Tablas De Daimiel National Park Research Articles

Multilevel responses of emergent vegetation to environmental factors in a semiarid floodplain

Wetland emergent vegetation of Tablas de Daimiel National Park (Central Spain), mainly composed by Cladium mariscus, Phragmites australis and Typha domingensis, was studied to test if population responses to environmental factors were invariant to scaling-up conditions from the single plant to the entire wetland. While the significance of the main controlling, abiotic factors (wetland location, sedimentary and water nitrogen and phosphorus, water level, duration of flooding) was that of earlier studies, the importance of them changed along with the level of plant organization. Our study showed that multiple effects occurred in the responses of helophyte populations to abiotic factors, and that these responses appeared to depend upon the level of observation involved, showing positive ( Typha biomass and sedimentary phosphorus), negative ( Cladium biomass and sedimentary phosphorus, Cladium large patch growth and total phosphorus), delayed (landscape cover of Phragmites and Cladium and water level of the previous year), saturation ( Cladium biomass and water level), threshold (small patch growth rate of Cladium and water level of the previous month) and non-linear (landscape cover of Phragmites and Cladium and total phosphorus in water) effects.

Environmental and geochemical record of human-induced changes in C storage during the last millennium in a temperate wetland (Las Tablas de Daimiel National Park, central Spain)

Environmental and geochemical record of human-induced changes in C storage during the last millennium in a temperate wetland (Las Tablas de Daimiel National Park, central Spain)

Environmental and geochemical record of human-induced changes in C storage during the last millennium in a temperate wetland (Las Tablas de Daimiel National Park, central Spain)

Las Tablas de Daimiel National Park has experienced many hydrological and ecological modifications through out its history, both of natural as well as anthropogenic origin, which have affected its carbon storage capacity and carbon fluxes. The study of those variations has been carried out by the analysis of its sedimentary record (geochemistry and pollen) and historical data. The natural changes have a wider variation range than the anthropogenic ones, showrepetitive patterns and the system reacts readjusting the equilibrium among its components. Anthropogenic effects depend on the direct or indirect impact on the wetlands of change and its intensity. In addition, the anthropogenic impacts have the capacity of breaking the natural balance of the ecosystem and the internal interactions.

Las Euglenófitas en las Tablas de Daimiel como ejemplo de las limitaciones de los indicadores biológicos de la degradación ambiental

Las Tablas de Daimiel National Park is a semiarid, hypertrophic wetland located in La Mancha (Ciudad Real, Central Spain). During the period 1996-2002 we carried out monthly samplings at three sites of Las Tablas. Thirty five taxa of Euglenophytes of the genera Astasia (1 taxon), Euglena (15), Lepocinclis (6), Phacus (9), and Trachelomonas (4) were identified. Six taxa are new records for Spain. Abundance, species richness, species groups and absolute and relative biomass of Euglenophytes widely fluctuated spatio-temporally in Las Tablas, without any statistically significant relationship (P > 0.05) with organic carbon (either particulate or dissolved), which has been long considered the main factor controlling the occurrence and abundance of Euglenophytes. The same lack of relationship was observed for other nutrients, such as ammonia, soluble reactive phosphorus and total nitrogen and phosphorus. Our results challenge the role of Euglenophytes for assessing environmental degradation in hypertrophic ecosystems, a topic of increasing interest in view of the newly implemented European Water Framework Directive and its proposals for biological monitoring. However, these results might invigorate ecological studies on Euglenophytes, still in its infancy unlike in other algal groups.

Descomposición de helófitos en un humedal semiárido hipertrófico

This study represents the first attempt to outline the dynamics of litter decomposition of Cladium mariscus (cut-sedge) and Phragmites australis (common-reed) in Las Tablas de Daimiel National Park (Central Spain). From April 1998 to September 1999, two experiments were conducted to measure the overall decomposition in large-pore bags (7 months) and the chemical-microbiological decomposition in entire bags (14 months). Despite the hypertrophic condition of the wetland, that might have enhanced plant litter decaying rates, decomposition was a slow process in Las Tablas de Daimiel for both species, resulting in more than 50% of initial biomass a year and a half later. There were no significant correlations between environmental variables and decomposition rates. An initial phase of leaching with the highest rates (P –1 for C. mariscus and 0.0029 ± 0.002 day –1 for P. australis in the overall decomposition experiment, and respectively 0.0019 ± 0.001 day –1 and 0.0016 ± 0.001 day –1 due to chemical-microbiological decomposition, suggesting the negligible significance of invertebrates in the plant decomposition process. Furthermore, no significant difference was observed for nutrient release, except that Phragmites lost more phosphorus (P Cladium . Plant litter decaying rates were roughly an order of magnitude lower than nutrient release rates in both species. Our results suggest that slow decomposition rates of helophitic plant biomass increases organic matter sedimentation and reduces water quality of Las Tablas de Daimiel National Park.

