Deadwood In Forests Research Articles

Effect of dead wood enrichment in the canopy and on the forest floor on beetle guild composition

In managed forests, the abundance and diversity of saproxylic insect species and beetles in particular has been argued to be primarily limited by the amount of dead wood while the importance of other factors for community composition of this functional group has been largely neglected. It has also been argued that management regimes that lead to increasing amounts of dead wood in forests will increase the abundance and diversity of saproxylic species, but experimental evidence for this assumption is rare. We studied the importance of dead wood and a number of abiotic and biotic factors for community composition of saproxylic species in a range of managed forests in Germany for 2years and found that the total amount of dead wood in the forests only played a minor role in explaining the composition of the saproxylic beetle community compared to other factors such as precipitation, temperature, tree species and vertical stratum. We then tested for eight forest plots whether dead wood experimentally exposed in the canopy and forest floor is attractive to saproxylic beetles. We found that a high diversity and abundance of beetles of various habitat and feeding guilds, were attracted to fresh dead wood, many more than in control areas without dead wood manipulation. Thus, in managed forests where abundance and diversity of saproxylic beetles is low, enrichment of dead wood resulted in an immediate increase of species and a change of guild composition particularly in the canopy. Our results suggest that the amount of ground dead wood is by itself not a sufficient measure for the local diversity of saproxylic beetles. We conclude that dead wood enrichment in managed forests is an effective strategy to promote saproxylic beetle diversity. Changes in the functional composition are expected to be large enough to influence ecosystem processes such as decomposition of dead wood or the control of herbivores.

Disjunct Occurrence ofHarpanthus drummondii(Taylor) Grolle (Geocalycaceae, Jungermanniopsida) in the Boreal Forest of West-Central Canada

The liverwort Harpanthus drummondii (Taylor) Grolle (Geocalycaceae, Jungermanniopsida) is known mostly from temperate regions of eastern North America where it is restricted to dead wood in forests. Recently, the species was discovered in the boreal forest of west-central Canada, demonstrating a substantial disjunction from the next closest known occurrence. A distribution map is provided along with features that distinguish it from the closely related H. scutatus (F.Weber & D.Mohr) Spruce.

Sustainability impact assessment using integrated meta-modelling: Simulating the reduction of direct support under the EU common agricultural policy (CAP)

Assessing the impact of macro-level policy driven land use changes on regional sustainability is an important task that can facilitate complex decision making processes of introducing reforms. The research work demonstrates the ability of Sustainability Impact Assessment Tool (SIAT), a meta-model, in conducting ex ante spatially explicit cross sectoral impact assessments of changes in common agricultural policy (CAP). The meta-model is able to appraise impacts of CAP amendments on land use and their repercussions on multiple indicators of sustainability. The presented study comprehensively analyses the possible impacts of discontinuing direct financial support to farmers under CAP. The simulations of the meta-model are able to reveal the land use changes both at EU and regional levels as well as to bring forth the subsequent changes in a number of indicators representing the regional sustainability (for five case study regions). In a nutshell, the simulations indicate that a reduction in direct support brings in general, a decrease in farmed area, an increase in forested land, less fluctuation in natural vegetation coverage, increase in abandoned arable land area and negligible changes in built-up area despite regionally diverging land use trends. The simulated changes in sustainability indicators for the study regions in consequence to these land use changes show that the discontinuation of subsidies evokes responses that are in general climate friendly (reduction in methane and N2O emissions, diminishing energy use and reduction in global warming potential), economically beneficial (increase in gross value of agriculture) and socially desired (decrease in unemployment rate) as well as environmentally harmful (increase in pesticide use). Even though the appraisals of diversity indicators such as forest deadwood and farmland birds are not conclusive for all regions, the changes are positive for the former indicator and slightly negative for the latter in general. The trade-offs among these regional sustainability indicators using their directional associations are also presented for a comprehensive assessment of the impacts.

