Articles containing the keyword 'ALS'

There is no doubt that tree survival, growth, and reproduction in North America's boreal forests would be directly influenced by the projected changes in climate if they occur. The indirect effects of climate change may be of even greater importance, however, because of their potential for altering the intensity, frequency, and perhaps even the very nature of the disturbance regimes which drive boreal forest dynamics. Insect defoliator populations are one of the dominating disturbance factors in North America's boreal forests and during outbreaks trees are often killed over vast forest areas. If the predicted shifts in climate occur, the damage patterns caused by insects may be considerably changed, particularly those of insects whose temporal and spatial distributions are singularly dependent on climatic factors. The ensuing uncertainties directly affect depletion forecasts, pest hazard rating procedures, and long-term planning for pest control requirements. Because the potential for wildfire often increases in stands after insect attack, uncertainties in future insect damage patterns also lead to uncertainties in fire regimes. In addition, because the rates of processes key to biogeochemical and nutrient recycling are influenced by insect damage, potential changes in damage patterns can indirectly affect ecosystem resilience and the sustainability of the multiple uses of the forest resource.

In this paper, a mechanistic perspective is developed based on available information describing how defoliating forest insects might respond to climate warming. Because of its prevalence and long history of study, the spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is used for illustrative purposes in developing this perspective. The scenarios that follow outline the potential importance of threshold behaviour, historical conditions, phenological relationships, infrequent but extreme weather, complex feedbacks, and natural selection. The urgency of such considerations is emphasized by reference to research suggesting that climate warming may already be influencing some insect lifecycles.

• Fleming, E-mail: rf@mm.unknown

To project the changes in wood production of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) in Finland as a result of climate change, two separate studies were made. The first study, at the Faculty of Forestry, University of Joensuu, based its projections on mathematical models; the second one, at the Finnish Forest Research Institute, based projections on measurements of wood production in two series of aged provenance experiments. The results of the two studies were similar for both species: after a 4°C increase of the annual mean temperature a drastic increase in wood production in northern Finland, but little effect, or even some decrease in the southern part of the country. However, the assumptions used in the two studies differed. One important difference was that in the models the temperature is assumed to be increasing gradually over the years, whereas in the provenance experiments, climate changed immediately when the seedlings were transferred to the planting sites. Another problem with the provenance experiments is that when material is moved in a north-south direction in Finland, not only temperature but also photoperiod changes markedly. To compare these two studies, site factors (e.g. soil type, temperature, precipitation) and silvicultural factors (e.g. plant spacing, survival, time of thinning, thinning intensity) from the provenance experiments were included a variable in the mathematical models.

• Beuker, E-mail: eb@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Kolström, E-mail: mk@mm.unknown

The article is a literature review focusing on the reaction of soil respiration, litter decomposition and microflora of forest soils to various pollutants like acidic deposition, heavy metals and unusual high amounts of basic cations. There is a great deal of evidence indicating that environmental pollution affects soil microbial activity and community structure. Much of the data originates from experimental designs where high levels of pollutants were applied to the soil under field or laboratory conditions. Furthermore, many were short-term experiments designed to look for large effects. These experiments have an indicative value, but it has to be kept in mind that environmental pollution is a combination of many pollutants, mostly at low concentrations, acting over long periods of time. There is therefore consequently a demand for research performed in natural forest environments polluted with anthropogenic compounds. 

• Fritze, E-mail: hf@mm.unknown

The element content (Ca, Mg, K, Na, Fe, Mn, Zn, Cu, Pb, S) of Scots pine (Pinus sylvestris L.) bark and Bryoria lichens, as well as the occurrence and coverage of epiphytic lichens and the length of Bryoria species, were studied in the vicinity of Kolari cement works, NW Finland. Fruticose Bryoria species had the highest coverage on pine trunks at a distance of 2 km or more from the cement works. At a distance of 1 km the foliose – or even crustose – Parmeliopsis species were most abundant, while nearer to the works lichens were almost completely absent. The length of Bryoria was reduced at distances of less than 2 km from the cement works. The calcium content in Bryoria species increased very steeply close to the works; by a factor of 60 at a distance of 1 km compared to 16 km. No corresponding increase in other elements was observed near the cement works. All the elements studied in pine bark showed a significant negative correlation with distance, and a significant positive correlation with the calculated dust deposition levels. There were only minor differences between the north and south of the pine trunks, or the side facing or away from the works. Pine bark analysis is recommended for element accumulation studies.

The PDF includes an abstract in English.