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.

Picoplankton dynamics in a hypertrophic semiarid wetland

This study was carried out on a neglected component of wetlands: the picoplankton community. We analyzed the picoplanktonic community patterns and their related environmental factors in a hypertrophic semi-arid wetland located in Central Spain (Las Tablas de Daimiel National Park, TDNP). We determined the bacterial and autotrophic picoplankton (APP) abundance over a three-year period (1996: the end of a long drought period and 1997–1998: after flooding) in five sites of the wetland. The overall range of bacterial abundance was 0.2 × 106 to 10 × 106 cells/ml. The annual mean abundance increased in the wettest 1997. APP was composed mainly by coccoid phycocyanin-containing cyanobacteria, with the greatest abundance up to 25 × 105 cells/ml. The annual mean also increased considerably in wetter 1997–98. Despite the large APP biomass in some sites, its percentage of total phytoplankton biomass was low (the annual average did not exceed 1.5%). We observed spatial heterogeneity in the picoplankton fraction depending on the fluctuating hydrology: bacteria tends to spatial homogeneity after flooding while APP showed only similarity among the output sites. Among the considered predictive variables (temperature, phosphorus, nitrogen, zooplankton, phytoplankton) of the picoplanktonic dynamics, temperature was the most closely correlated to picoplankton, especially to bacterial abundance. Further, in two factorial, coupled-hierarchical laboratory experiments (constant temperature), we searched for control mechanisms of picoplankton. We tested (a) the trophic cascade hypothesis by analyzing the effect of presence/absence of mosquitofish (experiment 1) or directly modifying the zooplanktonic community (experiment 2) and (b) the bottom-up regulation by altering the nutrient conditions (presence/absence of sediment in experiment 1; reducing the nutrient content in experiment 2). Bacterioplankton failed to show any behavior related to trophic cascade direct effects, while nutrients increased its abundance. APP was affected positively by nutrients and negatively by zooplankton grazing.

Climatic changes since the Late-glacial/Holocene transition in La Mancha Plain (South-central Iberian Peninsula, Spain) and their incidence on Las Tablas de Daimiel marshlands

A palynological and lithological continuous record from La Mancha Plain (South-central Iberian Peninsula, Spain) is presented. The obtained results have permitted the reconstruction of the climatic evolution in the area since the Late-glacial/Holocene transition. The end of the Late-glacial was characterized by a cold and arid climate and it concluded at about 9890±180 yr BP. In the Early Holocene a slight climatic amelioration began, being interrupted by a more arid phase around 8500 yr BP. The Holocene Climatic Optimum started from ca. 8000 yr BP and was characterized by higher temperatures and more humidity. During the Mid-Holocene–Late Holocene times a stage of marked aridity occurred towards 5000 yr BP that preceded the development of a dry mediterranean climate. Under this new climate a short-time arid phase took place around 2500 yr BP after which the mediterranean conditions became accentuated, with an increasing dry climate. This climatic evolution has affected the characteristics of the marshlands of Las Tablas de Daimiel National Park, originating changes in the sedimentary environment. This environment was mainly fluvial until the end of the Holocene Climatic Optimum and became lacustrine–palustrine from the beginning of the more arid conditions.

Sedimentation in the semi-arid freshwater wetland las tablas de Daimiel (Spain)

Abstract Despite sedimentation being recognized as a very important process in wetlands, very little is known about its dynamics. This study analyzed sedimentation on a short-term scale in the semiarid floodplain wetland Las Tablas de Daimiel National Park (central Spain). In monthly sampling intervals during 1997 and 1998, we measured seasonal and spatial sedimentation patterns of total solids, organic and mineral matter, nitrogen, and phosphorus using sediment traps. The highest mean mass accumulation rates were obtained at the wetland-input site (135 ± 57 g m−2 d−1), but a decrease in sedimentation rates was noted with increasing distance from the inflow (49 ± 39 g m−2 d−1 in the terminal zone of the wetland). Flow and water level explained only 13% of variance in sedimentation. The sedimentation patterns presented clear seasonality, coinciding with the period of vegetation growth. There existed a marked spatial heterogeneity in sedimentation that can be attributed to differences in vegetative cover. I...

