Norway Spruce Research Papers - Academia.edu (original) (raw)

Individual tree mortality models were developed for the six major forest species of Austria: Norway spruce (Picea abies), white ®r (Abies alba), European larch (Larix decidua), Scots pine (Pinus sylvestris), European beech (Fagus silvatica), and oak (Quercus spp.); a joint model for the remaining broadleaf species was also developed. Data came from 5-year remeasurements of the permanent plot network of the Austrian National Forest Inventory. Parameters of the logistic equation were estimated using maximum likelihood methods. For all species, we found the hyperbolic transformation of diameter (D À1) to be highly signi®cant in predicting the high mortality rates for small diameter trees and decreasing mortality rates for larger diameters. For spruce, a quadratic transformation in D was needed to accurately model the increase in mortality observed for large, low-vigor trees with diameter >70 cm, which resulted in a U-shaped distribution. Crown ratio was also consistently signi®cant, except for oak. We likewise found basal-area-in-larger-trees (BAL) to be a highly signi®cant predictor of mortality rate for all species except ®r and oak. Predicted mortality rate increases as the basal area in larger trees increases and as crown ratio decreases. The resulting logistic mortality model had the same general form for all species, with the signs of all parameters conforming to expectations. In general, chi-square statistics indicate that the most important variable is D À1 , the second most important is crown ratio, and the third most important predictor is BAL. The relative importance of crown ratio appears to be greater for shade tolerant species (®r, beech, spruce) than for shade intolerant species (larch, Scots pine, oak). Examination of graphs of observed vs. predicted mortality rates reveals that the species-speci®c mortality models are all well behaved, and match the observed mortality rates quite well. The D À1 transformation is¯exible, as can be seen by comparing the rather different mortality rates of larch and Scots pine. Predicted and observed mortality rates with respect to crown ratio are quite close to the observed mortality rates for all but the smallest crown ratios (CR<20%), a class with very few observations. Finally, the logistic mortality models passed a validation test on independent data not used in parameter estimation. The key ingredient for obtaining a good mortality model is a data set that is both large and representative of the population under study, and the Austrian National Forest Inventory data satisfy both requirements.

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- Methodology, Comparative Study, Neural Network, Parameter estimation

Nitrogen (N) and phosphorus (P) and N: P ratio in terrestrial plants and the patterns at a large geographical scale are an important issue in ecological stoichiometry. In particular, it is essential to know that for a single species, how... more

Current broadband sensors are not capable of separating the initial stages of forest damage. The current investigation evaluates the potential of hyperspectral data for detecting the initial stages of forest damage at the canopy level in the Norway spruce (Picea abies (L.) Karst) forests of Czech Republic. Hyperspectral canopy reflectance imagery and foliar samples were acquired contemporaneously for 23 study sites in August 1998. The sites were selected along an air pollution gradient to represent the full range of damage conditions in even-aged spruce forests. The changes in canopy and foliar reflectance, chemistry and pigments associated with forest damage were established. The potential of a large number of spectral indices to identify initial forest damage was determined. Canopy hyperspectral data were able to separate healthy from initially damaged canopies, and therefore provided an improved capability for assessment of forest physiology as compared to broadband systems. The 673-724 nm region exhibited maximum sensitivity to initial damage. The nine spectral indices having the highest potential as indicators of the initial damage included: three simple band ratios, two derivative indices, two modelled red-edge parameters and two normalized bands. The sensitivity of these indices to damage was explained primarily by their relationship to foliar structural chemical compounds, which differed significantly by damage class.

- by Petya Campbell
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- Remote Sensing, Air pollution, Czech Republic, Geomatic Engineering
- by Ola Heide
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- Plant Biology, Picea abies, Norway Spruce, Biochemistry and cell biology

Process-based models are increasingly being used to model growth dynamics of forest ecosystems. Ideally, estimates of the parameters for these types of models should be obtained through physiological experiments. However, in many situations there is little or no experimental data available to parameterize such models. This paper presents some results of an ongoing study on alternative methods to estimate physiological parameters that are not readily available. The specific focus of this paper is the use of a Bayesian approach based on rejection sampling for estimating physiological parameters using observed state variables of process-based models for forest growth. The method is computationally intensive and can be used to estimate model parameters and their multi-dimensional distributions. The method is used to estimate some of the physiological parameters of a process-based growth model for Norway spruce [Picea abies (L.) Karst.] in Denmark. The estimated one-, two-, and three-dimensional distributions of the parameters of the process-based growth model are given. : S 0 3 0 4 -3 8 0 0 ( 9 9 ) 0 0 0 6 7 -8

- by George Gertner
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- Multidisciplinary, Ecological Modelling, Forest ecosystem, Three Dimensional

Forest damages caused by red deer and some other large herbivore species occasionally feeding on tree bark, are a grave ecological and economic problem in many parts of the world. Winter supplemental feeding is commonly used to mitigate the problem, but its effects are poorly known. this study, carried out at Pohorje (Slovenia) and including over 2,300 trees, used binary logistic regression to analyse the effects of supplemental feeding and many other factors on the probability of bark stripping on spruce. the probability of bark stripping depends on distance from the forest edge, density, age and tree species diversity of stands, slope and aspect of terrain, and red deer density; contrary to expectations, it is not related to distance from feeding places. as much as 35% of spruce trees were damaged. the damage was the highest in younger, denser pure spruce stands, whose favourable protective and microclimatic conditions (thinner snow cover, higher effective temperatures) make them a preferred winter habitat for red deer. they contain, however, little other food but bark. to prevent / diminish bark stripping we propose a stronger thinning of such stands. Supplemental feeding may reduce damage only in exceptional cases, when animals are lured and concentrated in less sensitive areas, but in general we advise against the use of this measure due to its other negative effects.

- by Klemen Jerina and +1
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- Red deer, Cervus elaphus, Spatial Distribution, Forest Edge

This study deals with the problem of quantifying economic effects linked to the transformation of even-aged pure stands of Norway spruce to mixed uneven-aged stands of Norway spruce and beech. The investigation is based on a simulation experiment with a single tree growth simulator. A theoretical approach is presented in which the economic effects occurring during the transformation process (the cost of the transformation) are separated from long-term economic effects occurring after the transformation. The results of the study showed that the costs of the transformation were highly dependent on the interest rate (IR) chosen. With IR 1%, the net present value of the transformation regime is 27% less than the net present value of a conventional age class regime. A discount rate of 3% reduces these costs of transformation to 13%. For the unevenaged model the minimum perpetual yearly net revenue to achieve the same holding value as the age class variant was computed. A mixed uneven-aged stand should at least yield 347 per year and per ha (IR 1%). This value is close to net revenues that are achieved by pure uneven-aged coniferous stands under the same price±cost relations. #

