Consistently positive correlations between amount of dead wood and biodiversity in the forest ecosystem across biogeographic regions

Keywords: meta-analysis, biogeographic patterns, conservation, saproxylic species, forests
Abstract Type: Paper Abstract

Abstract

Deadwood supports a diverse variety of life and is essential for at least a quarter of forest biodiversity. Many studies have investigated the relationship between deadwood amount and the biodiversity of saproxylic, non-saproxylic, and/or epixylic species such as fungi, beetles, lichens, and bryophytes, in the forest ecosystem. However, there is no recent quantitative synthesis evaluating up-to-date global patterns on correlations between deadwood volume and species diversity, and whether the relationships vary among deadwood traits, bioclimatic regions, and forest management regimes. Here we present the findings of a meta-analysis that synthesized results from 37 studies from 20 countries. We used the random effects model to pool mean effect sizes and Knapp-Hartung adjustments to compute the 95% confidence interval around the pooled effect.
We found that the overall correlation between deadwood volume and biodiversity is significantly positive but moderate. Deadwood had the strongest correlation with diversity of epixylic bryophytes, weakest with lichens, and moderate in the case of beetles and fungi. The summary effects as per bioclimatic regions, forest types, and management regimes are all positive and moderate, however, the between-group differences were not statistically significant suggesting the consistent positive effect of deadwood amount on biodiversity. Our results support the idea that dead wood volume can largely be considered as an indicator of forest biodiversity. However, we would like to emphasize the need for more research, specifically to fill the current gaps in (sub-)tropics in general, and incorporating rare and threatened species as well.