Nutrient Dynamics and Eutrophication Patterns in a Semi-Arid Wetland: The Effects of Fluctuating Hydrology

A three-year study was carried out in Las Tablas de Daimiel National Park, a Spanish semi-arid wetland, to describe eutrophication patterns and the responses of the main primaryproducers in contrasting inundation years. Total and dissolved nitrogen and phosphorus, phytoplankton chlorophyll-a(monthly) and emergent macrophyte cover (yearly) were measured together with water levels. Water balances were taken to assessphosphorus and nitrogen annual nutrient budgets. The wetland could be termed hypertrophic. Nutrients displayed distinct seasonality because nitrogen peaked both in winter and summer,whereas phosphorus did so in late spring and early summer. A reduction in both total nitrogen and phosphorus in humid yearsdue to higher water levels was also observed. An important spatial heterogeneity in nutrient content occurred throughout the study, part of which could be ascribed to hydrological fluctuations since the input site showed higher mean values in rainy years. Mass balances suggested that sedimentation played a key role in nutrient dynamics, with macrophyte leaching and waterfowl additions being minor sources. Internalloading was much higher than external loading in this wetland,thereby being responsible for higher sedimentation rates.Phytoplankton chlorophyll-a displayed seasonality, withpeaks in late summer, when macrophyte activity was decreasing.No relationship between either chlorophyll-a and nutrients or hydrological conditions could be ascertained formost sampling stations and years of study. However, the waterlevel-dependent, emergent macrophyte sawgrass (Cladium mariscus) presented a statistically significant relationship with both nitrogen and phosphorus. Our results demonstrate thatmacrophytes must be taken into account in wetland eutrophicationmodels. A conceptual model comparing the responses of primary producers to eutrophication in lakes and wetlands is outlined.

The influence of Procambarus clarkii (Cambaridae, Decapoda) on water quality and sediment characteristics in a Spanish floodplain wetland

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 sediment bound nutrients to the water column. Water quality impoverishment was mainly due to the increase of dissolved inorganic nutrients (soluble reactive phosphorus and ammonia), and a significant increase of total suspended solids occurred likely as a result of crayfish associated bioturbation. At the same time, crayfish reduced the content of organic matter in the sediment and we observed a slight increase of total sediment phosphorus and nitrogen content as a result of crayfish benthic activity. P. clarkii effects, in terms of internal nutrient loading (229.91 mg TP m−2 d−1), were shown to be important on a local scale, indicating the significance of internal nutrient supply to water column primary producers particularly under low external supply (summer). Extrapolations to the whole ecosystem, however, revealed a negligible crayfish contribution (0.06%) to total internal nutrient loading (0.035 mg TP m−2 d−1). Hence, crayfish spatial heterogeneity patterns are important in global and local matter fluxes and nutrient cycles in wetlands.

The significance of water inputs to plankton biomass and trophic relationships in a semi-arid freshwater wetland (central Spain)

This study attempts to describe changes in plankton biomass (including bacteria, phyto- plankton, ciliates, rotifers, and crustaceans) in the semi-arid, hypertrophic, freshwater wetland, Las Tablas de Daimiel National Park (central Spain), in relation to water inflow. An inter-annual compari- son of 1996 and 1997, with contrasting rainfall, reveals that inflows in the form of flooding act as a bottom-up structuring force on total plankton biomass. However, the responses of plankton biomass to flooding were different in strength between the two years, which can be attributed to shifts in plankton community structure. Crustacean zooplankton conditioned total plankton biomass in 1996, based on the relationship between the high individual biomass and community development. Crust- aceans decreased in 1997, while bacteria, phytoplankton and rotifers increased. The quantitative increase of the latter groups resulted in a higher total plankton biomass in 1997. The key position of crustaceans in the wetland plankton is also reflected in their capability for exerting significant top- down control, which was clearly evident in 1996 but weaker in 1997, based on their numerical reduction. Statistical analyses provide evidence that the decline of trophic interactions in 1997 is related to the strength of flooding in that year, thereby highlighting the significance of the disruptive action of physical disturbance on biotic interactions in the plankton. Flooding and areal inundation were also shown to be significant for spatial heterogeneity. In 1996, site-specific development took place in the absence of prolonged flooding effects, resulting in high spatial heterogeneity. In 1997, however, remarkable homogenization of plankton biomass occurred along the major water flow path. Thus, wetland landscape heterogeneity depends on inflows which condition areal inundation. This, in turn, influences plankton dynamics.

