The effect of bedrock type,temperature and moisture on species richness of Pyrenean Scots pine (Pinus sylvestris L.) forests

The relationship between environmental parameters (bedrock type, temperature and moisture index) and understorey species richness was studied from a large phytosociological data base on Pyrenean Scots pine (Pinus sylvestris L.) forests. Generalized linear models were used to test this relationship. Total species richness and species richness of the different life forms were considered. The results suggest different patterns for the different life forms, and that the richest forest was on the calcareous bedrock of north-facing slopes at low altitudes.