The meadows of helofitic vegetation are very productive biotopes which generate a great amount of dead vegetal material all along their annual cycle. In the wetland of La Nava, previous studies have estimated that the production of this organic matter reached approximately ten tons/ha.. All that vegetation remains accumulated in the wetland, filling in the basin.

That's why it is necessary to take steps to avoid the wetland disappearance. Four ways to control the vegetation will be experimentally studied in this project:

1.- Decapping Photo: Enrique Gómez	2.- Harvesting
3.- Controlled fire Photo: Enrique Gómez	4.- Grazing

The three first methods are realized in a controlled way, once a year, when the wetland is dry during the summer months.The grazing implies the maintenance a small livestock of horses coming from Doñana National Park, specialized in feeding on aquatic vegetation and adapted to live in semi liberty.

The control of the wetland vegetation through grazing, harvesting, decapping and controlled fires of previously selected pieces of ground, will favour, with other methods, the improvement of the quality of habitat of the aquatic warbler, contributing to the reduction of the water eutrophy by excess of vegetal biomass. The project seeks in this way to create spaces of water where could grow submerged aquatic plants very beneficial for the wetland.