• Kortesharju, E-mail: mk@mm.unknown
• Kortesharju, E-mail: jk@mm.unknown

Quantitative variation in the elemental composition of living Scots pine needles was studied along an atmospheric pollutant gradient in the surroundings of the industrial town Harjavalta, south-western Finland. Two 9-km-long transects, each with nine sample plots, running to the S and SW from factory complex were delimited in a homogenous Scots pine (Pinus sylvestris L.) forest. Needle samples were taken from 10 trees at each site, and from two separate sites in Tuusula near Helsinki. There was considerable spatial variation in the elemental composition of the needles. Heavy metals (Cu, Fe, Zn) showed a clear pattern of exponentially decreasing concentration with increasing distance from the emission source. Sodium and potassium concentrations, as well as the ash weight and air-dry weight, also decreased. Magnesium, manganese and calcium concentrations increased with increasing distance.

The PDF includes an abstract in Finnish.

• Heliövaara, E-mail: kh@mm.unknown
• Väisänen, E-mail: rv@mm.unknown

The woodland mosses Pleurozia shcreberi (Willd. ex Brid.) Mitt. and Hylocomnium splendens (Hedw.) Schimp. were used in air pollution monitoring. During late summer and autumn 1977, 44 samples of Pleurozia shcreberi were collected in semi-open coniferous forests from Southern Finland (60°N) to Northern Finland and Northern Norway (70°N). Additional 26 samples of Hylocomnium splendens were collected in similar places south of 61°30’N. Analysis of both moss species revealed decreasing concentration gradients from south to north for Cu, Fe, Pb and Zn. Conversely, Mn and Mg levels increased with latitude, while Ca did not change significantly. Some decreasing west to east concentration gradients for Cu, Zn and Pb were measured in P. schreberi and in H. splendends collected from Southern Finland.

A comparison between these two mosses showed significant differences in Cu content (ave. 22% higher in H. splendends) and Zn content (ave. 8% higher in P. schreberi). However, the differences were considered minor in relation to regional differences in Finland.

In local study of emissions from the Koverhar steel works in Southern Finland, Fe and Zn concentrations in P. schreberi and H. splendens were found to decrease significantly with increasing distance up to 6 kilometres north and south of the source.

The PDF includes a summary in Finnish.

• Rinne, E-mail: rr@mm.unknown
• Mäkinen, E-mail: am@mm.unknown

The yield of Gyromitra esculenta (Pers.) Fr. was surveyed during 1973–82 in a Norway spruce (Picea abies (L.) H. Karst.) dominated stand in Central Finland. The soil surface was treated with different light methods, mainly removing the vegetation and humus layer.

It was shown that is possible to improve the natural yield of G. esculenta by breaking the soil surface. In the 286 m² of treated the yield could be improved over 50 fold compared to the control area. In the untreated control area, the yield per hectare was 0.98 kg/yr. In treated plots the yield was 52.4 kg/yr (in the best year 191 kg/ha/yr). Fruit bodies of G. esculenta were found in treated plots every year after the soil treatment. The yield was at its best in the two first years declining later to the level of 10–20% of the first year’s yield.

The best natural yield was reached in the last year. The previous year’s precipitation was an important factor influencing the yield of the mushroom.

The PDF includes a summary in English.

• Jalkanen, E-mail: rj@mm.unknown
• Jalkanen, E-mail: ej@mm.unknown
• Jalkanen, E-mail: jj@mm.unknown
• Jalkanen, E-mail: mj@mm.unknown

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.

• Bramryd, E-mail: tb@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

A monitoring program is planned for the terrestrial environment around industries in Sweden, which emit acid compounds and heavy metals. Directions for the County Government Boards are being prepared. The paper deals with the present pollution situation in Sweden, based on recent scientific results, the justifications for local monitoring, and the organizing of the monitoring including the parameters suggested.

Four examples from a case study at an oil power station illustrate reporting of the data and the difficulties in interpreting the results. The examples are the distribution of a lichen indicator, heavy metal content and phosphatase activity in the moor layer, soil respiration and tree growth.

• Westman, E-mail: lw@mm.unknown

Gleysol profiles of five southern Finnish sites dominated by Norway spruce (Picea abies (L.) H. Karst.) were described according to the Canadian system of soil classification, and the total contents of five metals (Pb, Zn, Cu, Mn, Fe) were analysed in each soil profile. Lead, zinc and manganese showed highest concentrations in the organic surface horizons with a decrease towards mineral soil horizons. Vopper distribution was somewhat irregular. Iron had maximum values in the mineral soil: in A-horizon of Rego Gleysols and in B-horizon of Fera Gleysols. A preliminary comparison of metal pools in soil (root layer) with annual atmospheric input shows that the role of atmospheric deposition is relatively greater in the case of Cu, Zn and Pb than for Fe or Mn.

The PDF includes a summary in English.

