RESUMO

Here we analyze the trends of rainfall and the frequency of rainy days over the Brazilian Cerrado between 1960 and 2021 in four distinct periods according to the seasonal patterns over the region. We also evaluated trends in evapotranspiration, atmospheric pressure, winds, and atmospheric humidity over the Cerrado to elucidate the possible reasons for the detected trends. We recorded a significant reduction in rainfall and frequency of rainy days in the northern and central Cerrado regions for all periods except at the beginning of the dry season. The most pronounced negative trends were recorded during the dry season and the beginning of the wet season, where we recorded reductions of up to 50% in total rainfall and the number of rainy days. These findings are associated with the intensification of the South Atlantic Subtropical Anticyclone, which has been shifting atmospheric circulation and raising regional subsidence. Moreover, during the dry season and the beginning of the wet season, there was a reduction in regional evapotranspiration, which also potentially contributed to the rainfall reduction. Our results suggest an expansion and intensification of the dry season in the region, potentially bringing broad environmental and social impacts that transcend the Cerrado boundaries.

RESUMO

Currently campo rupestre (CR) is a name accepted and used internationally by botanists, zoologists, and other naturalists, usually applied to a very specific ecosystem, despite the lack of a consensual published circumscription. We present a tentative geographic circumscription of the term, combining data on climate, geology, geomorphology, soil, flora, fauna and vegetation. The circumscription of campo rupestre proposed herein is based on the following premises: (1) the classification of vegetation is not an exact science, and it is difficult to attain a high degree of consensus to the circumscription of vegetation names; (2) despite this, vegetation classification is useful for conservation and management. It is thus desirable to circumscribe vegetation types with the greatest attainable precision; (3) there is a need to preserve all montane and rocky vegetation types, regardless of classification, biome, etc; (4) the CRs are formed by a complex mosaic of vegetation types including rock-dwelling, psammophilous, aquatic, epiphytic, and penumbral plant communities. Campos rupestres stricto sensu are a Neotropical, azonal vegetation complex endemic to Brazil, forming a mosaic of rocky mountaintop "archipelagos" inserted within a matrix of zonal vegetation, mainly in the Cerrado and Caatinga provinces of the Brazilian Shield (southeastern, northeastern and central-western regions), occurring mainly above 900 m asl. up to altitudes exceeding 2000 m, having measured annual precipitation between 800 and 1500 mm, and an arid season of two to five months.

Assuntos

RESUMO

Currently campo rupestre (CR) is a name accepted and used internationally by botanists, zoologists, and other naturalists, usually applied to a very specific ecosystem, despite the lack of a consensual published circumscription. We present a tentative geographic circumscription of the term, combining data on climate, geology, geomorphology, soil, flora, fauna and vegetation. The circumscription of campo rupestre proposed herein is based on the following premises: (1) the classification of vegetation is not an exact science, and it is difficult to attain a high degree of consensus to the circumscription of vegetation names; (2) despite this, vegetation classification is useful for conservation and management. It is thus desirable to circumscribe vegetation types with the greatest attainable precision; (3) there is a need to preserve all montane and rocky vegetation types, regardless of classification, biome, etc; (4) the CRs are formed by a complex mosaic of vegetation types including rock-dwelling, psammophilous, aquatic, epiphytic, and penumbral plant communities. Campos rupestres stricto sensu are a Neotropical, azonal vegetation complex endemic to Brazil, forming a mosaic of rocky mountaintop “archipelagos” inserted within a matrix of zonal vegetation, mainly in the Cerrado and Caatinga provinces of the Brazilian Shield (southeastern, northeastern and central-western regions), occurring mainly above 900 m asl. up to altitudes exceeding 2000 m, having measured annual precipitation between 800 and 1500 mm, and an arid season of two to five months.(AU)

Atualmente campo rupestre (CR) é um termo aceito e internacionalmente usado por botânicos, zoólogos e outros naturalistas, geralmente aplicado a um ecossistema muito específico apesar de não haver uma circunscrição de consenso. Nós apresentamos uma ciscunscrição geográfica tentativa do termo, combinando dados de clima, geologia, geomorfologia, solo, flora, fauna e vegetação. A circunscrição de campo rupestre aqui proposta se baseia nas seguintes premissas: (1) a classificação da vegetação não é uma ciência exata e é difícil atingir um alto grau de consenso sobre a circunscrição de nomes de vegetação; (2) apesar disto, a classificação da vegetação é útil para conservação e manejo. Assim é desejável descrever os tipos de vegetação com a maior precisão tangível; exista a necessidade de se preservar todos os tipos de vegetação montanos e rochosos, independentemente de sua classificação, bioma, etc. (4) os CRs são formados por um complexo mosaico de tipos de vegetação incluindo comunidades sobre rocha, psamíóilas, aquáticas, epífitas e penumbrais. Os campos rupestres stricto sensu são um complexo de vegetação endêmico ao Brasil, azonal, Neotropical, inserido numa matriz de vegetação zonal, sobretudo nas províncias do Cerrado e da Caatinga do Escudo do Brasil (regiões Sudeste, Nordeste e Centro_Oeste), ocorrendo principalmente acima de 900 m de altitude, até altitudes superiores a 2000 m, tendo uma precipitação anual mensurada entre 800 e 1500 mm, e uma estação árida de dois a cinco meses.(AU)

Assuntos