Interception and Redistribution of Precipitation by Parkinsonia aculeata L.: Implications for Palo Verde National Park Wetlands, Costa Rica

Abstract

Seasonal wetlands in the tropics are important habitats for local and migratory bird species. In the northwestern Pacific of Costa Rica, Palo Verde National Park has one of the most important seasonal wetlands of Central America. The management history of this wetland has shown the impact of invasive plant species such as Parkinsonia aculeata L. whose cover extension and canopy structure impact not only the ecological niches of bird species, but also the wetland hydrology. A 300 m2 plot was established in a P. aculeata stand to evaluate the role of P. aculeata on the partitioning and redistribution of precipitation. Gross precipitation (PGr), throughfall (PTF) and stemflow (PSF) were measured on a daily basis to determine the interception of precipitation (PI) and net precipitation (PNet). A total of 43 precipitation events were sampled during the wet season of 2003. We measured 530.5 mm of PGr and 458 mm of PTF, with an average sampling error of 0.7 mm or 6.1%. Canopy storage capacity was estimated at 1.47 mm, throughfall 88.73%, stem flow 2.63% and a total interception of 8.64%, with a PNet coefficient of 0.9475. The relationships between gross precipitation (PGr) with throughfall (PTF), stemflow (PSF) and net precipitation (PNet) were evaluated using linear regression models. P. aculeata showed to have one of the highest net precipitation and lowest precipitation interception among small trees.