Ecological niche structure and rangewide abundance patterns of species

Abstract

Spatial abundance patterns across species' ranges have attracted intense attention in macroecology and biogeography. One key hypothesis has been that abundance declines with geographical distance from the range centre, but tests of this idea have shown that the effect may occur indeed only in a minority of cases. We explore an alternative hypothesis: that species' abundances decline with distance from the centroid of the species' habitable conditions in environmental space (the ecological niche). We demonstrate consistent negative abundance -ecological distance relationships across all 11 species analysed (turtles to wolves), and that relationships in environmental space are consistently stronger than relationships in geographical space.

Climate change influences on global distributions of dengue and chikungunya virus vectors

“…no establishment in Australia despite repeated introductions) to presenting conditions that do permit maintenance of populations. Clearly, even within the present distributional areas of these species, changing conditions may cause changes in their abundance and dominance, although those shifts are not included in our present modeling efforts [46].…”

Process‐based and correlative modeling of desert mistletoe distribution: a multiscalar approach

“…Other studies of such dynamics in P. californicum have been carried out at much finer resolutions than ours, and are very illuminating when compared with our macro-geographic approximations (e.g., Overton 1994, 1996, Aukema and Martínez del Rio 2002, Liu et al 2011. From an ecological point of view, for example, these analyses would allow exploring whether abundance, genetic variation, population differentiation, or gene flow vary as functions of centrality within the geographic range (Thuiller et al 2010, Torres et al 2012, Martínez-Meyer et al 2013 or the ecological niche of the species, thus presenting different opportunities for local optima and associated adaptation (VanDerWal et al 2009, Martínez-Meyer et al 2013). …”

“…In particular, the extinction function used was a simple exponential of the difference between the estimated optimal niche and the environments of a given cell: clearly, more complex may prove more appropriate (Martínez-Meyer et al 2013). However, based on extensive initial exploration and simulations (not shown), in which our basic results were supported, it is not likely that major differences and conclusions from our current findings would emerge.…”

The impact of climate change on the geographical distribution of two vectors of Chagas disease: implications for the force of infection

“…In agreement with these considerations, we observed a differential impact of climate change on the two vector species analysed here: R. prolixus shows a future expansion to new areas, whereas T. infestans shows a future decrease in its geographical range compared with current conditions. Several authors, based on sample theory models, have proposed a link between presence (or occupancy) of species and their population abundance [70,72,81,90]. Despite the fact that the house infestation-vector density relationship used here is beginning to become recognized in certain other vector species such as phlebotomine sandflies associated with the transmission of leishmaniasis [85], R. prolixus and T. infestans do not seem to show such a direct relationship, and this could be due to the existence of other variables (socio-environmental or economic among others) that were not included in our ecological niche models.…”