ground vegetation. The stands were classified according Cajander’s forest site classification. The article presents the most common plants and other characteristics of every forest site type and studied stands. The relation of the height of the trees and their age is represented in diagrams for every forest type.

The presence of indicator plants is somewhat dependent on the stand age and crown coverage. The amount of species is lowest when the crown coverage is at the greatest.

As conclusion of the study it can be seen that the growth of the stand differentiates clearly depending on the forest site type, being greater at the more nutritious sites. Since the differently growing stands need different management, it would be natural to direct the management of the stand according the forest site type. 

• Björkenheim, E-mail: rb@mm.unknown

Microcatchment water harvesting (MCWH) improved the survival and growth of planted trees on heavy soils in eastern Kenya five to six years after planting. In the best method, the cross-tied furrow microcatchment, the mean annual increment (MAI; based on the average biomass of living trees multiplied by tree density and survival) of the total and usable biomass of Prosopis juliflora (Sw.) DC. were 2,787 and 1,610 kg ha^-1 a^-1 respectively, when the initial tree density was 500 to 1,667 trees per hectare. Based on survival, the indigenous Acacia horrida Span., A. mellifera (Vahl) Benth. and A. zanzibarica (S. Moore) Taub. were the most suitable species for planting using MCWH. When both survival and the yield were considered, a local seed source of P. Juliflora was superior to all other species. The MAI in MCWH was at best distinctly higher than that in the natural vegetation (163–307 and 66–111 kg ha^-1 a^-1 for total and usable biomass respectively); this cannot satisfy the fuelwood demand of concentrated populations, such as towns or irrigation schemes.

The density of seeds of woody species in the topsoil was 40.1 seeds/m² in the Acacia-Commiphora bushland and 12.6 seeds/m² in the zone between the bushland and the Tana riverine forest. Rehabilitation of woody vegetation using the soil seed bank alone proved difficult due to the lack of seeds of desirable species.

The regeneration and dynamics of woody vegetation were also studied both in cleared and undisturbed bushland. A sub-type of Acacia-Commiphora bushland was identified as Acacia reficiens bushland, in which the dominant Commiphora species is C. campestris. Most of the woody species did not have even-aged population but cohort structures that were skewed towards young individuals. The woody vegetation and the status of soil nutrients were estimated to recover in 15–20 years on Vertic Natrargid soils after total removal of above-ground vegetation.

• Kaarakka, E-mail: vk@mm.unknown

The relationship between site characteristics and understorey vegetation composition was analysed with quantitative methods, especially from the viewpoint of site quality estimation. Theoretical models were applied to an empirical data set collected from the upland forests of Southern Finland comprising 104 sites dominated by Scots pine (Pinus sylvestris. L.) and 165 sites dominated by Norway spruce (Picea abies (L.) H. Karst.). Site index H₁₀₀ was used as an independent measure of site quality.

A new model for the estimation of site quality at sites with a known understorey vegetation composition was introduced. It is based on the application of Bayes’ theorem to the density function of site quality within the study area combined with the species-specific presence-absence response curves. The resulting probability density function may be used for calculating an estimate for the site variable

Using this method, a jackknife estimate of site index H₁₀₀ was calculated separately for pine- and spruce-dominated sites. The results indicated that the cross-validation root mean squared error (RMSE_cv) of the estimates improved from 2.98 m down to 2.34 m relative to the ”null” model (standard deviation of the sample distribution) in pine-dominated forests. In spruce-dominated forests RMSE_cv decreased from 3.94 m down to 3.19 m.

In order to assess these results, four other estimation methods based on understorey vegetation composition were applied to the same data set. The results showed that none of the methods was clearly superior to the others. In pine-dominated forests RMSE_cv varied between 2.34 and 2.47 m, and the corresponding range for spruce-dominated forest was from 3.13 to 3.57 m.

• Lahti, E-mail: tl@mm.unknown

The vegetation and number of physical and chemical soil properties were studied on a random sample of closed upland forest stands in Southern Finland. The material consists of a total of 410 sample plots. Two-way indicator species analysis (TWINSPAN) was carried out in order to produce a hierarchical clustering of samples on the basis of the vegetation data. Discriminant analysis and analysis of variance were applied in order to find environmental correlations of the vegetation clustering.

The vegetation was found to indicate the nutrient regime of the humus layer well, but to a less extent the properties of the sub-soil. The understorey vegetation was found to be jointly dependent on the site fertility and on the properties of the tree stand, especially on the tree species composition. Although the forest vegetation appears to be distributed rather continuously along an axis of increasing site fertility, relatively unambiguous classification can be based on the appearance of indicator species and species groups.

The results of the study were interpreted as indication that operational site classification done using the vegetation is rather good method for classification in closed forest stands. Different methods produce relatively consistent, natural and ecologically interpretable classifications. The results also imply that the vegetation cover and the humus layer develop concurrently during the development of the ecosystem, but the differentiation of the site type is regulated simultaneously by a number of interacting factors ranging from mineralogical properties of the parent material to the topographical exposition of the site. As the plant cover depicts all these primary factors simultaneously, only a relatively rough ecological site classification can be based on the vegetation.

