Navegando por Assunto "Invertebrates"
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- Cave lithology effect on subterranean biodiversity: A case study in quartzite and granitoid caves(2020-10) Souza-Silva, Marconi; Iniesta, Luiz Felipe Moretti; Ferreira, Rodrigo LopesPhysical features and lithology variations contribute to promoting changes in faunal composition and richness between caves in Neotropics. Cave lithology effects on biodiversity were reported to iron ore caves in Brazil, however, it is less clear to granitoid and quartzite caves. Hence, based on these two kinds of rocks we correlate invertebrates species richness and composition with some cave features (lithology, the distance between caves, cave extension, number of entrances, entrance size, environmental stability, and altitude). Overall, 1,027 invertebrate species were recorded in 50 sampled caves. From this total, 11 obligate cave species were found. Invertebrate assemblages showed considerable turnover between caves and rock types with a strong contribution of replacement component of beta diversity. Replacement influence was greatest in quartzite caves mainly because of altitude and distance among caves. Furthermore, richness was determined by cave extension in both lithotypes, although this relationship was much more pronounced for the granitoid caves, which contradicts previous studies. The granitoid caves studied here are predominantly structured by stacked blocks with macro and meso anastomosed subterranean spaces that provide an extensive network of interstices with structural characteristics similar to shallow subterranean habitats that may increase in habitat availability and species richness. The study highlight that the lithology-mediated effects of cave extension on richness must be considered for quartzite and granitoid in the ecological and conservational proposal. Furthermore, altitude and distance among caves were important elements determining invertebrate composition.
- Epigean and hypogean drivers of Neotropical subterranean communities(2020-10-29) Rabelo, Lucas Mendes; Souza-Silva, Marconi; Ferreira, Rodrigo LopesIn addition to cave size and other subterranean habitat characteristics, cave entrances are important structurers of neotropical cave communities. However, little is known about the epigean ecosystems factors that might dictate the influence of entrances and the relationship among surface and cave communities, as entrance re-gions are ecotonal zones between the epigean and hypogean ecosystems. We aimed to assess the influence of epigean and hypogean factors as potential drivers of inver-tebrate species richness in Neotropical caves as well as the influence of the regional pool of invertebrate diversity on cave invertebrate diversity.
- Priorities for cave fauna conservation in the Iuiú karst landscape, northeastern Brazil: a threatened spot of troglobitic species diversity(2021-03-20) Cardoso, Rafael Costa; Ferreira, Rodrigo Lopes; Souza-Silva, MarconiThe definition of priority for conservation becomes an emergency because habitat loss and degradation are among the main impacts on karst landscapes. In this sense, the present study aimed to evaluate the priorities for cave conservation through the combination of indexes that use species richness, species distribution, and proportion of the deforested area (PDA). The caves presented 287 non-troglobitic species and 37 species (11.7 %) with troglomorphic traits that are distributed in 50 % of the caves. The caves also present a high phylogenetic and functional diversity of terrestrial, aquatic, and amphibious cave-restricted species, including many predators, scavengers, and one phytophagous species, most of them presenting remarkable specialized traits and restrict distribution in a few caves and in specific biotopes. The PDA were positively related to the distance from the limestone outcrop, because of the restrictive landforms for agropastoral activities. At least two caves present extremely high priority for conservation (Baixão and Baixa da Fortuna caves), while four caves present high priority, and almost all others require at least a conservation action. Suggestively, in this specific case, a coherent strategy was shown to maintain the preserved vegetation around the caves, improving the restoration of small fragments and minimizing alterations. Despite the results of the indices, the singularity of the area regarding the taxonomic and functional diversity of troglobites also reinforces the urgent need for conservation actions.