• Vasander, E-mail: hv@mm.unknown
• Mäkinen, E-mail: am@mm.unknown
• Pakarinen, E-mail: pp@mm.unknown

The aim of the present study was to describe the diffusion of the professional insight in forestry taking place among forest owners and as factors attached thereto. The material is based on interviews of 289 forest owners in municipalities of Jämsä and Karstula in Central Finland in 1966. The forest owners were a random sample of all males in the municipalities, who were in the possession of at least 2 ha of cultivated land and 10 ha of forest.

Mass media (papers, radio and television) was an important source of information for the forest owners. Forest educational events are specially planned to spread information on forestry to forest owners, but 40% told that they had never participated any such event. Only 8% had got professional forest education. Knowledge concerning forests and forest management may also be inherited from the forest owner’s parents, or in discussions with professional forest officers or neighbours. About 73% of the forest owners had been in touch with professional foresters at least once during the last three years.

A third of the forest owners regarded professional insight their most important source of information on forestry, a little smaller group considered instruction in forestry questions the most important source. The third largest group had achieved their knowledge on forestry on own experience and inherited knowledge. Forest owners favouring mass media, own experience and inherited knowledge were often owners of a small forest holding.

The PDF includes a summary in English.

• Järveläinen, E-mail: vj@mm.unknown
• Vadén, E-mail: tv@mm.unknown

This paper concentrates on analysing advertising of building materials used in residential, agricultural and factory building, power station construction, warehouse building and the joinery industry in Great Britain, concentrating on advertising to consumers, including architects, engineers, building entrepreneurs, farmers and do-it-yourself practitioners. The material is based on questionnaires answered by 8 professionals of the field, and assessment of two leading English paper in the field of construction in January 1 – June 30, 1959.

It was concluded that forest products were clearly less advertised than other building materials. The unweight average degree of advertising of all forest products was. 1.7, while the score was 2.6 for other materials. Of the different forest products stand out advertising of plywood and sawn good. The most extensively advertised materials were metals, concrete and cement, and some covering materials. Forest products accounted only ¼ of the advertising space in the publications.

The most important media used in advertising building materials were trade journals, calendars and yearbooks, courses and lectures, exhibitions and fares and direct advertising. The most important audience of advertising were architects, followed by the entrepreneurs. It is suggested that the advertising of Finnish products in Great Britain might be best organized by placing it in the hands of two organizations: the sales organisation and a separate body for advertising. The producers would manage the advertising of individual brands to sales level, while the other levels (agents, importers, merchants) would manage the joint advertising of the forest products to the lower sales levels and consumers. A Finnish market research and information offices might be established in Great Britain.

The PDF includes a summary in Finnish.

• Ervasti, E-mail: se@mm.unknown

This investigation concerns the felling volumes in Finland in 1935-1945 as regards future fellings. The statistics are divided in two time periods: 1935-1939, when there was an upward trend in the trade cycle, and 1940-1945, when the trade was disturbed by the Second World War. Fellings of household timber and for sales are presented separately.

Removal was annually in average 38.1 million cubic meters (cbm) without bark in 1935-1939, and 29.8 million cbm in 1940-1945. According to the statistics, felling volumes decreased by about one quarter after the period of 1935-1945. Reduction was largest in private and company forests, but smaller in the state forests. The increment balance for the 1935-1945 shows an excess of growth that gives an accumulated yield of 24.4 million cbm.

In private forests the cut is about half as large as the growth of the standing stock due to the poor silvicultural condition of the forests. Private forests account for about ¾ of the total forest area in Finland. In the state lands the cut is 130% of the growth. The report introduces also rental cut, a method developed by the writer, which defines the volume to be cut aiming at the same time to optimise the future increase of the yield. The principle is to preserve the young and vigorous stands, while cutting stands that have low growth.

According to the statistics, the felling volume of private forests has followed the variations in demand. It seems likely that in the coming years the fellings will not be kept within the limits calculated by the rental cut. Consequently, the reserve formed during the war will be utilized. To meet the demand of wood, forest management must be improved and preference should be given to regeneration fellings. Improving transportation systems, such as roads, would give access to forest resources that are now difficult to harvest.

The PDF includes a summary in English.

• Lihtonen, E-mail: vl@mm.unknown

The shape of land lots formed in parceling of land has been affected by many variables. It is an important economic factor when the land is used in forestry or agriculture. The report concentrates on the larger farms with relatively large forest holdings. In the general parceling of the land that started in the middle of 1700s, the allotted plots were often long and narrow, and the width of the plot could be 20‒50 meters. Later these farms may have been further parceled.