The PDF includes a summary in Finnish.

• Kuusipalo, E-mail: jk@mm.unknown

The Oulanka National Park is situated in the district of Kuusamo on the eastern border of Finland, close to the Arctic Circle and within the coniferous forest zone. It covers a surface area of 107 km², and is known for the richness of its vegetation and flora, a product of a varied bedrock pattern including occurrences of dolomite. A description is given of the vegetation of the 9 forest and 47 peatland types distinguishable in the area by means of tables based on quadrat surveys. The distribution of each forest and peatland type is described in a vegetation map. The vegetation types are discussed in terms of the structure of their soil and the ecological and floristic features of their plant cover.

The PDF includes a summary in English.

• Söyrinki, E-mail: ns@mm.unknown
• Salmela, E-mail: rs@mm.unknown
• Suvanto, E-mail: js@mm.unknown

The trampling tolerance of ground vegetation of different types of forest stands has been examined in this study in the light of short-term trampling. The trampling treatment was simulated by a mechanical tamp. The relation between deterioration of the ground vegetation and the amount of the trampling was presumed to follow a curvilinear pattern when the material was being analysed. In order to quantify this relationship, a mathematical equation was developed for every plant community and their members of which the trampling tolerance was analysed. The trampling tolerance was compared using a parameter of the developed equations. Vegetation growing on sites of the Myrtillus, Vaccinium and Calluna types was included in the study.

The study showed a clear difference in the trampling tolerance between the ground vegetation of sites differing in their fertility. The ground vegetation typical of the Calluna type was found to have a lower trampling tolerance than the vegetation of the most fertile sites which were studied. It can be concluded that the relationship between the site fertility and the trampling tolerance of the ground vegetation is a curvilinear one such that the trampling tolerance of the vegetation on the poorest and the richest sites is lower than that of the vegetation growing on sites of medium fertility. However, it does appear that the most fertile sites have a higher trampling tolerance than the poorest sites. In addition, information about the trampling tolerance of a number of commonly occurring forest plants is also presented.

The PDF includes a summary in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Saastamoinen, E-mail: vs@mm.unknown

• Jetsonen, Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 University of Helsinki, Finland E-mail: johanna.jetsonen@helsinki.fi
• Laurén, Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 University of Helsinki, Finland; Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland https://orcid.org/0000-0002-6835-9568 E-mail: annamari.lauren@helsinki.fi
• Peltola, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland E-mail: heli.peltola@uef.fi
• Muhonen, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland https://orcid.org/0009-0007-4051-8567 E-mail: olli.muhonen@forestvital.com
• Nevalainen, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland https://orcid.org/0009-0000-2972-4385 E-mail: juha.hs.nevalainen@gmail.com
• Ikonen, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland https://orcid.org/0000-0003-1732-2922 E-mail: veli-pekka.ikonen@uef.fi
• Kilpeläinen, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland https://orcid.org/0000-0003-4299-0578 E-mail: antti.kilpelainen@uef.fi
• Tuittila, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland E-mail: eeva-stiina.tuittila@uef.fi
• Männistö, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland https://orcid.org/0000-0003-3869-6739 E-mail: elisa.mannisto@uef.fi
• Kokkonen, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, 80101 Joensuu, Finland https://orcid.org/0000-0003-0197-2672 E-mail: nicola.kokkonen@uef.fi
• Palviainen, Department of Forest Sciences, University of Helsinki, P.O. Box 27, 00014 University of Helsinki, Finland E-mail: marjo.palviainen@helsinki.fi

Mechanical site preparation (MSP) is a common practice that precedes the planting of Norway spruce (Picea abies (L.) H. Karst.) in Nordic forests. Mounding has become the most used method in spruce planting in recent years. This study examined the effects of different mounding treatments (spot and ditch mounding, inversion, unprepared control with or without herbicide application) and a mechanical vegetation control (MVC) treatment done 3–4 years after planting on the post-planting growth of spruce container seedlings and their development to saplings during the first 11–13 years on two forest till soils in central Finland, one on flat terrain and other on a southwest slope. On these fine-textured soils the spot and ditch mounding methods favoured spruce saplings development. Inversion and unprepared plots showed weakest growth. On the site with flat terrain, 11 years post planting, spruce saplings were 78–144 cm (38–80%) taller and their breast height diameters were 11–13 mm (60–74%) thicker for ditch or spot mounding than for inversion or herbicide treatment. On the site with sloped terrain the differences were minor between the MSP treatments. MVC improved spruce height growth on sites which did not have intensive MSP, especially on control saplings planted on unprepared soil in herbicide and inversion treatments. On the flat terrain, MVC reduced the density of resprouts to be removed later in pre-commercial thinning. As a conclusion, spot or ditch mounding favoured the growth of spruce over inversion especially on flat terrain with fine-textured soil.

