Rainfall Partitioning in Amazon Forest: Implications of Reduced Impact Logging on Litter Water Conservation

Abstract

This study aimed to investigate how sustainable forest management can affect litter hydrological properties. We investigated the net precipitation, litter mass, water-holding capacity, effective water-holding and retention capacity, maximum water retention and water content in unlogged and logged forests over 13 months in the Amazon Forest, where reduced-impact logging is allowed. The mean litter mass was similar for unlogged and logged forests. The litter water-holding capacity was 220% for unlogged and 224% for logged forests, and for fractions followed: unstructured > leaves > seeds > branches for both forests. The effective water-holding capacity was 48.7% and 49.3% for unlogged and logged, respectively, and the effective water retention was 10.3 t·ha−1 for both forests. The effective water retention in the rainy and dry seasons accounted for 12.5 t ha−1 and 7.2 t ha−1 for unlogged and logged, respectively. The maximum water retention was slightly greater for logged forests (16.7 t ha−1) than unlogged (16.3 t ha−1). The litter water content had 40% less water in the dry season than in the rainy in both forests. In general, there were no significant differences in litter storage and hydrological properties between stands. This suggests that reduced-impact logging did not significantly affect the hydrological dynamics of the litter layer in the Amazonian forests studied.

Keywords

• forest hydrology
• logging concessions
• reduced-impact logging
• selective logging
• stemflow
• Jamari National Forest