Narrow plots are difficult to manage from the forestry point of view. For example, it is not possible to build a forest road in the plot, and wood harvesting is difficult. To use natural regeneration for a specific tree species is impossible, because the seed trees in the adjacent plot are so near. When the boundaries are long and the properties narrow, there is bigger risk for felling trees on the land of the neighbour. The optimal form for a plot is rectangle which is 3‒6 times longer than its width. Local examples of parceling and the effects of the shape of the plots are given in the article.

The PDF includes a summary in German.

• Kokkonen, E-mail: pk@mm.unknown

Knowledge on the roots systems and their properties is needed when for example assessing the wintering properties of a plant. The article presents the studies on the roots and their functions made with rye, wheat, oat and barley.

The data has been collected during the whole growing season. The experiments took place in the green houses of the University of Helsinki and on the experiment field in Tikkurila, some kilometres north from Helsinki.

The roots of cultivable crop can be divided according their function, state of development, structure and position in the root system into four classes. The classes are sprouting roots, nutriment roots, nutriment-support roots and support roots.

The PDF contains a summary in Finnish. 

• Kokkonen, E-mail: pk@mm.unknown

In attempts to improve the autumn cereals, wheat and rye, hibernation plays an essential role. Those varieties that hibernate well should be marketed and others rejected. Concerning roots, it seems that varieties that hibernate well have more extent root system than those hibernating poorly.

Four varieties of rye were chosen for experiments, two that knowingly hibernate well and two that don’t. The experiments were grown in the Botanical gardens of the university and at the same time in experiment field in Tikkurila.

The results proof that plant hibernating well have more extensible roots than others and hence they survive better in frosting soil that extents.

The PDF contains a summary in English and in Finnish.

• Kokkonen, E-mail: pk@mm.unknown

The study area is state owned forest of Vesijako in southern middle Finland that has earlier been intensively managed with slash-and-burn agriculture and then partly reforested with foreign coniferous tree species after controlled burnings. The total area planted with foreign species consists of 66 sample areas, altogether 28 hectares. The data has been collected in summer 1909. 

The most of studied sample areas have been unsuccessful, but there are still many areas that are too young to be assessed. The originally with foreign species reforested areas are now pine stands. The tree species in experiments have been e.g. larch (Larix sibirica and L. europaea), Siberian stone pine (Pinus cembra sibirica), Siberian fir (Abies sibirica o. pichta), balsam fir (Abies balsamea), white fir (Abies pectinate also Abies alba), white spruce (Picea alba also Picea glauca), Weymouth pinen (Pinus strobus) and European / Swiss mountain pine (Pinus montana  also P. mugo, P. mugho).

• Ilvessalo, E-mail: li@mm.unknown

Resistance to browsing by mammals differs among birch species, and among origins and families of European white birch (Betula pendula Roth). The variation in resistance is large even among individual seedlings of the same family.

On the surface of the bark of European white birch seedlings there are resin droplets, and the number of droplets is strongly and positively correlated with resistance to browsing by hares. The resistance of European white birch apparently is not expensive metabolically because the rapid growth rate of seedlings was positively correlated with hare resistance, and no correlation was found between seedling size and vole resistance. In cafeteria experiments voles and hares were very discriminating in their feeding on birch seedlings. In field experiments, however, environmental heterogeneity partly masked differences in vole resistance among birch families. Fertilization of seedlings seems not to have a clear effect on resistance to hares. On the other hand, there were indications that greenhouse temperature had an effect on resistance to voles. Practical forestry applications of differences in resistance, e.g. use of species hybrids and clonal forestry, are discussed. The prospects for resistance breeding are good.

The PDF includes a summary in Finnish.

• Rousi, E-mail: mr@mm.unknown

• Haapanen, Natural Resources Institute Finland (Luke), Latokartanonkaari 9, 00790 Helsinki, Finland https://orcid.org/0000-0003-3294-501X E-mail: matti.haapanen@luke.fi

Newly developed positioning systems in cut-to-length harvesters enable georeferencing of individual trees with submeter accuracy. Together with detailed tree measurements recorded during processing of the tree, georeferenced harvester data are emerging as a valuable tool for forest inventory. Previous studies have shown that harvester data can be linked to airborne laser scanner (ALS) data to estimate a range of forest attributes. However, there is little empirical evidence of the benefits of improved positioning accuracy of harvester data. The two objectives of this study were to (1) assess the accuracy of timber volume estimation using harvester data and ALS data acquired with different scanners over multiple years and (2) assess how harvester positioning errors affect merchantable timber volume predicted and estimated from ALS data. We used harvester data from 33 commercial logging operations, comprising 93 731 harvested stems georeferenced with sub-meter accuracy, as plot-level training data in an enhanced area-based inventory approach. By randomly altering the tree positions in Monte Carlo simulations, we assessed how prediction and estimation errors were influenced by different combinations of simulated positioning errors and grid cell sizes. We simulated positioning errors of 1, 2, …, 15 m and used grid cells of 100, 200, 300 and 400 m². Values of root mean square errors obtained for cell-level predictions of timber volume differed significantly for the different grid cell sizes. The use of larger grid cells resulted in a greater accuracy of timber volume predictions, which were also less affected by positioning errors. Accuracies of timber volume estimates at logging operation level decreased significantly with increasing levels of positioning error. The results highlight the benefit of accurate positioning of harvester data in forest inventory applications. Further, the results indicate that when estimating timber volume from ALS data and inaccurately positioned harvester data, larger grid cells are beneficial.

