Leaf litter decomposition in bamboo, neem and eucalyptus plantations

Abstract

The litter decomposition process regulates the accumulation of organic matter in the soil and the cycling of nutrients, playing an important role in the forest ecosystems maintenance. The objective of this study was to evaluate the decomposition of the leaf fraction in the litter from homogeneous plantations of Bambusa vulgaris, Azadirachta indica, and Eucalyptus urophylla, using as reference an area of seasonal semi-deciduous forest. The study areas are located in the city of Vitória da Conquista, Bahia, Brazil. To evaluate the decomposition, we used the litterbags method, collecting specimens on days 30, 75, 120, 180, 240, and 350. From the results of the remaining mass, we estimated the decomposition constant (k) and the half-life time. The leaf litter was submitted to chemical analyses to determine the contents of carbon, nitrogen, polyphenols, cellulose, and lignin. By the end of one year, more than 65% of the litter from bamboo and Indian neem had decomposed with constants k equal to 0.0033 and 0.0069 g g^-1 day, respectively. The Eucalyptus plantation and the native forest presented a mass loss lower than 50% and k values below 0.0020 g g^-1 day. The leaf litter from bamboo and Indian neem is more prone to decomposition, with rates higher compared to eucalyptus and the native forest, which gives these two species a greater capacity to recycle organic matter and nutrients.

Keywords:
Nutrient cycling; Bambusa vulgaris; Azadirachta indica; Eucalyptus urophylla