• Uotila, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: karri.uotila@luke.fi
• Luoranen, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-6970-2030 E-mail: jaana.luoranen@luke.fi
• Saksa, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-1776-2357 E-mail: timo.saksa@luke.fi
• Laine, Metsä Forest, Revontulenpuisto 2, FI-02100 Espoo, Finland https://orcid.org/0000-0002-6448-8274 E-mail: tiina.laine@metsagroup.com
• Heiskanen, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-0549-835X E-mail: juha.heiskanen@luke.fi

Since fire frequency is expected to increase globally due to climate change, it is important to understand its effects on forest ecosystems. We studied the long-term patterns in species diversity, cover and composition of vascular plants and bryophytes after forest fire and the site-related factors behind them. Research was carried out in northwestern Estonia, using a chronosequence of Scots pine (Pinus sylvestris L.) stands, located on nutrient poor sandy soils, where fires had occurred 12, 23, 38, 69, 80 and 183 years ago. In every stand three 100 m² vegetation plots were established to collect floristic and environmental information. The effects on floristic characteristics of time since fire, light, and soil variables were evaluated with linear mixed models, followed by backward variable selection. Compositional variation was analysed with non-metric multidimensional scaling, Multi-response Permutation Procedures, and Indicator Species Analysis. Altogether, 31 vascular plant and 39 bryophyte species were found in vegetation plots. The cover of the vascular plant and bryophyte layers increased with a longer time since fire. Soil and light variables impacted the richness of several vascular plant and bryophyte groups, whereas only the richness of liverworts and dwarf-shrubs correlated with time since fire. Considerable compositional differences were observed in vascular plant and bryophyte assemblages between recently vs. long-time ago burned stands. To conclude, time since fire significantly impacted compositional patterns of vascular plants and bryophytes in pine forests on nutrient poor soils, although time-related trends in species richness were less evident.

• Orumaa, Institute of Forestry and Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, 51006, Tartu, Estonia E-mail: argo.orumaa@emu.ee
• Köster, Department of Environmental and Biological Sciences, University of Eastern Finland, PO Box 111 (Yliopistokatu 7), 80130, Joensuu, Finland E-mail: kajar.koster@helsinki.fi
• Tullus, Department of Botany, Institute of Ecology and Earth Sciences, University of Tartu, Lai 40, Tartu, 51003, Estonia E-mail: arvo.tullus@ut.ee
• Tullus, Institute of Forestry and Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, 51006, Tartu, Estonia E-mail: tea.tullus@emu.ee
• Metslaid, Institute of Forestry and Engineering, Estonian University of Life Sciences, Kreutzwaldi 5, 51006, Tartu, Estonia E-mail: marek.metslaid@emu.ee

Over 20% of regeneration operations will be on drained peatland in the next decade in Finland. There are only a few studies comparing the planting success and the risk of pine weevil (Hylobius abetis (L.) feeding damage on mineral soil and drained peatland. Thirty sites planted with Norway spruce (Picea abies (L.) H. Karst.) container seedlings in 2009 in Southern and Central Finland were inventoried three growing seasons after planting. Prediction models for the probability of survival, pine weevil damage and the presence of ground vegetation cover were done separately for peatland and mineral soil sites. The planting success was 17% lower on peatland sites (1379 surviving seedlings ha^–1) than on mineral soil (1654 seedlings ha^–1). The factors explaining the survival were the ground vegetation cover and type of the planting spot on the peatland, and the ground vegetation cover on mineral soil. On mineral soil, 76% of the planting spots were on cultivated mineral soil while on peatland only 28% of the seedlings were planted on similar spots. There were also fewer seedlings that were surrounded by dense ground vegetation on mineral soil (4%) than on peatland (14%). Pine weevil feeding damage did not differ significantly on peatland (23%) or mineral soil (18%). The more time there was from clear-cutting, the more the probability of pine weevil feeding damage was reduced on both soil classes. Additionally, cover vegetation in the vicinity of the seedlings increased on mineral soil. Cultivated planting spots, especially those covered by mineral soil, prevented pine weevil feeding and reduced the harmful effects of vegetation on the seedlings both on mineral soil and peatland.

• Luoranen, Natural Recourses Institute Finland (Luke), Production systems, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-6970-2030 E-mail: jaana.luoranen@luke.fi
• Viiri, UPM Forest, Peltokatu 26 C, P.O. Box 85, FI-33100 Tampere, Finland https://orcid.org/0000-0003-3952-9481 E-mail: heli.viiri@upm.com