A two-year long field experiment was established in May 1993, on clearcuts ranging in age from fresh to 4 years old at Ž four sites in southern Sweden. The aim of the experiment was to study the effect of clearcut age and removal of slash i.e.,. Ž. twigs, branches, and tops of harvested trees on browsing damage by roe deer Capreolus capreolus L. on planted Norway Ž Ž. . spruce Picea abies L. Karst seedlings. The cover and height of the vegetation, as well as the number of plant species increased rapidly during the first two years after cutting, whereafter these variables continued to increase, although more Ž. slowly. Hairy grass Deshampsia flexuosa L. made up about 90% of the vegetation cover. The nitrogen concentration of hairy grass was highest in two-and three-year old clearcuts. The height of the slash was lower on older clearcuts. Roe deer density increased with clearcut age. Browsing occurred during winter and the frequency of browsed seedlings was 31.2% in the 1993-1994 period and 24.8% in the 1994-1995 period. During both years the browsing damage tended to be highest on Ž. the one-year old clearcuts, but the effect was not statistically significant p s 0.058. The level of damage was about equal on the clearcuts of other ages. The level of browsing damage was not correlated with the quantity or quality of associated vegetation, slash quantity, or roe deer density on the clearcuts. q 1998 Elsevier Science B.V.

The novel flavonol, syringetin 3-O-(6"-acetyl)-fl-glucopyranoside, has been isolated from needles of Norway spruce (Picea abies) together with the 3-O-(6"-acetyl)-fl-glucopyranosides of isorhamnetin and kaempferol, the 3-O-(6"-~t-rhamnopyranosyl)-fl-glucopyranosides of laricitrin, isorhamnetin, myricetin, quercetin and kaempferol and the 3-O-fl-glucopyranosides of laricitrin, isorhamnetin, myricetin, quercetin and kaempferol. Most of the flavonols have been isolated for the first time from Norway spruce. Kaempferol 3-O-(6"-acetyl)-fl-glucopyranoside has previously been isolated from Senecio aureus, but without determination of the binding site of the acetyl group. Structure determination of the flavonols was achieved from TLC, IH NMR and UV shift reagent data, and, in most cases, 13C NMR and MS.

- by George Francis
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- Phytochemistry, Biological Sciences, CHEMICAL SCIENCES, Picea abies

Norway spruce bore an abundance of cones in Finland in 2000, but these cones were often fungalinfected. The seeds had structural injuries that were revealed when seed samples were examined using light (LM) and a field emission scanning electron microscope (FESEM). Two main types of spores were found either in the tissues inside the seed coat or on the sarcotesta, the outermost layer of seed coat. The spores of Chrysomyxa pirolata appeared particularly in the nucellar tissue, where the cell walls were disintegrated at the middle lamellae and cytoplasm was disrupted. Degenerated remnants of fungal structures resembling aecial peridium were found close to aeciospores. The tissue of the megagametophyte differed also from that of a normal mature seed. Conidia of Thysanophora penicillioides were often encountered on the sarcotesta where the ordinary wax cover was missing. Fungal injury occurred in the nucellar layers that shelter the embryo and megagametophyte from desiccation and oxidation. Destruction of these structures together with rapid opening of the seed coat advance deterioration of seeds during storage and may cause unexpected economic losses in forest plant production.

- by Juha Kaitera
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- Plant Biology, Fungal Infection, Trees, Seed Coat

Land use change Forest regeneration pattern Spatially-explicit model a b s t r a c t In addition to the effects of climate change, land use change is expected to trigger dynamic processes that may shift alpine tree lines upwards. To gain a conceptual understanding of the spatio-temporal processes shaping tree line patterns, we developed an individual-based and spatially-explicit model of spontaneous forest regeneration at the alpine tree line. Remote sensing data were integrated with the succession processes for individual trees in an object based image analysis approach. The model presented here predicts patterns of natural forest regeneration on a summer pasture in the Austrian Central Alps between 1954 and 2006. Different model scenarios are compared to the actual forest regeneration during the study period to validate the model's structure and its sensitivity to changing input parameters. The model's main process parameters are tested in four scenarios: A baseline scenario with the most likely input parameters derived from empirical studies in the literature; and three scenarios with differing parameters for seed production, seed dispersal kernel, and seedling competition with the ground vegetation. The tests largely confirm the model's formulation. The baseline scenario correctly predicts a significant upwards shift of the tree line elevation. Moreover it is demonstrated that (1) fecundity is a crucial factor in the expansion of forest into open land, (2) land cover and land use history have a significant impact on the emergence of forest regeneration patterns and (3) the dispersal kernel of Norway spruce has a long-distance component. We thus identified the key processes operating under environmental change from the characteristics of spatial changes in tree line patterns over the last 50 years.

- by Gudrun Wallentin and +2
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- Climate Change, Seed Dispersal, Environmental Change, Multidisciplinary

Solid biofuels such as wood chips are common fuels in many heating plants. The fuels are by nature heterogeneous and the fuel particles can form a stable structure across openings, which may stop the fuel ow in the feeding systems of heating plants. This phenomenon is known as bridging and in the present paper the bridging properties of several common wood fuels are studied and the in uence of particle size and proportion of long particles, bed depth, raw material, species and moisture content is described. The fuels tendency to bridge was deÿned as the maximum slot opening over which a fuel will create a bridge. Measurements were done for wood fuels made from whole trees, logging residues and roundwood from coniferous species (Norway spruce, Sitka spruce and Contorta pine) and various deciduous trees and cut by two chippers to four di erent nominal particle sizes (30 and 35 mm chip and 50 and 100 mm chunk). The most important variable was the proportion of particles longer than 100 mm, which was a result of chipper type, knife setting and raw material. For most fuels, a higher moisture content increased the tendency to bridge. Wood fuels made from roundwood showed no signiÿcant correlation between tendency to bridge and moisture content. The study shows that the bridging problems can be reduced by adaptation of the fuel preparation to the given opening. ?

- by pieter d kofman
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- Engineering, Technology, Biofuels, Raw materials

Fire history and stand structure was examined in twelve virgin forest stands situated within forest reserves in northern Sweden. The selected stands represented fire refuges as well as different successional stages after fire. Six of the stands were dominated by Norway spruce (Piceu abies L. Karst.), three were dominated by Scats pine (Pinus sylvestris L.), and three were dominated by hairy birch (Be&a pubescens Ehrh.) or aspen (Populus tremulu L.). In 3 of the southernmost stands, the average fire interval was 34 to 65 years during the late 1600s to late 18OOs, but since 1888 no fires had occurred in any of the stands. The absence of fire disturbance since 1888 is probably caused by the fire suppression in the overall landscape. The standing volume of living trees ranged between 87 and 5 11 m3 ha-' while the volume of dead trees, including both snags and logs, ranged between 27 and 201 m3 ha-'. The volume of dead trees constituted ca. 30% of the total stem volume. In the conifer dominated stands, there was a statistically significant relationship between total stem volume, including both living and dead trees, and site productivity. A comparison between the amount of dead and living trees indicated substantial changes in tree species composition in several stands. It is suggested that data on the amount of dead trees, especially logs, and its distribution over decay classes could be used to examine the continuity of certain tree species. All stands had a multi-sized tree diameter distribution, which in most cases was similar to a reversed J-shaped distribution. In general spruce was numerous in the seedling cohort and in small diameter classes, indicating that its proportion in the stands was stable, or was increasing at the expense of pioneer tree species such as pine, aspen and silver birch (Beth pendulu Roth.). The most numerous species in the seedling cohort, rowan (Sorbus aucupuriu L.), was almost totally missing in the tree layer, indicating a high browsing pressure preventing rowan seedlings from growing into trees. The general increase of spruce and the sparse regeneration of pioneer species, in the stands previously affected by fire, are discussed in relation to natural disturbance regimes, biological diversity and nature conservation policies. It is proposed that reintroduction of fire disturbance is a necessity for future management plans of forest reserves. Other management practices to increase species diversity within forest reserves are also discussed. 0 1997 Elsevier Science B.V.