• Noordermeer, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail: lennart.noordermeer@nmbu.no
• Næsset, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail: erik.naesset@nmbu.no
• Gobakken, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NMBU, P.O. Box 5003, NO-1432 Ås, Norway E-mail: terje.gobakken@nmbu.no

Our main objective was to determine whether various genetically improved reproductive materials of Scots pine (Pinus sylvestris L.) differ in growth rhythm, autumn cold acclimation and resilience from unimproved materials. The study consisted of two successive indoor experiments with Scots pine seedlings representing four levels of genetic gain (unimproved natural stands, first-generation seed orchards, 1.5-generation seed orchards and seed orchards established with freezing-tested parents) and a wide range of geographical origins within Finland. The seedlings were assessed for terminal shoot elongation, growth cessation, bud set, freezing injuries and bud flushing over the first growth period. All the adaptive traits showed a latitudinal trend regardless of the genetic level. Seed orchard progenies and natural stand progenies did not differ significantly in the timing of growth cessation, bud set, and the flushing rate of the frost-injured seedlings, after the trait variation was adjusted to the latitude of origin. The differences in autumn frost hardiness were insignificant, too, except for the somewhat higher injury rate displayed by the first-generation seed orchard materials. The finding was not conclusive due to ambiguous results from the two experiments. Overall, we did not find evidence of alarming compromises in the adaptive performance of genetically improved materials.

• Haapanen, Natural Resources Institute Finland (Luke), Production systems, Latokartanonkaari 9, FI-00790 Helsinki, Finland https://orcid.org/0000-0003-3294-501X E-mail: matti.haapanen@luke.fi
• Ruotsalainen, Natural Resources Institute Finland (Luke), Production systems, Vipusenkuja 5, FI-57200 Savonlinna, Finland https://orcid.org/0000-0002-2547-0282 E-mail: seppo.ruotsalainen@luke.fi

Two different pulse density airborne laser scanning datasets were used to develop a quality assessment methodology to determine how airborne laser scanning derived variables with the use of reference surface can determine forest road quality. The concept of a reference DEM (Digital Elevation Model) was used to guarantee locally invariant topographic analysis of road roughness. Structural condition, surface wear and flatness were assessed at two test sites in Eastern Finland, calculating surface indices with and without the reference DEM. The high pulse density dataset (12 pulses m^–2) gave better classification results (77% accuracy of the correctly classified road sections) than the low pulse density dataset (1 pulse m^–2). The use of a reference DEM increased the precision of the road quality classification with the low pulse density dataset when the classification was performed in two-steps. Four interpolation techniques (Inverse Weighted Distance, Kriging, Natural Neighbour and Spline) were compared, and spline interpolation provided the best classification. The work shows that applying a spline reference DEM it is possible to identify 66% of the poor quality road sections and 78% of the good ones. Locating these roads is essential for road maintenance.

• Waga, Faculty of Science and Forestry, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland https://orcid.org/0000-0003-1496-7012 E-mail: katalin.waga@uef.fi
• Malinen, Faculty of Science and Forestry, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland; Metsäteho Ltd., Vernissakatu 1, FI-01300 Vantaa, Finland https://orcid.org/0000-0002-5023-1056 E-mail: jukka.malinen@uef.fi
• Tokola, Faculty of Science and Forestry, University of Eastern Finland, Yliopistokatu 7, FI-80100 Joensuu, Finland E-mail: timo.tokola@uef.fi

