The role of charophytes in a Mediterranean pond created forrestoration purposes

Autores UPV


tA small, shallow basin was created and flooded with groundwater in a Reserve Area in Albufera deValència Natural Park (AVNP) under the scope of a restoration program intended to mimic typical envi-ronments such as freshwater springs, abundant in the past but currently suffering from deterioration(desiccation, pollution, etc.), with the ultimate goal of increasing local biodiversity of submerged macro-phytes, particularly charophytes. In this study we have monitored, from April 2009 (a few months afterits first flooding) to September 2012, the dynamics of charophyte growth and related physical, chem-ical and biotic variables to highlight the factors determining charophyte success. Just after flooding,five charophyte species grew spontaneously when oospores germinated in the sediments. Chara hispidapopulations largely dominated the community and developed dense meadows that covered virtuallythe entire pond floor. Charophytes exerted a negative influence on phytoplankton densities, increasingwater transparency. C. hispida stands precipitated substantial CaCO3in the form of incrustations on theplants, accompanied by coprecipitation of inorganic phosphorus, maintaining low concentrations of sol-uble P in the water. Reduced groundwater inflow, increased salinity, nutrient concentration, turbidityand augmented feeding pressure by waterfowl, separately or by synergistic effects, considerably reducedcharophyte development during the final year of the study; however, charophytes still represent one ofthe most extensive and dense stands of submerged vegetation within AVNP, verifying the achievement ofthe goal of the restoration plan. The knowledge obtained has allowed us to recommend several measuresto counteract the decrease of charophytes, which can also be applied in other regions affected by the same stressors