Dead Wood Quality Research Articles

Co-variation and indicators of species diversity: Can richness of forest-dwelling species be predicted in northern boreal forests?

Design and establishment of ecologically good networks of conservation areas often requires quick assessments of their biodiversity. Reliable indicators would be useful when doing such assessments. In order to explore the potential indicators for species richness in boreal forests, we studied (1) the co-variation of species richness and composition of species assemblages among beetles, polypores, birds and vascular plants, (2) the relationships between species richness and four boreal forest site types, (3) the relationship between species richness and forest physical structure and (4) the suitability of potential indicator groups within the four taxa to predict the species richness generally. The data show that there are probably not a single taxonomic or forest structural characteristic to be used as a general biodiversity indicator or surrogate for all the species. The correlations in species richness among the four taxa studied were low. However, group-specific indicators were obvious: forest site type was a good surrogate for vascular plant richness, and quantity and quality of dead wood predicted the species richness of polypores. The results support the view that different indicators shall be used for different forest types and taxonomic groups. These indicators should facilitate relatively rapid methods to assess biodiversity patterns at the forest stand level.

Influence of Forest Management on the Species Richness and Composition of Wood-inhabiting Basidiomycetes in Swiss Forests

In order to investigate the diversity of wood-inhabiting aphyllophoroid basidiomycetes in Swiss forests, 86 plots of 50 m 2 were established. They harboured a total of 3339 samples of woody debris, classified according to three categories (coarse, fine, and very fine woody debris), yielding 238 species of wood-inhabiting fungi. The selected sites cover the main forest types of Switzerland and various degrees of management intensity. A multiple linear regression analysis showed that substrate variation, i.e. differences in the quality of dead wood, including volume, age, degree of decomposition and host tree species, are the most important factors influencing diversity of wood-inhabiting fungi. In addition, a Principle Coordinate Analysis highlighted differences in the fungal communities in the different forest types. The greatest fungal species richness is found on thermophilic deciduous tree and woody shrub species. Fine and very fine woody debris, even present in intensively managed forests, often serve as important refuges for many species. Forests with a recent management intervention were found to be either species poor or species rich. Possible reasons for these differences may lay in forest size and landscape fragmentation, the distance to the nearest species pool or microclimatic factors. In Switzerland intensively managed forests harbour significantly less wood-inhabiting, aphyllophoroid fungi than non-managed or extensively managed forests. This is the case in both deciduous forests and in conifer forests. However, occasionally intensively managed forest will also harbour rare and endangered species.

Selective felling as a potential tool for maintaining biodiversity in managed forests

In Sweden one forestry method, the clear-cutting method, has been used all over the country despite differences in climate, topography etc. At present there is a growing interest in using alternative methods such as selective felling, which to a larger extent mimic natural disturbances. In this study we compare virgin forests with stands which have been cut with old selective felling (dimension felling), new selective felling (single tree selection felling), and clear-cutting with respect to frequency of characters important to biodiversity (mainly dead wood). The frequency of different types of dead wood decreases with increasing intensity of the cutting method in the following order: old selective felling, new selective felling, and clear-cutting. New selective felling had higher amounts and quality of dead wood compared to clear-cutting. New selective felling also showed less differences compared to virgin forests than clear-cutting. Dead wood in new selective felling compared to clear-cutting may offer substrate for different types of faunas because of the environment surrounding the dead wood. Even if the new selective felling method seems to provide higher amounts of dead wood compared to the clear-cutting method, further studies of organisms utilising the dead wood are needed. New selective felling does not seem to solve the problem of decreasing availability of dead wood in managed forests and there is still a need to preserve unmanaged forest patches in a landscape perspective in order to offer habitats with a high amount of dead wood.

A review of potential biodiversity indicators for application in British forests

Summary A review of potential indicators of biodiversity in British forests is presented, with a focus on the usefulness of selected biotic parameters as surrogate measures of different aspects of biodiversity in managed forests. To be effective in this respect, indicators must satisfy a number of criteria. They must be readily quantifiable, easily assessed in the field, repeatable and subject to minimal observer bias, cost effective, and ecologically meaningful (i.e. close association with, and identification of, the conditions and responses of other species). It is suggested that a combination of structural (physiognomy of stands and associated structures) and compositional indicators (indicator species or species groups) is selected which is appropriate to the aims of management and to the particular forest type in question. A useful approach is to identify two to three key compositional indicators, shown to be functionally linked to a broad range of other species, such as the extent and species composition of the broadleaved component in conifer forests; and two to three key structural indicators, which act as surrogates for general species richness or diversity, such as the quantity and quality of deadwood.

Mass and nutrient content of dead wood in a central Illinois floodplain forest

The quantity and quality of dead wood in a central Illinois floodplain forest was measured to determine its role in organic matter and nutrient budgets. Dead wood (downed wood and standing dead trees) was inventoried using plots and the line intersect method for mass, and samples were analyzed for density and concentration of ash. N, and P. Total dead wood was estimated at 15.9 Mg ha−1 and was comprised of 9.3 Mg ha−1 as standing dead (59%) and 6.6 Mg ha−1 as downed wood (41%). Most of the downed wood (82% of the total) was in the intermediate decomposition class. Density of downed wood (0.19–0.47 g cm−3) decreased and concentrations of N (0.18–1.29%), P (0.12–0.56 mg g−1, and ash (1–23%) increased with increasing state of decomposition. Mean N, P, and ash pools in dead wood were 47 kg ha−1, 3.1 kg ha−1, and 481 kg ha−1, respectively. Downed wood contained 56%, 54%, and 69% of the total N, P, and ash pools, respectively. During periods of rapid decomposition of leaves and reproductive parts, downed dead wood is the dominant and often sole component of the floor litter mass.

Research note. Dead wood in the Caledonian pine forest

Dead wood is increasingly being regarded as a major component and useful indicator of biodiversity in forests (Ratcliffe, 1994; Sammuelsson et al., 1994). However, there is as yet no standardized method for assessing the quality and quantity of dead wood habitats, and little baseline information about this resource in the UK (and particularly in Scotland) against which to set standards for its appropriate conservation and management. The study aims to assess the quantity and quality of dead wood within the native Scottish pine forests under a variety of management regimes by using and developing the Line Intersect Method (Warren and Olsen, 1964; Kirby et al., 1991). This information may provide a guide to the expected characteristics of the dead wood resource within this forest type, with potential for use in formulating and adapting management prescriptions.