Creating a safe operating space for wetlands in a changing climate

Many of the world’s wetlands may be profoundly affected by climate change over the coming decades. Although wetland managers may have little control over the causes of climate change, they can help to counteract its effects through local measures. This is because direct anthropogenic impacts, such as water extraction and nutrient loading, work in concert with climate change to damage wetlands. Control of these local stressors may therefore ameliorate undesired effects of climate change, such as a shift towards dominance by invasive floating plants, increasingly frequent cyanobacteria blooms, or extinction of key species. Using the iconic Doñana wetlands in Spain as a case study, we illustrate how the concept of creating a “safe operating space” may be implemented to better ensure that ecosystems do not surpass thresholds for collapse during an era of global change.WIMEK grant for a research stay at WUR. JAE DOCTORES. European Union. European Social Fund. Grant Number: ESF2007‐2013. Spanish Ministry for Economy and Competitiveness. EU FP7 project FAST. Grant Number: 607131. European Union's Horizon 2020 research and innovation program. Grant Number: 641762Peer reviewe

Condicionantes ecológicos de la distribución de anfibios en el Parque Nacional de Doñana

[ES] En esta tesis se analizan los requerimientos de hábitat de las especies de anfibios en el Parque Nacional de Doñana, prestando una atención especial a los aspectos metodológicos que pueden sesgar los resultados inferidos. En particular, se ha tenido en cuenta la dinámica temporal del sistema y la fiabilidad de las ausencias, una consecuencia directa de la detectabilidad imperfecta de la especie en el área. También se ha evaluado la utilidad de la teledetección en el estudio de la variación espacial y temporal de los hábitats reproductivos de los anfibios y en la elaboración de modelos estadísticos de distribución de las especies.[EN] In this thesis there are analyzed the requirements of habitat of the species of amphibians in Doñana's National Park, giving a special attention to the methodological aspects that can slant the inferred results. Especially, there has been born in mind the temporary dynamics of the system and the reliability of the absences, a direct consequence of the imperfect detectabilidad of the species in the area. Also the usefulness of the teledetección has been evaluated in the study of the spatial and temporary variation of the reproductive habitats of the amphibians and in the production of statistical models of distribution of the species

Effect of Protection Level in the Hydroperiod of Water Bodies on Doñana’s Aeolian Sands

Mediterranean temporary ponds on Doñana’s aeolian sands form an extensive system of small dynamic water bodies, dependent on precipitation and groundwater, of considerable importance for biodiversity conservation. Different areas of the aeolian sands have received different levels of environmental protection since 1969, and this has influenced the degree of conservation and the flooding dynamic of these temporary surface waters. We use the Landsat series of satellite images from 1985 to 2014 to study the temporal dynamic of small temporary water bodies on the aeolian sands in relation to the protection level and to distance to water abstraction pressures from agriculture and residential areas. The results show that even with small and ephemeral water bodies optical remote sensing time-series are an effective way to study their flooding temporal dynamics. The protected areas of the aeolian sands hold a better preserved system of temporary ponds, with a flooding dynamic that fluctuates with precipitation. The unprotected area shows an increase in mean hydroperiod duration, and surface flooded, and a decline in hydroperiod variability. This seems to be due to the creation of irrigation ponds and the artificialization of the flooding regime of the natural temporary ponds, that either receive excess irrigation water or dry-up due to the lowering of the groundwater table level. Although a decline in hydroperiod duration of temporary ponds is seen as negative to the system, an increase in hydroperiod of surface waters due to artificialization, or a decline in variability cannot be considered as positive compensatory effects.Peer reviewe

Permanent and temporary ponds in Doñana National Park (SW Spain) are threatened by desiccation

In Doñana 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 decades, groundwater abstractions have severely affected the park. Using Landsat images (1975-2014), we estimated the variation in the inundated areas of the park’s largest ponds. All ponds have increased their dependency on annual rainfall in recent decades. Two seasonal ponds located close to urban pumping stations are currently dry. We found that other seasonal ponds have tended to have shorter hydroperiod and have dried up in the summer in recent years, including in very rainy years. The largest permanent pond had not such wide interannual fluctuations in its inundated area in the 1970s as those experienced recently. During the last decades, its inundated area is strongly correlated with annual rainfall, and the pond is close to desiccation in years of low rainfall. These results show that this pond network is severely threatened by desiccation. It is urgent to control groundwater extraction in the area to preserve the integrity of this important wetlandEn Doñana, la mayoría de los hábitats acuáticos son temporales. Las lagunas se desecan en verano y vuelven a inundarse con la elevación del nivel freático que se produce tras las abundantes lluvias otoñales o invernales. En la zona central del parque se localizan las lagunas permanentes y semipermanentes, que junto con otras de largo hidroperiodo forman una cadena de lagunas donde coinciden las descargas del acuífero dunar y el gran acuífero regional. En las últimas décadas, se han realizado extracciones de agua del acuífero que han afectado seriamente al parque. En este estudio, usando imágenes del satélite Landsat (1975-2014), hemos estimado la variación de la superficie inundada de las mayores lagunas del parque. En todas se observa un incremento en las últimas décadas de su dependencia de las lluvias anuales. Dos lagunas estacionales, situadas en las proximidades de estaciones de bombeo de aguas se consideran actualmente secas. En algunas lagunas, se observa una tendencia a acortar su periodo de inundación, secándose en los veranos de los años más recientes, incluso en años lluviosos. La laguna más permanente no sufría tan amplias variaciones en la superficie que mantenía inundada en verano en los años 70, como las que observan en la actualidad, cuando su inundación en verano está estrechamente correlacionada con las lluvias anuales, llegando en los últimos veranos a niveles muy próximos a la desecación. Estos resultados indican que la red de lagunas está severamente amenazada de desecación. Para preservar la integridad de este importante humedal, es urgente controlar las extracciones de agua del acuíferoPeer reviewe

