Litter fall consists of all organic material deposited on the forest floor, being of extremely important for the structure and maintenance of the ecosystem through nutrient cycling. This study aimed to evaluate the production and decomposition of litter fall in a secondary Atlantic forest fragment of secondary Atlantic Forest, at the Guarapiranga Ecological Park, in São Paulo, SP. The litter samples were taken monthly from May 2012 to May 2013. To assess the contribution of litter fall forty collectors were installed randomly within an area of 0.5 ha. The collected material was sent to the laboratory to be dried at 65 °C for 72 hours, being subsequently separated into fractions of leaves, twigs, reproductive parts and miscellaneous, and weighed to obtain the dry biomass. Litterbags were placed and tied close to the collectors to estimate the decomposition rate in order to evaluate the loss of dry biomass at 30, 60, 90, 120 and 150 days. After collection, the material was sent to the laboratory to be dried and weighed again. Total litter fall throughout the year reached 5.7 Mg.ha-1.yr-1 and the major amount of the material was collected from September till March. Leaves had the major contribution for total litter fall (72%), followed by twigs (14%), reproductive parts (11%) and miscellaneous (3%). Reproductive parts had a peak during the wet season. Positive correlation was observed between total litter and precipitation, temperature and radiation (r = 0.66, p<0.05; r = 0.76, p<0.05; r = 0.58, p<0.05, respectively). The multiple regression showed that precipitation and radiation contributed significantly to litter fall production. Decomposition rate was in the interval expected for secondary tropical forest and was correlated to rainfall. It was concluded that this fragment of secondary forest showed a seasonality effect driven mainly by precipitation and radiation, both important components of foliage renewal for the plant community and that decomposition was in an intermediate rate.
RESUMOAs florestas urbanas desempenham importante papel na dinâmica da comunidade em áreas urbanas. Além disto, estas áreas verdes são importantes componentes da paisagem que atenuam os efeitos da poluição atmosférica e sonora. Sendo assim, este trabalho teve por objetivo avaliar a ciclagem de nutrientes na interação solo-planta num fragmento de uma floresta urbana Atlântica. A área de estudo foi delimitada em uma parcela de 50 m X 100 m, onde foram distribuídos, para a análise de serapilheira, 40 coletores (litter traps) medindo 55 cm de diâmetro e 30 sacolas de decomposição (litter bags). Amostras de solos foram coletadas por meio de trincheiras estabelecidas na área. O material de serapilheira e as amostras de solo foram analisadas quimicamente quanto ao conteúdo nutricional. Observou-se que a produção de serapilheira foi maior em outubro. A taxa de decomposição se mostrou mais acentuada nos primeiros meses de exposição do material. A contribuição nutricional apresentou-se dentro dos padrões encontrados na literatura no que se refere a florestas tropicais. Em relação aos solos, os resultados obtidos mostraram uma grande disponibilidade de todos os elementos minerais estudados na camada 0-10 cm. A relação entre os nutrientes indicou rápida taxa de decomposição no sítio de estudo. Sugere-se que o solo estudado apresenta uma alta taxa de decomposição, pois a ciclagem desses nutrientes está ocorrendo de forma rápida e eficiente para a manutenção da floresta. PALAVRAS-CHAVE:Mata Atlântica, Parque Ecológico Guarapiranga, Ciclagem de nutrientes, Solo. NUTRIENT CYCLING IN A URBAN FOREST OF SÃO PAULO CITY, SP ABSTRACT
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.