Research topics

LTER

We monitor a number of biogeochemical and biodiversity variables in atmospheric deposition, lakes and streams in several experimental catchments of the Central Pyrenees. Our aim is to reveal environmental changes that, because the remoteness of our study sites, are a reflection of global change. Multi-decadal data series allow us to detect early indications of change and to establish the causal links.

Palaeolimnology

A number of sediments cores retrieved from different lakes have allowed us to reconstruct climate and human influence on remote mountain lakes and surrounding ecosystems during the last 15,000 years. In the current context of global change, mountain lake sediments contain an invaluable information on postindustrial changes that can be benchmarked against early, predisturbance, intervals. The palaeolimnological reconstructions allow us to extend our contemporary observations back in time, and offers a reference to assess the importance of present day changes.

Atmospheric N deposition

Humans have dramatically disturbed the earth's N cycle to the point that this alteration is considered one of the most serious threats to the global ecosystem. Part of the excess N circulates through the atmosphere and is deposited with precipitation, reaching areas that would otherwise be free of direct human impact. Atmospherically deposited N has an acidifying effect on aquatic ecosystems, and causes also changes in the pattern of ecological nutrient limitation in lakes. Pyrenean catchments are saturated of N of human origin and streams are leaching that N excess.

Lead pollution

Mining and smelting have been a source of lead atmospheric pollution since ancient times. Atmospheric lead may travel long distances before it is deposited on remote ecosystems like alpine lakes. A sediment core retrieved in Lake Redon revealed that lead pollution started here already 2,700 years ago, and peaked in the VII century. Further studies have shown a widespread contamination in sediments from lakes accross the Pyrenees. And moreover, there is a lead legacy stored for centuries in soils that is been leached nowadays causing a delayed pollution to lakes.

Regional limnology

The Pyrenees hold a lake district with a few more than one thousand alpine lakes. Lithological, climatic, and altitudinal gradients have an effect on the physics, chemistry and biology of the lakes. Several surveys, carried since 1987 at decadal intervals, have provided a synoptic picture of the variability in the Pyrenean limnology and revealed the major time trends caused by the diverse environmental drivers at a regional scale.

Free business joomla templates