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Aquatic insects are key to wetland ecological functioning, and the distribution of amphibious insects such as Odonata jointly depends on environmental conditions in the aquatic and terrestrial settings. Therefore, untangling the relative effects of within-wetland and landscape composition can help predict the responses of Odonata to environmental alterations in wetlands. Using data from 19 wetlands spanning over the southern Brazilian Pampa (center-western Rio Grande do Sul state), we assessed the relative importance of water chemistry and land-cover variables to the richness and composition of larval Odonata assemblages (and suborders Anisoptera and Zygoptera). Anisoptera richness decreased with pH and bare soil area. Water pH and areas of bare soil, mosaic of agricultural land use, and waterbodies land cover were the main drivers of Odonata and Zygoptera composition. Our results indicate that land cover is the main driver of the assemblage structure of larval Odonata, although a complex interplay of mechanisms associated with land conversion and water quality drive the distribution of larval Odonata in freshwater wetlands of the Brazilian Pampa. The major implication of our findings is that land cover modification is the major threat to Odonata distribution in Pampean wetlands, with potential impacts on the trophic structure and functioning of these ecosystems. © 2024 The Ecological Society of Japan.

The distribution, status, and phenology of the anostracan Phallocryptus spinosus in Sicily are described. The only population of the species to date known to occur with certainty on the island inhabits a few temporary water bodies located within the Natura2000 site “ITA010006 - Paludi di Capo Feto e Margi Spanò”. In these sites, the species co-occurs with an interesting halophilous flora and crustacean fauna. Based on available data, the concentration of dissolved salts in the water bodies seem to be the main driver of the life histories of the co-existing populations of the anostracans Artemia salina and Phallocryptus spinosus.&nbsp

Temporary wetlands are recognised biodiversity hotspots. Dormant egg banks, as part of their cryptic biodiversity, are responsible of wetlands resilience. Egg banks are also known to be sensitive indicators of anthropogenic disturbances. This study aims to assess the current state of research of toxicants impact on dormant egg banks in temporary wetlands. The systematic literature review carried out has shown the small number of studies on this topic. This study provides evidence of commonality concerning negative impact effect on the organisms, reducing hatching success, dormant eggs production and emergence, or species richness, among others, which might weaken ecosystem stabilization mechanisms by reducing biodiversity. Our review also revealed a glaring lack of in situ and long-term studies for understanding ecosystem consequences of toxicants on temporary wetlands. These gaps in knowledge hamper our ability to design and implement evidence-based conservation and management programs but opens opportunities for new research lines., Los humedales temporales son sistemas que atesoran alta biodiversidad. Los bancos de huevos de resistencia, como parte de su críptica biodiversidad, responsables de la resiliencia también son indicadores sensibles de perturbaciones antropogénicas. Este estudio tiene como objetivo evaluar grado de conocimiento sobre el impacto de los tóxicos en los huevos de resistencia en humedales temporales. La revisión sistemática de la literatura realizada ha puesto de manifiesto el escaso número de estudios sobre este tema. La mayoría indican impacto negativo: menor éxito de eclosión, producción y emergencia, o la riqueza de especies, lo que debilita el ecosistema al reducir la biodiversidad. Hay una evidente falta de estudios in situ y a largo plazo para comprender las consecuencias de los tóxicos en los humedales temporales. Esto dificulta nuestra capacidad para diseñar e implementar programas de conservación y manejo basados ​​en evidencia pero abren oportunidades para nuevas líneas de investigación.