Condicionantes ecológicos de la distribución de anfibios en el Parque Nacional de Doñana (2009)

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Extended Adolescence: The Ecology and Endocrinology of Facultative Paedomorphosis

Phenotypic plasticity is an adaptation to unpredictable environments whereby an organism of a single genotype may express more than one phenotype under differing environmental conditions. Phenotypic plasticity can manifest as polyphenisms, which is an extreme form of phenotypic plasticity that produces two or more discrete, alternative phenotypes. The expression of alternative phenotypes is controlled by biotic and abiotic environmental factors, which variably affect the strength and direction of phenotypic outcomes. Using a model polyphenic salamander, I sought to understand the ecological and hormonal processes that regulate alternative phenotype expression. The mole salamander (Ambystoma talpoideum) and eastern newt (Notophthalmus viridescens) are facultatively paedomorphic, which is a polyphenism with two alternative adult phenotypes: paedomorphs and metamorphs. Paedomorphs retain juvenile characteristics at sexual maturity (i.e., gills and an aquatic morphology), while metamorphs transition to terrestrial environments. The expressed phenotype depends on the environment context in which the larvae develop, with paedomorphosis often occurring under favorable aquatic conditions. I conducted a series of experiments to investigate the roles of population density, predator presence, hydroperiod, and stress hormones in regulating the expression of paedomorphosis. Results indicated the regulation of paedomorphosis through multiple ecological factors may be reducible to density-mediated effects, with a few notable exceptions. I also show that elevated stress hormones play a central role in regulating metamorphosis suggesting that all ecological factors affecting facultative paedomorphosis may funnel through a simple stress physiology framework. In conclusion, environmental factors affecting this polyphenism may share a comthread of inducing a stress response that initiates metamorphosis, thereby regulating phenotype in the population

Ecohydrology of temporary ponds

Temporary ponds (TP) comprise a complex ecohydrology and are extremely vulnerable to habitat degradation. These ecosystems contain species rarely found elsewhere but the environments are highly exposed to human and climate change pressures. TP have been recognised as priority habitats for conservation in Europe by the Habitats Directive, and work towards improved knowledge, understanding and conservation has increased since. This thesis focuses on the ecohydrological controls on the cladoceran species and communities in coastal temporary ponds in two geographic regions along a northwest Europe latitudinal gradient: the northwest coast of Ireland and the southwest coast of Portugal. It explores local time-variance in two dune slack ponds at Sheskinmore, Co. Donegal, Ireland, local spatial-variance across 24 ponds at the same site, and regional controls on temporary pond Cladocera ecohydrology at two sites in southwest Portugal (Malhão (MAL) and Vila do Bispo (VB)). The focus of investigation here is the seasonal hydrological balance and dependence of this dynamic on the ecology and biology of the habitats. This research aims to achieve a better understanding of individual, local and regional ecohydrological dynamics of TP’s and characterise the drivers of ecosystem variation within. Results uncover that ponds and slacks of Sheskinmore are highly dependent on rainfall and their vulnerability is confirmed when precipitation levels are not met. Increased variability inter-annually of cladocerans as opposed to intra-annual seasonal variation showed this. Weather changeability is the most important aspect of future climate change but there is a complex interaction between weather variability, local hydroregime and topography of a waterbody, impacting species’ temporal and spatial assemblages varyingly. Spatial dynamics of these dune ponds evaluated that within a rather small area, cladoceran composition differs, mainly according to hydrological categories, which are then linked to proximity of each site to the water table. Water chemistry was not so relevant to the spatial patterns in species. At a regional scale, sediment composition and water chemistry were better predictors of differentiation of the cladoceran composition within the Portuguese ponds, rather than geomorphological differentiations between regions. MAL ponds contained higher cladoceran abundance, whereas VB ponds contained higher cladoceran richness. Regionally, cladoceran communities are shaped by a combination of important factors and explanations vary according to the individual characteristics and to the collective groups of ponds. Results corroborate the importance of hydrology, topology and climatic factors as ecological drivers of ecosystem functioning in TP. This work demonstrates the uniqueness and sensitivity of TPs, therefore supporting the need to conserve these habitats

Groundwater abstraction has caused extensive ecological damage to the Doñana World Heritage Site, Spain

Se incluye información suplementaria.Acreman et al. (2022) reviewed evidence for ecological damage to the Doñana wetlands (UNESCO World Heritage Site [WHS] and Ramsar site), Spain, associated with intensification of groundwater use, particularly for agriculture. Acreman et al. presented a multistep methodology for evidence-based risk assessment that involves identification of conservation issues, and a systematic review of scientific evidence for ecological damage and its causes. However, they involved few local scientists, used a questionable methodology in stakeholder selection and involvement, used a flawed conceptual framework, and an incomplete literature review. We propose improvements to their methodology. They overlooked or misinterpreted key evidence, and underestimated the impacts that abstraction for irrigation for red fruits (mainly strawberries), rice and other crops has had on Doñana and its biodiversity. They reported groundwater level depletion of up to 10 m in the deep aquifer, but wrongly concluded that there is no evidence for impacts on the natural marsh ecosystem, the dune ponds or the ecotone. Groundwater drawdowns are actually up to 20 m, and have inverted the formerly ascending vertical hydraulic gradient in discharge areas. Phreatic levels have been lowered from 0.5 to 2 m in some areas. Groundwater abstraction has caused multiple ecological impacts to temporary ponds and marshes in the WHS, as well as to terrestrial vegetation, and should be urgently reduced. Furthermore, Acreman et al. focused on groundwater quantity while overlooking the importance of severe impacts on quality of both surface and groundwater, intimately connected to the use of agrochemicals for irrigated crops.Part of this work (marsh hydroperiod and water depth) has been funded by eLTER Plus project (INFRAIA, Horizon 2020, Agreement No 871128) and FEDER actions [SUMHAL, LIFEWATCH-2019-09-CSIC-13, POPE 2014-2020] by the Ministry of Science, Innovation and Universities, Subtask LWE2103022: Integration into VRE in the framework of the CSIC Interdisciplinary Thematic Platforms (PTI) PTI EcoBioDiv and Teledetect. PMRG was funded by the Portuguese Foundation for Science and Technology (FCT), through the Individual Stimulus to Scientific Employment Programme with the 2020.03356.CEECIND grant, and Forest Research Centre by the FCT (UIDB/00239/2020) grant.N

Dinámica espacio temporal de la comunidad de macroinvertebrados de las lagunas temporales de Doñana

Las lagunas temporales son medios acuáticos de pequeño o mediano tamaño que sufren una fase de desecación recurrente de longitud variable y que suele ser impredecible en su forma y duración (Williams 1997). El periodo de inundación de los medios acuáticos temporales puede definirse por un conjunto de características que algunos autores engloban en lo que denominan “hidrorégimen” (ver Wissinger 1999; Hulsmans et al. 2008; Vanschoenwinkel et al. 2009): 1) La regularidad de la inundación es la frecuencia anual de la inundación-desecación; 2) La previsibilidad de la inundación es la probabilidad de que la inundación se produzca en el mismo momento cada año así como la probabilidad de que un cuerpo de agua se inunde todos los años; 3) El hidroperiodo es la duración del periodo de inundación desde la formación hasta la desecación de las lagunas. La principal fuente de variabilidad del “hidrorégimen” viene determinada por la gran variabilidad del hidroperiodo (Hulsmans et al. 2008). En un área se puede detectar una amplia variabilidad en hidroperiodo entre las diferentes lagunas que componen un sistema. A su vez, el hidroperiodo de estas lagunas puede variar con la estacionalidad de la abundancia y distribución de las precipitaciones y de la evaporación, y según la cantidad de la precipitación anual. Esta complejidad hace que algunos autores hayan definido el hidroperiodo como eventos separados a lo largo de un mismo año (Boix et al. 2004) o como la duración media entre diferentes años (Schneider 1999), en vez de considerar la duración total de la inundación en el ciclo anual (Florencio et al. 2009). Las lagunas pueden considerarse permanentes, semipermanentes o temporales (Wissinger 1999) en función de la longitud del hidroperiodo. Pero dentro de las lagunas temporales existe un amplísimo gradiente de hidroperiodo que abarca desde las lagunas de duración más efímera, que se inundan de manera esporádica, hasta las lagunas semipermanentes que sólo se secan en años de sequía extrema (Grillas et al. 2004; Williams 2006). La longitud del hidroperiodo constituye un factor importante para determinar la composición faunística que albergan las lagunas temporales (Wiggins et al. 1980; Grillas et al. 2004; Williams 2006)

Dinámica espacio temporal de la comunidad de macroinvertebrados de las lagunas temporal de Doñana

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