Five Scots pine (Pinus sylvestris L.) progeny field trials, each established in different Lithuanian regions of provenance in 1983, were studied. Each progeny field trial consists of 140 half-sib families from seven populations (20 families from each population). The evaluation was carried out in 2012 and 2018 to assess the families resistance to Heterobasidion annosum (Fr.) Bref. An index of resistance in the infected plots was calculated. To verify the accuracy of the method, total phenolic compounds (TPC) was chosen as key parameter to compare with the plant resistance index. During the six years between the two assessments, the percentage of living Scots pine trees in the progeny field trials decreased up to 20 percentage points (range: 4 p.p. to 20 p.p.). In 2018 the area of H. annosum damaged plots (in percentage from total field trial area) varied from 17 to 27%. Tree mortality in the trial correlates with site soil fertility – more fertile soils were distinguished by higher tree percentage loss and vice versa. Using analysis from combined data of all progeny trials, the family variance component reached 13.3 ± 2.2% and family heritability was 0.81. Family heritability estimates for root rot resistance show possibilities of high breeding effectiveness. The correlations between the trials in family resistance estimates were negligible (ranging from 0 to 0.28). The significant high correlation coefficient was determined between the resistance index and TPC concentration (r = 0.77, p = 0.0003). This allows us to assume that plant resistance is directly linked on TPC synthesis. The results indicate that the chosen methods of chemical resistance for identification of root rot-resistant genotypes are applicable for the selection of Scots pine half-sib families in the field trials with higher resistance to pathogens.

• Marčiulynas, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, LT-53101 Girionys, Kaunas District, Lithuania E-mail: adas.marciulynas@mi.lt
• Sirgedaitė-Šėžienė, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, LT-53101 Girionys, Kaunas District, Lithuania E-mail: vaida.seziene@mi.lt
• Žemaitis, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, LT-53101 Girionys, Kaunas District, Lithuania E-mail: povilas.zemaitis@mi.lt
• Jansons, Latvian State Forest Research Institute “Silava”, Department of Forest Tree Breeding, Rigas St.t. 111, Salaspils LV-2169, Latvia E-mail: aris.jansons@silava.lv
• Baliuckas, Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų str. 1, LT-53101 Girionys, Kaunas District, Lithuania E-mail: virgilijus.baliuckas@mi.lt

The Green River precommercial thinning (PCT) trial was established between 1959–1961 in New Brunswick (Canada) within natural balsam fir (Abies balsamea (L.) Mill.)-dominated stands. Three silviculture scenarios differing only by the increasing nominal spacings of PCT treatments (1.2 m, 1.8 m, 2.4 m) were compared to an unthinned control within randomized replicates that were clearcut harvested in 2008 and treated with herbicide in 2011. During the fourth post-harvest growing season, we assessed regeneration, competing vegetation and coarse woody debris (CWD; differentiated between large woody debris and slash) to assess the legacy effects of PCT on regeneration of next rotation stands. Our results confirmed that silviculture scenarios including PCT significantly increased conifer stocking in treated plots compared to control conditions, but only in the 1.8 m nominal spacing. Considering that treated and untreated stands were fully stocked, we conclude that PCT using the spacing gradient tested has no legacy effect on the regeneration of next rotation natural balsam fir stands. Given the known sensitivity of balsam fir to future climate conditions in this region, we suggest that future treatments should promote tree species diversity to support ecosystem resilience to climate change by favouring more warm-adapted species, such as some hardwoods.

• Canuel, Faculté de foresterie, géographie et géomatique, Université Laval, Québec, QC G1V 0A6, Canada;  Canadian Wood Fibre Centre, Natural Resources Canada, 1055 du P.E.P.S., P.O. Box 10380, Sainte-Foy Stn., Québec, QC G1V 4C7, Canada E-mail: claudie-maude.canuel.1@ulaval.ca
• Thiffault, Canadian Wood Fibre Centre, Natural Resources Canada, 1055 du P.E.P.S., P.O. Box 10380, Sainte-Foy Stn., Québec, QC G1V 4C7, Canada http://orcid.org/0000-0003-2017-6890 E-mail: nelson.thiffault@canada.ca
• Hoepting, Canadian Wood Fibre Centre, Natural Resources Canada, 1219 Queen St. E., Sault Ste. Marie, ON P6A 2E5, Canada E-mail: michael.hoepting@canada.ca
• Farrell, Canadian Wood Fibre Centre, Natural Resources Canada, 1350 Regent Street, P.O. Box 4000, Fredericton, NB E3B 5P7, Canada E-mail: jamescg.farrell@canada.ca

Despite the influence of cavities on the survival and distribution of cavity-dependent fauna, the variation in the density and characteristics of tree cavities across different habitat types in tropical forests is unknown. In this study, we surveyed 26 312 living trees from 376 species and compared cavity density and characteristics (height, size, type, and orientation) across five habitat types (valley, low-slope, high-slope, high-gully, and high-plateau) in a 20-hectare tropical rainforest in southwest China. From a total of 2047 cavities, we found that cavity density was mainly driven by habitat rather than tree species richness or diameter at breast height (DBH), and the characteristics of cavities were not uniformly distributed across habitats. Cavities were significantly more abundant in high- and low-slope than high-plateau habitats. Compared with other habitats, more “butt hollow” cavity types were found in high-slope habitat and they occurred at a lower tree height, whereas more “crack” cavities were found in low-slope habitat and they had a narrower entrance diameter. Although the mean orientation of cavities faced towards the northeast, cavity orientation varied significantly across habitat types. Our results indicate that certain types of cavities are concentrated in specific habitat types, which can provide avenues for forest management and biodiversity conservation. We highlight the importance of habitat heterogeneity in providing resources for cavity nesters.