Mechanical site preparation methods that used tools mounted on lightweight excavators and that provided localised intensive preparation were tested in eight experimental sites across France where the vegetation was dominated either by Molinia caerulea (L.) Moench or Pteridium aquilinum (L.) Kuhn. Two lightweight tools (Deep Scarifier: DS; Deep Scarifier followed by Multifunction Subsoiler: DS+MS) were tested in pine (Pinus sylvestris L., Pinus nigra var. corsicana (Loudon) Hyl. or Pinus pinaster Aiton) and oak (Quercus petraea (Matt.) Liebl. or Quercus robur L.) plantations. Regional methods commonly used locally (herbicide, disk harrow, mouldboard plow) and experimental methods (repeated herbicide application; untreated control) were used as references in the experiments. Neighbouring vegetation cover, seedling survival, height and basal diameter were assessed over three to five years after plantation. For pines growing in M. caerulea, seedling diameter after four years was 37% and 98% greater in DS and DS+MS, respectively, than in the untreated control. For pines growing in P. aquilinum, it was 62% and 107% greater in the same treatments. For oak, diameter was only 4% and 15% greater in M. caerulea, and 13% and 25% greater in P. aquilinum, in the same treatments. For pines, the survival rate after four years was 26% and 32% higher in M. caerulea and 64% and 70% higher in P. aquilinum, in the same treatments. For oak, it was 3% and 29% higher in M. caerulea and 37% and 31% higher in P. aquilinum. Herbicide, when applied for three or four years after planting, provided the best growth performances for pines growing in M. caerulea and P. aquilinum and for oaks growing in P. aquilinum. For these species and site combinations, DS+MS and DS treatments reduced the neighbouring vegetation cover for one to four years following site preparation.

• Dumas, Université de Lorraine, AgroParisTech, INRAE, UMR Silva, 54000 Nancy, France E-mail: noe.dumas@inrae.fr
• Dassot, EcoSustain, Environmental Engineering Office, Research and Development, 31, rue de Volmerange, 57330 Kanfen, France; Institut National de l’Information Géographique et Forestière, 1 rue des Blanches Terres, 54250 Champigneulles, France E-mail: mathieu.dassot@ign.fr
• Pitaud, Office National des Forêts, Département Recherche Développement et Innovation, route d’Amance, 54280 Champenoux, France E-mail: jonathan.pitaud@onf.fr
• Piat, Office National des Forêts, Département Recherche Développement et Innovation, 3 rue du petit château, 60200 Compiègne, France E-mail: jerome.piat@onf.fr
• Arnaudet, Office National des Forêts, Département Recherche Développement et Innovation, 100 boulevard de la Salle, 45760 Boigny-sur-Bionne, France E-mail: lucie.arnaudet@onf.fr
• Richter, Office National des Forêts, Département Recherche Développement et Innovation, Boulevard de Constance, 77300 Fontainebleau, France E-mail: claudine.richter@onf.fr
• Collet, Université de Lorraine, AgroParisTech, INRAE, UMR Silva, 54000 Nancy, France https://orcid.org/0000-0003-0861-7796 E-mail: catherine.collet@inrae.fr

Fire is a common disturbance in boreal forests causing changes in biological diversity at various spatial scales. In the past 100 years, forest management has limited fire outbreaks, but in the future, the fire-affected forest area is expected to increase in many regions due to climate change. Burned forests are typically salvage-logged, but the effect of this type of management versus natural regeneration on biological diversity is not well understood, particularly the mid-term effect to tree establishment and understory vegetation composition and diversity. Various management methods were used after a large fire in 1992 in a peatland-forest complex and neighbouring managed forests, which created an experimental setup for study of the effect of management after fire in the Sliteres National park, northwestern Latvia. Understory vegetation was described in plots using a design of four forest and three management types: natural regeneration (unmanaged) and managed sites with salvage logging followed by no further human intervention and salvage logging with planting. Post-fire management had different effect in each forest type. Species richness was higher in forest types with salvage logging than in natural regenerated sites on rich wet and rich dry forest types, but not for the poor forest types. Tree regeneration was generally greater in salvage-logged stands, but differed between forest types. Species composition was related to tree regeneration and canopy openness. In contrast to other studies, salvage logging had a positive mid-term effect to ground vegetation diversity and tree establishment in the studied stands, implying potential for concomitant management and conservation of ground cover vegetation in semi-natural stands.

• Kārkliņa, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: annija.karklina@silava.lv
• Brūmelis, University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia E-mail: guntis.brumelis@lu.lv
• Dauškane, University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia E-mail: iluta.dauskane@lu.lv
• Elferts, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia; University of Latvia, Faculty of Biology, Jelgavas street 1, LV-1004, Riga, Latvia E-mail: didzis.elferts@lu.lv
• Freimane, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: lasma.freimane@silava.lv
• Kitenberga, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: mara.kitenberga@silava.lv
• Lībiete, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: zane.libiete@silava.lv
• Matisons, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: robism@inbox.lv
• Jansons, Latvian State Forest Research Institute “Silava”, 111 Rigas Street, LV-2169, Salaspils, Latvia E-mail: aris.jansons@silava.lv

Leaf reflectance and transmittance spectra are essential information in many applications such as developing remote sensing methods, computing shortwave energy balance (albedo) of forest canopies, and monitoring health or stress of trees. Measurement of coniferous needle spectra has usually been carried out with single integrating spheres, which has involved a lot of tedious manual work. A small double integrating sphere would make the measurements considerably faster, because of its ease of operation and small sample sizes required. Here we applied a compact double integrating sphere setup, used previously for measurement of broad leaves, for measurement of coniferous needles. Test measurements with the double integrating sphere showed relative underestimation of needle albedo by 5–39% compared to a well-established single integrating sphere setup. A small part of the bias can be explained by the bias of the single sphere. Yet the observed bias is quite significant if absolute accuracy of measurements is required. For relative measurements, e.g. for monitoring development of needle spectra over time, the double sphere system provides notable improvement. Furthermore, it might be possible to reduce the bias by building an optimized measurement setup that minimizes absorption losses in the sample port. Our study indicates that double spheres, after some technical improvement, may provide a new and fast way to collect extensive spectral libraries of tree species.

