Groei en productie van fijnspar in Nederland

From 1951 to 1989 growth and yield research was done on Norway spruce in the Nether-lands. This includes studies by Becking and by the Dorschkamp/IBN research institute. Together with the permanent sample plots from the timber prognosis system HOSP, all this comprises a dataset of 116 plots with 388 recordings. For the development of top height htop with age t Cieszewski’s model with site index h50 and 3 additional parameters fitted best. The diameter development up to stand height of 7 m was best described with a Gompertz function based on htop and initial density N0. The basal area increment iG was best described by a power function based on htop, age and S%. For S% > 14.7 the basal area increment drops non-linear with S%. Year of recording and site index were not significant. The effect of thinning on the diameter after thinning was modelled with a modified La Bastide-Faber model. With all models together, a stand projection model was constructed, which de-scribes the measured stand development reasonably well. The model was used to construct yield tables with five site classes and five thinning intensities

Multi‐variable approach pinpoints origin of oak wood with higher precision

Aim Spatial variations of environmental conditions translate into biogeographical patterns of tree growth. This fact is used to identify the origin of timber by means of dendroprovenancing. Yet, dendroprovenancing attempts are commonly only based on ring‐width measurements, and largely neglect additional tree–ring variables. We explore the potential of using wood anatomy as a dendroprovenancing tool, and investigate whether it increases the precision of identifying the origin of oak wood. Since different tree–ring variables hold different information on environmental conditions prevailing at specific times of the growing season—which vary between source regions—we hypothesize that their inclusion allows more precise dendroprovenancing. Location Europe, Spain. Taxon Quercus robur L., Quercus petraea (Matt.) Liebl., Quercus faginea Lam., Quercus pyrenaica Willd. Methods We sampled four oak species across Northern Spain, i.e. from the Basque country and Cantabria and—in the Basque country—from low to high elevation (topographic/latitudinal gradient). We measured multiple tree–ring variables to (a) extract complementary variables; (b) present statistical relations among them; (c) analyse region‐specific variation in their patterns based on time–series of individual trees; and (d) determine underlying climate–growth relationships. Leave‐one‐out analysis was used to test whether a combination of selected variables allowed dendroprovenancing of a randomly selected tree within the area. Results A combination of latewood width (LW) and earlywood vessel size was used to pinpoint the origin of oak wood with higher precision than ring width or LW only. Variation in LW pinpointed the wood to east and west areas, whereas variation in vessels assigned wood to locations along a latitudinal/topographic gradient. The climatic triggers behind these gradients are respectively an east–west gradient in June–July temperature and a north–south gradient in winter/spring temperatures. The leave‐one‐out analyses supported the robustness of these results. Main conclusions Integration of multiple wood–xylem anatomical variables analysed with multivariate techniques leads to higher precision in the dendroprovenancing of ring‐porous oak species.This research work is part of the ForSEAdiscovery project (Forest Resources for Iberian Empires: Ecology and Globalization in the Age of Discovery), and was funded by the Marie Curie Actions programme of the European Union (PITN‐2013‐607545). This work was supported by a postdoc fellowship of the German Academic Exchange Service (DAAD)S

EFO-LCI: A New Life Cycle Inventory Database of Forestry Operations in Europe

Life cycle assessment (LCA) has become a common methodology to analyze environmental impacts of forestry systems. Although LCA has been widely applied to forestry since the 90s, the LCAs are still often based on generic Life Cycle Inventory (LCI). With the purpose of improving LCA practices in the forestry sector, we developed a European Life Cycle Inventory of Forestry Operations (EFO-LCI) and analyzed the available information to check if within the European forestry sector national differences really exist. We classified the European forests on the basis of "Forest Units" (combinations of tree species and silvicultural practices). For each Forest Unit, we constructed the LCI of their forest management practices on the basis of a questionnaire filled out by national silvicultural experts. We analyzed the data reported to evaluate how they vary over Europe and how they affect LCA results and made freely available the inventory data collected for future use. The study shows important variability in rotation length, type of regeneration, amount and assortments of wood products harvested, and machinery used due to the differences in management practices. The existing variability on these activities sensibly affect LCA results of forestry practices and raw wood production. Although it is practically unfeasible to collect site-specific data for all the LCAs involving forest-based products, the use of less generic LCI data of forestry practice is desirable to improve the reliability of the studies. With the release of EFO-LCI we made a step toward the construction of regionalized LCI for the European forestry sector

Creating a Regional MODIS Satellite-Driven Net Primary Production Dataset for European Forests