• Liu, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China; Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China E-mail: liujunyan2300@163.com
• Tang, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China E-mail: jft@nn.ch
• Chen, Royal Botanic Gardens, Kew, Wakehurst Place, West Sussex RH17 6TN, UK; Mitrani Department of Desert Ecology, Swiss Institute for Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion, Beer-Sheva 8499000, Israel E-mail: chensichong0528@gmail.com
• Ma, Ecological Restoration and Conservation of Forests and Wetlands Key Laboratory of Sichuan Province, Sichuan Academy of Forestry, Chengdu 610081, China E-mail: mawenbao_2000@126.com
• Zheng, Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China E-mail: dioeco@outlook.com
• Dong, Key Laboratory of Southwest China Wildlife Resources Conservation of Ministry of Education, Key Laboratory of Environmental Science and Biodiversity Conservation (Sichuan Province) and Institute of Plant Adaptation and Utilization in Southwest Mountains, China West Normal University, Nanchong, Sichuan 637009, China E-mail: dongtf@aliyun.com

At present, there are no means for reliably comparing the wood fiber contents of different material streams within the paper industry material chain with each other. The aim of this article is to introduce conversion factors that make it possible to quantify the volume of wood expressed in roundwood equivalent (RWE) values for different paper industry-related materials in the material chain. These conversion factors apply to wood pulp, paper, and recovered paper. European data are used in quantifying the paper industry material streams and calculating the RWE conversion factors. The introduced conversion factors can be used to estimate RWE volumes at a global scale. With assumption that paper recycling did not occur and that paper production volume remained unchanged, an additional volume of 666 million m³ RWEs would be required globally per annum to produce 167 million tons of virgin wood pulp to replace 222 million tons of recovered paper utilized by the paper industry in 2010. This volume is approximately the same as 1.6 times the total removal of wood in Europe (EU27), or the total annual removal of wood in the USA, Canada, and Brazil combined.

• Ervasti, Aalto University, Industrial Engineering and Management, Maarintie 8, 02150 Espoo, Finland E-mail: ilervasti@gmail.com

• Franklin, Department of Renewable Resources, University of Alberta, 751 General Services Building, Edmonton, Alberta, T6G 2H1, Canada E-mail: cfrankli@ualberta.ca
• Harper, School for Resource and Environmental Studies, Dalhousie University, Suite 5010, 6100 University Ave., Halifax, Nova Scotia, B3H 3J5, Canada E-mail: Karen.Harper@dal.ca
• Murphy, Department of Environmental Science, Saint Mary’s University, 923 Robie St., Halifax, Nova Scotia, B3H 3C3, Canada E-mail: liamkmurphy@gmail.com

• Sullivan, Department of Forest and Conservation Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: tom.sullivan@ubc.ca
• Sullivan, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail: dru.sullivan@appliedmammal.com

• Holmgren, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail: johan.holmgren@slu.se
• Barth, The Forestry Research Institute of Sweden, Uppsala, Sweden E-mail: ab@nn.se
• Larsson, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail: hl@nn.se
• Olsson, Swedish University of Agricultural Sciences, Forest Resource Management, Umeå, Sweden E-mail: ho@nn.se

• Pulkkinen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: pertti.pulkkinen@metla.fi
• Varis, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: sv@nn.fi
• Jaatinen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: rj@nn.fi
• Leppänen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: al@nn.fi
• Pakkanen, Metla, Haapastensyrjä, Läyliäinen, Finland E-mail: ap@nn.fi

• Sullivan, Department of Forest Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: tom.sullivan@ubc.ca
• Sullivan, Department of Forest Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: dss@nn.ca
• Lindgren, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail: pmfl@nn.ca
• Ransome, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail: dbr@nn.ca

• Rekola, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki E-mail: mika.rekola@helsinki.fi
• Valkeapää, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki E-mail: av@nn.fi
• Rantala, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki E-mail: tapio.rantala@helsinki.fi

