The relative role of climate and biotic interactions in shaping the range limits of a neotropical orchid

Aim
The center-periphery hypothesis (CPH) explains the decline of species abundance towards range limits and how this is driven by increasing ecological marginality. So far, most studies testing the CPH have focused on abiotic factors contributing to marginality, while the role of biotic interactions in limiting species distribution has been neglected. Here, we investigate both drivers' roles in potentially restricting an orchid's range along a broad environmental gradient.
Location
Brazilian Atlantic Forest and Pampas biomes (south and southeastern Brazil) Taxa Sand dune orchid Epidendrum fulgens (Orchidaceae).
Methods
We integrated empirical data on geographical distribution, pollinator richness, and niche models to investigate whether range limits match predicted niche limits and whether habitat suitability declines towards low- and high-latitude species ranges. In addition, we used genetic-derived metrics to test whether populations at range edges are indeed small and isolated, as p..., ,