Multi‐trophic guilds respond differently to changing elevation in a subtropical forest

Abstract

Negative relationships between species richness and elevation are common and attributed to changes in single environmental properties associated to elevation, such as temperature and habitat area. However, research has lacked taxonomic breadth and comprehensive elevation studies that consider multiple groups from different trophic levels are rare. We thus analysed 24 groups of plants, arthropods, and microorganisms grouped into six trophic guilds (predators, detritivores, herbivores, plants, bacteria and fungi) along a relatively short elevational gradient (~600 m) in a subtropical forest in south‐east China. The total species richness of all organisms was not related to elevation, nor was the richness of plants, herbivores or microorganisms. However, species richness and abundance in two major trophic guilds of arthropods changed with elevation, which was mediated by changes in elevation‐associated habitat properties. Specifically, deadwood mass increased with elevation, which increased detritivore richness indirectly via detritivore abundance, thus supporting the ‘more individuals hypothesis’. In contrast, lower predator richness at higher elevations was directly related to lower mean temperatures, which had no effect on abundance. Our study demonstrates that even along relatively short gradients, elevation can have strong direct and abundance‐mediated effects on species richness, but with effects varying from positive to negative signs depending on local resource availability and the characteristics of groups or trophic guilds. If elevation positively influences local environmental properties that benefit a given group, richness can increase towards higher elevations. Thus, the effect of global change in mountainous regions should be evaluated within the local environmental context using multi‐taxon approaches.

Analysis of tropical and temperate elevational gradients in arthropod abundance

“…Moran's I was positive and significant for 6 of the 19 gradients. However, the values were low (Appendix 1) and a model with spatial correlation structure performed better than a non-spatial model for only one study (i.e., Binkenstein et al 2017). Predictors of abundance: Consistent with the expectations from our seasonality hypothesis, the peak in arthropod abundance is at higher elevations at higher latitudes (Fig.…”

Tree phylogenetic diversity structures multitrophic communities

“…A broad range of macro‐organisms and fungi were sampled with standardized methods in all plots during various sampling campaigns from 2008 to 2012 (see Binkenstein et al., 2018; Schuldt et al., 2015; data: Staab et al, 2019). Sampling for arthropods collected species communities at the forest floor and in the understorey by utilizing pitfall traps, flight interception traps, beating, baiting and trap nests (see Table 1 for a detailed overview).…”

“…The topography in the GNNR is heterogeneous and plots vary in elevation and further abiotic properties (Binkenstein et al., 2018; Table S1), which influences woody species and co‐occurring organisms (Schuldt et al., 2015). In addition to plot elevation (in m), we measured slope (in °) and aspect, i.e.…”

Habitat amount and ambient temperature dictate patterns of anuran diversity along a subtropical elevational gradient

“…More-individuals-hypothesis Abundance is positively related to productivity, and therefore, species richness is positively related to abundance (Binkenstein et al, 2018;Srivastava & Lawton, 1998) Frog…”

“…Warmer climates mostly lead to higher primary productivity, resulting in more available resources, which in turn ensure coexistence of more individuals (McCain, 2007). Therefore, productivity can indirectly promote diversity by maintaining more viable populations and reducing local extinction rates, also known as the more‐individuals‐hypothesis (MIH: Binkenstein et al., 2018; Srivastava & Lawton, 1998). Diversity also scales to the available habitat area, and montane regions covering larger areas or providing more available habitat should also harbour more species and individuals (Fahrig, 2013; Rosenzweig, 1995).…”