Habitat preferences of Cortaderia selloana in its native distributional range in Argentina

Abstract

Understanding the current and potential distribution of invasive species requires knowing their ecological preferences in their native ranges. Here, we study the climatic niche and habitat preferences of one of the invasive plants with stronger impacts globally, Cortaderia selloana (Pampas grass), in its native distributional range in Argentina. For this purpose, we evaluated the climatic optimum of C. selloana using species distribution models and its climatic variation in the study area. Through a 2800 km transect we sampled suitable areas for the species, from the Pampas to the Andes Mountain range, in order to describe the main habitats where it lives. We found populations of C. selloana from the sea level to 3200 m a.s.l., occupying a wide range of climatic variability. In drier climates, C. selloana mainly occupies riparian habitats subjected to seasonal flood disturbances, leaving open spaces colonized by other native opportunistic species such as Nicotiana glauca. In those regions with higher environmental humidity, C. selloana colonizes human-disturbed habitats. These habitats become the only habitat available for the species in subtropical rainforests. Our results suggest that the primary habitats of C. selloana in its native range are highly disturbed riparian areas of the Andes Mountain range. The adaptation of C. selloana to these environments have facilitated its establishment in areas recently disturbed by humans, both in its native and introduced ranges. Soil water stress seems the main limiting ecological factor for C. selloana in its native distributional range, determining the habitat occupied by the species in different phytogeographic provinces.