Temporary wetlands are recognised biodiversity hotspots. Dormant egg banks, as part of their cryptic biodiversity, are responsible of wetlands resilience. Egg banks are also known to be sensitive indicators of anthropogenic disturbances. This study aims to assess the current state of research of toxicants impact on dormant egg banks in temporary wetlands. The systematic literature review carried out has shown the small number of studies on this topic. This study provides evidence of commonality concerning negative impact effect on the organisms, reducing hatching success, dormant eggs production and emergence, or species richness, among others, which might weaken ecosystem stabilization mechanisms by reducing biodiversity. Our review also revealed a glaring lack of in situ and long-term studies for understanding ecosystem consequences of toxicants on temporary wetlands. These gaps in knowledge hamper our ability to design and implement evidence-based conservation and management programs but opens opportunities for new research lines., Los humedales temporales son sistemas que atesoran alta biodiversidad. Los bancos de huevos de resistencia, como parte de su críptica biodiversidad, responsables de la resiliencia también son indicadores sensibles de perturbaciones antropogénicas. Este estudio tiene como objetivo evaluar grado de conocimiento sobre el impacto de los tóxicos en los huevos de resistencia en humedales temporales. La revisión sistemática de la literatura realizada ha puesto de manifiesto el escaso número de estudios sobre este tema. La mayoría indican impacto negativo: menor éxito de eclosión, producción y emergencia, o la riqueza de especies, lo que debilita el ecosistema al reducir la biodiversidad. Hay una evidente falta de estudios in situ y a largo plazo para comprender las consecuencias de los tóxicos en los humedales temporales. Esto dificulta nuestra capacidad para diseñar e implementar programas de conservación y manejo basados ​​en evidencia pero abren oportunidades para nuevas líneas de investigación.

We describe four new vegetation units and propose 17 new typifications and 24 altered names of syntaxa belonging to Isoeto-Nanojuncetea. Information is also provided on the publication dates of the alliances Isoetion and Preslion, Depto. de Biodiversidad, Ecología y Evolución, Fac. de Ciencias Biológicas, TRUE, pub

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 peltatus subsp. saniculifolius over the course of five inundation events. During the first inundation event, percent germination was higher for terrestrial morphotype seeds (36.1%) than for aquatic morphotype seeds (6.1%). Seed germination peaked for both groups during the second inundation event (terrestrial morphotype: 47%; aquatic morphotype: 34%). Even after all five events, some viable seeds had not yet germinated (terrestrial morphotype: 0.6%; aquatic morphotype: 5%). We also compared germination patterns for the two morphotypes in Callitriche brutia: the percent germination was higher for terrestrial morphotype seeds (79.5%) than for aquatic morphotype seeds (41.9%). Both aquatic plant species use two complementary strategies to ensure population persistence despite the unpredictable conditions of temporary ponds. First, plants can produce seeds with different dormancy periods that germinate during different inundation periods. Second, plants can produce terrestrial morphotypes, which generate more seeds during dry periods, allowing for re-establishment when conditions are once again favorable.

The Azorean islands have been historically affected by human activities, mainly due to the combined effects of habitat degradation and fragmentation, and the introduction of exotic species. We here aim to analyze the role of environmental characteristics and spatial descriptors in supporting regional biodiversity of macroinvertebrates by considering natural ponds and artificial tanks. After the monthly variation of macroinvertebrate assemblages was assessed in three temporary and two permanent ponds in the Azorean island of Terceira during a complete inundation-desiccation annual cycle, the assemblage differences of 12 ponds (three temporary and nine permanent ponds) and 8 closely-located artificial tanks were analyzed across a range of landscape disturbances.

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 peltatus subsp. saniculifolius over the course of five inundation events. During the first inundation event, percent germination was higher for terrestrial morphotype seeds (36.1%) than for aquatic morphotype seeds (6.1%). Seed germination peaked for both groups during the second inundation event (terrestrial morphotype: 47%; aquatic morphotype: 34%). Even after all five events, some viable seeds had not yet germinated (terrestrial morphotype: 0.6%; aquatic morphotype: 5%). We also compared germination patterns for the two morphotypes in Callitriche brutia: the percent germination was higher for terrestrial morphotype seeds (79.5%) than for aquatic morphotype seeds (41.9%). Both aquatic plant species use two complementary strategies to ensure population persistence despite the unpredictable conditions of temporary ponds. First, plants can produce seeds with different dormancy periods that germinate during different inundation periods. Second, plants can produce terrestrial morphotypes, which generate more seeds during dry periods, allowing for re-establishment when conditions are once again favorable.

We describe four new vegetation units and propose 17 new typifications and 24 altered names of syntaxa belonging to Isoeto-Nanojuncetea. Information is also provided on the publication dates of the alliances Isoetion and Preslion.

The Azorean islands have been historically affected by human activities, mainly due to the combined effects of habitat degradation and fragmentation, and the introduction of exotic species. We here aim to analyze the role of environmental characteristics and spatial descriptors in supporting regional biodiversity of macroinvertebrates by considering natural ponds and artificial tanks. After the monthly variation of macroinvertebrate assemblages was assessed in three temporary and two permanent ponds in the Azorean island of Terceira during a complete inundation-desiccation annual cycle, the assemblage differences of 12 ponds (three temporary and nine permanent ponds) and 8 closely-located artificial tanks were analyzed across a range of landscape disturbances.

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 peltatus subsp. saniculifolius over the course of five inundation events. During the first inundation event, percent germination was higher for terrestrial morphotype seeds (36.1%) than for aquatic morphotype seeds (6.1%). Seed germination peaked for both groups during the second inundation event (terrestrial morphotype: 47%; aquatic morphotype: 34%). Even after all five events, some viable seeds had not yet germinated (terrestrial morphotype: 0.6%; aquatic morphotype: 5%). We also compared germination patterns for the two morphotypes in Callitriche brutia: the percent germination was higher for terrestrial morphotype seeds (79.5%) than for aquatic morphotype seeds (41.9%). Both aquatic plant species use two complementary strategies to ensure population persistence despite the unpredictable conditions of temporary ponds. First, plants can produce seeds with different dormancy periods that germinate during different inundation periods. Second, plants can produce terrestrial morphotypes, which generate more seeds during dry periods, allowing for re-establishment when conditions are once again favorable.

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 peltatus subsp. saniculifolius over the course of five inundation events. During the first inundation event, percent germination was higher for terrestrial morphotype seeds (36.1%) than for aquatic morphotype seeds (6.1%). Seed germination peaked for both groups during the second inundation event (terrestrial morphotype: 47%; aquatic morphotype: 34%). Even after all five events, some viable seeds had not yet germinated (terrestrial morphotype: 0.6%; aquatic morphotype: 5%). We also compared germination patterns for the two morphotypes in Callitriche brutia: the percent germination was higher for terrestrial morphotype seeds (79.5%) than for aquatic morphotype seeds (41.9%). Both aquatic plant species use two complementary strategies to ensure population persistence despite the unpredictable conditions of temporary ponds. First, plants can produce seeds with different dormancy periods that germinate during different inundation periods. Second, plants can produce terrestrial morphotypes, which generate more seeds during dry periods, allowing for re-establishment when conditions are once again favorable.

The Azorean islands have been historically affected by human activities, mainly due to the combined effects of habitat degradation and fragmentation, and the introduction of exotic species. We here aim to analyze the role of environmental characteristics and spatial descriptors in supporting regional biodiversity of macroinvertebrates by considering natural ponds and artificial tanks. After the monthly variation of macroinvertebrate assemblages was assessed in three temporary and two permanent ponds in the Azorean island of Terceira during a complete inundation-desiccation annual cycle, the assemblage differences of 12 ponds (three temporary and nine permanent ponds) and 8 closely-located artificial tanks were analyzed across a range of landscape disturbances.

The Azorean islands have been historically affected by human activities, mainly due to the combined effects of habitat degradation and fragmentation, and the introduction of exotic species. We here aim to analyze the role of environmental characteristics and spatial descriptors in supporting regional biodiversity of macroinvertebrates by considering natural ponds and artificial tanks. After the monthly variation of macroinvertebrate assemblages was assessed in three temporary and two permanent ponds in the Azorean island of Terceira during a complete inundation-desiccation annual cycle, the assemblage differences of 12 ponds (three temporary and nine permanent ponds) and 8 closely-located artificial tanks were analyzed across a range of landscape disturbances.