Fitoplancton del Parque Nacional Las Tablas de Daimiel. III. Diatomeas y clorofitas

Las Tablas de Daimiel National Park is an important semi-arid wetland, biodiversity reserve, that is experiencing an accelerated eutrophication process and dramatic hydrological changes in recent years. This paper reports the taxonomy, dynamics and ecology of 9 planktonic diatoms (2 centric, 7 pennate) and 37 chlorophytes (24 coccoids. 8 flageflated and 5 species of other groups) which were found from 1996 to 1998. Despite the higher diversity of Chlorococcales, diatoms made a major contribution to algal biomass. Most species are typical of eutrophic systems and some are salinity indicators ( Chaetoceros muelleri). Scenedesmus quadricauda, Cyclotella meneghiniana and Nitzschia acicularis were the most common species. Pteromonas limnetica is a new record for Spain. There was a remarkable decrease in phytoplankton density and a 50 % species substitution in comparison to the drier period 1992-1993. Species distribution through the wetland was very heterogeneous spatially and temporally, without any pattern.

Evolution of the water quality of a managed natural wetland: Tablas de Daimiel National Park (Spain)

The Tablas de Daimiel National Park is a Spanish continental wetland which is extremely important for the survival of many migratory birds. However, it is an ecosystem seriously threatened to a point that a Hydric Regeneration Plan was implemented in 1988 to restore this wetland, it has caused a situation of dependence for the use and management of water resources. The aim of this paper was to try to establish how the last years of artificial management have affected this ecosystem. To carry out this study we have analysed the water physico-chemical characteristics during the period 1995–1997 and these data have been compared with those obtained from a survey in 1974–1975, which represent the original situation. Different statistical techniques have been used for this purpose. A serious salinization process, which can affect the life in this wetland, has been pointed out. The present state of pollution, both organic and inorganic, has been evaluated. Trace metals data are reported for the first time. The global quality state has been established by using statistical quality indexes.

Fitoplancton del Parque Nacional Las Tablas de Daimiel. II. Las cianofíceas, los dinoflagelados, las criptofíceas, las crisofíceas y las xantofíceas

Las Tablas de Daimiel National Park is a semiarid wetland that exhibits a high biodiversity but is suffering an inexorable eutrophication process. The study of the phytoplankton in this wetland is interesting because of its hydrological fluctuations (drought period until 1996) and its trophic condition. This papers shows the taxonomy, dynamic, and ecology of microalgae in five areas of the Park from 1996 to 1998, which allow comparisons to be made between the present state and the 1992-1993 period. Twelve taxa of Cyanophyta , 4 of Dynophyceae , 8 of Cryptophyceae , 5 of Chrysophyceae and one of Xanthophyceae were found. Almost all species have been already cited in Spain and are typical for eutrophic environments. Cyanophyceae and Cryptophyceae were the most important groups (Planktothrix agardhii, Anabaenopsis elenkinii, Cryptomonas erosa as the most common algae). Moreover, oscillatorial Cyanophyceae (in 1992) have been replaced by N-fixing nostocal ones, related to the high level of pollution found in recent years.

Determination of lead in waters and sediments from the wetland Tablas de Daimiel National Park (Spain)

Electrothermal atomic absorption spectrometry (ETAAS) has been used for lead control in waters and sediments of the wetland Tablas de Daimiel National Park. The lead determination in the wetland water is hindered by an enhanced salt content, so matrix interference was evaluated. The use of stabilized temperature platform atomization technique, Zeeman background correction and palladium nitrate as matrix modifier were found advisable. For the sediments a closed-vessel microwave dissolution method has been proposed using a mixture of HCl-HNO3-HF and a heating time of 90 s. With subsequent ETAAS using platform atomization and Zeeman background correction, no chemical modification was necessary. Using these conditions, the interferences were completely removed for both waters and sediments and the calibration curve in ultrapure water (1% nitric acid) was linear up to 30 μg/L. The detection limits for waters and sediments were 0.95 μg/L and 0.78 μg/g, respectively. The accuracy of the proposed method for sediments was validated by analyzing certified reference materials (obtained values were within the certified ones) and spiked wetland sediments (mean recovery of 99.0%).

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 values were estimated in 1994. This linear relationship implies that a tenfold decrease in inundated area approximately cuts hydrophyte diversity in half.

Ecological study of Las Tablas de Daimiel National Park (Ciudad Real, central Spain): Differences in water physico-chemistry and vegetation between 1974 and 1989

Las Tablas de Daimiel National Park (TDNP) constitutes a SW-oriented continental wetland within the province of Ciudad Real (Central Spain). During the 1980s, the inundated area of the TDNP markedly decreased as a consequence of the apparent decline in both surface and groundwater resources. A Hydric Regeneration Plan was initiated in 1988 to increase water resources and enlarge the inundated area. This paper reports an ecological study of the water physico-chemistry and vegetation of the TDNP that was carried out in 1988–89. The data obtained are compared with previous data from a 1974–75 study to examine physico-chemical and botanical differences between both periods. Mean values of chloride and chemical oxygen demand were significantly higher in 1988–89 than in 1974–75, the spatial patterns of maximum and minimum values of conductivity tending to change. The number of hydrophyte species decreased in 1988–89 compared with 1974–75, hydrophytes inhabiting permanent waters being much more affected than hydrophytes inhabiting seasonal waters. Owing to the linear relationship between the area of habitats and the numbers of species living within them, it can be concluded that the reduction in inundated area during the 1980s, rather than the alteration in water quality, is the major environmental factor responsible for the decrease in species richness.

Funcionamiento hidrológico de un humedal ribereño, el Masegar, en el conjunto de los humedales de La Mancha Húmeda de la cuenca alta del rió Cigüela

Fifteen years ago «La Mancha Humeda» was deelared Biosphere Reserve by UNESCO, at the request of the Spanish Government. According to a recent deelaration by UNESCO in 1995, such title could be lost if the degradation processes of the wetlands of «La Mancha Humeda» continue. «La Mancha Humeda» was formed by a hundred of small lakes or wetlands that in area totalled about 200-300 km2 and they were distributed over an area of about 25.000 km2. These are different types of wetlands (saltwater and freshwater, permanent and ephimeral, riparian and closed basins, etc.). It is estimated that the actual surface of all the wetlands is about 20-30% of that occupied 20 or 30 years ago. The most famous degradation case is that of the «Tablas de Daimiel National Park» that has shrinked fram an area of about 15-20km2 to less than 1 km2 This article presents the general situation of the riverine wetlands of the Ciguela river and the results of the hydrological functioning of a wetland of modest dimensions, less than 1 km2, El Masegar. It is a riparian wetland located in the Ciguela River basin which has been severely affected by man actions. El Masegar can be considered as an artificial wetland. From an ecological point of view, this wetland seems to have been functioning in a proper way until 1988, when the so called «Plan de Regeneracion Hidrica del Parque Nacional de las Tablas de Daimiel» began. This Plan has not regenerated the Natural Park but has degradated or destroyed the riparian wetlands that existed along the Ciguela River valley which is about ISO km long. The surface of these wetlands all together was larger than that of Tablas de Daimiel National Park. The study shows that it could be feasible to restore or maintain most of the riparian wetlands of the «La Mancha Humeda» without a great economic investment and without social conflicts with the farmers.

Conflicts between wetland conservation and groundwater exploitation: Two case histories in Spain

The problems in two Spanish national parks located on wetlands are analyzed. The hydrogeological and ecological characteristics of the two parks are somewhat different as are their respective degrees of deterioration. The Tablas de Daimiel National Park is located on the Central Plateau of Spain. It used to consist of a marshy area of about 20 km2 around the confluence of two relatively small rivers. The area was marshy mainly because it was the natural discharge zone for a Tertiary aquifer system about 100 m thick extending over an area of some 5,000 km2, composed of calcareous and detrital material of continental origin. The average annual recharge has been estimated at approximately 350 hm3/yr. Current groundwater withdrawal is around 450 hm3/yr, mainly used to irrigate a surface area of some 1,000 km2. This overdevelopment has led to a continuous depletion of the regional water table and eventually to the drying out of the marshy area. Spontaneous combustion or fires caused by man have occurred in about 10 km2 of the desiccated areas since the spring of 1986. The Donana National Park is located on the estuary of the River Guadalquivir. The aquifer system of the Lower Guadalquivir estuary consists essentially of a permeable formation of unconsolidated Plioquaternary materials with an area of some 3,000 km2. Under the marshy area (about 1,800 km2) the aquifer system is confined below low-permeability estuary deposits which can be over 100 m thick. Around most of the marshland the aquifer crops out and is recharged by rain. The Donana National Park is over 700 km2 in size, part of which is in the marshland and part in the recharge area where the aquifer is phreatic. In the 1970s Spain's largest irrigation project using groundwater, covering a surface area of 240 km2, was planned in an area bordering on the national park. The initial project has been scaled down considerably as a result of protests by conservation groups. However, it seems likely that the water table depletion as a result of pumpage for irrigation could cause a large part of the ecotone situated at the contact-line between the marshland and the phreatic aquifer to disappear. This ecotone exists because it is a natural groundwater dischange area.