• Hovi, Aalto University, School of Engineering, Department of Built Environment, P.O.Box 14100, FI-00760 Aalto, Finland https://orcid.org/0000-0002-4384-5279 E-mail: aarne.hovi@aalto.fi
• Mõttus, VTT Technical Research Centre Finland, P.O. Box 1000, FI-02044 VTT, Finland https://orcid.org/0000-0002-2745-1966 E-mail: matti.mottus@gmail.com
• Juola, Aalto University, School of Engineering, Department of Built Environment, P.O.Box 14100, FI-00760 Aalto, Finland E-mail: jussi.juola@aalto.fi
• Manoocheri, Aalto University, School of Electrical Engineering, Metrology Research Institute, Maarintie 8, FI-02150 Espoo, Finland https://orcid.org/0000-0003-3935-3930 E-mail: farshid.manoocheri@aalto.fi
• Ikonen, VTT Technical Research Centre Finland, P.O. Box 1000, FI-02044 VTT, Finland; Aalto University, School of Electrical Engineering, Metrology Research Institute, Maarintie 8, FI-02150 Espoo, Finland https://orcid.org/0000-0001-6444-5330 E-mail: erkki.ikonen@aalto.fi
• Rautiainen, Aalto University, School of Engineering, Department of Built Environment, P.O.Box 14100, FI-00760 Aalto, Finland; Aalto University, School of Electrical Engineering, Department of Electronics and Nanoengineering, P.O. Box 15500, FI-00760 Aalto, Finland https://orcid.org/0000-0002-6568-3258 E-mail: miina.a.rautiainen@aalto.fi

In the forest areas of eastern China, there is a change from forest dominated by deciduous broad-leaved trees to forest dominated by evergreen broad-leaved trees as the latitude or altitude decreases. Different life forms have different survival strategies to deal with climate change, and studying the life form dynamics of the tree layers in the mixed forest in eastern China, with increasing temperature, can help us understand how the forest responds. This study was performed in a 1 ha plot in evergreen and deciduous broad-leaved mixed forest in Tianmu Mountain National Nature Reserve. Based on the data from two surveys (1996 and 2017), the changes in life form composition and biodiversity over the past 21 years were analyzed. We obtained the following results: (1) The proportion of evergreen trees increased from 55.0% in 1996 to 67.5% in 2017, and the dominance of evergreen species was enhanced. (2) The diversity of both life forms increased, and the tree species were more abundant. (3) The average annual recruitment rate of the evergreen species was 2.1% greater than their mortality rate, and the average annual recruitment rate of the deciduous species was 0.5% less than their mortality rate. (4) The competition among the trees in the small-diameter class (10 cm ≤ DBH < 20 cm) was fierce for many tree species. The proportion of the evergreen species in the small-diameter class was high. The life forms making up the mixed climax forest community has changed over the past 21 years, with the proportion and dominance of evergreen trees increasing significantly.

• Bai, State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China E-mail: baicheng111@gmail.com
• You, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310011, China E-mail: sxyou@zju.edu.cn
• Ku, State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China E-mail: 2732684475@qq.com
• Dai, State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China E-mail: 757692949@qq.com
• Wang, State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China E-mail: 237600341@qq.com
• Zhao, Management Bureau of Tianmu Mountain National Nature Reserve, Hangzhou 311311, China E-mail: 973659738@qq.com
• Yu, State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China E-mail: yushq@zafu.edu.cn

The time consumption (TC) of pre-commercial thinning (PCT) varies greatly among sites, stands and forest workers. The TC in PCT is usually estimated by field-assessed work difficulty factors. In this study, a linear mixed model for the TC in PCT was prepared by utilizing forest resources data (FRD). The modelling data included 11 848 and validation data included 3035 worksites with TC information recorded by forest workers within the period of 2008–2018. The worksites represented a range of site and stand conditions across a broad geographical area in Finland. Site and stand characteristics and previous management logically explained the TC in PCT. The more fertile the site, the more working time was needed in PCT. On sites of medium fertility, TC in the initial PCT increased with stand age by 0.5 h ha^–1 yr^–1. Site wetness increased the TC. PCT in summer was more time consuming than in spring. Small areas were more time consuming to PCT per hectare than larger ones. The between-forest worker variation involved in the TC was as high as 35% of the variation unexplained by the TC model. The coefficient of determination in validation data was 19.3%, RMSE 4.75 h ha^–1 and bias –1.6%. The TC model based on FRD was slightly less precise than the one based on field-assessed work difficulty factors (removal quantity and type and terrain difficulty): RMSE 4.9 h ha^–1 vs. 4.1 h ha^–1 (52% vs. 43%). The TC model could be connected to forest information systems where it would facilitate the predictions of the labour costs of PCT without field-assessing work difficulty factors.

