2008-2009
Conselh Generau d’Aran
Carrillo Ortuño, Amparo (IP). Batriu Vila, Efrem. Ninot Sugrañes, Josep M.. Pérez Haase, Aaron.


Ecological study of fens in the Aran valley (central Pyrenees)

The landscape of the Aran valley includes a good representation of the Pyrenean fen communities, which include a large number of plants particular of Boreo-alpine and Atlantic fens and bogs.

These hygrophytic plant communities lay along complex environmental gradients, which have beed mainly studied in northern Europe. Some of these studies have emphasized the role played by the water mineralization, the flooding regime, and the availability of some nutrients (N, Ph) in the space distribution of the fen species.

Our project in the Aran valley is aimed to study the environmental gradients driving the plant distribution. To this end, we seek at the relationships between fen communities, and physic-chemical variables. The field work is centred into a dozen of fen systems scattered on the Aran landscape. In each system, we take vegetation relevés and perform analyses of the plant communities found.

In each study plot, we record a vegetation relevé and take water and peat samples to perform chemical analyses: water conductivity, pH, and cations (mainly Ca); forms of N in the peat; etc. Moreover, we record the depth of the water table at the end of July, and the development of the histic horizon.
Together with the environmental data, our study gathers a thorough sampling of the flora (vascular plants and bryophytes) and the vegetation units of the main fen systems of the Aran valley.

The data sets yielded are analyzed by means of multivariate statistical tools, to obtain groups (clustering) and ordinations (correspondance analyses, etc.).These methods are useful in the detection of the main variables driving the species composition of the fen communities, and lead to new proposals in their ecological classification.


Research field:
Ecology of plant communities


Project results: