Santos Cirujano

Hydrological and botanical man-made changes in the Spanish wetland of Las Tablas de Daimiel

Man-made change in wetland ecosystems is mainly a 20th century process. Here, we report the changes over the last 55 years in the hydrology and botany of a Spanish semi-arid wetland, Las Tablas de Daimiel, a Ramsar site and a National Park. The landscape is valuable because of interesting waterfowl and plant species (particularly, Netta ruffina and Cladium mariscus) brought about by the fluctuations in water table arising from the interaction of surface flooding due to stream- and groundwater discharges and water retention by watermill dams. However, drainage reduced the wetland area to one seventh of its original value in 8 years between 1965 and 1973, and watermills were destroyed in the 1960s. Water pollution, mainly organic matter, nitrogen and phosphorus, coming from point (towns and agroindustry) and non-point sources (agricultural practices in the watershed) started in the late 1970s and peaked by the middle of next decade, decreasing later as a result of newly-implemented, water treatment plants in the catchment area. Water availability was reduced greatly between the late 1970s and the 1990s because of irrigation programs in the catchment area, which exhausted the groundwater aquifer, and their effects on plants were mediated by decreasing yearly average flooding and its variability. The combined effect of increased eutrophication and decreased water inputs reduced the Cladium cover 10-fold, reduced the extent of Charophyte meadows and three quarters of hydrophyte species were lost. The reed (Phragmites communis) cover increased 22-fold. Later, a sudden increase in water inputs coming from a nearby aquifer raised the number of hydrophytes and the Cladium cover, and reduced the reed cover. Thus, decreases in water quantity and quality have acted together on wetlands over the last 35 years affecting plant species richness and cover. Wetland survival is endangered if no remedial actions, such as those we propose, are implemented.

Las lagunas del Campo de Calatrava (Ciudad Real)

; En 1948, PARDO inventario 52 charcas y lagunas del Campo de Calatrava (Ciudad Real, Espana). En la actualidad la mayoria de ellas se encuentran desecadas o en vias de ello. Presentamos en este trabajo, la descripcion fisica, de la vegetacion acuatica, y de las caracteristicas de las aguas, de las que todavia se conservan.

Microinvertebrate and plant beta diversity in dry soils of a semiarid agricultural wetland complex

The relationship between environmental features and the β diversity of the propagule bank of dry soils of temporary wetlands has relevance to ecological theories of community structure and to the conservation of wetland biodiversity. The correlation of β diversity of microinvertebrates and macrophytes derived from propagules in dry soils with wetland habitat characteristics, catchment land-use, and the distance between wetlands in a remnant pond complex in central Spain was assessed. Redundancy analyses showed that β diversity of both groups correlated with habitat characteristics, whereas associations with catchment agricultural practices were weaker. Nestedness analyses showed that species-poor communities from degraded sites tended to form nested subsets of less degraded ponds with higher species richness. Distance between the ponds had no significant association with community similarity, suggesting that fragmentation did not shape β diversity at the scale of our study area. To maintain high β diversity in this area, ponds with species-rich propagule banks should receive conservation priority. Given the functional dependence by much wildlife on these propagule banks once these wetlands rewet, conservation of this hidden biodiversity is crucial for providing ecosystem services to humans and wildlife.

Feeding Preference of the Red Swamp Crayfish Procambarus clarkii (Girard) on Living Macrophytes in a Spanish Wetland

ABSTRACT We carried out field studies and laboratory experiments to investigate (1) the possible feeding preference of the red swamp crayfish Procambarus clarkii on living macrophytes, and (2) the influence that such a feeding preference can cause on the distribution and bundance of P. clarkii in wetland systems. Field studies, at two sampling areas of the Spanish wetland Tablas de Daimiel National Park (TDNP), showed that P. clarkii had significantly higher mean values of density and biomass at S-2 (with Char a hispida as the dominant macrophyte) than at S-1 (with Ceratophyllum submersum as the dominant macrophyte). Laboratory experiments showed that P. clarkii had a significant feeding preference for C. hispida versus C. submersum. Analyses of the biochemical composition of each macrophyte species showed that the unpreferred macrophyte (C. submersum) had higher amounts (per unit of biomass) of total protein, nitrogen, phosphorus, sodium, potassium, magnesium and phenolic compounds than the preferred macrophyte (C. hispida). By contrast, C. hispida had more calcium per unit of biomass than C. submersum. Overall, we conclude that the presence of higher amounts of phenolic compounds in C. submersum might be the foremost factor responsible for the observed feeding preference of P. clarkii on living macrophytes in TDNP.

Effects of invasive fish and quality of water and sediment on macrophytes biomass, and their consequences for the waterbird community of a Mediterranean floodplain

Floodplains are among the most threatened ecosystems world-wide because of multiple stressors, i.e., invasive species, pollution and aquifer overexploitation; the Tablas de Daimiel National Park (Spain) is a clear example of these kinds of impact. This work aims to test whether invasive fish and/or the water and sediment quality are significant drivers of the decline of stonewort (Chara spp.) meadows in the Tablas de Daimiel, investigating how this could explain changes observed in the waterbird community. Bird surveys performed monthly between June 2010 and April 2014 have shown that herbivorous species like the red-crested pochard (Netta rufina) reached historical records between September 2010 and June 2011, but have decreased since then. Piscivorous waterbirds like the great cormorant (Phalacrocorax carbo) and herons increased in population after 2011, however. These changes may be due to the decline of Chara spp. meadows, connected to overexploitation by herbivores, or to changes in water and sediment quality. To test this hypothesis, we studied the growth of Chara spp. biomass in ten sites of the Tablas de Daimiel, where experimental exclosures were set up to exclude herbivory by birds, and bioturbation and herbivory by fish. Our results have shown that the absence of Chara spp. in the Tablas de Daimiel is mostly explained by presence of invasive fish (i.e. common carp). Moreover, the physicochemical characteristics of the water (lower values of conductivity and higher values of inorganic carbon and organic nitrogen), as well as of the sediment (lower values of inorganic and organic phosphorus), favour the increase of Chara spp., in the absence of the fish effect. These results led the National Park managers to begin the control of invasive fish as an urgent measure to assure the ecological conservation of this Mediterranean wetland.