- Priorities for cave fauna conservation in the Iuiú karst landscape, northeastern Brazil: a threatened spot of troglobitic species diversity(2021-03-20) Costa Cardoso, Rafael; Lopes Ferreira, Rodrigo; Souza-Silva, MarconiThe definition of priority for conservation becomes an emergency because habitat loss and degradation are among the main impacts on karst landscapes. In this sense, the present study aimed to evaluate the priorities for cave conservation through the combination of indexes that use species richness, species distribution, and proportion of the deforested area (PDA). The caves presented 287 non-troglobitic species and 37 species (11.7 %) with troglomorphic traits that are distributed in 50 % of the caves. The caves also present a high phylogenetic and functional diversity of terrestrial, aquatic, and amphibious cave-restricted species, including many predators, scavengers, and one phytophagous species, most of them presenting remarkable specialized traits and restrict distribution in a few caves and in specific biotopes. The PDA were positively related to the distance from the limestone outcrop, because of the restrictive landforms for agropastoral activities. At least two caves present extremely high priority for conservation (Baixão and Baixa da Fortuna caves), while four caves present high priority, and almost all others require at least a conservation action. Suggestively, in this specific case, a coherent strategy was shown to maintain the preserved vegetation around the caves, improving the restoration of small fragments and minimizing alterations. Despite the results of the indices, the singularity of the area regarding the taxonomic and functional diversity of troglobites also reinforces the urgent need for conservation actions.
Item Priority caves for biodiversity conservation in a key karst area of Brazil: comparing the applicability of cave conservation indices(2018-05-09) Rabelo, Lucas Mendes; Souza‑Silva, Marconi; Ferreira, Rodrigo LopesLandscapes in tropical regions have been greatly altered by human activities, as a product of growing demands for mineral and agricultural production, as well as those related to the generation of energy (e.g., hydroelectric, wind). In this scenario, caves have suffered several impacts, sometimes irreversible, as they are generally associated with rocks of high economic value and are closely related to epigean systems. Several indices have been proposed to guide conservation policies for the world’s speleological heritage, although few of them consider cave biodiversity as a criterion. To address this knowledge gap, we tested the applicability of four newly proposed indices to assist researchers and policy-makers select priority areas for global cave biodiversity conservation. To compare indices, we used data from 48 caves of the largest carbonate region of South America (Bambui geological group), all found within the Cerrado, a global biodiversity hotspot. Each of the four indices considered cave biodiversity as a criterion, although only three adequately evaluated this attribute. Based on results of Simões index and CCPi, which were the most appropriate in relation to indicate priority caves for biodiversity conserva-tion in regions where the fauna and its distribution are not fully known, 15 of the 48 caves were identified as conservation priorities.Item The ticking clock in the dark: review of biological rhythms in cave invertebrates(2024-05-09) de Souza, Priscila Emanuela; Souza-Silva, Marconi; Ferreira, Rodrigo LopesCircadian clocks, internal mechanisms that generate 24-hour rhythms, play a crucial role in coordinating biological events with day-night cycles. In light-deprived environments such as caves, species, particularly isolated obligatory troglobites, may exhibit evolutionary adaptations in biological rhythms due to light exposure. To explore rhythm expression in these settings, we conducted a comprehensive literature review on invertebrate chronobiology in global subterranean ecosystems, analyzing 44 selected studies out of over 480 identified as of September 2023. These studies revealed significant taxonomic diversity, primarily among terrestrial species like Coleoptera, with research concentrated in the United States, Italy, France, Australia, and Brazil, and a notable gap in African records. Troglobite species displayed a higher incidence of aperiodic behavior, while troglophiles showed a robust association with rhythm expression. Locomotor activity was the most studied aspect (>60%). However, approximately 4% of studies lacked information on periodicity or rhythm asynchrony, and limited research under constant light conditions hindered definitive conclusions. This review underscores the need to expand chronobiological research globally, encompassing diverse geographical regions and taxa, to deepen our understanding of biological rhythms in subterranean species. Such insights are crucial for preserving the resilience of subsurface ecosystems facing threats like climate change and habitat loss.