0000000000177348
AUTHOR
María Sahuquillo
Relaciones entre las aportaciones a la zona regable del río Jucar y la conductividad de la Albufera de Valencia.
Las aportaciones a la zona regable del río Júcar condicionan la conductividad de la Albufera porque recibe las aguas sobrantes de riego. Se ha observado una relación inversa entre ambas variables. La demanda de agua para otras zonas pretende satisfacerse a partir del trasvase de los sobrantes de riego basándose en una mejora de la eficiencia del regadío. Estas actuaciones deben realizarse sólo cuando se aseguren previamente las aportaciones necesarias para mantener la calidad del lago. The water inflows to the irrigation area of the Júcar river determine the conductivity of the Albufera because it receives the surplus irrigation water. It has been observed an inverse relationship between bo…
The role of historic and climatic factors in the distribution of crustacean communities in Iberian Mediterranean ponds
SUMMARY 1. We studied 140 freshwater ponds in eastern Spain spanning a wide range of water source, hydroperiod and regional heterogeneity attributable to orographic and climatic differences. Our aim was to provide a typology for Mediterranean ponds using crustacean assemblages and to find key environmental thresholds that define these pond types. 2. To search for the environmental variables that define these communities, two complementary analyses were used: correspondence analyses (CA) and multivariate regression trees (MRT). We found a high level of specificity of crustaceans defining the different pond types. Three ponds, which were not associated with any of the large set of environment…
Increase of rotifer diversity after sewage diversion in the hypertrophic lagoon, Albufera of Valencia, Spain
The Albufera of Valencia is a large oligohaline hypertrophic lagoon, regulated by sluice gates according to the needs of the surrounding rice field cultivation. It is in a turbid state with permanent cyanobacterial blooms. A slight improvement was detected after diversion in the 1990s of part of the sewage flowing into it. After sewage diversion, we found that: (1) Chlorophyll concentration and rotifer densities decreased; (2) Rotifer proportions declined, due mainly to a relative increase in cladocerans; (3) Rotifer diversity increased. The two dominants of the 1980s, Polyarthra spp. in the colder period and Brachionus angularis in the warmer one, reverted after sewage diversion to a more …
Residence Time Analysis in the Albufera of Valencia, a Mediterranean Coastal Lagoon, Spain
The Albufera of Valencia is a coastal lagoon located in the western area of the Mediterranean Sea, in the Iberian Peninsula. It has an area of 23.1 km2 and an average depth of only 1 m, with a maximum depth of 1.6 m. This lagoon is the remnants of an original and more extensive wetland of about 220 km2 which is now mostly dedicated to rice cultivation. Surface water is supplied through several main and many secondary canals for a total of 64 water entry points and three exit points to the sea. It is difficult to evaluate the residence time due to the lack of reliable measurements of the inflow or outflow, as well as continuous measurements. Between 1988 and 2018, several procedures were use…
Metacommunities from bacteria to birds: stronger environmental selection in mediterranean than in tropical ponds
AbstractThe metacommunity concept provides a theoretical framework that aims at explaining organism distributions by a combination of environmental filtering, dispersal and drift. With the development of statistical tools to quantify and partially isolate the role of each of these processes, empirical metacommunity studies have multiplied worldwide. However, few works attempt a multi-taxon approach and even fewer compare two distant biogeographical regions using the same methodology. Under this framework, we tested the expectation that temperate (mediterranean-climate) pond metacommunities would be more influenced by environmental and spatial processes than tropical ones, because of stronge…
Macroinvertebrate communities in sediment and plants in coastal Mediterranean water bodies (Central Iberian Peninsula).
Sediment and plant-associated macroinvertebrates were sampled in six shallow water bodies along the central part of the coast of Mediterranean Spain. The size of ponds, salinity and hydroperiod were highly variable. Seventy-one taxa were recorded, some of them were endemic or uncommon species, evidencing the important contribution of these ponds to biodiversity. Crustaceans and gastropods of biogeographical interest were found in the most primeval site. Correspondence analysis showed that macroinvertebrate assemblages responded to environmental variables such as salinity, temporality and eutrophication. The brackish water fauna was dominated by crustaceans, while oligochaeta and insect larv…
Nutrient dynamics in water and sediment of Mediterranean ponds across a wide hydroperiod gradient
Abstract In Mediterranean ponds, summer drought enhances seasonality whose intensity varies along topographic and climatic gradients. The alternation of wet and dry periods in rain dependent ponds affects their biogeochemistry and differentiates them from ponds fed by more stable water sources, such as groundwater springs. Superimposed onto this, land use is also a very strong factor of variability. In this study we compared nutrients and organic matter concentrations, in water and in sediment, among different types of Mediterranean ponds based on the source of water, hydroperiod and land use. Forty-three ponds were sampled in Eastern Spain corresponding to five pond types: (1) permanent sp…
Response of a shallow Mediterranean lake to nutrient diversion: does it follow similar patterns as in northern shallow lakes?
Summary 1. In view of the paucity of data on the response of warm shallow lakes to reductions in nutrient loading, this paper presents a long-term limnological data set to document changes in the food-web of a shallow Mediterranean lake (Lake Albufera, Valencia, Spain) that has experienced reductions in phosphorus (P) (77%) and nitrogen (N) (24%) loading following sewage diversion. 2. Nine years after sewage diversion, P concentration in the lake was reduced by 30% but remained high (TP = 0.34 mg L−1), although the mean water retention time in the lake was only 0.1 years. Nitrate concentrations did not significantly change, probably because the lake continued to receive untreated effluents …