Litterfall Assessement in a Fragment of Secondary Tropical Forest, Ibiúna, Sp, Southeastern Brazil1

Abstract

-The present study aimed to analyze the production and decomposition of litterfall in a fragment of secondary Atlantic forest in the region of Ibiúna, SP, from April 2012 to March 2013. The litterfall production was estimated by 30 collectors distributed randomly in an area of 1000 m 2 , where the deposited material was collected every 15 days. The decomposition of litterfall was estimated through the mass loss in the period of study. After collecting, the material was dried in an oven at 65 °C for seven days to achieve a constant weight. The decomposition constant k was obteined according to Shanks and Oslon (1961) and the time for 50% and 95% of decomposition was estimated. It was found a higher litterfall production in October (454.3 kg ha -1 ) and lower production in July (164.9 kg ha -1 ), with a total amount produced of 3.5 Mg ha -1 year -1 . A delay of one month in the precipitation and relative humidity showed great influence in the litter production during the study. The decomposition rate (k) was 3.1 and the time to decompose 50% of the material was estimated in 2 and ½ months and for 95% of the litterfall the time was estimated in 11 and ½ months. The production and decomposition values of this work are within the range found in other sites of secondary tropical forests.Keywords: Decomposition; Tropical forest; Plant-soil interaction.AVALIAÇÃO DA SERAPILHEIRA NUM FRAGMENTO DE FLORESTA SECUNDÁRIA TROPICAL, IBIÚNA, SP, SUDESTE DO BRASIL RESUMO -Este estudo teve como objetivo analisar a produção e decomposição de serapilheira em um fragmento de Mata Atlântica secundária na região de Ibiúna, SP, durante abril de 2012 a março de 2013. A produção de serapilheira foi estimada por meio de 30 coletores distribuídos aleatoriamente em uma área de 1.000 m 2 , onde o material depositado foi coletado quinzenalmente. A decomposição da serapilheira foi estimada por meio da perda de massa no período do estudo. Após a coleta, o material foi seco em forno a 65 °C, durante sete dias, para atingir peso constante. A constante de decomposição (k) foi obtida de acordo com Shanks e Oslon (1961), sendo, em seguida, calculado o tempo para decomposição de 50% e 95% do material. Foi encontrada maior produção de serapilheira em outubro (454,3 kg.ha -1 ) e menor em julho (164,9 kg.ha -1 ), com uma quantidade total produzida de 3,5 Mg.ha -1 .ano -1 . A precipitação com atraso de um mês e a umidade relativa do ar mostraram grande influência na produção de serapilheira durante o estudo. A taxa de decomposição (k) foi de 3,1 e o tempo de decomposição, de 50 e 95% do material, estimado em dois meses e meio e 11 meses e meio, respectivamente. Os valores de produção e decomposição deste trabalho estão dentro da faixa encontrada em outros sítios de florestas tropicais secundárias.

Soil fertility and litterfall assessment in a peri-urban forest of São Paulo, SP: understanding for urban green areas manegement

“…The litterfall curve found in this work was similar to the some other authors who studied in areas of primary and secondary Atlantic forests, including an urban forest of São Paulo (Pereira et al, 2008;Menezes et al, 2010;Ferreira et al, 2014a;Ferreira and Uchiyama, 2015). The few works involving litterfall production in urban and peri-urban areas of the brazilian cities, especially those located in the Atlantic Forest biome, limits a greater understanding of the possible impacts that the metropolitan region of São Paulo might have in the dynamics of leaf litter.…”

“…However, it is possible to infer that atmospheric pollution coming from São Paulo are reaching Curucutu nucleous, thus interfering in phenological processes (Kraepiel et al, 2015). Ferreira and Uchiyama (2015) studied the litter in a secondary forest near the metropolitan region of São Paulo and found a similar trend to the present study, but with a strong influence of the rainfall and relative humidity on litterfall production. The authors suggested a possible hormonal response as a key factor for the leaves fall early in the season with the highest rainfall rates, probably triggered by decreased soil water availability (Zalamea and González, 2008;Menezes et al, 2010).…”

“…This value of decomposition constant was lower than the values found in other studies in the Atlantic Forest. Arato et al, (2003) found a decay constant of 1.17 in an agroforestry system deployed in degraded area in Viçosa -MG. Ferreira and Uchiyama (2015) found k value of 3.1 for a secondary forest in Ibiúna, SP, and for 50% and 95% of the litterfall decomposition the authors found 2.58 and 11.28 months, respectively. Ferreira et al (2014a) found k = 0.0027 for an urban forest in São Paulo and Pereira et al, (2008) found k = 0.0023 in a fragment of the Atlantic forest.…”

Soil Biodiversity in Urban Forests as a Consequence of Litterfall Management: Implications for São Paulo’s Ecosystem Services

“…Only the upper layer of litterfall was sampled, without rotating any portion of the O horizon, i.e., the top, organic layer of soil, made up mostly of leaf litter and humus, or living roots. The sampled material was stored in separate plastic bags and properly identified with number, date and site and taken to the laboratory for analysis [9].…”

“…The largest fraction of litterfall in tropical regions consists of leaves, accounting for approximately 70% of the organic matter returned to the forest soils [9].…”