Climatic variables influence the richness, composition and distribution of exotic invasive plants?

Abstract

In this work we seek to evaluate the influence of climatic variables (precipitation and temperature) on the distribution of invasive alien plants in Sergipe, Brazil. To do this, we traveled 550 km of state highways recording invasive exotic plants and then relating them to climate variables available in database. In total, 46 species distributed in 17 families were sampled. Our results demonstrate that community is influenced by the tested climatic variables. The greatest species richness occurred in the semiarid zone of Sergipe. Richness was mainly influenced by annual precipitation, showing a negative relationship. Species composition, in turn, was affected by four variables (annual precipitation, seasonality of precipitation, maximum temperature in the hottest month and mean annual temperature) that determine their distributions. Some aggressive invaders were limited mainly by annual rainfall and rainfall seasonality. However, others had a high range of occurrence, thus being able to spread over several regions as they do not have limitations due to climatic conditions. Thus, we conclude that climatic conditions can positively or negatively influence the composition, richness and distribution of invasive alien species in the state. Our results help to understand the effects of environmental conditions on the distribution of invasive alien species.