Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Wood
Type of Medium
Language
Year
  • 1
    Language: English
    In: Forest Ecology and Management, 01 January 2015, Vol.335, pp.87-98
    Description: The production of defect-free, high quality stem wood may be promoted through pruning of branches in hardwood species, yet this practice may also lead to wood defects, such as stem discoloration. Here, models to predict stem discoloration and the time of branch occlusion were developed for L. (sycamore maple) and L. (common ash) based on a pruning experiment in southwest Germany. The dataset consisted of 449 completely occluded branches originating from 115 destructively sampled sycamore maple and common ash trees that had been pruned either in late winter or summer, or had not been pruned and underwent natural branch shedding instead. We analyzed these data with linear and generalized linear mixed-effects models to predict (1) the time until branch occlusion, (2) the length of branch discolorations and (3) the occurrence of discolorations in the stem wood. For all treatments, the time until complete branch occlusion was negatively related to stem radial increment during branch occlusion and positively related to the branch diameter in case of green pruning or the length of the dead branch portion in case of natural branch shedding. The extent of branch discoloration was positively correlated with branch diameter (green pruning) or the dead branch length (natural shedding), which was itself correlated to branch diameter. The probability of stem discoloration after pruning increased with branch diameter and showed large interspecific differences, with a much higher risk for common ash. Thresholds for decay risk based on pruned branch diameters are reported for each species. In both branch and stem discoloration models, there was no evidence of significant effects related to the time of pruning. When analyzing a subset of the original data containing only branches with diameters up to 30 mm, we found that green pruning significantly reduced the duration of branch occlusion. The extent of branch discoloration was positively related to branch diameter and occlusion time and was not affected by pruning treatment or species. Our results indicate that pruning reduces the duration of branch occlusion and, hence, has the potential to increase the proportion of defect-free wood. Furthermore, the duration of branch occlusion after artificial pruning should be minimized in order to reduce the risk of discoloration and decay. Therefore, green pruning should start early in the life of a tree when its branches are still thin and be applied only to vigorous trees that can occlude the wounds rapidly.
    Keywords: Green Pruning ; Natural Branch Shedding ; Wood Quality ; Branch Occlusion ; Wood Discoloration ; Noble Hardwoods ; Forestry ; Biology
    ISSN: 0378-1127
    E-ISSN: 1872-7042
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Forest Ecology and Management, 01 August 2015, Vol.349, pp.94-105
    Description: Improved knowledge concerning nutrient removals through harvesting in former coppice forests is crucial for the sustainable management of these forests. This is especially true if the resumption of coppicing is being considered to serve increasing fuel wood demands. In this study the nutrient contents of various tree compartments of sessile oak ( (Mattuschka) Liebl.) and hornbeam ( L.) from two sites differing in soil fertility were determined using allometric equations to calculate nutrient removal associated with different harvesting intensities. Stand level nutrient contents in tree compartments were comparable between both study sites. The results for exchangeable base cations, plant available P, and total N indicate that coppicing is not a priori an unsustainable forest management system. On sites with large soil nutrient pools, even whole trees may be harvested without substantial reductions in ecosystem nutrient pools. However, on sites with a low nutrient capital, current harvesting practices would result in relatively high rates of nutrient export. In these stands, harvesting intensity should be based on careful selection of the tree compartments removed, e.g. stem only, to conserve nutrients on site. This study describes the impact of simulated tree harvesting on soil nutrient pools in aged coppice forest for the first time. Based on our findings, general assumptions related to soil sustainability of coppicing are replaced by clear recommendations regarding silvicultural nutrient management. Considering the large areas of aged coppice forests in Europe this study provides a methodological template which is needed to enhance their sustainable management.
    Keywords: Aged Coppice ; Oak ; Hornbeam ; Nutrient Content ; Nutrient Export ; Harvesting Intensity ; Forestry ; Biology
    ISSN: 0378-1127
    E-ISSN: 1872-7042
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Forest Ecology and Management, 01 March 2015, Vol.339, pp.57-70
    Description: The rapid re-establishment of forests following large disturbances is being seen as one option to increase the contribution of forests to climate change mitigation. The temporary inclusion of pioneer trees as nurse crops on disturbed sites can facilitate the establishment of target tree species and may additionally benefit productivity and soil fertility. In this study we compared productivity and nutrient cycling between stands of oak target species ( and ) that were established with and without widely spaced ssp. or ssp. nurse crops. Simulation results for a full rotation of oaks (180 years) indicated that both types of forests, with and without nurse crops, have a comparable total productivity. However, stands with nurse crops supplied 59–96 Mg ha harvestable biomass after 20 years, whereas the first harvest of biomass from stands without nurse crops would occur at least 30 years later. Nutrient element costs associated with the removal of ssp. wood were low compared to ssp. Also, nurse crop stands had up to 2.5 times larger pools of exchangeable base cations in top mineral soils (0–30 cm) compared to mono-specific oak stands. The high soil cation pools may have resulted from reduced leaching under nurse crops or the increased recycling of cations, also from deeper soil depth, via litter fall and fine-root turnover. Our results show that forest reestablishment with pioneer tree species may be a suitable tool for the rapid recovery of forest productivity and mitigation potential following disturbances while simultaneously helping to maintain or increase soil fertility.
    Keywords: Nurse Crops ; Populus Ssp ; Betula Ssp ; Biomass Production ; Nutrient Cycling ; Forest Restoration ; Forestry ; Biology
    ISSN: 0378-1127
    E-ISSN: 1872-7042
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    In: Journal of Ecology, May 2017, Vol.105(3), pp.761-774
    Description: Promoting mixed‐species forests is an important strategy for adaptation and risk reduction in the face of global change. Concurrently, a main challenge in ecology is to quantify the effects of species diversity on ecosystem functioning. In forests, the effects of individual tree species on ecosystem functions depend largely on their dimensions, which are commonly predicted using allometric equations. However, little is known about how diversity influences allometry or how to incorporate this effect into allometric equations. Ignoring the effects of interspecific interactions on allometric relationships may result in severely biased predictions. This study examined the effects of tree‐species diversity, competition and tree social status on crown‐projection area (cpa), height (h) and live‐crown length (lcl) of trees using a European‐wide data set containing 17 target species and 12 939 trees. The cpa, h and lcl were predicted as functions of stem diameter at 1·3 m, tree‐species diversity, tree height relative to the stand mean height (rh) and a competition index (CI) that accounted for stand density and interspecific differences in competitive ability based on species‐specific wood density or shade tolerance. Averaged across species, diameter had the greatest effect on cpa and lcl, followed by the competition index, while rh had the greatest effect on lcl. Tree‐species diversity had the smallest effect on cpa, h and lcl. Interspecific variability in cpa, h or lcl responses to diversity, CI, or rh was sometimes related to wood density or shade tolerance. Synthesis. This study shows the strong influence of stand structure and species composition on allometric relationships. These influences can be quantified using measures of competition, tree‐species diversity and relative tree height so that general equations can be developed for a given species to be applied to a wide range of species compositions and stand structures. This new approach will greatly improve predictions of biomass and carbon stocks in structurally and compositionally diverse forests. Tree allometry is influenced by, and influences, many forest functions. However, little is known about how allometry of a given species varies with forest structure and tree‐species composition, or whether any interspecific differences in allometric responses relate to species traits. Using a European wide data set, this study shows how stand structural characteristics and tree‐species diversity can influence tree allometry.
