Environmental and geometric drivers of small mammal diversity along elevational gradients in Utah

Abstract

The mechanisms shaping patterns of biodiversity along spatial gradients remain poorly known and controversial. Hypotheses have emphasized the importance of both environmental and spatial factors. Much of the uncertainty about the relative role of these processes can be attributed to the limited number of comparative studies that evaluate multiple potential mechanisms. This study examines the relative importance of six variables: temperature, precipitation, productivity, habitat heterogeneity, area, and the mid‐domain effect on patterns of species richness for non‐volant small mammals along four neighboring mountain ranges in central Utah. Along each of these elevational gradients, a hump‐shaped relationship of richness with elevation is evident. This study evaluates whether the processes shaping this common pattern are also common to all gradients. Model selection indicates that no one factor or set of factors best explains patterns of species richness across all gradients, and drivers of diversity may vary seasonally. These findings suggest that commonality in the pattern of species richness, even among elevational gradients with a similar biogeographic history and fauna, cannot be attributed to a simple universal explanation.

Elevational patterns and determinants of plant diversity in the Baekdudaegan Mountains, South Korea: Species vs. functional diversity

“…Studies using remote sensing-based vegetation indices as surrogates of primary productivity have found significant productivity-diversity relationships, both linear and unimodal, suggesting that such estimates can be used to evaluate biodiversity patterns [6], albeit at different spatial scales depending on the taxonomic group in question [52]. This study finds little support for productivity (as measured by EVI) as a primary driver in shaping patterns of species and functional diversity along the elevational gradient.…”

“…Climate is considered to be the most widely supported predictor of worldwide biodiversity because climate can directly control species distributions when climatic conditions exceed the physiological tolerances of species and can indirectly affect photosynthetic activity and biological processes. Several studies have also found that the area of elevational bands explained a large proportion of the variation in diversity [6,11], similarly to the well-known species-area relationships. Recent studies have suggested the middomain effect (MDE), or geometric constraints, is highly effective at explaining elevational diversity patterns [7,12].…”

“…The elevational gradient present in mountainous areas provides the most powerful natural experimental system available to clarify the ecological and evolutionary responses of living organisms to geophysical influences [4]. Many studies have documented the elevational diversity patterns of plants, mammals, birds, and invertebrates and different patterns have been observed in different taxa and regions [5][6][7][8]. There are three main types of diversity patterns in relation to increasing elevation: (1) a monotonic decrease; (2) a plateau at low elevations; and (3) a "hump-shaped" distribution with high diversity at intermediate elevations [9].…”

The Early–Middle Pleistocene environmental and climatic change and the human expansion in Western Europe: A case study with small vertebrates (Gran Dolina, Atapuerca, Spain)☆

“…Analyses of the species diversity of small, non-flying mammals are common in ecology for the description of present-day communities (McCain, 2004;Rowe, 2009). The determinants of the species richness of present-day non-flying small-mammal associ ations (Rowe, 2009) are limited by numerous variables, including temperature, precipitation, productivity, habitat heterogeneity, area and restrictions peculiar to the distribution of the species, as well as the mid-domain effect or topography (McCain, 2004).…”

“…The determinants of the species richness of present-day non-flying small-mammal associ ations (Rowe, 2009) are limited by numerous variables, including temperature, precipitation, productivity, habitat heterogeneity, area and restrictions peculiar to the distribution of the species, as well as the mid-domain effect or topography (McCain, 2004). According to McCain (2004), the geometric constraints of montane topography appear to influence the diversity pattern of small mammals, although climatic conditions (rainfall and temperature regime) are correlated with the pattern of species richness.…”