摘要：The anisotropic structure of climatic space may cause significant (and to a large extent unappreciated) nonevolutionaryniche shifts. This can be seen mostly in the context of spatial transferability of ecological niche models.We explore this effect using a virtual species in the United States. We created a simple virtual species by postulating itsfundamental niche as an ellipse in a two-dimensional realistic climatic space. The climatic combinations defined by theellipse were projected in the geography of the United States and 2 regions of equal area were selected. The structure ofniche in the 2 areas is compared. It is shown that the 2 regions have differently positioned subsets of the environmentalspace, which creates “shifts” in the realized niches despite the fact that no evolution and no biotic interactions arepresent. The most parsimonious hypothesis when ecological niche modeling reveals shifts in the realized niche is thatenvironmental space is heterogeneous. Without considering differences in the structure of environmental space nospeculation about niche evolution or the role of competitors should be attempted.
关键词：Biología; Ecología;fundamental niche; realized niche; existing niche; ecological niche modeling; species distribution modeling; environmental space
