Influência de fatores abióticos no padrão de distribuição de plantas lenhosas no cerrado sensu stricto
Carregando...
Arquivos
Data
2019-02-27
Autores
Canassa, Nathália Fernandes
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Questões: Como é o padrão da diversidade e composição de espécies lenhosas ao longo do cerrado sensu stricto? Quais fatores abióticos estruturam essa diversidade e composição de espécies? Localização: Região do Cerrado no central do Brasil. Metodologia: Distribuímos 34 parcelas permanentes em sete unidades de conservação que possuíssem porções de vegetação cerrado sensu stricto. Aplicando modelos lineares mistos para investigar como é o padrão de distribuição da diversidade – riqueza e alfa de Fisher – e composição de espécies estariam relacionados com os fatores edáficos, climáticos e de pontos de incêndios, no qual o sítio foi tratado como variável randômica nos modelos. Para as análises de composição de espécies utilizamos dados de ocorrência e aplicamos um índice de dissimilaridade estendido para obter os eixos de ordenação em análises de coordenadas principais (PCoA). Análises de matrizes de Mantel simples e parcial também foram aplicados para explorar o papel do espaço na estruturação da comunidade e dos fatores abióticos. Resultados: Embora em nossa escala de amostragem não tenha sido possível identificar fatores preditivos da riqueza de espécies lenhosas, a composição de espécies esteve relacionada com o gradiente de precipitação e frequência dos pontos de incêndio ao longo do Cerrado. Os fatores edáficos não parecem ser determinantes, e sua importância relativa deve ser menor dentro dessa fitofisionomia do Cerrado ou na escala sob estudo. Embora o fogo, como fonte de distúrbio recorrente no Cerrado, tenha ganho importância maior na literatura explicando grande parte das diferenças na biomassa vegetal entre as fitofisionomias aqui nós discutimos sua importância na modificação da composição de espécies dentro do Cerrado sensu stricto, favorecendo o aumento da diversidade regional entre sítios. Neste trabalho investigamos a relação entre diferentes gradientes ambientais e a riqueza e composição de espécies lenhosas no Cerrado sensu stricto em escala regional pouco explorada até aqui na literatura sobre o Cerrado. Conclusão: Neste trabalho investigamos a relação entre diferentes gradientes ambientais e a riqueza e composição de espécies lenhosas no Cerrado sensu stricto em escala regional pouco explorada até aqui na literatura. O gradiente de intensidade de fogo parece ser determinante para a mudança da composição de espécies, embora não explique a riqueza de espécies. Esse aspecto da vegetação de Cerrado retoma discussões sobre o papel do fogo para além da manutenção de sua estrutura e adensamento.
Questions: How is the diversity pattern and composition of woody species through cerrado sensu stricto? Which abiotic factors structure this species diversity and composition? Location: Brazilian’s central Cerrado region Methodology: We distributed 34 permanent plots into seven conservation units that had portions of cerrado sensu stricto vegetation. Applying the linear mixed model to investigate how the diversity distribution pattern and species composition would be related with edaphic factors, climatic, and fire frequency in which the site was treated as random variable in the models. For the analysis of species composition, we used a dataset of occurrence, and we applied an index of extended dissimilarity to obtain the ordered axis in Principal Coordination of Analysis (PCoA). Analyses of simple and partial Mantel were also applied to explore the role of distance in the community structural and abiotic factors. Results: Although in our scale of samples were not possible to identify predictive factors of woody species richness, the composition of species were related with the precipitation gradient and frequency of fire frequency through Cerrado. The edaphic factors do not seem to be determined, and its relative importance should be lower in the fitofisionomy of Cerrado or the studied scale. Though the fire, as a source of disturbance recurrent on Cerrado, has given more significant importance in literature explaining a great part of differences in the vegetation biomass between the fitofisionomy here we are discussing it is important in the species composition modification inside Cerrado sensu stricto, supporting the increase of regional diversity between sites. In this study, we investigate the relation in different environmental gradients and the richness and woody species compositions in Cerrado sensu stricto in the little-explored regional scale in the literature so far about Cerrado Conclusion: In this paper, we investigated the relationship between different environmental gradients and the richness and composition of woody species in Cerrado sensu stricto in the little-explored regional scale in the literature so far. The intensity of fire gradient seems to be determinant to species composition changes, although it does not explain the species richness. This aspect of Cerrado vegetation resume arguments about the role that fire beyond support of its structure and densification.
Questions: How is the diversity pattern and composition of woody species through cerrado sensu stricto? Which abiotic factors structure this species diversity and composition? Location: Brazilian’s central Cerrado region Methodology: We distributed 34 permanent plots into seven conservation units that had portions of cerrado sensu stricto vegetation. Applying the linear mixed model to investigate how the diversity distribution pattern and species composition would be related with edaphic factors, climatic, and fire frequency in which the site was treated as random variable in the models. For the analysis of species composition, we used a dataset of occurrence, and we applied an index of extended dissimilarity to obtain the ordered axis in Principal Coordination of Analysis (PCoA). Analyses of simple and partial Mantel were also applied to explore the role of distance in the community structural and abiotic factors. Results: Although in our scale of samples were not possible to identify predictive factors of woody species richness, the composition of species were related with the precipitation gradient and frequency of fire frequency through Cerrado. The edaphic factors do not seem to be determined, and its relative importance should be lower in the fitofisionomy of Cerrado or the studied scale. Though the fire, as a source of disturbance recurrent on Cerrado, has given more significant importance in literature explaining a great part of differences in the vegetation biomass between the fitofisionomy here we are discussing it is important in the species composition modification inside Cerrado sensu stricto, supporting the increase of regional diversity between sites. In this study, we investigate the relation in different environmental gradients and the richness and woody species compositions in Cerrado sensu stricto in the little-explored regional scale in the literature so far about Cerrado Conclusion: In this paper, we investigated the relationship between different environmental gradients and the richness and composition of woody species in Cerrado sensu stricto in the little-explored regional scale in the literature so far. The intensity of fire gradient seems to be determinant to species composition changes, although it does not explain the species richness. This aspect of Cerrado vegetation resume arguments about the role that fire beyond support of its structure and densification.
Descrição
Palavras-chave
Fogo, precipitação, fatores edáficos, escala regional, gradientes geográficos, Fire, Precipitation, Edaphic factors, regional scale, geographic distribution