Demography and structures population of Actinostemon concolor (Spreng.) Müll. Arg. (Euphorbiaceae) in flooded areas in Southern Brazil

Abstract

The aim of this work was to analyze the size and spatial structures and demography of Actinostemon concolor (Spreng.) Müll. Arg. (Euphorbiaceae) in the flooded areas of Mata dos Godoy State Park. Fifty plots of 100 m 2 were established and three surveys were conducted. All the individuals were measured, mapped and divided into categories as seedlings, juveniles and adults. The coefficient of skewness, L-function of Ripley, and the matrix population models were used in the study. The population showed positive coefficient of skewness and the individuals were distributed in groups. The population growth rates (λ) were equal or lower than 1.0 and the adult survival and recruitment of juvenile to adult were the vital rates that most affected the values of λ. Considering these results and the unpredictability of the environment, it could be concluded that the individual numbers of A. concolor would fluctuate over time, but the species would remain as one of the most important in the Park.

Native forest metacommunity structures in Uruguay shaped by novel land‐use types in their surroundings

“…The woody understory Actinostemon concolor was registered once in the regeneration layer (Table ). This species was classified as nontolerant to flooding and with high mortality in areas with high cover of herbs and litter (Bianchini et al, 2013). Population of Maytenus dasyclados , also recorded once in the regeneration layer, other studies showed that the species is decreasing in Southern Brazil as a result of anthropogenic fragmentation (Reichmann et al, 2017).…”

Ciências Agrárias: limites e potencialidades em pesquisa - Volume 2

“…A relação positiva da densidade de indivíduos com os terços superiores em ambas as pedoformas pode ser uma resposta direta ao efeito do relevo, visto que as cotas mais elevadas, próximas ao topo, apresentam menor declividade e terreno mais plano (Tabela 5), impondo menos restrições ao estabelecimento das plantas, especialmente aquelas ocasionadas por ação da gravidade. & Monteiro, 2002;Lorenzi, 2009a;Bianchini et al, 2013). Portanto, sua associação forte à pedoforma côncava (as 2 últimas foram encontradas exclusivamente nela) pode ser reflexo da maior disponibilidade de água proporcionada pela curvatura do terreno.…”