Vegetation and bird community dynamics in fragmented coppice forests

Richness and composition of plant and bird communities were used to evaluate the importance of seven within-forest factors on biodiversity in fragmented coppice forests in south-western France. Plants and birds were sampled on the same 98 plots. Plant abundance-dominance was measured on 400 m(2) plots. Birds were sampled using a 50-m fixed radius point-count method in the early and late periods of the breeding season. The selected factors were: years since logging (YSL), retention of standards (STANDARD), ownership (OWNER), distance to the nearest edge (EDGE), tree richness (TREE), density of vegetation in low (ST2) and high (ST16) strata. Paired comparisons of richness were carried out between YSL classes, according to other variables. The respective influence of each variable was evaluated using adapted CCA (canonical correspondence analysis) on plant and bird composition. Plant richness varied strongly between YSL classes, was independent of STANDARD, increased with TREE and was higher in collective owned forests. Bird richness seemed to be independent of YSL and was higher in low YSL plots with standards. Bird and plant richness was not correlated. Plant community composition was mainly explained by YSL/ST16 on the first axis and by OWNER on the second axis. STANDARD and OWNER explained bird community composition. OWNER must be considered as a synthetic variable. This could be useful in adapting forestry practices for a better management of biodiversity, taking into account the very different taxonomic groups involved.