Species richness, alien species and plant traits in Central Argentine mountain grasslands

Abstract Pattern of native vegetation, distribution of alien species and variation of environmental parameters were studied in mountain grasslands in a lithologically homogeneous Cordoba mountain range in Central Argentina. CCA showed that altitude was the most important factor determining the compositional variation of the vegetation, with soil nutrient status and stoniness as additional factors. Short-grass communities, associated with the driest habitats on plateaus, showed higher small-scale native species richness than wet-turf communities in valleys and tall-grass communities on slopes. Species richness was negatively correlated with soil parameters that indicate nutrient status and water availability. Also, there was a negative correlation between soil Ca- and Mg-content and richness. High native species richness coincided with high alien species richness. When smaller units – community types – were considered, it became evident that within short-grass vegetation, the three most species-rich commun...