Current issue: 58(4)
The water retention characteristics and their variation in tree nurseries and related physical properties were determined for commercially produced growth media made of light slightly humified Sphagnum peat. A total of 100 samples of peat media were collected from filled seedling trays in the greenhouses of four Finnish nurseries in 1990. In addition, the physical properties were determined for two growth media made of compressed peat sheets and chips. The variation in water retention characteristics in nurseries was described using linear models with fixed and random effects. The sources of variation in the mixed linear models were producer, grade, batch (greenhouse) and sample (tray).
The water retention of the peat media at different matric potentials was comparable to that given in the literature. The media shrank an average of 0–16% during desorption. The peat grades were finer than the Nordic quality standards for peat growth media. Particles < 1 mm increased and particles 1–5 mm decreased the water retention characteristics measured. The greatest total variation in water retention was at -1 kPa. The water retention of the peat media differed least at -5 and -10 kPa. The water retention characteristics of media from different producers usually differed significantly. The grades, on the other hand, did not differ from each other in their water retention characteristics nor were there significant interactions between producer and grade. The batch effect was marked but was lower than the effect within batches, where the sample (tray) effect was greater than the effect due to random measurement error. At -10 kPa, the measurement error was, however, clearly greater than the sample effect. The random measurement error was comparable to the batch effect. Aeration of the growth media is dependent on the water content retained between saturation and -1 kPa. The water availability to seedlings at the nursery phase is affected mainly by water retention between -1 and -10 kPa.
The PDF includes an abstract in Finnish.
The author first introduced the cut-block seedling production method to Finland in 1969. The aim is to raise seedlings whose lateral roots do not become deformed as a result of a restricting container or other external pressure. The seedlings are raised in a large, fairly compact substrate block where the roots can freely develop in a normal fashion. The blocks are then cut up into individual cubes, each containing a seedling. The precise positioning of the sowing point permits mechanization of the work.
The PDF includes an abstract in English.
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.
The ultrastructure of Hypogymnia physodes (L.) Nyl. and Alectoria capillaris (Bryoria capillaris (Ach.) Brodo & D. Hawksw.) grown or transplanted near a fertilizer plant and a pulp mill was compared to normal ultrastructure of these lichen species. The ultrastructural changes observed were highly similar in the symbionts of both species and near both the factories although the emissions are different. In the lichens grown near the factories the number of algae had clearly increased. The appearance of the chloroplasts was roundish compared to controls. The pyrenoglobuli and cytoplasmic storage bodies were smaller than normally and the number of polyphosphate bodies had increased. Also, in mycobionts storage droplets were very small or absent and many vacuoles and dark inclusions appeared to hyphae in contrast to controls. In transplanted lichen there existed mainly the same ultrastructural changes as in the lichen grown near factories. Near the fertilizer plant the damage was, however, more severe because all the lichens died during 6–7 months after transplantation. Near the pulp mill part of the lichens survived and seemed to adapt to air pollution.
Increased prices on oil have resulted in the search for alternative energy sources, e.g. coal, peat, biomass, different types of waste. Combustion especially of waste, coal and peat emits large quantities of air pollutants such as heavy metals but also harmful organic substances. Heavy metals are not easily separated from the smoke, and the concentrations are often high in the emissions even with advanced fly-ash separators.
Ecological investigations carried out around a coal burning power plant in Finland using mosses and pine needles as parameters are presented in the paper. Increased concentrations of Pb, Cd, Cr, Ni, Cu and V have been found near the plant. Often a clear gradient was found with increased concentrations at decreased distance from the power plant.
A semi-statistical model is suggested for monitoring injuries of plants for long-time field exposures (months). The model is based on the following assumptions:
1. The concentrations of air pollutants in the atmosphere follow the Johnson SB distribution.
2. The degree of plant injury is proportional to the logarithm of air pollutant dose.
3. No injuries occur below a certain dose level.
4. A dose is defined as the air pollutant concentration multiplied by the duration of exposure raised to an exponent.
Based on the air pollutant frequency distribution a total dose for the exposure period is calculated by integration, and the total dose is related to the observed plant injury by non-linear regression. The model is tested for long-time exposures of sulphur dioxide to transplant lichen in natural environment.
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.
Hydroelectric plants are being planned or already built in Northern Finland. The complete terracing and regulation of watercourses necessary for the power plants will mean great changes in floating conditions and hence for forestry, for which floating is the principal means of transport. Consequently, the Cabinet appointed a committee in 1958 to ascertain the economic, technical and legislative questions connected with timber transport in the area.
The committee has found that about half of the country’s forest area and two thirds of its water power resources are situated in Northern Finland. A prerequisite for the wise utilization of the forest in Northern Finland is an increase in fellings. This can only be put into effect by improving the means of transport, especially the floating channels. The financing required by the organization of floating connected with the building of the hydroelectric power plants amounts to about 10,000 million marks over a period of 20 years.
The committee has suggested that an advisory committee on floating should be established. Its most important task would be to try to produce a general programme for the organization of floating under the changed conditions, and that the State should participate in the expenditure caused by the organization as regards the capital investment needed for changing over to bundle floating.
The PDF includes a summary in English.
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.
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.
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.
Forest site type classification based on the vegetation has not been developed in India. The classifications made by forest officers have been based on the upper storeys of trees. Shrubs have been used to class such sites where grasses are the dominant species. However, some observers in India have used grass and bamboo species to identify sites suitable on unsuitable for certain valuable tree species. In Burma, some bamboo species have been noticed to be good indicators for sites suitable or unsuitable for teak (Tectona grandis L. f.). Studies in the western sub-Himalayan area suggest that certain grasses could be used as indicators for sites suitable for sal (Shorea robusta Gaertn.). Grasses have also been identified as indicators for certain kinds of forests and soils in the area between Ganges and the Jumna.
The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander.
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.
Since the 1950s, more than 200 000 km of roads have been built in Sweden’s forests, making them easily accessible and open to multiple uses. The aim of this study was to review the impacts of forest roads in Sweden from a broad perspective encompassing social, ecological, and environmental factors. The Swedish case is interesting because it has an extensive network of permanent forest roads which were built primarily for forestry-related transportation but are currently used by many other stakeholders for many different purposes. Forest roads not only facilitate transportation of wood, machinery, personnel, and equipment into and out of the forest but also enable emergency response to wildfires and support berry and mushroom picking, hunting, recreation, tourism, and access to second homes. The roads increase the opportunities for members of the public to experience forests in various ways. Conflicts arise when different interests collide, for example when the interests of the forest owner clash with those of commercial berry-picking companies, tourism entrepreneurs, or reindeer (Rangifer tarandus L.) herding. Forest roads may have ecological impacts such as barrier and disturbance effects, fragmentation or loss of habitats, altering fauna movement patterns, and changing the composition of plant and insect species. The environmental impacts of forest roads relate to, among other things, hydrology, water quality, and erosion. Predicted changes in the climate are likely to place new demands on Swedish forest roads but, despite their extent, this review shows that there is only a small amount of rather fragmented research on their social, ecological, and environmental consequences. Overall, few studies appear to cover both social and ecological/environmental factors and their interactions, either in Sweden or elsewhere. This review provides examples of such interactions in the case of Sweden, and suggests that more research into these and the specific social, ecological, and environmental factors involved is warranted.