CECAV
URI permanente desta comunidadehttps://bdc.icmbio.gov.br/handle/cecav/1
Centro Nacional de Pesquisa e Conservação de Cavernas
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2 resultados
Resultados da Pesquisa
Item Modern anthropogenic drought in Central Brazil unprecedented during last 700 years(2024-02-26) Stríkis, N.M; Buarque, P.F.S.M; Cruz, F.W; et al.A better understanding of the relative roles of internal climate variability and external contributions, from both natural (solar, volcanic) and anthropogenic greenhouse gas forcing, is important to better project future hydrologic changes. Changes in the evaporative demand play a central role in this context, particularly in tropical areas characterized by high precipitation seasonality, such as the tropical savannah and semi-desertic biomes. Here we present a set of geochemical proxies in speleothems from a well-ventilated cave located in central-eastern Brazil which shows that the evaporative demand is no longer being met by precipitation, leading to a hydrological deficit. A marked change in the hydrologic balance in central-eastern Brazil, caused by a severe warming trend, can be identified, starting in the 1970s. Our findings show that the current aridity has no analog over the last 720 years. A detection and attribution study indicates that this trend is mostly driven by anthropogenic forcing and cannot be explained by natural factors alone. These results reinforce the premise of a severe long-term drought in the subtropics of eastern South America that will likely be further exacerbated in the future given its apparent connection to increased greenhouse gas emissions.Item Persisting while changing over time: modelling the historical biogeographic of cave crickets (Orthoptera, Grylloidea) in Neotropics(2023) Castro-Souza, Rodrigo Antônio; Sobral-Souza, Thadeu; Rabelo, Lucas Mendes; Zefa, Edison; Ferreira, Rodrigo LopesUsing species distribution modelling (SDMs) techniques, we predicted the biogeographic history of crickets commonly found in Neotropical caves as a way to detect potential long-term environmental refuges in South America. Our models were built based on a thorough investigation of existing database regarding the genus Endecous Saussure, 1878 (Ensifera: Phalangopsidae) occurrences. The predictions of their distribution were obtained for two paleoclimate scenarios (LGM — 21 ka and Mid-Holocene — 6 ka), the current climate scenario (0 ka) and one future global warming climate scenario (RCP8.5, 2080–2100). Our findings suggest that in the past, the potential distribution of the crickets was wider, with potential forest corridors connecting different karst areas with caves within their occupancy area. The future prediction indicates a drastic reduction in their spatial distribution with an increased potential for isolation in subterranean ecosystems. Atlantic humid forest patches and caves represent the main environmental refuges for these crickets. Considering the ongoing impacts on surface environments and future climate change, the conservation of caves and karst landscapes has become one of the main strategies for the maintenance of these crickets and all the correlated subterranean communities.