Above-ground standing biomass and tree species diversity in natural stands of Central Europe

Questions: 1. Is the above-ground biomass in natural temperate forests positively correlated with tree species diversity? 2. Is this biomass related to the diversity of tree functional Groups? Location: We used published data from over 100 permanent plots located in natural temperate forests in the Czech Republic, Poland and Slovakia. Methods: We related the number of tree species and Simpson's index of tree species diversity to the above-ground biomass in natural forest stands, and we repeated the same calculations for the identification of functional groups of trees using PCA analysis of functional traits. Results: Analysed sites ranged from almost pure subalpine spruce stands to mixed deciduous lowland forests with eight tree species per stand. The above-ground biomass accumulation ranged from 169 to 536 tons of dry mass per hectare. For the analysed data set the relationship between tree species diversity and biomass accumulation was not significant but showed a negative trend. Similar results were obtained in analyses employing tree functional groups instead of tree species. A significant negative relationship was found after four stands located in the highest elevations had been removed from the data set. Conclusions: There is a weak negative relationship between tree species diversity and above-ground biomass in natural forests of Central Europe.