    Keywords: Biodiversity ; Biomass Partitioning ; Complementarity ; Plant Allometry ; Plant–Plant Interactions ; Stand Structure ; Tree Height
    ISSN: 0022-0477
    E-ISSN: 1365-2745
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Forest Ecology and Management, 15 December 2016, Vol.382, pp.129-142
    Description: In forest ecosystems, deadwood is an important component that provides habitat and contributes to nutrient cycles, as well as to carbon and water storage. The change of wood constituents, nutrients and microbial species richness in the field over the whole time of decomposition has only rarely been studied, in particular not in relation to oxidative enzyme activities (mediating lignin degradation) and different forest management regimes. To describe wood decomposition, we selected coarse woody debris (CWD) in form of 197 logs of , and in forests with different management regimes across three regions in Germany. They were sampled and analyzed for wood density, water content, wood constituents (Klason and acid-soluble lignin, organic extractives, water-soluble lignin fragments), carbon, nitrogen and metals (Al, Ca, Cu, K, Mg, Mn and Zn). Furthermore, the activities of oxidative enzymes like laccase, manganese peroxidase, and general peroxidase were measured. Since filamentous fungi (Basidiomycota, Ascomycota) are the major biological agents of wood decomposition, fungal species richness based on sporocarps and molecular fingerprints was recorded. Higher forest management intensity had a negative effect on deadwood volume and in consequence on fungal species richness (sporocarps), but hardly to other analyzed variables. Furthermore, there were significant differences between the tree species for the concentrations of wood constituents and most nutrients as well as the activities of oxidative enzymes, although their course during decomposition was mostly similar among the tree species. We found that molecular species richness increased with the period of decomposition in contrast to the number of fruiting species, which was highest in the intermediate stage of decomposition. Both types of species richness increased with increasing volume of the CWD logs. Regarding the entire period of decomposition, white-rot fungi (WRF), based on identification of sporocarps, were the most abundant group of wood-decaying fungi in all three tree species. This corresponds well with the overall presence of laccase and peroxidases and the concomitant substantial loss of lignin, which points to the importance of these enzymes in deadwood decomposition. We found a continuous decomposition and decline of volume-related concentrations in wood constituents and nutrients with time of decomposition. Contrary to volume-related concentrations, the concentrations related to dry mass frequently increased.
    Keywords: Saproxylic Fungi ; Oxidative Enzyme ; Nutrients ; Lignin ; Forest Management Intensity ; Coarse Woody Debris ; Forestry ; Biology
    ISSN: 0378-1127
    E-ISSN: 1872-7042
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    In: PLoS ONE, 2014, Vol.9(2)
    Description: Nitrogen availability in dead wood is highly restricted and associations with N-fixing bacteria are thought to enable wood-decaying fungi to meet their nitrogen requirements for vegetative and generative growth. We assessed the diversity of nifH (dinitrogenase reductase) genes in dead wood of the common temperate tree species Fagus sylvatica and Picea abies from differently managed forest plots in Germany using molecular tools. By incorporating these genes into a large compilation of published nifH sequences and subsequent phylogenetic analyses of deduced proteins we verified the presence of diverse pools corresponding to functional nifH , almost all of which are new to science. The distribution of nifH genes strongly correlated with tree species and decay class, but not with forest management, while higher fungal fructification was correlated with decreasing nitrogen content of the dead wood and positively correlated with nifH diversity, especially during the intermediate stage of wood decay. Network analyses based on non-random species co-occurrence patterns revealed interactions among fungi and N-fixing bacteria in the dead wood and strongly indicate the occurrence of at least commensal relationships between these taxa.
    Keywords: Research Article ; Biology
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Journal of Environmental Management, 15 June 2014, Vol.139, pp.109-119
    Description: The impact of changes within a single land-use category or land-use intensity on microbial communities is poorly understood, especially with respect to fungi. Here we assessed how forest management regimes and a change in forest type affect the richness and community structure of wood-inhabiting fungi across Germany. We used molecular methods based on the length polymorphism of the internal transcribed spacers and the 5.8S rRNA gene to assess fungal operational taxonomic units (OTUs). A cloning/sequencing approach was used to identify taxonomic affinities of the fungal OTUs. Overall, 20–24% and 25–27% of native fungal OTUs from forest reserves and semi-natural forests became undetectable or were lost in managed and converted forests, respectively. Fungal richness was significantly reduced during a regeneration phase in age-class beech forests with a high level of wood extraction (  = 0.017), whereas fungal community structures were not significantly affected. Conversion of forests from native, deciduous to coniferous species caused significant changes in the fungal community structure (  = 0.64–0.66,  = 0.0001) and could reduce fungal richness (  〈 0.05) which may depend on which coniferous species was introduced. Our results showed that , sp., , and , all known for wood-decaying abilities were strongly reduced in their abundances when forests were converted from beech to coniferous. We conclude that changes within a single land-use category can be regarded as a major threat to fungal diversity in temperate forest ecosystems.
