Turnover, richness difference and nestedness of rodent assemblages along the southern Andes elevation gradient

Abstract

Beta diversity in ecological communities can reflect adaptations of species to differences in climate, environmental characteristics and site history, as well as local ecological dynamics. These dissimilarities among communities may reflect different processes as species replacement and richness difference or nestedness, which can be generated by different factors. Assemblages in mountain regions are expected to exhibit high beta diversity due to sharp environmental variation and historical events promoting isolation. Diversity patterns of small mammals along elevation gradients in the southern dry Andes exhibit high richness among high elevations and a humped shape pattern for abundances. However, it is not clear how beta diversity changes along this gradient, or the processes involved in this variation. Here we aim to evaluate small mammal beta diversity patterns along the elevation gradient. Therefore, we decomposed beta diversity into spatial turnover, richness differences and richness differences as a result of nestedness. Assemblage structure variation was assessed qualitatively and quantitatively. Also, we evaluate the local contribution of beta diversity (LCBD) and species contribution to beta diversity, to identify priority conservation sites and species. Our results show contrasting patterns among qualitative and quantitative beta diversity components. The former was mainly explained by species turnover, while the latter showed a higher contribution of richness difference than species turnover. Most components of beta diversity decreased with elevation, except for abundance turnover that showed an opposite trend. Furthermore, LCBD was higher at lower and mid‐elevation sites and exhibited a negative relationship with species richness and abundance.

Host sweet host: Rodent communities support similar ectoparasite diversity regardless of anthropogenic disturbance

“…They carry out a variety of important ecosystem functions, including dispersal and predation of seeds and spores, and pollination (Dickman, 1999). Moreover, rodents occupy a wide range of ecological niches and occur throughout most terrestrial ecosystems, in part, due to their high competitiveness and adaptability to harsh environmental conditions, such as those found at high altitudes or in deserts (Dreiss et al., 2015; Martin‐Regalado et al., 2019; Novillo & Ojeda, 2021). Some rodent species also have remarkably broad habitat ranges (e.g., Rattus rattus ), while others have more specialised habitat requirements (e.g., Otonyctomys hatti , a forest dweller with limited dispersal capability) (Banks & Smith, 2015; Zaragoza‐Quintana et al., 2021).…”

Neutral‐based processes overrule niche‐based processes in shaping tropical montane orchid communities across spatial scales

“…The complex geological history of mountains boosted the evolution of many plant groups by promoting speciation through, for instance, the provision of new habitats, or ecological and dispersal barriers to other species and other populations of the same species (Luebert & Weigend, 2014; Pérez‐Escobar, Gottschling, et al, 2017). The replacement of species between sites—compositional turnover—is the prevailing pattern across African (Peters et al, 2019), European (Fontana et al, 2020) and Andean mountainous regions (Herrera‐Pérez et al, 2019; Muñoz Mazón et al, 2021; Novillo & Ojeda, 2021). However, the ecological processes governing high compositional turnover typical of mountainous ecosystems remain understudied at multiple spatial scales.…”