El declive de la vegetación acuática en los humedales como respuesta a la degradación ambiental: el caso de la masiega (Cladium mariscus) en Las Tablas de Daimiel y su restauración potencial

Miguel-Ruano, M., Sanchez-Carrillo, S. 2020. The decline of aquatic vegetation in wetlands in response to the environmental degradation: the case of the cut-sedge (Cladium mariscus) in Las Tablas de Daimiel and its potential restoration. Ecosistemas 29(3):1963. https://doi.org/10.7818/ECOS.1963 Wetlands disappear at the rate that their biodiversity does. This study evaluates the causes of the serious decline that the cut-sedge (Cladium mariscus) experienced in Las Tablas de Daimiel National Park (PNTD) wetland, where the population has decreased from 1,100 ha in 1956 to 10 ha in 2019. To do this, we have carried out a comparative study in the La Mancha Humeda Biosphere Reserve, using the PNTD's cut-sedge population and the populations of other wetlands where this macrophyte is not in decline (Laguna del Masegar and Lagunas de Ruidera), which were grown in controlled conditions in the laboratory and later transplanted in PNTD wetland. Differences in C and N content, survival and growth rates, and seed viability and germination capacity indicated that the decline in the PNTD cut-sedge population is related to the hydrological degradation of the wetland, which has caused (i) population aging due to long-term use of clonal reproduction, (ii) a very low colonization of environmental-favorable habitats within the wetland due to a limited dispersion of generative propagules by hydrochory and (iii) a genetic isolation of the population due to the lack of hydrological connection with the other wetlands in the Upper Guadiana river basin. Restoration measures must be immediate, to recover stands in key areas of the wetland with specimens from nurseries and in the medium and long-term to promote the expansion of the cut-sedge to other areas of the wetland ecosystem.