Aims Climate and soil are among the most important factors determin-ing variation in tree communities,but their effects have not been thoroughly elucidated to date for many vegetation features.In this study,we evaluat...Aims Climate and soil are among the most important factors determin-ing variation in tree communities,but their effects have not been thoroughly elucidated to date for many vegetation features.In this study,we evaluate how climate and soil gradients affect gradients of vegetation composition,species diversity and dominance,structure and functional traits(seed mass and wood density)using over 327000 trees in 158 sites distributed along environmental gradients in the transitions among the Atlantic forest,Cerrado and Caatinga in Minas Gerais State(MG),Brazil(nearly 600000 km2).Methods Gradients in species,genus and family abundance in addition to basal area,stem density,species diversity(Fisher’s alpha),domin-ance percentage,seed mass and wood density were correlated using multiple regressions with environmental variables,as summarized in four principal component analysis axes(two climatic-precipi-tation seasonality and temperature range-and two edaphic-soil fertility and soil moisture).Additionally,ordinary kriging maps were used to better illustrate the gradients.Important Findings Multiple regression models indicate that all variables but domin-ance percentage were affected by one or more of the environmental gradients,but the average R2 was low(26.25%).Kriging maps rein-forced the patterns observed in the regression models.Precipitation seasonality and soil moisture gradients were the most important gra-dients affecting vegetation features.This finding suggests that water availability is an important determinant of vegetation features in these vegetation transitions.展开更多
文摘Aims Climate and soil are among the most important factors determin-ing variation in tree communities,but their effects have not been thoroughly elucidated to date for many vegetation features.In this study,we evaluate how climate and soil gradients affect gradients of vegetation composition,species diversity and dominance,structure and functional traits(seed mass and wood density)using over 327000 trees in 158 sites distributed along environmental gradients in the transitions among the Atlantic forest,Cerrado and Caatinga in Minas Gerais State(MG),Brazil(nearly 600000 km2).Methods Gradients in species,genus and family abundance in addition to basal area,stem density,species diversity(Fisher’s alpha),domin-ance percentage,seed mass and wood density were correlated using multiple regressions with environmental variables,as summarized in four principal component analysis axes(two climatic-precipi-tation seasonality and temperature range-and two edaphic-soil fertility and soil moisture).Additionally,ordinary kriging maps were used to better illustrate the gradients.Important Findings Multiple regression models indicate that all variables but domin-ance percentage were affected by one or more of the environmental gradients,but the average R2 was low(26.25%).Kriging maps rein-forced the patterns observed in the regression models.Precipitation seasonality and soil moisture gradients were the most important gra-dients affecting vegetation features.This finding suggests that water availability is an important determinant of vegetation features in these vegetation transitions.