- by Per Linder
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- Forest Ecology And Management, Fire History, Forest fire, Biological Sciences

The resolution of the Kyoto Protocol to include effects of land use and land-use change in global carbon budgets has put focus on C sequestration following afforestation of former arable land. Carbon is sequestered in the aggrading biomass of the new forests, but the question remains, to what extent the former arable soils will contribute as sinks for CO 2 . The present study explored changes in soil C stores following afforestation of former arable land with oak (Quercus robur L.) and Norway spruce (Picea abies (L.) Karst.). Seven stands of each tree species on nutrient-rich soils made up a chronosequence ranging from 1 to 29 years. An adjacent $200-year-old mixed deciduous plantation was included to give information on the possible long term changes in soil C. Soil sampling included organic layers and three layers of the mineral soil to a depth of 25 cm.

Our study compared the soil collembolan community at three semi-natural sites (a beech forest, a beech-fir forest and a fir stand) and three managed sites (Norway spruce, beech-fir and fir). Collembola were extracted from a total of 60 samples with a Berlese-Tullgren funnel, counted and identified to species level. A total of 7187 specimens, representing 51 species and 37 genera, were collected. There were significant differences between managed and natural forests (t-test, P ¼ 0:000). The communities and their population densities were significantly lower in the managed site: 51 species with 708,498 ind m À2 in the semi-natural forests to 36 species and 306,042 ind m À2 in the managed stands. The endemic component suffered a particularly severe decrease in species richness and abundance (57% and 71% lower in the managed forests, respectively). These species with narrow distribution and small local populations are doubly vulnerable to alterations of environmental conditions. They are very sensitive to loss of their natural habitat owing to human intervention and thus represent useful indicators of tolerance to environmental stress. We highlight the need to take endemic species into consideration in studies on the conservation of biodiversity because they are most at risk of extinction. Seminatural forests are refuges for endemic species and should be protected.

- by Marie Bal
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- Plant Biology, Biodiversity Conservation, Forest Management, Population Density

The radial variation of the selected physical and mechanical properties of Norway spruce (Picea abies (L.) H. Karst) wood from the provenance area in Głuchów. Spruce wood (Picea abies (L.) H. Karst) is one of the main species used in building constructions. Due to the wide occurrence, it is important to test various origins and in this way select those with the best material properties. Wood was obtained from one habitat from a provenance experimental area in Głuchów from 40-year-old trees. For the study, trees from three different origins were selected: Nowe Ramuki, Bliżyn and Rycerka Praszywka II (origin from respectively northern, central and southern Poland-seedlings came from these places). Spruce wood from Bliżyn, which is the closest to the proven research area in Głuchów, reached the highest average values in all studied traits (density, ultrasonic wave velocity, dynamic and static modulus of elasticity and static bending strength) and was characterized by the highest variability of these features. Regardless of the origin, the above-mentioned features of the wood showed a clear upward trend going from the pith to the to the side of the trunk.

Concentrations of seven elements (As, Cd, Cr, Mn, Pb, V, Zn) in mosses (Hylocomium splendens, Pleurozium schreberi, Eurhynchium angustirete) and needles of Norway spruce (Picea abies) and juniper (Juniperus communis) were determined at 48 sites in Lithuania. Conifer needles consistently showed many times lower concentrations than mosses collected at the same site. Correlations between heavy-metal concentrations in needles and mosses indicated that accumulation processes may be similar, but mosses appear to be clearly preferable as biomonitors of atmospheric deposition because of their higher elemental concentrations and more quantitative re#ection of deposition rates. Precipitation in the open "eld and under the canopy was investigated at two stations with respect to the same metals. The canopy was shown to retain a considerable part of lead, whereas elements such as Zn and Mn were enriched in precipitation under the canopy. Study of metal concentrations in moss growing, respectively, below and outside the canopy showed that none of so studied elements was signi"cantly retained by the canopy. Most of the metals (Cu, Fe, Zn, Cr, Ni, V) were leached from the canopy to a smaller or greater extent.

disturbances that occurred in the two stands were ABSTRACT logging activities as a part of a group shelterwood 1. Three permanent plots (100×0 m) were system. The stand in plot 2 has developed without established in the subalpine Norway spruce (Picea significant human interference for about half a abies (L.) Karst.) forest of Paneveggio in the spring century as confirmed by the presence of many dead of 1993, to begin a long-term forest ecosystem trees. The stand in plot 3 consists of old trees that were research project. The main purpose of these plots

- by Paola Nola
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- Ecology, Biogeography, Picea abies, Norway Spruce

The objective of this work was to find a rapid, high-yield process to obtain an aqueous stable colloid suspension of cellulose nanocrystals/whiskers. Large quantities are required since these whiskers are designed to be extruded into polymers in the production of nano-biocomposites. Microcrystalline cellulose (MCC), derived from Norway spruce (Picea abies), was used as the starting material. The processing parameters have been optimized by using response surface methodology. The factors that varied during the process were the concentration of MCC and sulfuric acid, the hydrolysis time and temperature, and the ultrasonic treatment time. Responses measured were the median size of the cellulose particles/whiskers and yield. The surface charge as calculated from conductometric titration, microscopic examinations (optical and transmission electron microscopy), and observation of birefringence were also investigated in order to determine the outcome (efficiency) of the process. With a sulfuric acid concentration of 63.5% (w/w), it was possible to obtain cellulose nanocrystals/whiskers with a length between 200 and 400 nm and a width less than 10 nm in approximately 2 h with a yield of 30% (of initial weight).

