CLIMATIC VARIABILITIES AND DYNAMICS OF THE PASTURES IN ZONE SOUDANO-GUINEENNE OF BENIN

The pastoral ecosystems of the tropical countries are confronted with enormous constraints related on climatic variabilities and the degradation of the pastures. This article aims at studying the dynamics of the pastoral course in conditions of variabilities climatic in the Benign Center and Northern. The climatic data of 1965 to 2016 of the pluviometry stations and synoptic stations of the zone of study were used. The cuts of biomass built in 48 plots of phytosociological statements made it possible to obtain the productivities of the types of pasture. The multivariate analysis carried out thanks to the software “R” based on the climatic and anthropic variables made it possible to know the impacts related to the anthropic disturbances on the habitats of the plants. The got results show a trend in fall of pluviometry, unequally distributed, of 1955 to 2016 in the zone of study. However, the surplus rainy decades (55,55%) took a preponderance on those overdrawn (44,44%) during the last 46ans. The strong positive anomalies of precipitations are recorded during the decades 1960.1990 and 2000. The strongest negative anomalies are observed at the start of 1970 and 1980. The maximum temperatures vary according to the various synoptic stations. The specific wealth in savannas is correlated with the weak disturbances and pluviometry; while this correlation is strongly high in grassy savanna. This specific wealth varies by commune and year with a higher with Pehunco in 1997 and lower value with Kerou in 2016.