Aspetti dendroauxometrici, assortimentali e caratteristiche della necromassa in cedui di castagno

Abstract: Chestnut (Castanea sativa MILL.) is one of the most important forest tree species in Europe, and it is considered a symbol of the natural vegetation in southern Europe. In Calabria (southern Italy) chestnut forest covers an area of approximately 87000 hectares, most of which (about 80%) managed as coppice. In this study a growth and yield table has been elaborated. Thurthermore, assortment type and quantity of deadwood have been evaluated according to age of coppice and forest fire prevention, respectively. The study site is located in the “Presila of Catanzaro” and the research was carried out in 15 plots; the age of the examined stands ranged from 2 to 50 years old. More than 30000 shoots per hectare were recorded in the first two years after coppicing. As opposed, about 2300 and 1000 shoots per hectare were observed 15 and 50 years after coppicing, respectively. The culmination of the mean annual increment of the forest standing volume (16 m3 ha-1 year-1) was highlighted 25 years after coppicing, while the current annual increment culmination (21 m3 ha-1 year-1) was observed at 15 years. Fifteen years after coppicing, most of the wood production was constituted by small dimension assortments. Twenty five years after coppicing small and large poles were the prevailing assortments while telegraph poles and timber beams increased after 50 years. The amount of deadwood in forest ranged between 11.9 and 68.7 m3 ha-1. The largest component was represented by standing dead shoots. The results show that coppice management can be adopted even if the main purpose of the chestnut stand is the production of large size assortments. In chestnut coppice, highly vulnerable to fire, the reduction of stand density with silvicultural practices (thinning and displacement) is the main way to promote the efficiency of forest and a higher strength and resiliency against forest fire.

Richness of Lichen Species, Especially of Threatened Ones, Is Promoted by Management Methods Furthering Stand Continuity

Lichens are a key component of forest biodiversity. However, a comprehensive study analyzing lichen species richness in relation to several management types, extending over different regions and forest stages and including information on site conditions is missing for temperate European forests. In three German regions (Schwäbische Alb, Hainich-Dün, Schorfheide-Chorin), the so-called Biodiversity Exploratories, we studied lichen species richness in 631 forest plots of 400 m2 comprising different management types (unmanaged, selection cutting, deciduous and coniferous age-class forests resulting from clear cutting or shelterwood logging), various stand ages, and site conditions, typical for large parts of temperate Europe. We analyzed how lichen species richness responds to management and habitat variables (standing biomass, cover of deadwood, cover of rocks). We found strong regional differences with highest lichen species richness in the Schwäbische Alb, probably driven by regional differences in former air pollution, and in precipitation and habitat variables. Overall, unmanaged forests harbored 22% more threatened lichen species than managed age-class forests. In general, total, corticolous, and threatened lichen species richness did not differ among management types of deciduous forests. However, in the Schwäbische-Alb region, deciduous forests had 61% more lichen species than coniferous forests and they had 279% more threatened and 76% more corticolous lichen species. Old deciduous age classes were richer in corticolous lichen species than young ones, while old coniferous age-classes were poorer than young ones. Overall, our findings highlight the importance of stand continuity for conservation. To increase total and threatened lichen species richness we suggest (1) conserving unmanaged forests, (2) promoting silvicultural methods assuring stand continuity, (3) conserving old trees in managed forests, (4) promoting stands of native deciduous tree species instead of coniferous plantations, and (5) increasing the amount of deadwood in forests.

Assessing and modeling standing deadwood attributes under alternative silvicultural regimes in the Acadian Forest region of Maine, USA

