Miguel Álvarez-Cobelas

Learn More
This study describes the effects of the American red swamp crayfish, Procambarus clarkii Girard, on water quality and sediment characteristics in the Spanish floodplain wetland, Las Tablas de Daimiel National Park. Our short term enclosure study during a summer drawdown revealed that crayfish acted as a nutrient pump that transformed and translocated(More)
The difficulty in advancing in Ecology is due, in part, to the fact that this science uses a mainly qualitative language instead of a more formal or mathematical one. Therefore, many ecologists' efforts are expended in controversies resulting from the vagueness of ecological concepts, for example: stability, equilibrium, ecosystem, community, and so on.(More)
We carried out enclosure experiments to assess the potential deleterious effects of the alien species common carp (Cyprinus carpio L.), mosquitofish (Gambusia holbrookii Gir.), and pumpkinseed sunfish (Lepomis gibbosus L.) on water quality and food web in a severely degraded floodplain wetland, the Spanish National Park Las Tablas de Daimiel. With addition(More)
This study reviews nitrogen export rates from 946 rivers of the world to determine the influence of quantitative (runoff, rainfall, inhabitant density, catchment area, percentage of land use cover, airborne deposition, fertilizer input) and qualitative (dominant type of forest, occurrence of stagnant waterbodies, dominant land use, occurrence of point(More)
Although our understanding of environmental risk assessment in temporary wetlands has been improved by the use of multi-species toxicity testing, we still know little of how landscape variables mediate the strength of, and recovery from, anthropogenic stress in such ecosystems. To bridge this research gap, we provide a theoretical framework of the response(More)
Ecological systems may occur in alternative states that differ in ecological structures, functions and processes. Resilience is the measure of disturbance an ecological system can absorb before changing states. However, how the intrinsic structures and processes of systems that characterize their states affects their resilience remains unclear. We analyzed(More)
In Science we cannot say that `the exception proves the rule'. We have been looking to define patterns in phytoplankton occurrence across trophic spectra where conspicuous covariations between algae and trophic states have been reported. We consider quite different phytoplankton communities observed under similar trophic conditions: we illustrate this point(More)
In this study we compare phytoplankton community similarity between sites in a semiarid floodplain wetland over a 6-year period with variable hydroperiod and connectivity regimes. Phytoplankton communities showed a relatively high site idiosyncrasy during most parts of the study; however, during situations of low connectivity when individual sites were(More)
Wetlands are considered vulnerable ecosystems of both high species richness and socio-economic value. In semi-arid regions, these ecosystems often experience long drought periods that are usually aggravated by local water overexploitation. Drought leads to: (i) reduced flooding area, (ii) isolation of water bodies, (iii) increased areas of dry sediments and(More)
This study describes the long-term changes of spatial patterns of cut-sedge (Cladium mariscus) and common reed (Phragmites australis) in the Spanish floodplain wetland Las Tablas de Daimiel. Using seven sets of aerial photographs, we determined changes in their spatial patterns (size of patches) between 1945 and 2001 that resulted from combinations of(More)