Evaluación de la lixiviación de nutrientes en la cuenca de páramo andino del río Zhurucay

Abstract

Due to the importance of nutrient cyclefor the integrity of ecosystems in general, the lack of knowledge about their relation in hydrology in the paramo and the importance of this ecosystem in the Andean Region, leaching evaluation of total organic carbon (TOC), nitrite (NO2-N), nitrate (NO3-N), ammonium (NH4), and total phosphorus (P) was conducted in rainfall, runoff, and organic and mineral soil layers of Andosols and Histosols. The study was carried out in the basin of the Zhurucay River (7.53 km2) in southern Ecuador above 3000 m.a.s.l. The water samples were taken fortnightly from October of 2012 until October of 2013. Results suggest seasonal independence in precipitation for all the elements studied, discarding effects of dilution. Different leaching of TOC and NH4 leaching between soils was identified, whereas only TOC showed in their layers a variation of the concentration due to the seasonal variation and the high content of organic matter. Leaching of P and TOC in discharge could be associated with the soil distribution in the basin. The results of this study allow a better understanding of the leaching process of nutrients in the paramo and of their average concentrations.