• Uotila, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: karri.uotila@luke.fi
• Miina, Natural Resources Institute Finland (Luke), Natural resources, Yliopistokatu 6 B, FI-80100 Joensuu, Finland E-mail: jari.miina@luke.fi
• Saksa, Natural Resources Institute Finland (Luke), Natural resources, Survontie 9, FI-40500 Jyväskylä, Finland E-mail: timo.saksa@luke.fi
• Store, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Teknologiakatu 7, FI-67100 Kokkola, Finland E-mail: ron.store@luke.fi
• Kärkkäinen, E-mail: kauko.karkkainen@gmail.com
• Härkönen, Tornator Oyj, Pielisentie 2–6, FI-81700 Lieksa, Finland E-mail: mika.harkonen@tornator.fi

Accurate mapping of the spatial distribution of understory species from spectral images requires ground reference data which represent the prevailing phenological stage at the time of image acquisition. We measured the spectral bidirectional reflectance factors (BRFs, 350–2500 nm) at varying view angles for lingonberry (Vaccinium vitis-idaea L.) and blueberry (Vaccinium myrtillus L.) throughout the growing season of 2017 using Finnish Geospatial Research Institute’s FIGIFIGO field goniometer. Additionally, we measured spectra of leaves and berries of both species, and flowers of lingonberry. Both lingonberry and blueberry showed seasonality in visible and near-infrared spectral regions which was linked to occurrences of leaf growth, flowering, berrying, and leaf senescence. The seasonality of spectra differed between species due to different phenologies (evergreen vs. deciduous). Vegetation indices, normalized difference vegetation index (NDVI), moisture stress index (MSI), plant senescence reflectance index (PSRI), and red-edge inflection point (REIP2), showed characteristic seasonal trends. NDVI and PSRI were sensitive to the presence of flowers and berries of lingonberry, while with blueberry the effects were less evident. Off-nadir observations supported differentiating the dwarf shrub species from each other but showed little improvement for detection of flowers and berries. Lingonberry and blueberry can be identified by their spectral signatures if ground reference data are available over the entire growing season. The spectral data measured in this study are reposited in the publicly open SPECCHIO Spectral Information System.

• Forsström, Aalto University, School of Engineering, Department of Built Environment, FI-00076 Aalto, Finland https://orcid.org/0000-0002-2357-2517 E-mail: petri.forsstrom@aalto.fi
• Peltoniemi, Finnish Geospatial Research Institute (FGI), Department of Geodesy and Geodynamics, Geodeetinrinne 2, FI-02430 Masala, Finland https://orcid.org/0000-0002-4701-128X E-mail: jouni.peltoniemi@nls.fi
• Rautiainen, Aalto University, School of Engineering, Department of Built Environment, FI-00076 Aalto, Finland; Aalto University, Department of Electronics and Nanoengineering, FI-00076 Aalto, Finland https://orcid.org/0000-0002-6568-3258 E-mail: miina.a.rautiainen@aalto.fi

Physical soil properties have a marked influence on the quality of forest sites and on the preconditions for forest growth and management. In this study, water retention characteristics (WRC) and related physical soil properties in addition to vegetation coverage and tree stand data were studied at upland forest sites in Finland. Fixed and mixed models between soil and site characteristics were formed to estimate physical and hydrologic soil characteristics and the site quality with indirect co-varying variables. In the present data, the site quality index (H100) shows a high coefficient of determination in respect to the temperature sum. It is also related to soil fine fraction content, topsoil pH and water retention at field capacity. The thickness of the humus layer is predictable from the pH and cover of xeric and mesic plant species. The soil fine fraction content (clay + silt) is closely related to water retention at field capacity, the soil layer and site type, and without WRC to the temperature sum and site index and type, as well as the slope angle. The soil bulk density is related to organic matter, depth (layer) or alternatively to organic matter, slope and field estimated textural class (fine, medium, coarse). Water retention characteristics were found to be best determinable by the fine fraction content, depth and bulk density. Water content and air-filled porosity at field capacity are closely related to the fine fraction. This study provides novel models for further investigations that aim at improved prediction models for forest growth, hydrology and trafficability.

