Surface waters monitoring in the LTER-Aigüestortes node: trends and indicators of the impacts of N and S atmospheric deposition

Abstract

Camarero,  L.,  Aniz,  M.  (2010).  Surface  waters  monitoring  in  the  LTER-Aigüestortes  node:  trends  and  indicators  of  the impacts of N and S atmospheric deposition. Ecosistemas 19(2):24-41.

In 2008, the node LTER-Aigüestortes was created in the Aigüestortes i Estany de Sant Maurici National Park. Several groups with a long record of previous research are involved in the node. In this paper, we present the activities of the whole node in brief, and the monitoring programme for the quantity and quality of surface waters in more detail. Some results from the monitoring are also presented, regarding the effects of the deposition of anthropogenic N and S on the biogeochemical dynamics of the monitored catchments. The results show the increase in the N deposition during the last decade, and how the streams reflect such an increase and indicate that the catchments are N saturated.  In  contrast,  lakes  do  not  necessarily  follow  this  trend,  and  act  as  bio-reactors  which  eliminate  N  out  of  the  cycling  in  the catchment.  Regarding  S,  there  is  a  decoupling  in  the  trends  of  emissions,  deposition  and  chemistry  of  lakes  and  streams.  This  can  be interpreted as a delayed response to the reduction in emissions and deposition due to the effect of soils in the catchment.