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

Abstract

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.

Historical climate‐change influences modularity and nestedness of pollination networks

“…Linear relationship between Quaternary temperature-change velocity and nestedness in pollination networks on the mainland. Th is may result from either phenological shifts or range-size dynamics associated with climate-change between the LGM and the present (Price 2003, Memmott et al 2007, Ara ú jo et al 2008, Tylianakis et al 2008, Devoto et al 2009, Amano et al 2010, Nogu é s-Bravo et al 2010, Sandel et al 2011, possibly increasing the proportion of super-generalist ' network hub ' or ' connector ' species gluing the network together and blurring the borders between modules (Fig. To illustrate the global dataset, we also plotted island networks (n ϭ 31) as open symbols.…”

“…If indeed modularity decreases community persistence and nestedness increases resilience in pollination networks, the fi nding that pollination networks in climatically unstable North America and low-laying part of northern Europe have a low level of modularity and often relatively high level of nestedness (Fig. In light of the current anthropogenic climate-change and the global decline of pollinators and possible interlinked plant declines (Biesmeijer et al 2006, Devoto et al 2009), more research is clearly needed to address in detail the processes beneath the relationship between historical climate-change, modularity, nestedness and stability of pollination networks. In light of the current anthropogenic climate-change and the global decline of pollinators and possible interlinked plant declines (Biesmeijer et al 2006, Devoto et al 2009), more research is clearly needed to address in detail the processes beneath the relationship between historical climate-change, modularity, nestedness and stability of pollination networks.…”

“…Species may respond diff erently to climate-change, which, at a given locality, might disrupt species interactions through changed phenology and geographical distributions of species (Memmott et al 2007, Tylianakis et al 2008, Devoto et al 2009, Mart í n Gonz á lez et al 2009, Amano et al 2010, Gilman et al 2010, Lorenzen et al 2011. Species may respond diff erently to climate-change, which, at a given locality, might disrupt species interactions through changed phenology and geographical distributions of species (Memmott et al 2007, Tylianakis et al 2008, Devoto et al 2009, Mart í n Gonz á lez et al 2009, Amano et al 2010, Gilman et al 2010, Lorenzen et al 2011.…”

“…Why may historical climate-change off er an alternative, or complementary, hypothesis to contemporary climate in predicting the level of modularity and nestedness? Species may respond diff erently to climate-change, which, at a given locality, might disrupt species interactions through changed phenology and geographical distributions of species (Memmott et al 2007, Tylianakis et al 2008, Devoto et al 2009, Mart í n Gonz á lez et al 2009, Amano et al 2010, Gilman et al 2010, Lorenzen et al 2011. Although these changes may occur over many diff erent timescalesranging from short-term intra-annually variation to deep historical timescales -the strongest and most important climatic shifts in the Quaternary (last 2.6 million yr) are the repeated oscillations between glacial cold maxima and warm interglacials.…”

Partitioning interaction turnover among alpine pollination networks: spatial, temporal, and environmental patterns

“…Traditional investigations of plant communities have shown that plant species typically have nonrandom distributions through space at the spatial scale at which plant-pollinator networks are often quantified (,10 6 m 2 ; Kissling et al 2012) and are structured largely by microhabitat gradients, temperature, and precipitation (Kikvidze et al 2005). Likewise, pollinator species have a high degree of spatial, temporal, and environmental turnover (Minckley et al 1999, Devoto et al 2009). The interaction network approach to studying plant-pollinator communities has provided evidence of extremely high variability in plant-pollinator interactions between years (Petanidou et al 2008, Olesen et al 2011, with interannual interaction persistence ranging from 1.4-22% (Dupont et al 2009, Fang andHuang 2012).…”