Estimating the amount of standing deadwood in forests is crucial for assessing wildlife habitat and determining carbon stocks. In this analysis, snags (standing dead trees) in various stages of decay were inventoried across eight silvicultural treatments in eastern spruce–fir forests in central Maine nearly 60 years after treatments were initiated. Several modeling strategies were developed to estimate number of snags per hectare in various stages of decay. An unmanaged reference area displayed the highest basal area and volume of snags (5.4 ± 3.1 m2·ha–1 and 29.4 ± 23.6 m3·ha–1, respectively, (mean ± standard deviation)), while the lowest basal area and volume (0.9 ± 1.0 m2·ha–1 and 3.1 ± 5.2 m3·ha–1) were observed in selection system with a 5-year cutting cycle. Models indicated that snag abundance was related to stand density, depth to water table, and the average harvest interval of the treatment. At a fixed stand density, approximately 140% more snags were predicted to occur in treatments with an average harvest interval of 55 compared with 5 years. An index of error reflecting the number of snags found in certain decay classes was reduced by 40% when predictions from count regression models fit with a mixed modeling strategy were used over ordinal regression. Results from these analyses can help to reduce the disparities between observed and modeled snag stocking levels and further our understanding of the relationships between live and standing dead trees inherent to eastern spruce–fir forests.

Tracking downed dead wood in forests over time: Development of a piece matching algorithm for line intercept sampling

Emerging questions from bioenergy policy debates have highlighted knowledge gaps regarding the carbon and biomass dynamics of individual pieces of coarse woody debris (CWD) across the diverse forest ecosystems of the US. Although there is a lack of long-term measurements of CWD across the diverse forest ecosystems of the US, there is an abundance of line intersect sampling (LIS) transects used for monitoring efforts such as fuel loadings. In order to provide an objective method for monitoring the carbon/biomass dynamics of individual CWD pieces for use with LIS, this study developed and tested a CWD piece matching algorithm for inventory plots where LIS was used to sample CWD at two points in time across the eastern US. Results indicated that a CWD piece matching algorithm may be constructed using three steps: (1) matching the location of each piece, (2) matching individual piece metrics (e.g., large-end diameter), and (3) scoring an index of many CWD attributes with adjustment by decay and measurement error (i.e., quality control tolerances). For most forest types in the US, this study’s algorithm matched between 20% and 40% of CWD pieces over time (≈5years). The algorithm performed poorly in forests potentially disturbed by floods and/or with relatively high mean annual temperatures and subsequent fast decay rates. Due to this influence of decay, the algorithm attained low match rates for highly decayed or small-sized CWD pieces. The algorithm should not be used to estimate changes in carbon/biomass within a stock change accounting framework. However, the algorithm may provide a method to aggregate a subset of paired LIS CWD observations over time to inform CWD dynamics research at large-scales.

Cerambycidae (Insecta: Coleoptera) of the Parque Natural Municipal de Porto Velho, Rondônia, Western Amazon, Brazil

Cerambycidae is one of the largest families of beetles and it is estimated that there are about 25,000 species of longhorned beetles in the world. However, little is known about the distribution of many species in some regions, including the Amazon. The longhorned beetles are indispensable in the ecological chain, contributing mostly to the recycling of dead wood in forest. The present study is an inventory of the Cerambycidae of the Parque Natural Municipal de Porto Velho, Rondônia, Brazil. Insects were sampled from June 2008 to May 2009 using Malaise and light traps. A total of 61 species were identified, of which 33 are new records for Rondônia and one for Amazon region, i.e., Anisopodus melzeri Gilmour, 1965.

To thin or not to thin: bio-economic analysis of two alternative practices to increase amount of coarse woody debris in managed forests

Maintenance of biodiversity in commercial forests has become a main goal in forestry, and several new management principles to reach that goal have been introduced lately. For example, in even-aged forestry, tree retention (leaving a proportion of trees standing in clear-cut sites) is widely used to increase the structural diversity and the amount of dead wood in forests. However, the cost-efficiency of the new management principles is poorly studied. To increase the amount of dead wood, an alternative way could be a change in the thinning regime, so that the self-thinning builds up of woody debris of a growing stand. We used long-term (200 years) simulations to compare ecological and economical effects of the two alternative management practices to increase the amount of dead wood in forest stands: (1) green tree retention and (2) growing stands unthinned. We simulated stand growth and management of 12 pine and 12 spruce stands that represented sites in different parts of Finland. We found that growing stands unthinned produced about 5–6 times more dead wood than retention with 20 trees left per hectare. In terms of economical loss, leaving stands unthinned reduced the net present value of harvest revenues less than 20%. Consequently, leaving stands unthinned offers a cost-effective option to increase the amount of dead wood in commercial forests. The effects of unthinned management were, however, dependent on thermal sum and initial stand density, indicating that biodiversity-oriented management practices should be designed for local conditions.