    Keywords: Biodiversity ; Fungal Diversity ; Land-Use ; Changes Within Land-Use Category ; Forest Management ; Forest Conversion ; Environmental Sciences ; Economics
    ISSN: 0301-4797
    E-ISSN: 1095-8630
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Scandinavian Journal of Forest Research, 01 June 2013, Vol.28(4), pp.346-357
    Description: Coarse woody debris (CWD) is critical for forest ecosystem carbon (C) storage in many ecosystems. Since the turnover of CWD is mostly driven by mineralization, changes in temperature and precipitation may influence its pools and functions. Therefore, we analysed, under controlled conditions,...
    Keywords: Coarse Woody Debris ; Carbon ; Respiration ; Decomposition ; Forestry
    ISSN: 0282-7581
    E-ISSN: 1651-1891
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Forest Ecosystems, 2018, Vol.5(1), pp.1-15
    Description: Abstract Background Coarse woody debris (CWD) is very important for forest ecosystems, particularly for biodiversity and carbon storage. Its relevance as a possible reservoir and source of nutrients is less clear, especially in central Europe. Methods Based on a chronosequence of known ages...
    Keywords: CWD ; NIRS ; Decay ; Carbon ; F. sylvatica ; P. abies ; P. sylvestris
    ISSN: 20956355
    E-ISSN: 2197-5620
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    In: Journal of Applied Ecology, July 2018, Vol.55(4), pp.1647-1657
    Description: Forest recovery following management interventions is important to maintain ecosystem functioning and the provision of ecosystem services. It remains, however, largely unclear how above‐ground biomass (AGB) recovery of species‐rich tropical forests is affected by disturbance intensity and post‐disturbance (remaining) tree‐community attributes, following logging and thinning interventions. We investigated whether annual AGB increment (∆AGB) decreases with management‐related disturbance intensity (disturbance hypothesis), and increases with the diversity (niche‐complementarity hypothesis) and the community‐weighted mean (CWM) of acquisitive traits of dominant species (biomass‐ratio hypothesis) in the remaining tree community. We analysed data from a long‐term forest‐management experiment in the Brazilian Amazon over two recovery periods: post‐logging (1983–1989) and post‐thinning (1995–2012). We computed the ∆AGB of surviving trees, recruit trees and of the total tree community. Disturbance intensity was quantified as basal area reduction and basal area remaining. Remaining diversity (taxonomic, functional and structural) and CWM of five functional traits linked to biomass productivity (specific leaf area, leaf nitrogen and phosphorous concentration, leaf toughness and wood density) were calculated for the post‐intervention inventories. Predictors were related to response variables using multiple linear regressions and structural equation modelling. We found support for the disturbance hypothesis in both recovery periods. AGB increment of survivors and of the total tree community increased with basal area remaining, indicating the importance of remaining growing stock for biomass recovery. Conversely, AGB increment of recruit trees increased with basal area reduction because changes in forest structure increased resource availability for young trees. We did not find consistent support for the niche‐complementarity and biomass‐ratio hypotheses, possibly because of a high redundancy in these extremely species‐rich forests. Synthesis and applications. The intensity of disturbance through management, expressed as basal area reduction and basal area remaining, was consistently more important for explaining forest biomass recovery following harvesting and thinning than remaining diversity or trait composition. This points to the importance of controlling logging and thinning intensity in forests of the eastern Amazon. Given the high intervention intensities applied in this experiment, it is likely that low to moderate harvesting intensities permitted by the current legislation for the Brazilian Amazon (30 m³/ha) will not impair biomass recovery in these forests. The intensity of disturbance through management, expressed as basal area reduction and basal area remaining, was consistently more important for explaining forest biomass recovery following harvesting and thinning than remaining diversity or trait composition. This points to the importance of controlling logging and thinning intensity in forests of the eastern Amazon. Given the high intervention intensities applied in this experiment, it is likely that low to moderate harvesting intensities permitted by the current legislation for the Brazilian Amazon (30 m³/ha) will not impair biomass recovery in these forests.
    Keywords: Biomass And Forest Recovery ; Biomass‐Ratio Hypothesis ; Disturbance Intensity ; Functional Traits ; Niche‐Complementarity Hypothesis ; Selective Logging ; Species And Structural Diversity ; Stand Thinning
    ISSN: 0021-8901
    E-ISSN: 1365-2664
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages