Effect of seasonal flooding cycle on litterfall production in alluvial rainforest on the middle Xingu River (Amazon basin, Brazil)

M Camargo,Ajs Jesus,T Giarrizzo

doi:10.1590/1519-6984.00514bm

Abstract

The assumption for this study was that litterfall in floodplain environments of the middle Xingu river follows a pattern of seasonal variation. According to this view, litterfall production (total and fractions) was estimated in four alluvial rainforest sites on the middle Xingu River over an annual cycle, and examined the effect of seasonal flooding cycle. The sites included two marginal flooded forests of insular lakes (Ilha Grande and Pimentel) and two flooded forests on the banks of the Xingu itself (Boa Esperança and Arroz Cru). Total litterfall correlated with rainfall and river levels, but whereas the leaf and fruit fractions followed this general pattern, the flower fraction presented an inverse pattern, peaking in the dry season. The litterfall patterns recorded in the present study were consistent with those recorded at other Amazonian sites, and in some other tropical ecosystems.

Highlights

Litterfall in a forest ecosystem is constituted of all the organic material, including leaves, twigs, flowers, fruits, bark, and other plant parts, that fall to the forest floor (Randazzo et al, 2006)
The present study was conducted on a 180 km stretch of the middle Xingu River in Pará, in the eastern Brazilian Amazon basin (Figure 1)
In a semi-deciduous forest in southeastern Brazil, Dias and Oliveira Filho (1997) recorded a pattern similar to that observed in the present study, that is, a higher rate of litterfall during the rainy season, when the hydrological deficit was at its lowest

Summary

Introduction

Litterfall in a forest ecosystem is constituted of all the organic material, including leaves, twigs, flowers, fruits, bark, and other plant parts, that fall to the forest floor (Randazzo et al, 2006) This material functions primarily as a route for the transfer of nutrients from vegetation to the soil, maintaining its fertility, which is essential for the sustainability of forest systems (Sayer and Tanner, 2010; Ge et al, 2013; Silver et al, 2014; Zhang et al, 2014). Figueiredo Filho et al (2003) concluded that the litter found in a forest ecosystem is an index of its reproductive capacity, balancing the availability of nutrients with the ecological requirements of the species found in the forest

Methods

Results

Conclusion