• Heiskanen, Natural Resources Institute Finland (Luke), Soil ecosystems, Neulaniementie 5, FI-70100 Kuopio, Finland E-mail: juha.heiskanen@luke.fi
• Hallikainen, Natural Resources Institute Finland (Luke), Applied statistical methods, Eteläranta 55, FI-96300 Rovaniemi, Finland E-mail: ville.hallikainen@luke.fi
• Uusitalo, Natural Resources Institute Finland (Luke), Forest technology and logistics, Korkeakoulunkatu 7, FI-33720 Tampere, Finland E-mail: jori.uusitalo@luke.fi
• Ilvesniemi, Natural Resources Institute Finland (Luke), Biorefinery and bioproducts, Tietotie 2, FI-02150 Espoo, Finland E-mail: hannu.ilvesniemi@luke.fi

Different environmental factors were studied to determine which factors influence the species richness, composition and structure of vascular plants in Pinus sylvestris L. forests in a fixed dune landscape in south-western Estonia. In addition to site topographic factors, different environmental parameters were investigated. Thirty-four vascular plant species were recorded in 232 quadrats. The most abundant species was Vaccinium vitis-idaea L., which was in 82.8% of quadrats, followed by Vaccinium myrtillus L. (74.1%), Melampyrum pratense L. (71.1%) and Deschampsia flexuosa (L.) Trin. (69.8%). The multiple response permutation procedure (MRPP) showed considerable differences in species composition at the bottoms of dunes compared with that on the slopes and at the tops of dunes. Indicator species analysis (ISA) determined species exhibited characteristics specific to zone: V. myrtillus had the highest indicator value at the bottoms of dunes; Calluna vulgaris L., at the tops. Soils were Haplic Podzols, and the presence of humus horizon depended on zone. Soil conditions on the dunes were variable and site specific, in general, soils at the bottoms of the dunes were more acidic and moist compared with those of the slopes and tops of the dunes, and the nutrient content decreased toward the dune tops. According to non-metric multidimensional scaling (NMDS) and linear mixed model analyses, species coverage, composition and richness were controlled by site-specific factors such as absolute height, location and aspect of the quadrat on the dune; soil nitrogen, potassium and phosphorus contents; soil pH and moisture; light conditions; and the thickness of the litter horizon.

• Tilk, Department of Silviculture, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu, Estonia, 51014; Tallinn Botanic Garden, Kloostrimetsa Road 52, Tallinn, Estonia, 11913 E-mail: Mari.Tilk@botaanikaaed.ee
• Tullus, Department of Silviculture, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu, Estonia, 51014 E-mail: Tea.Tullus@emu.ee
• Ots, Department of Silviculture, Estonian University of Life Sciences, Kreutzwaldi 5, Tartu, Estonia, 51014 E-mail: Katri.Ots@emu.ee

The impacts of weed control, ash fertilization and their interaction were tested for the afforestation of former agricultural peat-based soil with Scots pine (Pinus sylvestris L.) in northern Finland in a factorial arrangement of four treatments. Weed control with herbicides was carried out in July 1 and 2 years from planting, and wood ash (5 Mg ha^–1) was applied in the spring of the 2nd year. Various vegetation, tree growth and nutrient assessments were made over the 21-year study period. Weed control decreased the weed cover by 36–56 percentage points, vegetation height by 4–26 cm and thus shading of seedlings by vegetation for at least 4 years after planting. For the same period, ash fertilization increased vegetation height by 6–15 cm and shading of seedlings. Weed control reduced seedling mortality by 27 percentage points in 21 years, but ash fertilization had no significant effect. Ash fertilization increased foliar potassium and boron concentrations, but its effect declined, and severe K-deficiency was recorded 21 years after planting. Up to the 9th year, weed control had a greater influence on growth than fertilization. Later the significance of fertilization increased due to an aggravated K-deficiency. Stand volume at year 21 for the untreated control plots was 8 m³ ha^–1. Weed control and fertilization increased stand volume by 20 and 35 m³ ha^–1, with a combined effect of 55 m³ ha^–1. The effects of weed control and fertilization were additive and no significant interactions were found. Due to severe K-deficiencies, re-fertilization of all treatments would be necessary for the continued survival and growth of Scots pine.

• Hytönen, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Teknologiakatu 7, FI-67100 Kokkola, Finland http://orcid.org/0000-0001-8475-3568 E-mail: jyrki.hytonen@luke.fi
• Jylhä, Natural Resources Institute Finland (Luke), Green technology, Teknologiakatu 7, FI-67100 Kokkola, Finland E-mail: paula.jylha@luke.fi
• Little, Nelson Mandela Metropolitan University, George Campus, Western Cape, South Africa E-mail: keith.little@nmmu.ac.za

We investigated the impact of natural enemies on the cocoon mortality of the common pine sawfly (Diprion pini L.) during a six-year period in eastern Finland. The enemies were classified into parasitoids (insect families Chalcidoidea, Ichneumonidae, and Tachinidae), and predators (birds, small mammals, and insect families Elateridae and Carabidae). The appearance of D. pini was estimated as the intensity of annual defoliation. The impact of stand characteristics on the performance of parasitoids and predators was also investigated. Influence of the natural enemy complex on cocoon mortality of D. pini was nearly stable, but defoliation intensity slowly declined towards the end of the study period. Annual cocoon mortality by natural enemies varied between 66% and 80%. Our results verified that the most significant mortality factors were ichneumonid parasitoids and small mammals. Random Forest classification indicated that stand characteristics, such as basal area, and coverage of lichen (Lichenes) and lingonberry (Vaccinium vitis-idaea L.) affected the performance of parasites and predators. We suggest that a combination of optimal stand characteristics, abiotic environmental factors and mild to moderate control by natural enemies acted as drivers, which drove the pine sawfly population to extended gradation. For future forest health management, detailed information on abiotic and biotic regulating factors, along with long-term monitoring campaigns for conifer sawflies are needed to adapt Fennoscandian forests to altered climatic and silvicultural conditions.