Net primary production (NPP) is an important ecological metric for studying forest ecosystems and their carbon sequestration, for assessing the potential supply of food or timber and quantifying the impacts of climate change on ecosystems. The global MODIS NPP dataset using the MOD17 algorithm provides valuable information for monitoring NPP at 1-km resolution. Since coarse-resolution global climate data are used, the global dataset may contain uncertainties for Europe. We used a 1-km daily gridded European climate data set with the MOD17 algorithm to create the regional NPP dataset MODIS EURO. For evaluation of this new dataset, we compare MODIS EURO with terrestrial driven NPP from analyzing and harmonizing forest inventory data (NFI) from 196,434 plots in 12 European countries as well as the global MODIS NPP dataset for the years 2000 to 2012. Comparing these three NPP datasets, we found that the global MODIS NPP dataset differs from NFI NPP by 26%, while MODIS EURO only differs by 7%. MODIS EURO also agrees with NFI NPP across scales (from continental, regional to country) and gradients (elevation, location, tree age, dominant species, etc.). The agreement is particularly good for elevation, dominant species or tree height. This suggests that using improved climate data allows the MOD17 algorithm to provide realistic NPP estimates for Europe. Local discrepancies between MODIS EURO and NFI NPP can be related to differences in stand density due to forest management and the national carbon estimation methods. With this study, we provide a consistent, temporally continuous and spatially explicit productivity dataset for the years 2000 to 2012 on a 1-km resolution, which can be used to assess climate change impacts on ecosystems or the potential biomass supply of the European forests for an increasing bio-based economy. MODIS EURO data are made freely available at ftp://palantir.boku.ac.at/Public/MODIS_EURO.Peer reviewe

Growth and yield of mixed versus pure stands of Scots pine (Pinus sylvestris L. ) and European beech (Fagus sylvatica L.) analysed along a productivity gradient through Europe

Mixing of complementary tree species may increase stand productivity, mitigate the effects of drought and other risks, and pave the way to forest production systems which may be more resource-use efficient and stable in the face of climate change. However, systematic empirical studies on mixing effects are still missing for many commercially important and widespread species combinations. Here we studied the growth of Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.) in mixed versus pure stands on 32 triplets located along a productivity gradient through Europe, reaching from Sweden to Bulgaria and from Spain to the Ukraine. Stand inventory and taking increment cores on the mainly 60-80 year-old trees and 0.02-1.55 ha sized, fully stocked plots provided insight how species mixing modifies the structure, dynamics and productivity compared with neighbouring pure stands. In mixture standing volume (+12 %), stand density (+20 %), basal area growth (+12 %), and stand volume growth (+8 %) were higher than the weighted mean of the neighbouring pure stands. Scots pine and European beech contributed rather equally to the overyielding and overdensity. In mixed stands mean diameter (+20 %) and height (+6 %) of Scots pine was ahead, while both diameter and height growth of European beech were behind (−8 %). The overyielding and overdensity were independent of the site index, the stand growth and yield, and climatic variables despite the wide variation in precipitation (520-1175 mm year−1), mean annual temperature (6-10.5 °C), and the drought index by de Martonne (28-61 mm °C−1) on the sites. Therefore, this species combination is potentially useful for increasing productivity across a wide range of site and climatic conditions. Given the significant overyielding of stand basal area growth but the absence of any relationship with site index and climatic variables, we hypothesize that the overyielding and overdensity results from several different types of interactions (light-, water-, and nutrient-related) that are all important in different circumstances. We discuss the relevance of the results for ecological theory and for the ongoing silvicultural transition from pure to mixed stands and their adaptation to climate change.The networking in this study has been sup-ported by COST Action FP1206 EuMIXFOR. All contributors thanktheir national funding institutions to establish, measure, and analysedata from the triplets. The first author also thanks the BayerischenStaatsforsten (BaySF) for supporting the establishment of the plots,the Bavarian State Ministry for Nutrition, Agriculture, and Forestryfor permanent support of the project W 07 ‘‘Long-term experimentalplots for forest growth and yield research’’ (# 7831-22209-2013) andthe German Science Foundation for providing the funds for the pro-jects PR 292/12-1 ‘‘Tree and stand-level growth reactions on droughtin mixed versus pure forests of Norway spruce and European beech’’.Thanks are also due to Ulrich Kern for the graphical artwork, and totwo anonymous reviewers for their constructive criticism

Bosecologie en bosbeheer

Bossen vervullen een belangrijke functie in het Nederlandse en Vlaamse landschap. Lag vroeger de nadruk vooral op de productie van hout als hernieuwbare grondstof, tegenwoordig is het belang van bossen voor natuurbehoud, recreatie en milieubescherming sterk toegenomen. Dit vraagt om een hoog kennisniveau van de beheerder. Bovendien vereisen veranderingen in de maatschappelijke en natuurlijke omgeving, zoals klimaatverandering, inzicht in de processen die in het bosecosysteem plaatsvinden. Deze inzichten zijn nodig om met kennis van zaken beheerstrategieën te ontwerpen die een duurzame functievervulling van het bos in de toekomst garanderen. In dit boek worden kennis en ervaringen over het beheer van bos en zijn ecologische grondslagen samengebracht. De teksten zijn geschreven door een brede groep van vakspecialisten uit Nederland en Vlaanderen met een goed inzicht in zowel de wetenschappelijke achtergronden alsook de praktische aspecten van bosbeheer. De basis van het boek wordt gevormd door inzicht in de opbouw en het functioneren van bomen en bossen. Vervolgens worden de belangrijkste beheermaatregelen besproken in het licht van brede maatschappelijke functievervulling en duurzaam gebruik van het bos op de lange termijn