Climatic variables drive temporal patterns of α and β diversities of dung beetles

Abstract

Understanding the mechanisms underpinning spatiotemporal diversity patterns of biological communities is a major goal of ecology. We aimed to test two ecological hypotheses: (i) temporal patterns of β-diversity will mostly be driven by nestedness, with a loss of species from summer to winter, and (ii) nestedness values will correlate with climatic variables instead of turnover values, indicating either a loss of species during winter or a gain of species during summer. We sampled dung beetles using standardized sampling protocols along a year in four Atlantic forest sites: two at the northwest and two at the central region of Rio Grande do Sul state, southern Brazil. We partitioned temporal patterns of β-diversity into turnover and nestedness in order to investigate if community changes are driven by species substitution or gain/loss across time. Our results highlighted five main findings: (i) dung beetle composition varied more with sites than site geographic position; (ii) there was almost one and a half 'true' dung beetle assemblages regarding the spatial distribution of species weighed by abundance; (iii) we found a positive influence of mean temperature and a negative influence of relative humidity on both species richness and abundance; (iv) both spatial and temporal dissimilarity among sites were dominated by species replacement, while the relative importance of nestedness was higher in temporal than spatial patterns; (v) there was an effect of precipitation and relative humidity on temporal patterns of β-diversity components, but these effects were site-dependent. Contrary to our expectations, the β-diversity component of turnover dominated both spatial and temporal patterns in dung beetle dissimilarity among sites and months. Distinct climatic variables affected differently the α-diversity and β-diversity components of dung beetle assemblages. Partitioning β-diversity into temporal components is a promising approach to unveil patterns of the community dynamics and to produce insights on mechanisms underlying such patterns.

Short- and long-term temporal changes in the assemblage structure of Amazonian dung beetles

“…However, some studies have found little seasonal variation in dung beetle abundance, richness, and assemblage structure in the humid forests of the Amazon region (Gardner et al 2008;Korasaki et al 2013). Following the results of Berioz et al (2017), such small seasonal variations may be an effect of the stochastic interannual variations in climate, where climatically milder years allow the maintenance of richer faunas throughout the whole year (see also Ferreira et al 2019).…”

“…The increase of perturbation in Amazon forests generates poor dung beetle assemblages in terms of both abundance and species richness (Barragan et al 2011;Braga et al 2013;Beiroz et al 2017), a well-known trend that we also identify in both Palmari and Monilla. This decay in diversity could be related to the loss of vegetation cover, changes in soil texture, and the disappearance of vertebrate fauna that affects resource availability and drastically changes the microclimatic conditions for dung beetles (Andrade et al 2011;Beiroz et al 2017;Cajaiba et al 2017;Ferreira et al 2019). Many low-intensity anthropogenic disturbances (e.g., reduced-impact logging, moderate hunting, or logging roads) may also affect negatively dung beetle assemblage structure (Bicknell et al 2014;Feer and Boissier 2015;Edwards et al 2017) and alter ecological functions (Hosaka et al 2014).…”

Communities of Dung Beetles (Coleoptera: Scarabaeoidea) in the Steppe of Mongolia

“…Errouissi et al (2004) demonstrated the seasonal variability of the communities of dung beetles in a grassland habitat. Past researchers evaluated how the interaction among climatic variables, such as air temperature, precipitation, and relative humidity, aff ected beetle assemblages more than each variable separately (Bertone et al, 2005;Kakkar, 2010;Batista et al, 2016;Ferreira et al, 2018;Lobo et al, 2019). Our results show signifi cant diff erences in beetle abundances between middle and late summer.…”

“…Dung beetles represent an ideal ecological indicator to explore the eff ects of land-use change on biodiversity (Nichols et al, 2008;Tocco et al, 2020). Diversity and composition of dung beetle communities are mainly restricted by food resources and local environmental conditions (Gittings & Giller, 1998;Ferreira et al, 2018).…”

Dung beetle β‐diversity across Brazilian tropical dry forests does not support the Pleistocene Arc hypothesis

“…Ferreira et al . (2019) found that spatial and temporal dissimilarity of dung beetles sampled over a year in a seasonal region (Rio Grande do Sul) was dominated by species substitution, while the relative importance of nestedness was higher in temporal than spatial patterns. These authors also found a positive influence of mean monthly temperature and a negative influence of relative humidity on species richness and abundance, but also an effect of precipitation and relative humidity on temporal patterns of β‐diversity components of dung beetles.…”