Carbon dynamics of nitrogen and phosphorus on the aquatic and terrestrial interface of the Leyre catchment area (supervised by Gwenaël Abril of the EPOC in partnership with ISPA).
This project focuses on biogeochemical transfers across catchment areas and exchanges of major elements between the atmosphere, vegetation, soil, and aquatic environments. More specifically, it aims to study the behaviour of carbon, nitrogen, and phosphorus (CNP) in one of the least well-documented catchment area interfaces: the soil-water-river transition zone. Proposing teams have complementary skills in agriculture, forestry, and water and also share knowledge about the Leire catchment area. This study area has the advantage of relative lithological and hydrological homogeneity and land is almost exclusively shared between pine forest, corn monoculture and riparian vegetation. The study is based on two interrelated and complementary strategies:
(1) very detailed sampling of soil, ground water, and alluvial aquifer (Plio-Quaternary aquifer), water and sediment in ditches and rivers covering all conditions in the Leyre catchment for chemical and isotopic analysis and in situ or laboratory experiments to study in detail CNP flow control at the land / water interface. We will also establish statistics of exportation by water systems, identifying that which comes from agricultural (according to the level of fertiliser) and forest (according to their age and management type) plots.
(2) In parallel, we will develop the existing database in the form of geographic information system of the Leyre catchment area before conducting exploratory modelling work on CNP transfer processes from the atmosphere to vegetation, soil, and into the aquatic environment. This model will be based on field data acquired during the project and will be used to upgrade hydrobiogeochemical models such as the STEPS model to simulate surface water quality according to different climate change and land use scenarios.