Disentangling the role of environment in cross-taxon congruence of species richness along elevational gradients

Abstract

Spatial patterns of species richness have been found to be positively associated, a phenom called cross-taxon congruence. This may be explained by a common response to environment or by ecological interactions between taxa. Spatial changes in species richness are related to energy and environmental heterogeneity but their roles in cross-taxon congruence remain poorly explored. Elevational gradients provide a great opportunity to shed light on the underlying drivers of species richness patterns. We study the joint influence of environment and biotic interactions in shaping the cross-taxon congruence of plants and orthopterans species richness, along three elevational gradients in Sierras Grandes, central Argentina. Elevational patterns of species richness of orthopterans and plants were congruent, being temperature the best single predictor of both patterns supporting the energy-related hypotheses. Using a structural equation model, we found that temperature explained plant richness directly and orthopteran richness indirectly via orthopteran abundance. Cross-taxon congruence is likely due to a common response of both taxa to temperature although via different theoretical mechanisms, possibly, range limitations for plants and foraging activity for orthopterans. We disentangled the role of temperature in determining the cross-taxon congruence of plants and orthopterans by showing that a common response to the environment may mask different mechanisms driving the diversity of different taxonomic groups.

Italian Vascular Flora: New Findings, Updates and Exploration of Floristic Similarities between Regions

“…Nowadays, it is mainly the wet areas and the presence of islands and mountain massifs that determine a greater plant diversity. Factors directly related to elevation (e.g., temperature, rainfall, light intensity, nitrogen availability) are indicated as the main factors that regulate the distribution and number of taxa [189,190]. Despite most of the studies on species richness variation along elevational gradients found either a monotonic decline with increasing elevation or a hump-shaped pattern with a mid-elevational peak [191][192][193], the presence of high mountains favors the processes of plant speciation.…”

Micro‐ and macroclimate interactively shape diversity, niches and traits of Orthoptera communities along elevational gradients

“…Within‐site microclimatic variation at even smaller scales than measured in our study (0.01–1 m) could also be crucial for the persistence of certain species, as shown for plants in alpine habitats (Ohler et al., 2020; Scherrer et al., 2011), possibly dampening the microclimate response we measured with this study. Likewise, species responses derived may be interfered by factors interacting with climate, such as moisture (Dvořák et al., 2022; Powell et al., 2007), management (Humbert et al., 2021; Marini et al., 2009), vegetation structure (Gardiner, 2022; Löffler & Fartmann, 2017; Schirmel et al., 2019), composition (Tobisch et al., 2023) and diversity (Fournier et al., 2017; Ramos et al., 2021).…”

Woody Plant Structural Diversity Changes across an Inverse Elevation-Dependent Warming Gradient in a Subtropical Mountain Forest

“…Structural diversity is mainly composed of three components, i.e., spatial distribution, species diversity, and tree size diversity [15,33]. Changes in structural diversity are often affected by a variety of factors, including climate change [34,35], land use history [36], habitat heterogeneity [37], and inter-and intraspecific competitions [38,39]. Compared with other indicators, tree size is easy to measure using forestry tools [15,40].…”