-Ecological theory of habitat heterogeneity and limited niche-similarity assumes that more heterogeneous environments provide a greater amount and diversity of resources than simple environments, resulting in a greater diversity of species. This study aimed to evaluate the effect of the habitat heterogeneity on the richness of dung beetles and to examine the spatial patterns of assemblage structure in relation to patterns of habitat heterogeneity. Dung beetles were collected using pitfall traps without bait in 30 points distributed in an area of cerrado sensu lato, in the region of Tangará da Serra, MT, Brazil, including areas of cerrado sensu stricto, campo sujo, cerradão and gallery forest. A total of 1,291 dung beetles were collected, distributed in 16 genera and 29 species. Overall habitat heterogeneity exerted a negative effect on patterns of dung beetles richness. Higher levels of species richness were observed in areas of cerrado campo sujo, while the areas of gallery forest were the most species poor. Regarding assembly structure, it was found that the dung beetles were separated into two major groups, one formed by the presence of specialized species in forest areas and other composed of species that occurred predominantly in cerrado. In conclusion, it was found that habitat complexity infl uenced the distribution of dung beetles, but the level of turnover in species composition along the heterogeneity gradient was relatively weak.
The aim of this study is to analyze the effects of habitat loss and forest replacement by cattle pasture on the alpha and beta diversity, abundance, biomass and species composition of dung beetles with different dispersal ability. Dung beetles were captured in 19 forest fragments and neighbouring pastures. Forest fragment area ranged from 3.7 to 4825 ha and in this study were grouped into four categories: small, medium, large and control forest. A total of 35,048 dung beetles representing 101 species were collected. Forest fragments had the highest richness with 81 species, followed by pasture with 58 species. Replacement of forest by pasture reduced species richness; however, due to the proximity and connectivity of these areas with Cerrado patches, pastures also had high species richness, but species composition was independent of adjacent fragments. Small fragments had lower abundance and species richness than our other habitat categories, even pastures. Our results highlight that proximity and connectivity with Cerrado areas influenced the patterns of alpha and beta diversity of dung beetles in fragments and pastures. We highlight that the ability to cross the pasture matrix is a strong adaptive trait for species living in humanmodified landscapes. Consequently, species with these abilities are less susceptible to the effects of forest fragmentation and local extinction. Our results reinforce the importance of considering the biogeographic location and distribution pattern of species in forest fragmentation studies.
Global climate change is currently a serious threat to biodiversity. The understanding of the effects of climate changes on the flora is urgent. Here, we analyze the effects of future climate change on the spatial distribution of the three remaining groups of Carapichea ipecacuanha (Poaia) in the Americas. We built niche-based models for current and optimistic and pessimistic climate scenarios projected for 2050 and 2090. Our findings showed that climatically suitable areas for the Atlantic and Amazon Forest groups will be strongly reduced. The greatest risk of extinction was observed for the Amazon group due to the drastic spatial reduction and abrupt spatial displacement of climate suitability. The climate suitability for the Atlantic Forest group will be reduced, comprising a small suitable area in the transition zone between Minas Gerais and Espirito Santo. The climate suitability for the Panama group remained in an continuous region in Panama and Colombia. Our results encourage future studies that develop conservation management plans in order to ensure the continuation of ecological refugia for this species.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.