Aproximación a las comunidades de carófitos que existieron en la Albufera de Valencia a partir del estudio de las oósporas del sedimento

Abstract

Aproximación a las comunidades de carófitos que existieron en la Albufera de Valencia a partir del estudio de las oósporas del sedimento L. papulosum). Esta última, indicadora de la época en la que la laguna poseía una mayor salinidad, se encontró en las capas más profundas del sedimento. Se ha observado un aumento del número y de la diversidad de oósporas en capas más profundas del sedimento, lo que indica, por un lado, que la laguna atravesó distintas fases ecológicas (con importantes cambios de salinidad principalmente) y, por otro, que el proceso de eutrofización que padece la laguna durante al menos los últimos 45 años afectó progresivamente a la abundancia y diversidad de carófitos.Palabras clave: Carófitos, oósporas, la Albufera, Valencia, España, Chara, Nitella, Tolypella, Lamprothamnium. Charophyte oospores and their features (size, shape, colour, outer wall ornamentation, etc.) are able to persist in seed banks of aquatic ecosystems. Thus, these characteristics can be used for taxonomic species identification, thereby providing knowledge about the specific composition of the charophyte community in a habitat that currently lacks, or has greatly altered, submerged vegetation. Several years ago, l'Albufera de Valèn-cia lost the charophyte meadows that covered the lake bottom in the past, which had never been studied in detail. Several sediment cores were extracted from the lagoon at three sites and the oospores and gyrogonites were isolated and characterized. The oospore/gyrogonite densities in the sediment layers were estimated. L. papulosum). The latter, which indicates the period when water salinity was high in the lagoon, was found in the deepest sediment layers. An increase in the oospore abundance and diversity was observed in line with sediment depth. This indicates, on the one hand, that the lagoon went through different ecological stages (with important changes in salinity, mainly) and, on the other hand, the eutrophication process that the lagoon has been undergoing for at least the last 45 years, has progressively affected the abundance and diversity of the charophyte community.

Ostracod palaeolimnological analysis reveals drastic historical changes in salinity, eutrophication and biodiversity loss in a coastal Mediterranean lake

“…The study of L'Antina core settled the question on the timing of the main salinity changes. We have shown that the transformation of a brackish to an oligohaline lagoon is much more recent than other authors proposed (Robles et al, 1985;Rodrigo et al, 2009;Sanjaume et al, 1992). Ostracod paleointerpretations clearly indicated a previous brackish stage (before ad 1850) that changed to a freshwater environment to the top of this core (Figure 7).…”

“…The Albufera of Valencia, one of the largest lagoons in the Mediterranean coast of the Iberian Peninsula has experienced important alterations due to changes in the socio-economic structure and land uses in its heavily populated surroundings in historical times, namely a decrease in salinity revealed by diatom, charophyte and mollusc remains (Margalef and Mir, 1973; Robles et al, 1985; Rodrigo et al, 2009; Soria, 2006) and an increase in trophic level (Vicente and Miracle, 1992), although the time frame for the strongest salinity changes is still lacking precision. Data on the ostracod fauna of the lake is scarce, with the exception of the work by Poquet et al (2008), where living populations were not found on top of sediment samples in Albufera of Valencia, but shell remains indicated a past rich ostracod palaeoassemblage.…”

In Memoriam Maria Rosa Miracle. Limnologist

“…The different waterscapes over the centuries have reflected the identities, ideas and technologies of the dominant stakeholders, and can be conceptualized as different "médiances", each of them attached to a particular water management system and to different forms of governance (Sanchis-Ibor et al, 2008). From Antiquity until the 17 th century, the Albufera was a large brackish lagoon (Rodrigo et al, 2009;Marco-Barba, 2009), connected to the sea through a regulated 200 m wide inlet. The spectrum of fluctuations of the water table was controlled by the local fishing community, closing and opening the inlet and artificially introducing water from the Xúquer and Túria rivers when it was necessary to raise the water level .…”

“…The lagoon came to be supplied exclusively with abundant fresh water through irrigation channels from the rivers, primarily from the Acequia Real del Júcar. Salinity decreased, and the wetland became an oligotrophic freshwater lagoon Rodrigo et al, 2009;Marco-Barba, 2009). 102 Small polders (the so-called tancats) were built to drain the lands located below the lagoon water level (5 200 hectares).…”

Girogonitos de carofitas en el Parque Nacional de Doñana: Su registro en sedimentos pleistocenos y holocenos

“…Este amplio rango ecológico ha sido puesto de manifiesto en medios acuáticos muy dispares de diversas regiones de España (p.e. Aboal, 1985;Cirujano et al, 2007;Rodrigo et al, 2009;López et al, 2022). En Doñana, se ha citado en las lagunas temporales de los sistemas dunares tanto estables como móviles, asociada a aguas carbonatadas y salinas (Florencio et al, 2014).…”