Carmen Díaz-Paniagua

Estación Biológica de Doñana · Wetland ecology

Globally, 41% of amphibian species are threatened with extinction. Temporary ponds are crucial ecosystems for amphibian breeding where large predators are typically absent, therefore reducing the predation pressure on their larvae. Also, in these ecosystems large branchiopods (LB) proliferate, becoming a significant food source for several species....

Biodiversity loss and declining ecosystem functioning is spreading at alarming rates worldwide. In this context, pondscapes, including temporary ponds, have emerged as potential Nature-based Solutions that offer valuable ecosystem services and connect freshwater habitats as stepping-stone ecosystems. However, agricultural intensification and hydrol...

Wetland ecosystems worldwide are threatened by habitat alteration, climate change and the introduction of invasive species, even within protected areas. Unravelling the reliance of sensitive wetland‐dwelling species, such as amphibians, on habitat characteristics is thus essential to identify conservation targets. Here we assess the distribution of...

Loss of biodiversity and ecosystem services (ESS) continues at alarming rates globally. In this context, pondscapes including temporary ponds have emerged as potential Nature-based Solutions which provide multiple ecosystem services and connect freshwater habitats. However, agricultural intensification and hydrological modifications have threatened...

The success of amphibian conservation efforts is highly dependent on the preservation of amphibian breeding habitats. Doñana National Park contains an abundance of ponds with heterogeneous characteristics, which has historically favoured its amphibian community. However, most of the park’s ponds are groundwater dependent, and aquifer overexploitati...

Temporary ponds are priority habitats for conservation under the Habitats Directive (code 3170), harbouring singular fauna and flora. Some of these emblematic species are large branchiopods, most of them rare and relict species considered flagship species of well-preserved temporary ponds , i.e., reflecting good conservation status (Brendonck et al...

Efforts to conserve the pond network in the Doñana National Park are being threatened by groundwater overexploitation. The dramatic expansion of farming and tourism in nearby areas has caused a severe lowering of the water table, reducing pond hydroperiod length or even instigating pond desiccation. It is important to document the link between grou...

Temporary ponds are priority habitats for conservation under the Habitats Directive, harbouring singular fauna and flora. Some of these emblematic species are large branchiopods, being some rare and relict species considered as ‘‘sentinels’’ in temporary ponds, i.e., reflecting good conservation status. In recent decades, the biodiversity of tempor...

Wetlands are among the most biodiverse yet endangered ecosystems on Earth. Despite being the most important wetland in Europe, the Doñana National Park (southwestern Spain) is no exception, and the increase of nearby groundwater abstractions for intensive agriculture and human supply has raised international concerns about the conservation of this...

The overexploitation of groundwater is directly altering the temporary pond network located in the sandy area of the Doñana National Park. Some ponds have disappeared, and many others have reduced their hydroperiod and flooded area which, in turn, have impacted the species inhabiting them. The most vulnerable species are those requiring a long hydr...

Phenotypic plasticity allows organisms to improve the match between their phenotype and heterogeneous environments. Theoretical models have argued that costs of maintaining the sensory and response machinery necessary for adaptive phenotypic plasticity are important determinants to the evolution of plasticity. Despite recurrent arguments invoking p...

In temporary ponds, submerged plants have adapted to recurrent periods of drought. These ponds often lack the impact of large herbivores but can harbor large numbers of herbivorous tadpoles. Tadpoles of the Iberian spadefoot toad (Pelobates cultripes) may reach large body size and consume large quantities of macrophytes during their long larval per...

In temporary ponds, seed germination largely determines how well aquatic plant assemblages recover after dry periods. Some aquatic plants have terrestrial morphotypes that can produce seeds even in dry years. Here, we performed an experiment to compare germination patterns for seeds produced by aquatic and terrestrial morphotypes of Ranunculus pelt...

Among invasive species, floating plants have a great impact on aquatic ecosystems, forming dense mats that cause a great alteration of the physical and chemical water features. We experimentally assessed the effect of Azolla filiculoides mats on Mediterranean temporary waters using mesocosms with sediments from an invaded marsh and amphibian larvae...

Diet has major effects on development, growth, health, and performance of animals. Photosynthetic pigments, in particular, are key components of the diet of many organisms that can play important roles in their development and performance. Compared to other taxa, we know relatively little about how these pigments impact amphibian larval development...