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 peltatus subsp. saniculifolius over the course of five inundation events. During the first inundation event, percent germination was higher for terrestrial morphotype seeds (36.1%) than for aquatic morphotype seeds (6.1%). Seed germination peaked for both groups during the second inundation event (terrestrial morphotype: 47%; aquatic morphotype: 34%). Even after all five events, some viable seeds had not yet germinated (terrestrial morphotype: 0.6%; aquatic morphotype: 5%). We also compared germination patterns for the two morphotypes in Callitriche brutia: the percent germination was higher for terrestrial morphotype seeds (79.5%) than for aquatic morphotype seeds (41.9%). Both aquatic plant species use two complementary strategies to ensure population persistence despite the unpredictable conditions of temporary ponds. First, plants can produce seeds with different dormancy periods that germinate during different inundation periods. Second, plants can produce terrestrial morphotypes, which generate more seeds during dry periods, allowing for re-establishment when conditions are once again favorable.

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 peltatus subsp. saniculifolius over the course of five inundation events. During the first inundation event, percent germination was higher for terrestrial morphotype seeds (36.1%) than for aquatic morphotype seeds (6.1%). Seed germination peaked for both groups during the second inundation event (terrestrial morphotype: 47%; aquatic morphotype: 34%). Even after all five events, some viable seeds had not yet germinated (terrestrial morphotype: 0.6%; aquatic morphotype: 5%). We also compared germination patterns for the two morphotypes in Callitriche brutia: the percent germination was higher for terrestrial morphotype seeds (79.5%) than for aquatic morphotype seeds (41.9%). Both aquatic plant species use two complementary strategies to ensure population persistence despite the unpredictable conditions of temporary ponds. First, plants can produce seeds with different dormancy periods that germinate during different inundation periods. Second, plants can produce terrestrial morphotypes, which generate more seeds during dry periods, allowing for re-establishment when conditions are once again favorable.

We describe four new vegetation units and propose 17 new typifications and 24 altered names of syntaxa belonging to Isoeto-Nanojuncetea. Information is also provided on the publication dates of the alliances Isoetion and Preslion.

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 nutrient cycling and even physico-chemical properties of the water bodies they occupy. Nevertheless, despite an extensive body of literature on most other aspects of their ecology, we know very little about spatial movements of amphibian larvae in their natural habitats, and the little information we have is restricted to lotic systems. Here we use a mark-and-recapture procedure using elastomers to determine movement patterns and microhabitat selection of western spadefoot toad tadpoles (Pelobates cultripes) in two large ponds in southwestern Spain. We observed maximum distances moved by these tadpoles of >67 m and >245 m, depending on the pond. These distances coincided with the maximum cross distance in each pond, suggesting that they could potentially move even farther in larger wetlands. Mean distances moved were 29.7 and 105 m in each pond. We sampled at two, four and nine days after release of tagged individuals, and we observed a stable, not expanding, movement pattern across sampling dates, suggesting that tadpoles resumed normal activity immediately after release. Tadpoles showed preference for deeper and more densely vegetated areas of the ponds, especially associated with plant species such as Ranunculus peltatus and Potamogeton pectinatus

In the frame of the activities of the LIFE11 NAT/GR/1014 ForOpenForests, some water bodies occurring in the "Ethnikos Drymos Oitis” (GR2440004) and “Oros Kallidromo” (GR2440006) (Sterea Ellada) were investigated with the aim of providing a first census of the composition and diversity of their crustacean fauna. Overall, the sampling of 15 water bodies (7 of them listed as “Mediterranean temporary ponds” sensu EU “Habitats Directive”) led to the finding of 13 branchiopod, 11 copepod, and 7 ostracod taxa, including 4 species new for mainland Greece, i.e. the copepods Arctodiaptomus alpinus (Imhoff, 1885) and Diaptomus cf. serbicus, and the branchiopods Leptestheria dahalacensis (Rüppel, 1837) and Wlassicsia pannonica Daday, 1904. The comparative analysis of the observed species assemblages and richness suggests that the protection of those ponds identified as “priority habitats” according to the “Habitats Directive” is effective for the specialized and peculiar crustacean biota of these ecosystems, but it is not sufficient in order to preserve efficiently the whole diversity of temporary pond-dwelling crustaceans occurring in the study area. Therefore, the implementation of synergistic conservation measures dedicated to both “priority” and “non-priority” habitats is desirable.