STRONG SITE EFFECTS DICTATE NUTRIENT PATTERNS IN A MEDITERRANEAN FLOODPLAIN

Nutrient patterns in wetlands are usually studied at a single sampling station and not for more than two or three hydrological years. This makes environmental assessment difficult, particularly when spatial heterogeneity and wetland responses depend upon water availability, as often occurs in Mediterranean wetlands. Furthermore, the spatial scale of environmental control of wetland dynamics is usually hypothesized to change as a result of water connectedness, so the higher the rate of water renewal, the larger the spatial scale of environmental control. To test this idea, we carried out a study of monthly nutrient loadings, organic carbon, total nitrogen, and phosphorus in a Spanish hypertrophic floodplain (Tablas de Daimiel National Park) for six years at three sites to ascertain the significance of both the spatial heterogeneity and the long-term responses of nutrient patterns to water availability. Our study demonstrated that strong site effects prevailed on nutrient chemistry in this wetland, irrespective of the degree of wetland connectivity, since there were very few significant correlations among different sites for a single nutrient and no significant correlations with loadings. Causes for this behavior might be that water inputs to this Mediterranean wetland were highly variable and leveling ecological effects were dampened by site processes. Spatially, an increasing gradient of total organic carbon and nitrogen occurred toward the outlet, but total phosphorus peaked in the middle of the wetland. Such a decoupling was also shown by PCA analysis where three different factors explained 69% of overall variability of nutrient patterns: flooding, both organic carbon and total nitrogen content, and total phosphorus. No temporal trend in nutrient content was observed. No simultaneous seasonal patterns were obvious in nutrient data from the same site or for the same nutrient at different sites. Periodicity analyses did not show overlapping of annual rhythms. That lack of patterns could be evidence of the major importance of site processes. This wetland behaved as a sink for nutrients, a fact also suggested by the increasing carbon and phosphorus content in sediments of all sites over time. Sediment nitrogen dynamics, however, might experience differential among-site processes resulting in no trend in accumulation in some areas. These results challenge current views on the spatial scale of environmental control on wetland performance and suggest that the role of water availability in ecological connectivity may be more complex than previously suspected.

Reduction in Diversity of Aquatic Plants in a Spanish Wetland: The Effect of the Size of Inundated Area

ABSTRACT The effect of subsequent decreases in inundated area on the reduction in diversity of aquatic plants in Las Tablas de Daimiel National Park was examined. This Spanish wetland was declared a national park in 1973 in an attempt to protect it from degradation. However, human actions, such as canalization of superficial waters and extraction of subterranean waters, together with the cumulative effects of successive years of low rainfall, resulted in a marked decline in both surface and groundwater resources during the 1980s and 1990s. Diversity of aquatic plants (number of hydrophyte species, genera and families) and size of inundated area (ha) in 1956, 1975 and 1994 were estimated. The power function model S = CAz (or log S = log C+ z log A) was applied to detect a linear relationship between hydrophyte diversity and inundated area. The number of hydrophyte species, genera, and families decreased with decreasing the size of inundated area; the highest values were estimated in 1956 whereas the lowest...

Aportación al conocimiento de Ranunculus peltatus Schrank subsp. saniculifolius (Viv.) C.D.K.Cook, y su comportamiento fitosociológico.

Se delimita R. peltatus subsp. saniculifolius (Viv.) C.D.K. Cook de otros ranunculos del subgenero Batrachium (DC) A. Gray, con los que muestra similitudes morfologicas, especialmente R. oloteucos LLoyd. Se estudia tambien el comportamiento fitosociologico de R. peltatus subsp. saniculifolius, presentando especial atencion a la composicion quimica del agua. Se describen tres nuevas comunidades.

Macrophyte Ecology and Its Long-term Dynamics

Dynamics of hydrophytic and helophytic vegetation is analyzed in relation to environmental changes from 1956 until the present day. These changes are mainly related to hydrological characteristics and water quality. In the case of submerged vegetation, community changes are related to alterations of the salinity and eutrophication regime, manifested in a decreased coverage and the extinction of some species. In the case of the helophytic vegetation, changes are associated with the fragmentation of the original vegetation patches, originally dominated by Cladium mariscus. Nowadays emergent vegetation is dominated by Typha domingensis, Phragmites australis, and, in the last years, by annual vegetation, nitrophilous taxa and woody species (Tamarix canariensis, T. gallica). This vegetation type indicates wet and saline conditions in soils. Despite these changes at the structural level, there is also evidence of a considerable increase in the biomass that accumulates every year in the wetland and which accelerates wetland siltation in the long term.

Rielletea helicophyllae una nueva clase fitosociológica de plantas acuáticas

A newaiiiance,orderunidclass(Rielliout, Rielletalia, Riel/erro), with two new associations (Riel/eruto helicoplcyllae, Riel/eruto noiorisii) aredescribed.Bothof themarecharactenized by thepreenceof differentspeciesof the genus Riella Mont.Ecologicaldataof te aquatichabitat in whichthey growarealso given.