[Relationships between plants and climate in France: calibration of 1874 bio-indicators].

The influence of climate on plants geography is studied through a probabilistic calibration between a botanical database, containing 12 000 plots, and a meteorological database composed of 574 climatic stations. The calibration measures the climatical optimum (position) and the indicator power (concentration) of 1874 plants for six climatic variables. The validation of these relations is based upon the comparison of the estimation of climate by plants and the values measured by climatic stations near the plots. This validation underlines that plants are accurate (accuracy=88.5%) and stable (stability=96.5%) bio-indicators of climate variables.