CECAV
URI permanente desta comunidadehttps://bdc.icmbio.gov.br/handle/cecav/1
Centro Nacional de Pesquisa e Conservação de Cavernas
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12 resultados
Resultados da Pesquisa
Item From the front door to the basement: Invertebrate communities' structure as a proxy for determining cave zonation in Neotropics(2024-06-25) Reis-Venâncio, Paulo C.; Ferreira, Rodrigo L.; Souza-Silva, MarconiIn caves, the absence of natural light in deeper regions starkly contrasts with the entrance areas, which still exhibit a light gradient extending into the cave interior. This interplay with the structural gradient of the environment potentially exerts distinct influences on invertebrate communities residing in different cave light zones. To investigate this, we formulated a hypothesis positing that communities within distinct cave light zones respond differently to habitat structure and microclimatic conditions. Our approach involved a spatial multi-scale sampling of invertebrates and the application of statistical analyses to contrast the responses of communities inhabiting photic and aphotic zones. Photic zone richness is influenced by factors such as air moisture, resource availability, root presence, and shelter diversity. In contrast, the richness of communities in aphotic zones is shaped by resource availability, the presence of roots, branches, and distance from the cave entrance. As expected, the richness in the photic zone surpasses that of the deeper regions, highlighting the challenges faced by invertebrates attempting to establish themselves in the aphotic zone. The species composition of faunal communities varied predictably from the entrance to the aphotic zone, and the three most important factors driving this variation were geographic distance, humidity, and distance from the entrance. The composition between these cave zones differs significantly, primarily due to the high number of obligate cave species predominantly inhabiting the aphotic region. Indeed, communities associated with different cave zones exhibit distinct responses to resource, microclimatic, and structural variables.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.Item A Highly Troglomorphic New Genus of Sminthuridae (Collembola, Symphypleona) from the Brazilian Semiarid Region(2022-07-19) Souza, Paolla Gabryelle Cavalcante de; Medeiros, Gleyce da Silva; Ferreira, Rodrigo Lopes; Souza-Silva, Marconi; Bellini, Bruno CavalcanteHere, we describe the highly troglomorphic Troglobentosminthurus gen. nov. from Água Clara cave system, Caatinga domain, Bahia, Brazil. Troglobentosminthurus luridus gen. nov. sp. nov. has remarkably long antennae, legs and furca, and lacks body pigments, except for small orange eye patches which also show a reduction in the number of eyes (5 + 5) and lens sizes. The overall morphology of the genus, with long and highly sub-segmented antennae, resembles other Sminthurinae of the Temeritas-group, especially Temeritas Richards and Galeriella Ćurčić and Lučić. However, it is unique, especially in the combination of the number of antennae IV subsegments and eyes, frontal head chaetotaxy and empodial complex morphology. Two type specimens have remnants of a mite and another specimen from the new species in their gut contents, supporting the species may be occasional predators and even cannibals. We also provide identification keys and comparative tables to the subfamilies of Sminthuridae and the Temeritas-group of genera.Item The Água Clara cave system in Northeastern Brazil: the richest hotspot of subterranean biodiversity in South America(2023-06-09) Ferreira, Rodrigo Lopes; Berbert-Born, Mylène; Souza-Silva, MarconiThe Água Clara Cave System (ACCS) in Brazil is the richest hotspot of subterranean biodiversity in South America. In this study, we present an updated list of cave-restricted species in the ACCS and compare it with previously published hotspots in Brazil. Our list of cave-obligate fauna comprises 31 species, including 23 troglobionts and 8 stygobionts. The exceptional diversity of the ACCS can be attributed to factors related to the high dispersal potential of cave fauna within the system, high surface productivity, and the large size of the cave system size. Notably, we observed highly troglomorphic species in the ACCS, some of which are the most troglomorphic species in their respective groups in Brazil. The huge volume of galleries, high humidity, and trophic conditions prevailing in the ACCS may have played a role in shaping the strong troglomorphic traits observed in these species. However, all the obligate cave species in the ACCS require conservation attention and are at an elevated risk of extinction due to their limited ranges, few occurrences, and many potential threats. This study sheds light on the biodiversity and conservation status of cave-restricted fauna in the ACCS and highlights the importance of protecting these unique ecosystems.Item Do different relevance attributes indicate the same conservation priorities? A case study in caves of southeastern Brazil(2021-09) Souza, Maysa F. V. R.; Alvarenga, Denizar A.; Souza-Silva, Marconi; Ferreira, Rodrigo L.In the last decade, the scientific community brought to the debate gaps that slow down the advance of knowledge regarding global biodiversity. More recently, this discussion has reached subterranean environments, where these gaps are even more dramatic due to the relict and vulnerable nature of their species. In this context, we tested ecological metrics related to some of these gaps, checking if the biological relevance of the caves would change depending on ecological attributes related to each metric. The study was carried out in caves from southeastern Brazil, located in a region presenting a high richness of troglobitic species restricted to a narrow geographical extent. Thus, we verified: (a) the cave invertebrate communities’ vulnerability with the Vulnerability Index and the Importance Value for Cave Conservation; (b) the distribution and endemicity of the troglobitic species with the Endemicity Index; (c) the phylogenetic diversity of the troglobitic species considering the average taxonomic distinction (∆+), their richness and evenness. We observed a considerable change in the ordering of the caves’ biological relevance according to each tested attribute (index). We discussed how each of these metrics and their attributes indirectly relate to: (a) the preservation and maintenance of the phylogenetic diversity of subterranean communities; (b) the spatial restrictions of different groups, where the greater their restrictions, the greater their vulnerability; (c) the preservation of caves with high biological relevance considering these different attributes together. Thus, we recommend the use of different metrics so that different ecological attributes can be considered, supporting actions that aim to preserve caves in highly altered regions. Finally, we find that the most biologically important cave in the region is not protected (Gruta da Morena Cave). We warn that this cave needs to be contemplated by a conservation unit in the region urgently.- 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 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.- 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.
- Phlebotomine sand flies (Diptera, Psychodidae) from iron ore caves in the State of Pará, Brazil(2021-01-11) Teodoro, Layane Meira; Carvalho, Gustavo Mayr de Lima; Campos, Aldenise Martins; Cerqueira, Roberta Fernanda Ventura; Souza-Silva, Marconi; Ferreira, Rodrigo Lopes; Barata, Ricardo AndradeThe present study aimed to evaluate the distribution of sand fly species in iron ore caves in the State of Pará, Brazil and to associate the richness and abundance of these insects with the capacity of leishmaniasis transmission. Entomological captures were carried out in the years 2010, 2013, 2014 and 2015, through-out active samples with brushes, along the entire caves’ extension, in dry and rainy periods. A total of 9,807 sand flies were counted during the 532 samplings events, being 4,340 in the dry period and 5,467 in the rainy period. A random sample of 802 morphologically identified specimens consisted of 8 genera and 17 species, being 369 males (46%) and 433 females (54%). The predominant species was Sciopemyia sordellii with 60.6% of the total of sand flies collected. Differences in composition and richness were observed between caves located inside of forest and anthropized areas. The mean richness and abundance were different between the wet and rainy periods, with a greater abundance of these insects in the rainy period. The phlebotomine fauna proved to be rich and abundant in the sampled caves, however, environ-mental degradation seems to be the main factor determining changes in the composition and richness, reinforces the importance of these places as a shelter for sand flies in degraded areas.
- 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.