A mechanistic model for assessing the risk of wind and snow damage to single trees and stands of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) Karst.), and birch (Betula spp.) is presented. The model predicts the critical turning moment and wind speed at which the trees will be uprooted or break at forest margins. The resistance to uprooting is predicted using the estimate of the root-soil plate weight to derive a resistive moment, while the resistance to stem breakage relies on values for the modulus of rupture determined for different species of timber. A tree is assumed to be uprooted if the total turning moment exceeds the support provided by the root-soil plate anchorage. Similarly, a tree is assumed to break if the breaking stress acting on the stem exceeds a critical value of the modulus of rupture. The model is in general quite sensitive to parameter changes, which partly results from the location in the forest to which it was designed to apply (the stand edge). The predictions of the critical turning moments needed to uproot and break trees nevertheless give a good agreement on average with the Finnish tree-pulling data for Scots pine, Norway spruce, and birch.

- by Seppo Kellomäki
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- Earth Sciences, Canadian, Environmental Sciences, Wind

Stand structure was studied on thirty 1-ha plots in mature managed and old-growth forest stands dominated by Norway spruce (Picea abies L. Karst.) in southern Finland. The forests were classi®ed into three categories (10 plots in each category) according to the age of the dominant spruces and signs of previous cutting: (1) mature managed (95±118 years), (2) overmature managed (124±145 years) and (3) old-growth (129±198 years).

- by Juha Siitonen
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- Forest Ecology And Management, Biodiversity, Forest Ecology, Ecosystem management

Conifer dominated plantations in central and northern Europe are associated with relatively low ecological values, and in some cases, may be vulnerable to disturbances caused by anthropogenic climate change. This has prompted the consideration of alternative tree species compositions for use in production forestry in this region. Here we evaluate the likely biodiversity costs and benefits of supplanting Norway spruce (Picea abies) monocultures with polycultures of spruce and birch (Betula spp.) in southern Sweden. This polyculture alternative has previously been evaluated in terms of economic, recreational, and silvicultural benefits. By also assessing the ecological implications we fill a gap in our understanding of the range of socio-ecological benefits that can be achieved from a single polyculture alternative. We project likely broad scale changes to species richness and abundance within production stands for five taxonomic groups including ground vegetation, tree-living bryophytes, lichens, saproxylic beetles, and birds. Our research leads us to three key findings. First, the replacement of spruce monocultures with spruce-birch polycultures in the managed forest landscapes of southern Sweden can be expected to result in an increase in biological diversity for most but not all taxa assessed, but it is unlikely to improve conditions for many red-listed forest species. Second, modification of other aspects of forest management (i.e. rotation length, dead wood and green tree retention, thinning regimes) is likely to contribute to further biodiversity gains using spruce-birch polycultures than spruce monocultures. Third, the paucity of empirical research which directly compares the biodiversity of different types of managed production stands, limits the extent to which policy relevant conclusions can be extracted from the scientific literature. We discuss the wider implications of our findings, which indicate that some climate change adaptation strategies, such as risk-spreading, can be readily integrated with the economic, environmental and social goals of multi-use forestry.

- by Ingrid Stjernquist
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- Sustainable forestry, Computer Model, Nutrient Uptake, Root Distribution

To increase the application domain (re-use) of LiDAR-based models the random replication effects in the predictor(s) must be considered. We quantify these effects in a linear predictor (X) of four forest inventory attributes (Lorey's height HT, basal area BA, volume VOL, and stem density TPH) with LiDAR data acquired over 40 spruce-dominated large plots in southeastern Norway. A grid-based random thinning of the raw multi-echo LiDAR data, to five target densities between 0.25m−2 and 2.0m−2, generated 100 replications with each density. A DTM was estimated for each replicate and target pulse density. The four linear predictors were constructed from two indicators of canopy density and a posited average effect of a power-transform of echoes classified as canopy returns. Replication variance varied significantly among plots but the reliability ratio of X was high (≥0.92) for HT, BA and VOL but lower for TPH, especially at low pulse densities. Reliability ratios increased with puls...

- by Erik Næsset
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- Errors in Variables, Change Point, Case Study, Geomatic Engineering

Conservation Host specificity Nitrogen mineralisation Saprotrophic and ectomycorrhizal (ECM) fungi Species richness Temperate forest a b s t r a c t Epigeous saprotrophic and ectomycorrhizal (ECM) fungal sporocarps were assessed during 7 yr in a French temperate experimental forest site with six 30-year-old mono-specific plantations (four coniferous and two hardwood plantations) and one 150-year-old native mixed deciduous forest. A total of 331 fungal species were identified. Half of the fungal species were ECM, but this proportion varied slightly by forest composition. The replacement of the native forest by mono-specific plantations, including native species such as beech and oak, considerably altered the diversity of epigeous ECM and saprotrophic fungi.

- by Bernd Zeller
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- Biological Sciences, Environmental Sciences, Fungal ecology, Nitrogen

The objective of this study was to identify candidate features derived from airborne laser scanner (ALS) data suitable to discriminate between coniferous and deciduous tree species. Both features related to structure and intensity were considered. The study was conducted on 197 Norway spruce and 180 birch trees (leaves on conditions) in a boreal forest reserve in Norway. The ALS sensor used was capable of recording multiple echoes. The point density was 6.6 m − 2 . Laser echoes located within the vertical projection of the tree crowns, which were assumed to be circular and defined according to field measurements, were attributed to three categories: "first echoes of many", "single echoes", or "last echoes of many echoes". They were denoted FIRST, SINGLE, and LAST, respectively. In tree species classification using ALS data features should be independent of tree heights. We found that many features were dependent on tree height and that this dependency influenced selection of candidate features. When we accounted for this dependency, it was revealed that FIRST and SINGLE echoes were located higher and LAST echoes lower in the birch crowns than in spruce crowns. The intensity features of the FIRST echoes differed more between species than corresponding features of the other echo categories. For the FIRST echoes the intensity values tended to be higher for birch than spruce. When using the various features for species classification, maximum overall classification accuracies of 77% and 73% were obtained for structural and intensity features, respectively. Combining candidate features related to structure and intensity resulted in an overall classification accuracy of 88%.

- by Erik Næsset
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- Airborne Laser Scanning, Geomatic Engineering, Boreal Forest, Norway Spruce

The aim of this thesis was to investigate potential ways to utilize water extracts from spruce bark. Spruce bark has been found to contain three main stilbene glucosides (astringin, isorhapontin, polydatin), which have potential in the treatment of skin aging and cosmetics applications. Since stilbene glucosides are water soluble, they are dissolved into the debarking process waters of the pulp and paper industry. These waters are not fully utilized at the moment, and being considered as a waste stream, which adds to the costs of the mill by increasing COD levels of the waste water. This waste stream could potentially be transformed to a source of stilbene glucosides, to provide additional revenue to the mill. In the experimental part, temperature eﬀect on hot water extraction yields of industrial spruce bark was studied. Mechanical pressing of heated spruce bark was performed with a laboratory scale mechanical press to study the eﬀect on the COD levels. Finally, bark press waters obtained from the mill were characterized, with partial puriﬁcation of stilbene glucosides by ultraﬁltration with 2 and 5 kDa ﬁlters. The yields were calculated by gravimetric and spectroscopic analysis. Two dimensional (2D) solution-state 1H–13C correlation NMR spectroscopy provided the structural veriﬁcation of the stilbene glucosides and other compounds present in the samples. Extraction yield of industrial spruce bark was increasing 1.4 times every 20 ◦C, on average, reaching yield of 5.0% at 80 ◦C. The mechanical pressing was able to press out 26±5% of the total mass of the sample. COD level was 75,100 mg/L for 80 ◦C sample. This was two times higher compared to bark press sample of taken from a paper mill, which had COD level of 37,500 mg/L. Ultraﬁltration could remove 90% of polyphenols and permeated 14% of the stilbenes of the feed. With 2D-HSQC NMR, all three major stilbene glucosides were identiﬁed from the ﬁltrate and the feed.