Indicator framework for measuring quantity and quality of biodiversity—Exemplified in the Nordic countries

In 2002, world leaders made a commitment through the Convention on Biological Diversity (CBD), to achieve a significant reduction in the rate of biodiversity loss by 2010. At the Conference of the Parties of the CBD in Nagoya, Japan in 2010, the target was renewed for 2020. We have developed a Biodiversity Change Index (BCI) to help measure progress towards this target. The BCI is constructed with a two-dimensional resolution, allowing for a direct evaluation of the relative importance of changes in quantity and quality, respectively, to the overall change in biodiversity. Quantity is measured as the area of a specified habitat type and quality as the abundance of indicator species and other habitat quality parameters, such as the proportion of old trees or dead wood in forests. The BCI enables easy comparison of changes in biodiversity between different habitat types and between different regions and nations. We illustrate the use of BCI by calculating the index for the Nordic countries for two common habitat types, farmland and forest, and one habitat type of similar importance in the northern hemisphere; mires. In the period 1990–2005 declines in biodiversity of similar magnitudes are seen for farmland and mires across the Nordic countries, while for forest, trends vary considerably. Our results show that the BCI framework can be a useful tool to communicate the complex issue of biodiversity change in a simple manner. However, in accordance with other studies of biodiversity change we conclude that existing monitoring data are too scarce to consistently calculate BCI for all habitat types in all Nordic countries. In order to reasonably evaluate changes in biodiversity, further efforts towards monitoring programmes to obtain reliable and quality assured data on biodiversity at acceptable spatial and temporal resolutions are needed. Moreover, common methods to apply and harmonise data from different monitoring schemes should be developed.

Making biodiversity a public problem – The case of dead wood in forests

Making biodiversity a public problem – The case of dead wood in forests

Deadwood density variation with decay class in seven tree species of the Italian Alps

Forest deadwood is an important indicator of the biodiversity level because it provides habitat for many species. A wide range of plants and animals is strongly associated with standing and lying deadwood. Deadwood is also a fundamental component of nutrient cycles, regulates water flows, prevents soil erosion and contributes to carbon storage in the forest. In consideration of this last aspect a method is proposed to sample and analyse wood density in deadwood (standing and lying) at different rates of decay. The wood density provides valuable information needed to calculate carbon content of the deadwood. The method has been applied on seven alpine forest species (fir, spruce, Swiss pine, black European pine, Scots pine, European larch and beech) localized in several valleys of Trentino province in north-east Italy. Laboratory analysis of the sample deadwood determined the moisture content, fresh density and dry density. Moisture content was significantly higher in logs than in snags; moreover, this value decreased from the first to the third decay class and thereafter increased from the third to the fifth class. The dry density decreased at a constant rate from lower to higher decay classes. For all species the maximum percentage of dry density reduction is found between the fourth and the fifth decay classes. This study provides a preliminary data set on deadwood density, above all taking into account the increasing importance of the carbon content closely connected with this attribute.

Steigende Bestandszahlen bei Spechten und anderen Vogelarten dank Zunahme von Totholz? | An increase in the population of woodpeckers and other bird species thanks to an increase in the quantities of deadwood?

Results from the monitoring programs of the Swiss Ornithological Institute show that the breeding populations of several forest species for which deadwood is an important habitat element (black woodpecker, great spotted woodpecker, middle spotted woodpecker, lesser spotted woodpecker, green woodpecker, three-toed woodpecker as well as crested tit, willow tit and Eurasian tree creeper) have increased in the period 1990 to 2008, although not to the same extent in all species. At the same time the white-backed woodpecker extended its range in eastern Switzerland. The Swiss National Forest Inventory shows an increase in the amount of deadwood in forests for the same period. For all the mentioned species, with the exception of green and middle spotted woodpecker, the growing availability of deadwood is likely to be the most important factor explaining this population increase.

