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Seidling W.,Thunen Institute of Forest Ecosystems | Travaglini D.,University of Florence | Meyer P.,Northwest German Forestry Research Station | Waldner P.,Swiss Federal Institute of forest | And 4 more authors.
IForest | Year: 2014

Dead wood and stand structural parameters were sampled in eleven countries using standardized methods at about 90 intensive forest monitoring sites across large parts of Europe. Besides descriptions and correlation analyses of dead wood and stand structure parameters, a joint evaluation of both fields was performed by principal component analysis (PCA). The extracted principal components were subsequently regressed against important numerical and categorical site-related parameters like soil pH, altitude, or forest type. Dead wood volumes varied largely across plots, however, 77 percent of them had volumes below 25 cubic meter per hectare. While all fractions of dead wood - except cut stumps - reveal high intercorrelation, different aspects of stand structure varied more independently. Clark-Evans index, number of tree species and standard deviation of tree trunk diameters revealed as most selfcontained. The 1st PCA axis covered 46 percent of the total variance and was mostly loaded by total dead wood volume denoting it as the feature differentiating forests most. The 2nd axis was primarily loaded by tree species diversity together with stem density and the Clark-Evans index. On the 3rd axis diameter differentiation of trees together with the volume of cut stumps prevailed, while the 4th was mainly related to the decay class of woody debris. Bivariate ex post analyses revealed country as a significant predictor of all PCA axes, underlining national forest legislations and management rules as crucial for all investigated structural features of forests. Forest type was related only to the 3rd and 2nd axis. Only the 3rd axis revealed significant relationships with some ecological site factors (age, number of tree layers, latitude, altitude). The outcome underlines the significance of nationally enacted forest legislations for both important structural and biodiversity-relevant features of forest ecosystems and encourages similar approaches with data from national forest inventories or monitoring systems. © iForest - Biogeosciences and Forestry.

Kawaletz H.,Thunen Institute of International Forestry and Forest Economics | Molder I.,Energieagentur Region Gottingen E.V. | Annighofer P.,University of Gottingen | Terwei A.,University of Gottingen | And 2 more authors.
Forestry | Year: 2014

Pot experiments, as a complement to field measurements, allow the investigation of plants under controlled conditions without distracting effects of heterogeneous environmental factors. Due to the longevity and larger dimensions of tree species, pot experiments with trees raise more problems than studies with herbaceous plants.Weanalysed 93studiesonpot experiments withwoodyforest speciesandprovideanoverviewof their practical implementation. The literature reviewrevealed that various factors should be taken into account in providing good growing conditions for pot experiments, including pot size, substrate, plant age and origin, and transplanting effects. Many studies did not follow existing recommendations, e.g. an appropriate pot size. Therefore, the transferability of the experimental results to natural conditions is limited and could be improved. We propose that investigation of tree response in pot experiments should be combined with additional measurements undernatural conditions. Unfortunately, manypapers using pot experiments did not provide completeinformation on the experimental set-up, making an evaluation on the quality of pot experiments difficult. We conclude that authors should provide more detailed information on the methodology that can be used to repeat or design future pot experiments. © 2014 Institute of Chartered Foresters. All rights reserved.

Janzen N.,Thunen Institute of International Forestry and Forest Economics | Weimar H.,Thunen Institute of International Forestry and Forest Economics
Wood Processing and Furniture Manufacturing Challenges on the World Market and Wood-Based Energy Goes Global - Proceedings of Scientific Papers | Year: 2015

In 2003 the EU proposed the Action Plan on Forest Law Enforcement, Governance and Trade (FLEGT) to combat illegal logging. In March 2013 the European Timber Regulation (EUTR) came into effect as a main mechanism of FLEGT. The objective of this study is to quantify the share of all wood and wood-based product imports into the EU to which the EUTR applies. We defined the scope of the wood-based products based on the definition of the forest-based sector and aggregated them to twelve product groups. We then calculated EUTR coverage ratios for three different reference units: import value (Euro), roundwood eq. and wood fibre eq. Our results show that approximately 90% of total imported wood quantities are covered by the EUTR. This means that 6 million m3 wood fibre eq. (17 million m3 roundwood-eq.) not covered by the EUTR were imported into the EU in 2013. Coverage ratios for product groups differ. Typically raw materials have a higher coverage ratio and finished products a lower coverage ratio. The wood not covered by EUTR is highly concentrated on a few commodities like wood charcoal, articles of wood, n.e.s. and printed books and brochures. The regional import structure of the EU differs between total imports and imports that are not covered by the EUTR. Eastern and South-Eastern Asia and Africa are gaining importance when looking at imports not covered by the EUTR.

Jochem D.,Thunen Institute of International Forestry and Forest Economics | Weimar H.,Thunen Institute of International Forestry and Forest Economics | Bosch M.,Thunen Institute of International Forestry and Forest Economics | Mantau U.,University of Hamburg | Dieter M.,Thunen Institute of International Forestry and Forest Economics
European Journal of Forest Research | Year: 2015

This paper presents an ex-post calculation approach for the use-side estimation of wood fellings in Germany. Based on an existing approach for calculating wood removals, all roundwood using sectors and available data sources are to be identified. An intensive analysis and evaluation of the data scope and quality, as well as the subsequent identification of data gaps on the use side are essential parts of the approach. A complementary part of the study is the development of individual sectoral models to close the identified data gaps on the use side. The calculated data on wood removals are then used for the estimation of wood fellings, taking into account variables such as logging residues. The comparison of the use-side calculated data for fellings in this paper, with supply-based data from official statistics, shows that there was a difference of about 16.1 million m3 in 2013. This tendency toward constant underestimation of fellings in the official statistics is known from various studies and can now be quantified for the complete period of investigation (1995–2013). The results also allow for a more realistic view on a possible sustainable increase in wood harvests and on decision making in forest-based industries. Moreover, they allow for more accurate calculations of carbon sequestration in forests and harvested wood products. © 2015, Springer-Verlag Berlin Heidelberg.

Suz L.M.,Royal Botanic Gardens | Suz L.M.,Imperial College London | Barsoum N.,Japan Forestry and Forest Products Research Institute | Benham S.,Japan Forestry and Forest Products Research Institute | And 18 more authors.
Molecular Ecology | Year: 2014

Ectomycorrhizal fungi are major ecological players in temperate forests, but they are rarely used in measures of forest condition because large-scale, high-resolution, standardized and replicated belowground data are scarce. We carried out an analysis of ectomycorrhizas at 22 intensively monitored long-term oak plots, across nine European countries, covering complex natural and anthropogenic environmental gradients. We found that at large scales, mycorrhizal richness and evenness declined with decreasing soil pH and root density, and with increasing atmospheric nitrogen deposition. Shifts in mycorrhizas with different functional traits were detected; mycorrhizas with structures specialized for long-distance transport related differently to most environmental variables than those without. The dominant oak-specialist Lactarius quietus, with limited soil exploration abilities, responds positively to increasing nitrogen inputs and decreasing pH. In contrast, Tricholoma, Cortinarius and Piloderma species, with medium-distance soil exploration abilities, show a consistently negative response. We also determined nitrogen critical loads for moderate (9.5-13.5 kg N/ha/year) and drastic (17 kg N/ha/year) changes in belowground mycorrhizal root communities in temperate oak forests. Overall, we generated the first baseline data for ectomycorrhizal fungi in the oak forests sampled, identified nitrogen pollution as one of their major drivers at large scales and revealed fungi that individually and/or in combination with others can be used as belowground indicators of environmental characteristics. © 2014 John Wiley & Sons Ltd.

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