Can Temperature and Water Availability Contribute to the Maintenance of Latitudinal Diversity by Increasing the Rate of Biotic Interactions?

Abstract

Abstract:Environmental gradients (such as average annual temperature increasing towards the tropics) are numerous across the globe. Here I propose a theory, comprised of progressive hypotheses, which links temperature and water availability to the maintenance of high genetic and phenotypic diversity in the tropics through enhanced biotic interactions. In terrestrial ecosystems higher temperatures and water availability, by allowing higher rates of mobility, growth and reproduction of organisms, should lead to higher rates of encounter among individuals in communities. Due to this, interactions in wet and warm environments, such as tropical rainforests, should be both more frequent and more diverse regardless of the number of species present. This diversity of interactions is illustrated at the genotype level, stressing whether genotypes interact positively or negatively with other genotypes, and considering species, as well as individuals, as genotypes. Such biotic interactions in environments can generate strong genotype-environment interactions that can promote the maintenance of high levels of (functional) genetic and phenotypic diversity. This can subsequently facilitate coexistence and speciation processes. The paper finishes by proposing future research to test the hypotheses and hence the overall theory presented here.

Biogeography of species richness gradients: linking adaptive traits, demography and diversification

“…(10) To assess effectively the importance of community context in driving diversification processes new research should be conducted in several areas: (1) the study of the spatial and temporal variation of community context (i.e. consumerresource interaction networks) along geographical gradients of species richness (Callaway et al, 2002;Olesen & Jordano, 2002;Schemske et al, 2009;Carnicer et al, 2009;Moya-Laraño, 2010;McKinnon et al, 2010, Rasmann & Agrawal, 2011, (2) the quantitative study of the spatial and temporal variation of resource distribution along species richness gradients (Johnson et al, 2005;Novotny et al, 2007;Ting, Hartley & Burns, 2008), and (3) the comparative examination of phenotypically plastic responses along species richness gradients (Smith et al, 1997;Price et al, 2003;Sol & Price, 2008;Carnicer et al, 2008a;Aubin-Horth & Renn, 2009;Pfennig et al, 2010;Snell-Rood et al, 2010;Moczek et al, 2011).…”

A quantitative review of pollination syndromes: do floral traits predict effective pollinators?

“…Under this scenario, stronger biotic interactions should lead to increased niche space and greater species diversification and coexistence in tropical regions (Schemske et al . ; Moya‐Laraño ). In the tropics the frequency of animal‐pollinated plants is greater than in temperate regions (Schemske et al .…”

Evolutionary Biology: Biodiversification from Genotype to Phenotype

“…Because the strength of biotic interactions is expected to increase with decreasing latitude, tropical species should have narrower niches, facilitating coexistence and promoting diversification (Schemske et al 2009;Moya-Laraño 2010). In tropical species, the pollinators expected by the syndrome are more efficient than in extra-tropical species (Rosas-Guerrero et al 2014).…”