Biogeographical patterns of soil bacterial communities.

This study provides the first maps of variations in bacterial community structure on a broad scale based on genotyping of DNA extracts from 593 soils from four different regions of France (North, Brittany, South-East and Landes). Soils were obtained from the soil library of RMQS ('Réseau de Mesures de la Qualité des Sols' = French soil quality monitoring network). The relevance of a biogeographic approach for studying bacterial communities was demonstrated by the great variability in community structure and specific geographical patterns within and between the four regions. The data indicated that the distribution of bacterial community composition might be more related to local factors such as soil type and land cover than to more global factors such as climatic and geomorphologic characteristics. Furthermore, the regional pools of biodiversity could be ordered: South-East ≥ North > Brittany > Landes, according to the observed regional variability of the bacterial communities, which could be helpful for improving land use in accordance with soil biodiversity management.