Habitat Heterogeneity and Geographic Location as Major Drivers of Cerrado Small Mammal Diversity Across Multiple Spatial Scales

Abstract

The Cerrado biome is one of the global hotspots of biodiversity, and non-volant small mammals represent a significant portion of Cerrado species richness (45%) and endemism (86%). Nevertheless, we still lack a comprehensive picture of small mammal diversity patterns and drivers throughout the Cerrado. Here we surveyed small mammals across 45 sites to address species richness, abundance, and composition patterns and their drivers within and across sites, habitats, and localities at the world’s most diverse tropical savanna. As hypothesized, we found: (1) rich assemblages (12–21 species) characterized by few abundant and several intermediate-level and rare species; dominated by oryzomyine and akodontine cricetid rodents, and thylamyine and marmosine within marsupials, each tribe showing distinct habitat requirements; (2) strong habitat selectivity, with assemblages composed of forest dwellers, savanna specialists, and grassland inhabitants; and (3) similar species richness (α-diversity) but high species turnover (β-diversity) across sites, habitats, and localities, suggesting that horizontal stratification (within localities) and geographic location (across the Cerrado) are key drivers of small mammal diversity in tropical savannas. Thus, habitat heterogeneity and geographic location can be inferred as the main factors shaping species richness, abundance, and composition across the analyzed multiple spatial scales. Moreover, we found that geographical distance as well as the distance to neighbor biomes better explained species turnover, indicating landscape history and phylogenetic constraints as the major determinants of Cerrado small mammal diversity, as also evidenced for plants and other animal groups. These data highlight the need to preserve the mosaic of habitats across the different regions of the biome to conserve most of the Cerrado biodiversity.

Distribution patterns and drivers of nonendemic and endemic glires species in China

“…Habitat heterogeneity is considered the most critical factor in shaping biological distribution patterns. Habitat variation creates a microhabitat for species reproduction by creating dramatic changes in climate and habitat differentiation on a small scale, enabling species to coexist locally (Carmignotto et al, 2022 ). Southwest China has a variety of hydrothermal conditions and habitats that result from a combination of topographic changes caused by elevation differentiation (Huang et al, 2011 ; Liu et al, 2015 ).…”

The pivotal role of land cover around forest fragments for small‐mammal communities in a Neotropical savanna

“…This suggests that both might be compelling habitats mitigating the negative effects of anthropogenic land use on functional groups. This is particularly relevant in tropical savannas, which are characterized by a mosaic of native forest remnants, savannas, and grasslands (Carmignotto et al, 2022). Such positive effects were even more obvious in crop‐dominated landscapes, in which an increase in pasture cover increased the abundance of most functional groups such as the small, forest‐specialist, frugivorous/granivorous, terrestrial, and scansorial mammals.…”

“…However, the most abundant species, Thrichomys fosteri, a forest specialist (Melo et al, 2022), was responsible for driving most patterns. Carmignotto et al (2022) showed that the overabundance of a single species associated with several rare species is typical of small-mammal assemblages in the Cerrado: T. fosteri (22.4% of captures) is dominant in the southwest (study region), Necromys lasiurus in the southeast (64%), and Gracilinanus agilis in the central Cerrado (63%, in Mattos et al, 2021). Therefore, our results may be specific to the small-mammal communities of the study region (Bodoquena) and reflect the effect of the loss of forested systems (e.g., forested cerrado, remnant Atlantic Forest) on forest specialists such as T. fosteri.…”

“…It should also be noted that 47% (7 out of 15) of the species captured were represented by <5 individuals. In Carmignotto et al (2022), 47% (27 out of 58 species) of species captured across the Cerrado were represented by <5 individuals. Consideration of these rare species is key to reliably examine the responses of small-mammal communities to land use in the Cerrado.…”

Distribution patterns and drivers of non-endemic and endemic rodent species in China

“…Habitat heterogeneity is considered the most critical factor in shaping biological distribution patterns. Habitat variation creates a microhabitat for species reproduction by creating dramatic changes in climate and habitat differentiation on a small scale, enabling species to coexist locally (Carmignotto et al, 2022). Southwest China has a variety of hydrothermal conditions and habitats that result from a combination of topographic changes caused by elevation differentiation (Huang et al, 2011;Liu et al, 2015).…”