Patterns of species turnover in plant-pollinator communities along a precipitation gradient in Patagonia (Argentina)

Recent studies have assessed the influence of different types of gradients (e.g. altitudinal, latitudinal and temporal, among others) on the structure and function of community-level plant-pollinator webs. Although the importance of humidity as a major driver of species-richness gradients worldwide has been stressed by recent reviews, no studies have been specifically designed to address the influence of precipitation gradients on pollination webs. In the present paper we describe for the first time the turnover of species of plants and their associated flower visitors between eight communities located along a steep precipitation gradient in north-west Patagonia, Argentina. Our results show that: (i) there is a high spatial turnover of plant communities and their associated pollinators; (ii) this turnover is strongly related to precipitation changes across the region; and (iii) the turnover rate is similar for plants and pollinators. Our results support the view that the precipitation gradient is a significant factor associated with the regional turnover of plants and their pollinators in the temperate forests of southern South America.