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.

Peer reviewed