Navegando por Autor "Almeida, Hernani Alves"

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Changes in the hydro-sedimentary balance : impacts of the use of a borrow pit in a low-order stream.
(2021) Silva Junior, Cláudio Tavares; Sant'Anna, Eneida Maria Eskinazi; Souza, Yuri Andrade Figueiredo de; Almeida, Hernani Alves; Leite, Mariangela Garcia Praça
Construction of dams for hydroelectric power requires significant quantities of soil and rock, which are often extracted in borrow pits from adjacent regions. Although the effects of dams on stream processes has received significant attention, the effects of borrow pits has not. The main objective of this study was to analyze the geomorphological and sedimentological aspects of two second-order streams, one of which was directly affected by the borrow pit located upstream of its source (Pedra Branca stream). Flow rates were measured and cross-sections of 600m stretches in both streams were monitored over a hydrological year. At the same time, sediments from the bed of the channels and soils on their banks had their physical and chemical characteristics evaluated. Streams sediments differed in their chemical and organic matter composition. The mean particle size of the sediment particles was different between the reference and degraded streams. The water flow was very similar to both streams, only varying along the seasonal seasons. However, the fluvial channels presented great geomorphological differentiation, mainly downstream, due to the location of the Pedra Branca stream and its proximity to the borrow pit. Despite the great importance for the production of clean electric energy, the construction of hydroelectric plants promotes persistent impacts that affect structural and functional aspects of the adjacent aquatic habitats. Borrow pits used for the construction of projects become large sources of sediment for aquatic environments, affecting the drainage network of the hydrographic basin and the balance of river erosion, transport and deposition processes. The results show the need to review the intervention protocols in borrow pits and the environmental legislation that regulates their rehabilitation.
Dung beetles can sow : the potential of secondary seed dispersers to assist ecological restoration.
(2022) Almeida, Hernani Alves; Itabaiana, Yasmine Antonini; Silva Junior, Cláudio Tavares; Braga, Rodrigo F.; Silva, Pedro Giovâni da; Silva, Wallace Beiroz Imbrosio da
1. Restoration of disturbed environments in which soil surface layers have been removed is challenging and its success depends on the characteristics of the exposed soil layers and neighbour organisms. Dung beetles are important elements in the restoration of degraded habitats as secondary seed dispersers. 2. In this study, we first assessed how the removal of upper soil layers affected the assemblage of dung beetle compared to adjacent reference areas without soil removal. We also evaluated the efficiency of dung beetles as secondary seed dispersers by experimentally testing their effect on the germination of wolf apple seeds (Solanum lycocarpum). 3. Degraded areas harboured a different dung beetle assemblage compared to the reference area, with a predominance of habitat generalist species. In addition, we found higher abundance and richness of dung beetles in the degraded than in reference areas. Despite dung removal being similar between areas, more seeds were removed in the reference area. 4. Dung beetles, especially rollers, positively influenced the probability of wolf apple seed germination in the degraded environment by up to 5%; germination occurred in 27% of treatments with dung beetle presence and no germination occurred when beetles were excluded. 5. Therefore, promoting the attraction of dung beetles from reference areas, together with other techniques that enhance primary seed dispersion, mainly by mammals and birds, could potentially increase the success of projects to restore areas with degraded soil.
Papel dos besouros rola-bosta (Scarabaeinae) na restauração através da dispersão secundária.
(2020) Almeida, Hernani Alves; Silva, Wallace Beiroz Imbrosio da; Itabaiana, Yasmine Antonini
Ressignificando o excremento : como uma assembleia de besouros rola-bosta pode ajudar a restaurar áreas degradadas.
(2020) Almeida, Hernani Alves; Itabaiana, Yasmine Antonini; Silva, Wallace Beiroz Imbrosio da; Louzada, Júlio Neil Cassa; Silva, Pedro Giovâni da; Itabaiana, Yasmine Antonini
O Cerrado passa por diversas alterações antrópicas que ocasionam perda de vegetação nativa. Estas mudanças no uso do solo, podem interferir em vários atributos relacionados à comunidade. Os besouros coprófagos, conhecidos como rola-bosta, são sensíveis a estas alterações e ainda desempenham funções ecossistêmicas importantes que quando perdidas podem comprometer a qualidade e resiliência do ambiente. Nesse capítulo avaliamos qual a influência de uma área degradada na diversidade taxonômica, composição e estrutura de uma assembleia de besouros rola-bosta, além de suas funções ecossistêmicas. Capturamos 7716 indivíduos em 22 pontos de amostragem, representados por 18 gêneros e 41 espécies. A abundância e riqueza média foram maiores na área degradada. A estrutura da assembleia diferiu entre as duas áreas, sendo o principal fator a compactação e granulometria do solo, que gerou um filtro ambiental forte capaz de interferir diretamente na assembleia. Houve ainda, perda de função ecossistêmica, dispersão secundária de sementes, com a degradação do ambiente. Concluímos que mesmo apresentando a média de diversidade taxonômica maior na área degradada, ocasionada possivelmente por algumas espécies suportarem condições limitantes, houve perda de função importante, capaz de comprometer o equilíbrio ambiental e ainda a houve a separação e simplificação da assembleia com a perda de habitat.