• Korpela, University of Helsinki, Department of Forest Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: ilkka.korpela@helsinki.fi
• Ørka, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O.Box 5003, NO-1432 Ås, Norway E-mail: hoo@nn.no
• Maltamo, University of Eastern Finland, School of Forest Science, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: mm@nn.fi
• Tokola, University of Eastern Finland, School of Forest Science, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: tt@nn.fi
• Hyyppä, Finnish Geodetic Institute, Department of Photogrammetry and Remote Sensing, P.O.Box 15, FI-02431 Masala, Finland E-mail: jh@nn.fi

• Kaitera, Finnish Forest Research Institute, Northern Finland Regional Unit, FI-91500 Muhos, Finland E-mail: juha.kaitera@metla.fi
• Nuorteva, Finnish Forest Research Institute, Southern Finland Regional Unit, FI-01301 Vantaa, Finland E-mail: hn@nn.fi

• Weiskittel, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: aaron.weiskittel@umit.maine.edu
• Kenefic, U.S. Forest Service, Northern Research Station, Bradley, ME 04411, USA E-mail: lsk@nn.us
• Seymour, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: rss@nn.us
• Phillips, School of Forest Resources, University of Maine, Orono, ME 04469, USA E-mail: lmp@nn.us

• Gronalt, BOKU – University of Natural Resources and Applied Life Sciences, Feistmantelstr. 4, 1180 Vienna, Austria E-mail: mg@nn.at
• Rauch, BOKU – University of Natural Resources and Applied Life Sciences, Feistmantelstr. 4, 1180 Vienna, Austria E-mail: peter.rauch@boku.ac.at

• Boston, Forest Fibre Solutions, Carter Holt Harvey, Tokoroa, New Zealand E-mail: kevin.boston@chh.co.nz
• Bettinger, Department of Forest Resources, Oregon State University, Corvallis, OR 97331 E-mail: pb@nn.us

• Zucchini, Georg-August-Universität Göttingen, Institute for Statistics and Econometrics E-mail: zucchini@wi-wiss.uni-goettingen.de
• Schmidt, Forest Research Station of Lower Saxony E-mail: ms@nn.de
• Gadow, Georg-August-Universität Göttingen, Institute for Forest Management and Yield Sciences E-mail: kvg@nn.de

Rasamala (Liquidambar excelsa (Noronha) Oken) is an endemic plant in Indonesia. Apart from its use as wood, Rasamala also produces an exudate, known as balsam. Rasamala balsam has the potential to be a substitute for other true balsams derived from Altingiaceae, namely Storax. However, local communities have not used Rasamala balsam to its full potential owing to a lack of knowledge about the tapping method and processing. Therefore, an easy and efficient induction method for plant exudates is required to boost productivity. The use of exogenous hormones as stimulants and less damaging tapping techniques for plant stems requires further investigation. In this study, mechanical and chemical inductions were conducted using 0.1%, 1%, 2%, 5%, and 10% (w/w) methyl jasmonate and ethephon as stimuli. These chemical compounds were applied to young twigs without incision (TW), by incision (TI), to branches perforated with an electric bore (BB), and by incision (BI). After exogenous application for 21 days, Rasamala balsam exuded in all induction techniques, except for the TW treatment. BI treatment showed the highest effective induction, as indicated by the highest balsam exudation. Furthermore, methyl jasmonate was a better chemical stimulant than ethephon. In addition, the induced balsam Rasamala exudate showed a physical characteristic of a clear, thick, sticky colorless to white liquid with a distinctive balsamic odor.

• Carolina, Department of Forest Products, Faculty of Forestry and Environment, IPB University, Jl. Lingkar Kampus IPB Dramaga, Bogor, 16680, Indonesia https://orcid.org/0000-0002-2129-8665 E-mail: a_caroline@apps.ipb.ac.id
• Sari, Department of Forest Products, Faculty of Forestry and Environment, IPB University, Jl. Lingkar Kampus IPB Dramaga, Bogor, 16680, Indonesia https://orcid.org/0000-0001-5377-1384 E-mail: rita_kartikasari@apps.ipb.ac.id
• Nawawi, Department of Forest Products, Faculty of Forestry and Environment, IPB University, Jl. Lingkar Kampus IPB Dramaga, Bogor, 16680, Indonesia https://orcid.org/0000-0001-8367-0349 E-mail: dnawawi@apps.ipb.ac.id
• Bahtiar, Department of Forest Products, Faculty of Forestry and Environment, IPB University, Jl. Lingkar Kampus IPB Dramaga, Bogor, 16680, Indonesia https://orcid.org/0000-0003-0003-5855 E-mail: bahtiar_et@apps.ipb.ac.id
• Kusumoto, The University of Tokyo Chiba Forest, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 770 Amatsu, Kamogawa, Chiba 299-5503, Japan https://orcid.org/0000-0002-4250-2469 E-mail: kusumoto@uf.a.u-tokyo.ac.jp