Totholzförderung – neue Wege mittels Totholz-Charta? | Promotion of deadwood: a new approach through the Deadwood Charter?

The necessity for deadwood in forests as a habitat for saprozoic organisms is scientifically proved and so far undisputed. However, in practice, the promotion of deadwood presents certain difficulties. The two half cantons Basel-Town and Basel-Country are trying a new approach. Together with all those concerned a “Deadwood Charter” has been created in which it is defined to what extent deadwood should be left in the forests over the next few years. This charter has been accepted and signed by all concerned, from nature protection organizations right through to forest owners. The definitive quantities of deadwood to be left are determined according to how intensively the forest is used for recreational purposes and various other functions. This will then be specified in the regional forestry development plans. Periodic regional sample surveys recording quantities of deadwood make it possible to check if objectives are being achieved.

Mapping dead wood distribution in a temperate hardwood forest using high resolution airborne imagery

Dead wood, in the form of coarse woody debris and standing dead wood, or snags, is an essential structural component of forest ecosystems. It plays a key role in nutrient cycling, ecosystem functions and provision of habitat for a wide variety of species. In order to manage dead wood in a temperate hardwood forest, an understanding of its availability and spatial distribution is important. This research evaluates airborne digital camera remote sensing for mapping temperate forest dead wood across an area within Gatineau Park, Canada. Two approaches were evaluated: (1) direct detection and mapping of canopy dead wood (dead branches and tall snags) through the combination of three techniques in a hybrid classification: ISODATA clustering, object-based classification, and spectral unmixing, and (2) indirect modelling of coarse woody debris and snags using spectral and spatial predictor variables extracted from the imagery. Indirect modelling did not provide useful results while direct detection was successful with field validation showing 94% accuracy for detected canopy level dead wood objects (i.e. 94% of validation sites with canopy dead wood were detected correctly) and 90% accuracy for control sites (i.e. 90% of validation sites with no canopy level dead wood were identified correctly). The procedures presented in this paper are repeatable and could be used to monitor dead wood over time, potentially contributing to applications in forest carbon budget estimation, biodiversity management, and forest inventory.

Assessing impacts of intensified biomass removal on deadwood in European forests

Abstract Deadwood is a key indicator for assessing policy and management impacts on forest biodiversity. We developed an approach to include deadwood in the large-scale European Forest Information Scenario (EFISCEN) model and analysed impacts of intensifying forest biomass removal on the amount and type of deadwood in forests of 24 European Union member states. In EFISCEN, deadwood consists of standing and downed deadwood, resulting from mortality, and stem residues from felling activities. To include deadwood in EFISCEN we developed mortality functions and re-estimated the model's increment functions. Further, we modelled the development of standing deadwood. Decomposition of downed deadwood and stem residues was modelled through the soil model YASSO. We used the extended model to analyse the impacts of a baseline scenario (no policy changes, a moderate increase in wood removals and no extraction of residues) and a bio-energy scenario (an increase of wood and residue removals to the maximum potential) on deadwood in 2030. In our baseline scenario the average amount of deadwood was 12.3 ton ha −1 in 2005 and increased by 6.4% in 2030. Intensified biomass removal could fully counteract this development and lead to a reduction of 5.5% in 2030 below the levels in 2005. The type of deadwood changed as well; residue removal led to a general decrease in the amount of smaller deadwood fractions (i.e. stem residues). Further, if felling levels are increased as in our bio-energy scenario, a decrease can be expected in the amount of standing deadwood and of large-diameter deadwood. We conclude that without additional management measures to protect deadwood, intensification of biomass removal could negatively affect deadwood-dependent species, which constitute an important part of biodiversity in European forests.