Invasive species have major impacts on biodiversity and are one of the primary causes of amphibian decline and extinction. Unlike other top ant invaders that negatively affect larger fauna via chemical defensive compounds, the Argentine ant (Linepithema humile) does not have a functional sting. Nonetheless, it deploys defensive compounds against co...

Telomere shortening with age has been documented in many organisms, but few studies have reported telomere length measurements in amphibians, and no information is available for growth after metamorphosis, nor in wild populations. We provide both cross-sectional and longitudinal evidence of net telomere attrition with age in a wild amphibian popula...

Non-native turtles are susceptible to pathogenic infections that may be transmitted to native species. We performed hematological, biochemical, histopathological, and microbiological analyses in two invasive populations of red-eared sliders (Trachemys scripta elegans), which were living alongside native turtle species in southwestern Spain. The red...

Understanding the movement of individuals across natural habitats is important to determine fundamental aspects of their ecology, from dispersal patterns and habitat selection to interactions with predators, pathogens or conspecifics. Amphibian larvae are key to aquatic systems, playing fundamental roles as both consumers and prey, affecting nutrie...

Ample variation in body size is common in vertebrates over extensive geographical distances, or in isolated populations, where effective geographical barriers may cause dwarfism or gigantism. Here we study potential causes of extreme size reduction in continental populations of amphibians within a short geographical distance and in the absence of g...

In Mediterranean temporary ponds, the timing of annual flooding is highly variable and depends on heavy seasonal rains. Ponds can flood in the autumn, winter, or spring, and thus the environmental conditions faced by emerging zooplankton can be very different. We performed an experiment in a climatic chamber where we simulated annual variation in n...

Organisms are exposed to multiple environmental factors simultaneously to which they often respond behaviorally, morphologically and/or physiologically. Amphibian larvae are quite plastic and efficiently adjust their phenotype and physiology to the reigning local conditions. Here we tested whether the combination of predator presence and low water...

In a very dry year, when aquatic habitats were scarce, we observed exceptionally massive corixid oviposition on terrapin shells in Doñana National Park, southwestern Spain. Most terrapins inhabiting a large pond devoid of aquatic vegetation exhibited a dense cover of corixid eggs, whilst terrapins from vegetated ponds had no egg cover. Corixid ovip...

Invasive species are one of the main causes of amphibian declines worldwide, often through direct predation. Even species or life stages that may not be prone to predation by invasive animals can be affected through alterations of their reproductive behaviour and/or performance. This aspect is less commonly investigated, and may be important for un...

The invasive aquatic fern Azolla filiculoides forms dense mats that shade submerged macrophytes. Here we show that submerged plants of Ranunculus peltatus switch to a different morphotype when shaded by Azolla filiculoides mats. We used outdoor mesocosms to assess the cover of submerged plants in tanks with presence or absence of the exotic fern. I...

Amphibian larvae are common prey to various types of predators, according to the type of aquatic system they develop in. When they detect water-borne chemical cues from predators (kairomones), amphibian larvae often produce inducible defenses. An important component of such defensesis the alteration of the shape of the larvae, which often consists...

Organisms react to environmental changes through plastic responses that often involve physiological alterations with the potential to modify life-history traits and fitness. Environmentally induced shifts in growth and development in species with complex life cycles determine the timing of transitions between subsequent life stages, as well as body...

Water level changes have been monitored over 25 years in several temporary ponds located at different distances to a pumping area of a tourist resort fringing the Doñana National Park (SW Spain). The numerical model MIKE SHE was set up to simulate pond water levels and hydroperiod fluctuations. It was calibrated for nine hydrological years and vali...

Invasive fish have a high disruptive potential in aquatic ecosystems, in which amphibians may be highly impacted due to intense competition and/or predation on their eggs and larvae. Most studies have focused on the effect of large invasive fishes such as salmonids, whereas the effect of smaller fish on amphibians has been seldom investigated. We e...

Aims Pond environmental conditions may differ among years with regards to the season in which ponds begin to fill. We experimentally evaluated how seedling emergence, plant growth and phenology differed among years in which filling occurred in winter, autumn or spring. Methods We collected sediments from a natural temporary pond and located them i...

The Doñana temporary pond network is characterized by a high flora and fauna species richness, including a high number of are and threatened species. This high biodiversity is due to the high abundance of ponds of different size across a broad hydroperiod range. The different geomorphological areas within the park contribute to increase the heterog...

The Doñana wetlands in SW Spain constitute what remains of the original 180,000 ha of marshland in the Guadalquivir delta. The natural wetlands are protected in the National Park and World Heritage Site (54,252 ha), and include more than 3,000 temporary dune ponds fed mainly from groundwater and 30,000 ha of seasonal marshes dependent on surface fl...

Eggs of theWestern spadefoot toad (Pelobates cultripes) reached a 100%mortality in all 29 clutches deposited at a pH below 5.0 in a temporary pond of the Doñana National Park (SWSpain) throughout the wet season of 2006– 2007. A similar trend was detected in a neighbouring pond. The proximity of these two ponds to a groundwater pumping area (b1.5 km...

Temporary ponds are unpredictable habitats that exhibit inundation periods of variable duration (hydroperiods). We hypothesised that changes in microcrustacean assemblages, namely among ponds (spatial variation) and within ponds at a monthly scale (intra-annual variation), would differ according to hydroperiod length. We found that the microcrustac...

The aim of this study was to assess aquatic plant distribution patterns in a Mediterranean temporary pond network (Doñana National Park, SW Spain). We analyzed differences in species composition employing multivariate ordination techniques; we specifically examined the importance of hydroperiod and physical and chemical variables in the five geomor...

El criterio fundamental para considerar que una especie es alóctona en el territorio español se basa en la constatación de que la coloniza-ción no ha sido natural, sino de origen antró-pico. Según este criterio, debemos considerar como poblaciones alóctonas la mayoría de las tratadas en este volumen, con algunas excepcio-nes como Testudo graeca en...

Ante una situación generalizada de dramáticos declives en las poblaciones de anfibios a nivel global, es fundamental caracterizar el papel funcional de los anfibios en los sistemas naturales para poder comprender las posibles consecuencias de su declive y extinción local. El principal objetivo de la presente tesis es conocer el potencial regulador...

Temporary ponds are highly variable systems where resource availability and community structure change extensively over time, and consequently the food web is highly dynamic. Amphibians play a critical role both as consumers and prey in aquatic communities and yet there is still little information on the trophic status of most amphibians. More impo...

In Donana National Park, most aquatic habitats are temporary. Ponds dry up during the summer, and are filled again when phreatic levels rise after heavy rains. Permanent and semipermanent ponds, and a chain of long-hydroperiod ponds are formed in an area of the park where discharges of the dune and regional aquifers coincide. Over the last few deca...

The presence of the exotic weevil Stenopelmus rufinasus (Coleoptera: Curculionidae) is closely related to the occurrence of the exotic red water fern, Azolla filiculoides. In this paper, we present the first records of S. rufinasus in Doñana National Park (SW Spain), based on sampling of macroinvertebrates in 91 temporary ponds, including monthly s...

We monitored reproductive females of Emys orbicularis and Mauremys leprosa during the summer of 2001 in Doñana National Park. Radiographs revealed that females of both species may lay at least two clutches from May to July. We recorded incubation temperatures in one nest of each species, and found them to be 24.7ºC in E. orbicularis and 28.7ºC in M...

Geomorphological and hydrological features can provide a sound basis for global wetland classification. Temporary ponds located on the sandy area of Doñana can be classified into five different geomorphological areas. We hypothesised that these ponds would differ in soil characteristics, which may also explain differences in the composition of thei...

Llamamos biodiversidad al conjunto de la variedad de la vida en todos sus niveles de organización, desde los genes a los individuos, las poblaciones, las especies, las comunidades y los ecosistemas. Pero la biodiversidad es más que la suma de los elementos que componen el mundo vivo. También son biodiversidad las relaciones entre esos elementos, lo...

Connections between consumers and resources in food webs are complex and affect the structure and functioning of ecosystems. We assessed the influence of amphibians as consumers on the structure and functioning of temporary ponds, determining their impact on macrophyte abundance, zooplankton diversity and water chemistry. The effect of amphibians m...

Las extracciones para regadío y sobre todo para abastecer a Matalascañas (Huelva) ponen en peligro el sistema de lagunas temporales de Doñana, el más importante de Europa de sus características. Mayor control del consumo de agua en la famosa urbanización litoral y la educación ambiental de los que veranean en ella son necesarios para garantizar la...

Invasive crayfish have severely impacted invaded aquatic ecosystems worldwide. We studied temporal and spatial variation in the range expansion of the red swamp crayfish at one of the first European localities to which it was introduced: Doñana National Park (SW Spain). In contrast to the rapid range expansion witnessed in other areas, this invasiv...

Macroinvertebrate assemblages of temporary ponds are ideal model systems to explore biodiversity patterns and metacommunity ecology. In addition, the study of the environmental variables driving such biodiversity patterns is essential in establishing proper guidelines for the conservation of the singular fauna of temporary ponds, especially since s...

The Espacio Natural Doñana, referred to here simply as Doñana, is internationally considered as an area of particular interest for the conservation of Odonata. We have compiled data on the species recorded in this area between 1959 and 2013, including the results of intensive surveys and observations of adults which took place between 2009 and 2013...

We radiotracked individuals of the exotic aquatic turtle Trachemys scripta elegans and 2 coexisting species of native turtles (Mauremys leprosa and Emys orbicularis) in southern Spain. Aquatic home range areas differed among species only in winter, when T. s. elegans moved in larger areas and showed shorter inactivity periods than the native turtle...

Seasonal variation in macroinvertebrate assemblages usually is attributed to environmental variability, but this relationship is unclear in temporary ponds because they are highly dynamic across time. We assessed the influence of environmental variables and biotic interactions on macroinvertebrate community structure in 22 temporary ponds sampled m...

Amphibian larvae constitute a large fraction of the biomass of wetlands and play important roles in their energy flux and nutrient cycling. Interactions with predators and competitors affect their abundance but also their foraging behaviour, potentially leading to non-consumptive cascading effects on the whole trophic web. We experimentally tested...

Presencia de Lestes macrostigma (Eversmann, 1836) (Odonata: Lestidae) en las lagunas temporales del Parque Nacional de Doñana (sudoeste de España) Resumen: Se han detectado adultos de la especie vulnerable Lestes macrostigma (Eversmann, 1836) (Odonata: Lestidae), de forma abundante y frecuente, en las lagunas temporales del Parque Nacional de Doñan...

Amphibian chytridiomycosis, caused by infection with the non-hyphal, zoosporic chytrid fungus Batrachochytrium dendrobatidis (Bd), is an emerging infectious disease recognised as a cause of recent amphibian population declines and extinctions worldwide. The Doñana National Park (DNP) is located in southwestern Spain, a country with widespread Bd in...

Aim The imperfect detection of species may lead to erroneous conclusions about speciesenvironment relationships. Accuracy in species detection usually requires temporal replication at sampling sites, a time-consuming and costly monitoring scheme. Here, we applied a lower-cost alternative based on a double-sampling approach to incorporate the reliab...

Southern Spain’s semi-arid habitats are a Mediterranean ecosystem modelled mainly by historic factors which make them unique in comparison with North African deserts. Southern Spanish vertebrates have adapted to the recent emergence of semi-arid habitats in varying degrees of success. This paper reviews the current status of these terrestrial verte...

Recent and increasing interest in temporary ponds as biodiversity reservoirs fosters our need to test sampling techniques for characterising their biological communities. We compared the efficiency of dip-netting to that of fyke nets in sampling the macroinvertebrate assemblage of a temporary pond in Doñana National Park (SW Spain). We sampled the...

Nowadays, established populations of exotic turtles, Trachemys scripta elegans, coexist with native turtles in the wild in southern Spain. We analysed the diet of this exotic species and compared it with the diet of the two native species (Mauremys leprosa and Emys orbicularis) in two ponds. The exotic turtle is an opportunistic omnivore. In one of...

Invasive species cause deep impacts on ecosystems worldwide, contributing to the decline and extinction of indigenous species. Effective defences against native biological threats in indigenous species, whether structural or inducible, often seem inoperative against invasive species. Here, we show that tadpoles of the Iberian green frog detect chem...

Reproduction in female spur-thighed tortoises (Testudo graeca) in a population from southwestern Spain was studied by X-radiography of thread-trailed and radio-tagged individuals. Most females reproduce every year, laying one to four clutches from April to June with internesting intervals ranging from 21 to 29 days. Clutch size varied from 1 to 7 e...

Activity, mobility, growth rates, and space use of 48 hatchling spur-thighed tortoises, Testudo graeca, were monitored over a period of 8 months, from emergence from the nest in September until May. Individuals were followed by means of thread trailing and radio tracking. Overall average distance moved was 4.42 m/day and average home-range size was...