• Blomqvist, University of Helsinki, Department of Forest Sciences, P.O. Box 27 (Latokartanonkaari 7), FI-00014 University of Helsinki, Finland http://orcid.org/0000-0003-2328-8839 E-mail: minna.blomqvist@helsinki.fi
• Lyytikäinen-Saarenmaa, University of Helsinki, Department of Forest Sciences, P.O. Box 27 (Latokartanonkaari 7), FI-00014 University of Helsinki, Finland E-mail: paivi.lyytikainen-saarenmaa@helsinki.fi
• Kantola, Knowledge Engineering Laboratory, Department of Entomology, Texas A&M University, College Station, TX 77843-2475, USA E-mail: tuula.kantola@helsinki.fi
• Kosunen, University of Helsinki, Department of Forest Sciences, P.O. Box 27 (Latokartanonkaari 7), FI-00014 University of Helsinki, Finland E-mail: maiju.kosunen@helsinki.fi
• Talvitie, University of Helsinki, Department of Forest Sciences, P.O. Box 27 (Latokartanonkaari 7), FI-00014 University of Helsinki, Finland E-mail: mervi.talvitie@dnainternet.net
• Holopainen, University of Helsinki, Department of Forest Sciences, P.O. Box 27 (Latokartanonkaari 7), FI-00014 University of Helsinki, Finland E-mail: markus.holopainen@helsinki.fi

The fusion of optical satellite imagery, strips of lidar data and field plots is a promising approach for the inventory of tropical forests. Airborne lidars also enable an accurate direct estimation of the forest canopy cover (CC), and thus a sample of lidar strips can be used as reference data for creating CC maps which are based on satellite images. In this study, our objective was to validate CC maps obtained from an ALOS AVNIR-2 satellite image wall-to-wall, against a lidar-based CC map of a tropical forest area located in Laos. The reference CC values which were needed for model training were obtained from a sample of four lidar strips. Zero-and-one inflated beta regression (ZOINBR) models were applied to link the spectral vegetation indices derived from the ALOS image with the lidar-based CC estimates. In addition, we compared ZOINBR and logistic regression models in the forest area estimation by using >20% CC as a forest definition. Using a total of 409 217 30 × 30 m population units as validation, our model showed a strong correlation between lidar-based CC and spectral satellite features (root mean square error = 12.8%, R² = 0.82). In the forest area estimation, a direct classification using logistic regression provided better accuracy than the estimation of CC values as an intermediate step (kappa = 0.61 vs. 0.53). It is important to obtain sufficient training data from both ends of the CC range. The forest area estimation should be done before the CC estimation, rather than vice versa.

• Korhonen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland; (current) University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland http://orcid.org/0000-0002-9352-0114 E-mail: lauri.z.korhonen@helsinki.fi
• Ali-Sisto, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: dheikkil@student.uef.fi
• Tokola, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland. E-mail: timo.tokola@uef.fi

• Uotila, Finnish Forest Research Institute, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: karri.uotila@metla.fi
• Saksa, Finnish Forest Research Institute, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@metla.fi
• Rantala, Metsä Group, Lielahdenkatu 10, FI-33400 Tampere, Finland E-mail: juho.rantala@metsagroup.com
• Kiljunen, Metsähallitus, Asemakatu 7, FI-70107 Kuopio, Finland E-mail: nuutti.kiljunen@metsa.fi

• Johansson, Skogforsk, The Forestry Research Institute of Sweden, Ekebo 2250, SE-268 90 Svalöv, Sweden & Southern Swedish Forest Research Centre, SLU, Box 49, SE-230 53 Alnarp, Sweden E-mail: karin.johansson@skogforsk.se
• Ring,  Skogforsk, The Forestry Research Institute of Sweden, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: eva.ring@skogforsk.se
• Högbom,  Skogforsk, The Forestry Research Institute of Sweden, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: lars.hogbom@skogforsk.se

• Hyppönen, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: mikko.hypponen@metla.fi
• Hallikainen, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: ville.hallikainen@metla.fi
• Niemelä, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: jn@nn.fi
• Rautio, Finnish Forest Research Institute, Rovaniemi Unit, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: pasi.rautio@metla.fi

• Uotila, Finnish Forest Research Institute, Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: karri.uotila@metla.fi
• Rantala, Metsä Group, Tampere, Finland E-mail: juho.rantala@metsagroup.com
• Saksa, Finnish Forest Research Institute, Suonenjoki Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@metla.fi

• Johansson, Skogforsk, Svalöv, Sweden E-mail: karin.johansson@skogforsk.se
• Langvall, SLU, Asa Forest Research Station, Sweden E-mail: ol@nn.se
• Bergh, SLU, Southern Swedish Forest Research Centre, Sweden E-mail: jb@nn.se