Beta diversity of aquatic invertebrates increases along an altitudinal gradient in a Neotropical mountain

Abstract

Mountains harbor rich biodiversity and high levels of endemism, particularly due to changes in environmental conditions over short spatial distances, which affects species distribution and composition. Studies on mountain ecosystems are increasingly needed, as mountains are highly threatened despite providing ecosystem services, such as water supply for half of the human population. We aimed to understand the patterns and drivers of alpha and beta diversities of aquatic invertebrates in headwater streams along an altitudinal gradient in the second largest South American mountain range, the Espinhaço mountains. Headwater streams were selected at each 100 m of elevation along an altitudinal gradient ranging from 800 to 1400 m asl, where three substrate types per stream were sampled: leaf litter, gravel, and cobbles. Environmental variables were sampled to represent local riparian canopy cover, instream physical habitat, water quality, climatic data, and land use. Generalized linear models and mixed models were used to test relationships between altitude and the richness and abundance of invertebrates and to assess the influence of environmental variables on the same metrics. Patterns of spatial variation in aquatic invertebrate assemblages along the altitudinal gradient were assessed using multiplicative beta diversity partitioning.The richness and abundance of aquatic invertebrates decreased with increasing altitude, whereas beta diversity increased with increasing altitude. Significant differences in assemblage composition and in relative abundance of invertebrates were observed for both substrates and altitude. We thus show that the high regional beta diversity in aquatic ecosystems in the studied site is due to the high turnover among areas.Abstract in Portuguese is available with online material. K E Y W O R D Saquatic ecosystems, elevation, macroinvertebrate assemblages, mountain ecology, rupestrian grassland, species distribution

Beta diversity of aquatic macroinvertebrate assemblages associated with leaf patches in neotropical montane streams

“…Similar to Castro et al (2019), we found that elevation range was a more important driver for Bray-Curtis beta diversity among stream F I G U R E 3 Proportion of taxa turnover and nestedness for Jaccard dissimilarity (left map) and Bray-Curtis distance (right map) for average pairwise beta diversity among sampling sites and seasons in each stream site sites than dissolved oxygen. Other authors have reached different conclusions for fish in Amazonian streams (Leal et al, 2018), macroinvertebrates in Cerrado streams (Castro et al, 2018;Firmiano et al, 2021), and fish in Cerrado streams (Pompeu et al, 2019).…”

“…The CR occupies < 1% of Brazil and yet hosts 15% of its plant species, including 40% endemics (Silveira et al., 2019). The synergy among environmental filters, geographical barriers related to changes in altitude and slope, and interactions between species is an important driving force for a wide variety of floral and faunal adaptations and speciation in the CR (Castro et al., 2019; Fernandes, 2016; Fernandes et al., 2018; Silveira et al., 2016). The CRs have been destroyed at alarming rates and these disturbances are reflected in their springs and headwater streams (Callisto et al., 2019; Callisto, Solar, et al., 2019).…”

Land use and local environment affect macroinvertebrate metacommunity organization in Neotropical stream networks

“…siltation and water quality alteration; Kaufmann et al., 1999; Macedo et al., 2018). Thereby, the high importance of environmental filters is not surprising, as both natural and anthropogenic environmental factors are strong drivers of macroinvertebrate communities in the Neotropical savanna (Castro et al., 2019). The higher importance of environmental distance in SS and TM can be attributed to a higher variance of local physical habitat variables compared to the other two HUs (Callisto et al., 2019).…”

Diversity patterns of aquatic macroinvertebrates in a tropical high-Andean catchment

“…As expected, and in accordance to previous studies, Sorensen's overall dissimilarity increased with increasing glacial influence (which is significantly correlated with altitude, Supp. Table S2) (Finn et al, 2013;Castro et al, 2019). This process could be explained by an increment of environmental heterogeneity between sites, which in turn, increases regional diversity Crespo-Pérez et al, 2020).…”