Background, main results and conclusions from a test phase for biodiversity assessments on intensive forest monitoring plots in Europe

Abstract: The Forest Biodiversity Test phase Assessments (ForestBIOTA) project was carried out on 97 intensive monitoring plots located in 12 European countries. It aimed at the development and test implementation of monitoring methods for forest biodiversity across Europe. More specifically it covered the fields of (i) stand structure, (ii) forest deadwood, (iii) ground vegetation and (iv) epiphytic lichens. A forest type classification was applied in addition. The project took into account policy requirements stated by a number of political processes and institutions including the Convention on Biological Diversity, the Ministerial Conference for the Protection of Forests in Europe, the Environment for Europe Ministerial Conference and the European Union. Whereas detailed results of the assessments are presented in additional publications (Stofer et al. 2007, in prep, Meyer et al. 2007, submitted), this paper draws a number of general conclusions and gives recommendations for future development of forest biodiversity monitoring in Europe.

Preliminary study on the assessment of deadwood volume by the French national forest inventory

• As the French national forest inventory does not currently monitor the lying compartment of the forest deadwood, the figures obtained on this topic are therefore partial. This study provides cost estimates and guidelines for assessing stumps, and standing and lying deadwood. • Comparisons were made between a fixed-area sampling method and a line-intersect one. LIS was judged more time-efficient, especially in dense understorey. Computer simulations were performed in order to estimate the gain in precision with increasing transect lengths. The results showed a continuous improvement in precision associated with increases in transect length. The longest transect tested (50 m) still had a large coefficient of variation, suggesting that improvement in precision at the plot level could still be gained with longer transects. • Therefore, from a practical standpoint in terms of fieldwork, we suggest that on a national scale lying deadwood should be measured by line-intersect sampling, whereas stumps, standing dead trees and snags can be monitored using standard fixed-area plots. To meet needs at the national level, we consider that local imprecision could be compensated for by the large number of plots measured each

Wood-decaying fungi in the forest: conservation needs and management options

Wood-decaying fungi are essential for the functioning of forest ecosystems. They provide habitat for many other organisms and enable the regeneration of forests throughout the world. Since wood decomposition is a decisive process in nutrient recycling, soil formation and the carbon budget of forest ecosystems, it is receiving increasing attention from forest ecologists, pathologists and managers. Research has focussed on the factors driving the species-richness of wood-decomposing organisms and is moving on to analyse the effects of this species-richness on ecosystem functioning. Coarse woody debris (CWD) and its associated wood-decaying organisms have been drastically reduced in abundance and diversity by forestry and so these features often have potential as conservation indicators. Protective measures at a landscape level are needed for threatened wood-inhabiting fungi. These include restricting salvage operations in windthrow stands, actively encouraging the accumulation of deadwood in forests, and facilitating decay in standing trees by inoculating them with fungi. Here, we aim to collect and summarize recently produced work on deadwood ecology, pointing out research gaps and perspectives.

Factors and scales potentially important for saproxylic beetles in temperate mixed oak forest

The influence of environmental factors on species richness and species composition may be manifested at different spatial levels. Exploring these relationships is important to understand at which spatial scales certain species and organism groups become sensitive to fragmentation and changes in habitat quality. At different spatial scales we evaluated the potential influence of 45 factors (multiple regression, PCA) on saproxylic oak beetles in 21 smaller broadleaved Swedish forests of conservation importance (woodland key habitats, WKH). Local amount of dead wood in forests is often assumed to be important, but two landscape variables, area of oak dominated woodland key habitats within 1 km of sites and regional amount of dead oak wood, were the main (and strong) predictors of variation in local species richness of oak beetles. The result was similar for red-listed beetles associated with oak. Species composition of the beetles was also best predicted by area of oak woodland key habitat within 1 km, with canopy closure as the second predictor. Despite suitable local quality of the woodland key habitats, the density of such habitat patches may in many areas be too low for long-term protection of saproxylic beetles associated with broadleaved temperate forests. Landscapes with many clustered woodland key habitats rich in oak should have high priority for conservation of saproxylic oak beetles.