- by Evgen Multia
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- Biomass, Ultrafiltration, Resveratrol, Cosmetics

Ecological studies require environmental descriptors to establish the response of species or communities to ecological conditions. The soil water resource is an important factor, but it is difficult for plant ecologists to use because of the lack of accessible data. We explored whether collecting a large number of plots with basic soil information within the framework of forest inventories would make it possible to map the soil water holding capacity (SWHC) with sufficient accuracy to predict tree species growth over large areas. We first compared the performance of the available pedotransfer functions (PTFs) and found significant differences in the SWHC prediction quality based on the PTFs selected. We also found that the most efficient class PTFs and continuous PTFs compared had similar performances. However, there was a significant reduction in efficiency when they were applied to soils that were different from those used to calibrate them. With a root mean squared error (RMSE) of 0.046 cm 3 cm -3 (n = 227 horizons), we selected the Al Majou class PTFs to predict the SWHC in the soil horizons described in every plot. Thus, 84% of the measured SWHC variance have been explained in soils that were free of stones (n = 63 plots). We then estimated the soil water holding capacity by integrating the stone content collected at the soil pit scale (SWHC') and both the stone content at the soil pit scale and rock outcrop at the plot scale (SWHC") for the 100,307 forest plots recorded in France within the framework of forest inventories. The SWHC" values were interpolated by kriging to produce a map with a 1-km² cell size, a wider resolution leading to a decrease in map accuracy. The SWHC" values given by the map ranged from 0 to 148 mm for soil down to a depth of 1 m. The RMSE between the map values and plot estimates was 33.9 mm for the entire France, with a prediction accuracy similar for a large range of scale, the best predictions being recorded for soils developed on marl, clay, and hollow silicate rocks, and in flat areas. Finally, the abilities of SWHC' and SWHC" to predict height growth for Fagus sylvatica, Picea abies and Quercus petraea were investigated, and we found that the predictive ability of SWHC" was much better than that of SWHC'. The SWHC" values extracted from the map were significantly related to tree height growth. They explained 10.7% of the height growth index variance for Beech (Fagus sylvatica, n = 866), 14.1% for Sessile oak (Quercus petraea, n = 877), and 10.3% for Norway spruce (Picea abies, n = 2067). These proportions of variance accounted by SWHC" were close to those found for the SWHC" values estimated from the plots (11.5, 11.7, and 18.6% for Fagus sylvatica, Quercus petraea, and Picea abies, respectively). We conclude that SWHC" can be mapped with sufficient accuracy to predict species growth using basic soil parameters collected from inventories plots. Thus, the map could be used just as well for small areas as for large areas, directly or indirectly through water balance indices, to predict forest growth and thus production, today or in the future, in the context of an increasing drought period linked to a global change in climatic conditions.

- by Christian Piedallu
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- Biological Sciences, Global change, Environmental Sciences, Water balance

Two independently developed mathematical models (GALES and HWIND) for predicting the critical wind speed and turning moment needed to uproot and break the stems of coniferous trees were compared and the results tested against field data on the forces experienced by forest trees and the wind speeds required to damage them. The GALES model calculates the aerodynamic roughness and zero-plane displacement of a forest stand. The aerodynamic roughness provides a measure of the stress (force/unit area) imposed on the canopy as a function of wind speed and the zero-plane displacement provides a measure of the average height on the tree at which the wind acts. Together they allow a calculation of the bending moment imposed on the tree for any wind speed. Data from almost 2000 trees uprooted during pulling experiments and destructive sampling of green wood then allow the model to make predictions of the wind speed at which the tree will be overturned and at which the tree will break for a number of coniferous species. The model assumes a linear relationship between tree stem weight and the maximum resistive moment that can be provided by the root system and it assumes that the stress in the outer fibres of the stem induced by the wind is constant with height. In the HWIND model the turning moment arising from the wind drag on the crown is calculated assuming a logarithmic upwind profile. Together with the contribution from the overhanging weight of the stem and branches caused by bending of the stem this provides the total bending moment. The angle of stem bend is explicitly calculated from the stiffness of the stem. The breaking strength of the stem and the support given by the root-soil plate are calculated from previous experiments on timber strength, and tree resistance to overturning by using root-soil plate mass to derive the resistive moment. This allows calculation of the wind speed required to break and overturn the tree. Model comparisons were performed for individual Scots pine (Pinus syl6estris L.) and Norway spruce (Picea abies L.) with varying tree height and stem taper (dbh/height). Tree location was at the forest stand edge on a podzolic soil. Model comparisons gave good agreement for the critical wind speeds at the forest edge required to break and overturn trees with a maximum difference in prediction of 26%. Slightly better agreement was obtained for Norway spruce (mean difference of 10.8%) than Scots pine (mean difference of 12.3%) and the best agreement was for trees with a taper of 100. At higher taper the GALES model generally predicted higher critical wind speeds than the HWIND model whereas at lower taper the reverse applied.

- by Seppo Kellomäki
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- Aerodynamics, Comparative Study, Multidisciplinary, Ecological Modelling

In Europe, spruce grows in two main regions which meet in Poland, one to the north and east, the other to the south and west. The northeastern area ranges from the northern treeline extending from Norway to Siberia, to southern Sweden, north-eastern Poland and the southern Ural mountains. The southwestern spruce region reaches the mountainous areas of the Alps and the Balkans, the mountains and uplands of the Sudety Mountains, the Carpathians and neighbouring lowlands. Opinions about the distribution of Norway spruce have changed over the years, and its scarcity in the centre of Poland has been strongly debated. The favoured current theory is that Norway spruce once had a continuous distribution in Poland. It is assumed that the rare occurrence in the central Polish lowland is due to a combination of unfavourable soil conditions and previous management activity. The main aim of this work was to analyse climate-growth relationships of Norway spruce in eastern Poland and distinguish regions with similar increment patterns with regards to spruce range. Spruce growth in northern Polish sites is positively correlated with rainfall from May to July. Tree-ring widths in southern sites are more correlated with March temperature. Selected homogenous regions are the same as range types. Trees from the so-called "spruceless area" seem to have similar climate-growth relationships to trees from the southern region. This finding does not settle the question of the origin of the trees, but it does indicate that similar environmental conditions exist in these two areas and proves that the climate was not a limiting factor there.

- by Andrzej Zielski
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- Statistical Analysis, Plant Biology, Trees, Forestry Sciences

In many forests of the Alps, permanent forest cover and, therefore, its continuous renewal is the main silvicultural goal. Regenerating these forests must be based on a sound understanding of the ecology of the tree species in question. The regeneration of silver fir (Abies alba Mill.) and Norway spruce (Picea abies (L.) Karst.) in the upper montane zone of the southern central Alps has so far received little attention. The aim of this study was, therefore, to characterize the ecological niche for the establishment and growth of silver fir and Norway spruce seedlings in this zone. The study was conducted as a case study on a plot of 1.5 ha in the upper montane zone of southern Switzerland, at an altitude of 1380 m. The basal area of the mixed Norway spruce-silver fir stand was 43.7 m 2 ha À1. Seedlings were censused on 375 plots of 1.0 m 2 area. Seedling density was 1.30 AE 4.25 m À2 (mean AE standard deviation) for Norway spruce and 0.87 AE 1.50 m À2 for silver fir. Logistic regression models were used to test the effect of microsite characteristics on seedling occurrence, and general linear models for effects on seedling height growth and biomass increment. Most seedlings received less than 10% light (photosynthetic photon flux density) as compared to values in the open. Silver fir occurrence was positively related to microsites at the edge of canopy trees, but unrelated to ground cover type, light and micro-relief. Norway spruce occurrence was only, and positively, related to the presence of mosses. Height growth and biomass increment of seedlings of both species were only loosely correlated with microsite conditions. Seedlings without canopy cover grew faster than those under canopy cover, probably as a result of light and moisture limitations under the canopy of adult trees. Diffuse radiation was positively correlated with average annual biomass increment of silver fir, but not of Norway spruce seedlings. In general, the results suggest that silver fir seedlings have less specific microsite requirements than Norway spruce seedlings in terms of ground cover. They are also more shade tolerant, and therefore, grow faster than Norway spruce in low-light environments of the upper montane zone of the southern Alps. While the microsite concept can be helpful in designing silvicultural operations, it has limitations when only patch characteristics that are easy to assess are used, and others neglected. Finally, our study www.elsevier.com/locate/foreco

- by Peter Brang
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- Regeneration, Biomass, Ecology, Biological Sciences

The pharmacological profile of the lignan 7-hydroxymatairesinol (HMR/lignan™, HMR) includes chemopreventive effects, antioxidant properties, and mild proestrogenic activity. The present study was devised to investigate the effects of HMR on THP-1 cells, an established model of human monocytes, and on human polymorphonuclear leukocytes (PMNs). In THP-1 cells, HMR concentration-dependently reduced LPSstimulated tumor necrosis factor (TNF)-α secretion in the supernatant. HMR at low, sub-μM concentrations also reduced TNF-α mRNA, which was however enhanced by supra-μM concentrations of HMR. In human PMNs, HMR concentration-dependently reduced ROS production induced by either N-formyl-Met-Leu-Phe, phorbol myristate acetate or angiotensin II, as well as interleukin-8 production induced by either N-formyl-Met-Leu-Phe or angiotensin II. Results indicate that HMR is an effective inhibitor of both monocytic THP-1 cells and of human PMNs and warrant further studies to assess their relevance for the prevention and treatment of several conditions characterized by chronic systemic inflammation.

- by Marco Cosentino
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- RNA, Immunopharmacology, Wood, Reactive Oxygen Species

The primary aim of this study was to investigate the suitability of interferometric X-band SAR (InSAR) for inventory of boreal forest biomass. We investigated the relationship between SRTM X-band InSAR height and above-ground biomass in a study area in southern Norway. We generated biomass reference data for each SRTM pixel from a field inventory in combination with airborne laser scanning (ALS). One set of forest inventory plots served for calibrating ALS based biomass models, and another set of field plots was used to validate these models. The biomass values obtained in this way ranged up to 250 t/ha at the stand level. The relationship between biomass and InSAR height was linear, no apparent saturation effect was present, and the accuracy was high (RMSE = 19%). The relationship differed between Norway spruce and Scots pine, where an increase in InSAR height of 1 m corresponded to an increase in biomass of 9.9 and 7.0 t/ha, respectively. Using a high-quality terrain model from ALS enabled biomass to be estimated with a higher accuracy as compared to using a terrain model from topographic maps. Interferometric X-band SAR appears to be a promising method for forest biomass monitoring.

- by Erik Næsset and +1
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- Remote Sensing, Airborne Laser Scanning, Reference Data, Geomatic Engineering

Forest growth simulators go beyond a mere tabulation of empirical measurements by employing biometric models that functionally describe the dependence of forest growth of the initial forest structure, growth conditions and management regime. This makes them very flexible and allows predicting growth reactions for unknown and/or complex forest growth scenarios. When simulation outcomes are to be used in silvicultural strategic planning, the results are of direct and delicate importance, and the correct simulator performance must be ascertained. This is especially so when the considered forest situation differs from the forest data used to parameterise the model (e.g. different geographical region).

- by Ulrich Kohnle and +1
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- Strategic Planning, Multidisciplinary, Ecological Modelling, Ecological

Carabids (Carabidae, Coleoptera) were studied for 2 years to explore changes in their diversity and composition during a forestry cycle in the Hungarian Mountain Range. Native beech forest was clear-cut and replanted with Norway spruce. Recently planted (5 years old), young (15 years old), middle-aged (30 years old) and old spruce plantations (50 years old) were studied using pitfall traps. Our results showed that the species richness of carabids was significantly lower in the plantations than in the native beech forest. Species composition was homogeneous in the beech forest. b-Diversity of the 15-30 year old plantations was also low, and it increased slightly towards ageing. Heterogeneity of the species composition of the 5 year old plantation was higher than that of the others, which reflected the patchiness of the young plantation. The main tendencies of the compositional changes were as follows. Deciduous forest specialists decreased significantly in abundance in the plantations; they appeared in high abundance only in the beech forest. Species characteristic of open habitats increased remarkably in abundance in the recently established plantation. Multiple linear regression between the diversity of carabids and of 12 environmental variables shows that the pH and compaction of the soil, and the cover of leaf litter had a significant effect in determining diversity of carabids.

- by Belas Gt
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- Ecology, Biodiversity Conservation, Forest Management, Indicator species

Numerous studies have analyzed the carbon sequestration potential of forests and forest management. However, most studies either focused on national and supra-national scales or on the project level in the context of the flexible mechanisms of the Kyoto Protocol. Few studies are available which analyze the effects of alternative silvicultural strategies on carbon sequestration, timber production and other forest services and functions at the operational level of the forest management unit (FMU). The present study investigates effects of three alternative management strategies for secondary Norway spruce forests (Picea abies (L.) Karst.) (Norway spruce age class forestry; continuous cover forestry; conversion to mixed broadleaved forests) and an unmanaged control variant on C sequestration in situ, in wood products and through bioenergy production at the level of a private FMU in Austria, and analyses the interrelationships with timber production and key indicators of biodiversity. The hybrid patch model PICUS v1.4 and a wood products model are employed to simulate forest ecosystem development, timber production, carbon storage in the forest and in wood product pools. Results show that in situ C sequestration is sensitive to forest management with the highest amount of carbon stored in the unmanaged strategy, followed by the continuous cover regime. All three management strategies store substantial quantities of C in the wood products pool. Considering alternative biomass utilization focused on bioenergy production, substantial C offsets could be generated from potential substitution of fossil fuels. Opportunity cost estimates for C sequestration reveal that C sequestration through forest management can be a cost efficient way to reduce atmospheric CO 2 , but the achievable quantities are limited due to biological limitations and societal constraints. The study emphasizes the importance of developing sustainable forest management strategies that serve the multiple demands on forests in the future. #

- by Werner Rammer
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- Forestry, Carbon, Forest Ecology And Management, Carbon Sequestration

Modern forestry management has reduced the amount of dead wood in forest ecosystems and this has become a serious threat to flora and fauna. Efforts are therefore being made to reverse this trend but one problem is that we still lack detailed knowledge regarding the substrate requirements of many saproxylic species. In a field experiment, conducted in three forest types (forest reserve, mature managed forest and clear-cut), we evaluated the value, from a conservation perspective, of different substrate types (logs, snags and tops) of Norway Spruce, Picea abies, and if the quality of spruce logs as saproxylic habitats can be improved by simple log treatments (scorching and shading). We collected 9982 individuals representing 262 saproxylic beetle species in window traps. Both substrate type and, to a lesser extent, log treatment had a significant effect on the abundance and species richness of saproxylic beetles attracted to the different dead wood substrates. However, more importantly, the composition of the beetle assemblages differed significantly between both substrates and log treatments. Snags, logs and tops all attracted significantly different beetle assemblages and scorched logs differed from untreated control logs. Sixteen red listed species were trapped, with the highest number (11 species) being found on scorched logs. We found strong evidence that some species preferred a specific substrate type, mainly logs, in some cases treated logs (scorched or shaded), but not snags, the substrate commonly provided for conservation purposes on e.g. clear-cuts. This stresses the importance of conducting forestry in such a way that a multitude of both forest habitats and ARTICLE IN PRESS www.elsevier.de/baae

- by Kjell Danell
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- Biological Sciences, Environmental Sciences, Picea abies, Norway Spruce

The amount of total anionic groups (TAGs) in laboratory-scale chemithermomechanical pulps (CTMP) were assessed by Methylene Blue (MB) and quinoline sorption. The amounts of surface anionic groups (SAGs) were determined by MB sorption followed by X-ray photoelectron spectroscopy (XPS) and by polyelectrolyte (PE) titration. The content of uronic acids in the pulps was determined by acid methanolysis and gas chromatography (GC) and the methyl-esterification degree of pectins by alkaline hydrolysis. Pulps were produced by chemical pretreatments of sapwood chips of Norway spruce (Picea abies) prior to refining in a small-scale batch refiner. The chips were pretreated with alkaline, sulphite, alkaline sulphite and alkaline peroxide liquors. The TAGs in the pulps increased linearly with alkali and sulphite dosages. Sulphonic groups in lignin and new carboxyl groups formed in pectins accounted for a major part of the new anionic groups. New anionic groups were also created in the fibre material due to lignin oxidation in alkaline peroxide treatment. Pretreatment with sulphite resulted in a lower surface lignin content compared to pretreatment with alkali or alkaline sulphite. This may indicate more preferential fibre separation in the primary wall layers than in the middle lamella or be a result of redeposition of alkali-dissolved lignin onto fibre surfaces. The amount of SAGs, determined by XPS, was doubled for the chemically pretreated pulps compared to a reference TMP. This is probably a result of primary wall exposure and substantial pectin demethylation. Sulphonation did not result in more SAGs.

- by Bjarne Holmbom
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- Engineering, Surface Chemistry, Physical sciences, Gas Chromatography

Heat-treatment changes the chemical and physical properties of wood. Wood polymers are degraded, dimensional stability is enhanced, equilibrium moisture content is lowered, colour darkens and biological durability is increased. The properties of heat-treated wood have been researched considerably, but the differences between sapwood and heartwood have not been reported separately. In this research, water absorption differences between sapwood and heartwood of Scots pine and Norway spruce heat-treated at temperatures 170 • C, 190 • C, 210 • C and 230 • C were investigated. The results were compared to industrially kiln-dried reference samples. Water absorption was determined with a floating test based on the EN 927-5 standard. The heartwood of both wood species absorbed less water than sapwood. Heat-treatment evidently decreased the water absorption of spruce and pine heartwood. The higher the heat-treating temperature, the lower the amount of absorbed moisture. However, a very interesting exception was pine sapwood, whose water absorption actually increased with heat-treatment after the three lowest heat-treatment temperatures compared to the reference material. Water absorption did not decrease until the heattreatment temperature was 230 • C.

- by Sini Metsä-kortelainen
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- Heat Treatment, Building, Water Absorption, Forestry Sciences

The prehistoric salt mine of Hallstatt together with its burial ground is one of the most prominent archaeological sites in Austria, which has also given name for the ''Hallstatt period'' of human civilisation (800-400 BC). Due to the perfect conservation in rock salt a great number of organic materials have been found, among mostly wooden artefacts. Currently, the major archaeological focus is on the Bronze Age salt mining activities with excavations taking place at the historic Christian von Tusch-Werk, Alter Grubenoffen mine.

- by Hans Reschreiter
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- Plant Biology, Bronze Age, Spectrum, Norway Spruce

Fine root bio-and necromass, net primary production (NPP) of fine roots and its proportion of the NPP of trees, as well as turnover rate were investigated in a fertile middle-aged Norway spruce (Picea abies (L.) Karst) stand by sequential core and ingrowth core methods. The stand's site type is Oxalis, the site quality class is I a and the soil type is Umbric Luvisol (FAO classification). Twenty soil cores (volumetric samples, core diameter 38 mm) were taken monthly during the period June-1996 to November 1996 and in June-1997. Ingrowth cores were collected, 15 at a time, during the growing seasons from 1997 to 1999, once after first year and three times in the second and third years. Spruce roots from samples collected by both methods were separated into living and dead roots (two diameter classes: <1 and 1 mm d <2 mm). The fine root NPP was calculated according to the decision matrix, and root turnover rate was calculated as annual root production divided by mean fine root biomass.

- by Ivika Ostonen
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- Biomass, Forest Ecology And Management, Biological Sciences, Environmental Sciences

ISBN 951-45-9568-8 ISBN 952-91-2708-1 (PDF) ISBN 952-91-2709-X (HTML) Yliopistopaino Helsinki 2000 Front cover: Somatic embryos of P. abies. On the left club-shaped embryos. On the right embryo with developing cotyledons and apical... more

- by arja santanen
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- Picea abies, Norway Spruce, Embryos

Allometric relations for tree growth modelling have been subject to research for decades, partly as empirical models, and partly as process models such as the pipe model, hydraulic architecture, mechanical approaches or the fractal-like nature of plant architecture. Unlike empirical studies, process models aim at explaining the scaling within tree architecture as a function of biological, physical or mechanical factors and at modelling their effect on functionality and growth of different parts of an individual tree. The goal of the underlying study is to link theoretical explanation to empirical approaches of tree biomass estimation by the example of Norway spruce (Picea abies [L.] Karst.). Decisively, this article tries to take allometry out of the purely curve-fitting exercise common in literature and derives implications for the use of allometric biomass functions.

Moisture as an important influence factor on fungal growth needs to be considered for service life prediction of wood and wood-based products. Therefore, a long-term moisture measuring and data logging method for wood in weathered conditions was developed. The method is based on measuring the electrical resistance with glued electrodes for sustainable connection. The measuring point at the tip of the electrodes was glued conductively into the wood, the remaining outer part of the electrodes was glued with an isolating glue. For this purpose, special conductive and isolating glues and electrodes were developed and comparatively evaluated in laboratory tests. The most suitable system consisted of a 2k-epoxy resin, serving for the isolating glue and also as conductive glue (when mixed with graphite powder and ethanol) in combination with a partly isolated stainless steel cable, acting as both, electrode and cable. This system was further tested in combination with mobile mini data logger at 29 different exposure sites in Europe and the United States. After 4-6 years of natural weathering with many extreme climatic and moisture changes, no loosening or other detectable abnormality in 541 pairs of electrodes was observed. The data logging systems were working without any problems for 5 years with the first and only battery, and without any additional maintenance. For the calibration of the measuring system, resistance characteristics were determined for different provenances of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies Karst.), and Douglas fir (Pseudotsuga menziesii Franco).

- by Andreas Rapp
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- Architecture, United States, Building, Stainless Steel

Five soil treatments in a 4-year-old clearcut in southern Sweden affected biomass increase and net nitrogen uptake by planted Norway spruce (Picea abies (L.) Karst.) seedlings through their on net mineralisation and root growth. The patch soil treatments studied were: (i) soil inversion in an old clearcut; (ii) mineral soil from the clearcut remaining, (iii) mineral soil from the clearcut with fertiliser application during the first season; (iv) mineral soil from a nearby uncut forest replacing the clearcut mineral soil; and (v) an untreated control. Growth increased in seedlings in treatments (i) and (iii), but growth in soil treatments with humus removal was not better than that of seedlings in untreated soil. High N uptake early in the first growing season resulted in increased growth during this season in contrast to late N uptake that resulted in a high N concentration in the seedlings after the first growing season. This in turn led to a high growth rate during the next growing season. Generally, both root growth and net N mineralisation were positively correlated to N uptake in the soil treatments. Therefore, a combination of low net N mineralisation and poor root growth as a result of high soil density appears to explain the low N uptake in seedlings in undisturbed soil. The importance of competition with field vegetation for N and water was not clear. Net mineralisation was larger in soil treatments where the humus layer was retained than where it was removed. Net N mineralisation in soil from old clearcuts was the same as in soil from fresh clearcuts.

- by Göran Örlander
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- Biological Sciences, Growth, Seasonality, Environmental Sciences

The distribution of natural and antrophogenic radioactive elements in soil and wood was investigated in a 30-year-old forest stand of Norway spruce. Forest plots treated with a single dose of granulated wood ash in 1989 were compared with untreated control plots. It was observed that the retention of radiocesium and radiostrontium by the forest soil is rather strong in spite of the high annual precipitation (1100 mm a−1) and the relatively acidic conditions of the soil. Most of the deposited nuclear weapon fall-out of radiocesium and radiostrontium is still residing in the forest soil. Radiostrontium, but not radiocesium, was found in the intrasoil water collected with lysimeters at soil depths of 20 and 50 cm. Wood xylem radial distributions of radiostrontium indicated a decreased bioavailability with time after deposition of nuclear weapons fall-out, and no major differences could be observed on comparison of wood from ash-treated plots with wood from untreated plots. The activity concentration of radiocesium in tree rings formed prior to 1986 and grown at the ash-treated plot was about two to three times that found in wood from the untreated control plot. In order to make a dosimetric assessment, the spectroscopic change in the radiation field was investigated at the forest plots and at a deposit for industrial waste (southeast Sweden). A portable spectroscopic system employing a semiconductor-type detector (HPGe) and a scintillation detector (3″ × 3″ NaI(Tl)) was used in order to compare the radiation field from deposited ash of various dates of disposal and ash-treated forest plots to controls, respectively. From depth distribution data obtained by activity determination of cores from the ash deposit, theoretical calculations of the primary radiation field showed a reasonable agreement (±2–8%) with results obtained from the field-gamma measurements. The main contributions to absorbed dose in air (105–130 nSv h−1) on the ash and sludge deposit are 214B, 40K, 208Tl, 137Cs, 214Pb, 228Ac, 134Cs and 212Pb. In the ash-treated forest and the corresponding control plots 137Cs and 40K were the main contributors of absorbed dose rate in air. A set of biomass effective filtration factors and biomass effective linear attenuation factors was calculated in order to depict how the forest stand modifies the intensity of the primary radiation field from the ash application.

Lignin content and composition are important traits in several tree breeding programs, but very little is known about their natural variation. This study compares the lignin content in 1-year-old plants and 9-year-old trees of Norway spruce belonging to the same full-sib families. It is shown that the lignin content, according to the modified acetyl bromide method, does not vary significantly within or among the different full-sib families either as plants or as young trees. There is, however, on average 4.0% higher lignin content (31.4% versus 27.4%) and lower standard error for the trees than for the plants. The number of C9-units g y1 lignin, analyzed by thioacidolysis, ranges from 516 to 1186 mmol C9-units g y1 lignin in plants and from 716 to 953 mmol C9-units g y1 lignin in trees, with no significant differences among the families. However, the extent of change in C9-units g y1 lignin varies among the families with age. The ratio of erythro and threo stereoisomers does not vary significantly among the families. However, the ratio changes differently with age among the families similar to the C9-units g y1 lignin. Additionally, the content of p-hydroxyphenyl (H) lignin is 0.6% higher in the trees than in the plants (1.4% versus 0.8%), estimated indirectly from GC-MS data by a novel subtractive technique, indicating a higher degree of compression wood in the young trees. In conclusion, the amount and composition of lignin does not vary within or among the families at the same age. However, the amount of lignin increases with age while the change in lignin composition varies between family and age.

- by David Clapham
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- Mass Spectrometry, Gas Chromatography, Chemical Analysis, Forestry Sciences