The geographic scaling of biotic interactions

Abstract

A central tenet of ecology and biogeography is that the broad outlines of species ranges are determined by climate, whereas the effects of biotic interactions are manifested at local scales. While the first proposition is supported by ample evidence, the second is still a matter of controversy. To address this question, we develop a mathematical model that predicts the spatial overlap, i.e. co-occurrence, between pairs of species subject to all possible types of interactions. We then identify the scale of resolution in which predicted range overlaps are lost. We found that co-occurrence arising from positive interactions, such as mutualism (/) and commensalism (/0), are manifested across scales. Negative interactions, such as competition (2/2) and amensalism (2/0), generate checkerboard patterns of co-occurrence that are discernible at finer resolutions but that are lost and increasing scales of resolution. Scale dependence in consumer-resource interactions (/2) depends on the strength of positive dependencies between species. If the net positive effect is greater than the net negative effect, then interactions scale up similarly to positive interactions. Our results challenge the widely held view that climate alone is sufficient to characterize species distributions at broad scales, but also demonstrate that the spatial signature of competition is unlikely to be discernible beyond local and regional scales.

Continental divide: Predicting climate-mediated fragmentation and biodiversity loss in the boreal forest

“…In both cases, climate-related effects are indirect through correlated biotic processes (i.e., food availability, predation) that are themselves associated with climate. Yet, there is debate regarding the importance of biotic interactions at large spatial scales [81,82], as well as specifically in the context of species distribution models [83], although we note that recent work (e.g., [38,39]) highlights that the MaxEnt approach yields models that closely match observed patterns of species occupancy and population growth. Therefore, we suggest that our models represent a reasonable first step in understanding how species occurrence may vary through space and time under climate change, despite that they exclude fundamental biotic processes [82].…”

“…Yet, there is debate regarding the importance of biotic interactions at large spatial scales [81,82], as well as specifically in the context of species distribution models [83], although we note that recent work (e.g., [38,39]) highlights that the MaxEnt approach yields models that closely match observed patterns of species occupancy and population growth. Therefore, we suggest that our models represent a reasonable first step in understanding how species occurrence may vary through space and time under climate change, despite that they exclude fundamental biotic processes [82]. That our predicted responses are remarkably consistent across many boreal species reinforces this contention while also implying that singular climate phenomena should transcend taxonomic groups and life histories to affect distribution and abundance for an array of species.…”

Speciation, Diversification, and Coexistence of Sessile Species That Compete for Space

“…As far as we know, this is a new proposal of a mechanism to create long-term isolated populations (meta-populations). The closest ecological data related to spatially driven speciation is the studies on how the dynamical change of geological environment affects the speciation events [21]–[23]. These studies consider the situation where the geological changes are due to external causes such as climate change, but it will be interesting to include the possibility that the change of species spatial distribution is caused by the interspecies interaction.…”

Competition between Silicifiers and Non-silicifiers in the Past and Present Ocean and Its Evolutionary Impacts

“…Experimental evidence suggests that biotic interactions not only shape the arms race between species, but also affect species range (Bateman et al, 2012;Araujo and Rozenfeld, 2014), inducing non-random co-distribution of species at large spatial scales of hundreds of kilometers for macro-organisms (Gotelli et al, 2010), both at regional and continental scales. Therefore, understanding the degree to which occurrences of species are constrained by the distributions of other species at broad scales of resolution and extent likely links back toward ecological and evolutionary mechanisms shaping the success of functional groups.…”