Aspects of forest restoration and hydrology: the hydrological function of litter

Although forests play important roles in the hydrological cycle, there is little information that relates the water retention capacity of litter in areas under passive restoration, especially in Cerrado savannas. This study relates litter levels to water holding capacity and effective water retention among forest fragments under different passive restoration stages: 46, 11, and 8 years to better understand litter hydrological functions in the Cerrado. Water retention capacity and effective water retention capacity of litters (unstructured materials, branches and leaves) in the field were monitored on a monthly basis. Total litter accumulation at 46 years was significantly higher than that of the other succession stages. Unstructured litter mass was significantly higher than that of leaves and branches. The 46-year stage had the highest water holding capacity in the leaf fraction, followed by unstructured material and branches. Although the water holding capacity was lower in the oldest restoration, this site showed the highest efficiency under field conditions. The process was quickly reestablished, as the 11-year restoration showed results closer to that for the 46-year stage in comparison to the area at 8 years. Thus, passive restoration plays a key role in soil water maintenance due to the influence of litter in Cerrado savannas. Deforestation and the imminent need of restoring degraded sites, highlight the need for further studies focused on better understanding of the process of forest restoration and its temporal effect on soil water recovery dynamics.