Canopy water retention capacity: Comparison between the Atlantic Rainforest and the forest plantation of eucalypt

Abstract

The Atlantic rainforest is one of the most endangered ecosystems of our planet, this area presents only 8% of its original distribution, needs special attention to improve its conservation goals. This study aimed to compare the water retention capacity of the canopy in two watersheds an entirely covered by Atlantic Forest (Rain Forest), located in “Parque Estadual da Serra do Mar” and other covered with Eucalyptus urophylla x Eucalyptus grandis in an adjacent area. Monitoring was carried out in the years of 2008 and 2009 through rain gauges and the water retention of the forest canopy was evaluated from linear regressions between precipitation (PR) and internal elevation (TR). The results showed that, with the exception of interception in the “dry” season that presented the lowest coefficients of determination (R2), being 77% in the eucalypt and 82% in the Atlantic Forest, the variables presented a good fit with the incident precipitation, with higher coefficients of 90%. The Atlantic Forest showed higher retention capacity of water in relation to Eucalyptus, where rainfall lower than 5 mm in the Atlantic Forest and 0.78mm in eucalypt are fully intercepted by the forest canopy and the wet period presented the greatest water retention capacity, probably due to the greater vegetation regeneration at this time, since in the dry period the leaves fall can decrease the retention.