In the frame of the activities of the LIFE11 NAT/GR/1014 ForOpenForests, some water bodies occurring in the "Ethnikos Drymos Oitis” (GR2440004) and “Oros Kallidromo” (GR2440006) (Sterea Ellada) were investigated with the aim of providing a first census of the composition and diversity of their crustacean fauna. Overall, the sampling of 15 water bodies (7 of them listed as “Mediterranean temporary ponds” sensu EU “Habitats Directive”) led to the finding of 13 branchiopod, 11 copepod, and 7 ostracod taxa, including 4 species new for mainland Greece, i.e. the copepods Arctodiaptomus alpinus (Imhoff, 1885) and Diaptomus cf. serbicus, and the branchiopods Leptestheria dahalacensis (Rüppel, 1837) and Wlassicsia pannonica Daday, 1904. The comparative analysis of the observed species assemblages and richness suggests that the protection of those ponds identified as “priority habitats” according to the “Habitats Directive” is effective for the specialized and peculiar crustacean biota of these ecosystems, but it is not sufficient in order to preserve efficiently the whole diversity of temporary pond-dwelling crustaceans occurring in the study area. Therefore, the implementation of synergistic conservation measures dedicated to both “priority” and “non-priority” habitats is desirable.

The Mediterranean bioregion is widely recognised as a biodiversity hotspot and its inland waters are among the species richest ecosystems of the northern hemisphere. However, the extent of such biodiversity has not been totally unravelled, especially in the Mediterranean islands. Here we present a first account of the crustaceans inhabiting 21 permanent and temporary ponds in Crete, the largest of the Greek islands and the fifth largest island in the Mediterranean Sea. The ponds, sampled between 2009 and 2018, cover all the island surface even though their number cannot be considered exhaustive to represent the entire non-malacostracan fauna of the island. Nevertheless, 46 taxa were identified and most of them are new records for Crete. Moreover, molecular taxonomy allowed to solve the systematic position of Arctodiaptomus piliger Brehm, 1955 and to synonymize this organism, previously considered endemic of the island, with Arctodiaptomus alpinus (Imhof, 1885). As regard branchiopods, this paper contributes a step ahead to clarify the taxonomic position of the Mediterranean Chirocephalus and Ceriodaphnia species. Finally, a review of all the non-stygobitic species present on the island is reported, including 78 taxa (21 Branchiopoda, 28 Copepoda and 29 Ostracoda). Overall, the achieved results offer new clues to solve the complex biogeographical pattern of the “entomostracan” crustaceans inhabiting the inland waters of the Mediterranean region., SCOPUS: ar.j, info:eu-repo/semantics/published

In the frame of the activities of the LIFE11 NAT/GR/1014 ForOpenForests, some water bodies occurring in the "Ethnikos Drymos Oitis" (GR2440004) and "Oros Kallidromo" (GR2440006) (Sterea Ellada) were investigated with the aim of providing a first census of the composition and diversity of their crustacean fauna. Overall, the sampling of 15 water bodies (7 of them listed as "Mediterranean temporary ponds" sensu EU "Habitats Directive") led to the finding of 13 branchiopod, 11 copepod, and 7 ostracod taxa, including 4 species new for mainland Greece, i.e. the copepods Arctodiaptomus alpinus (Imhoff, 1885) and Diaptomus cf. serbicus, and the branchiopods Leptestheria dahalacensis (Rüppel, 1837) and Wlassicsia pannonica Daday, 1904. The comparative analysis of the observed species assemblages and richness suggests that the protection of those ponds identified as "priority habitats" according to the "Habitats Directive" is effective for the specialized and peculiar crustacean biota of these ecosystems, but it is not sufficient in order to preserve efficiently the whole diversity of temporary pond-dwelling crustaceans occurring in the study area. Therefore, the implementation of synergistic conservation measures dedicated to both "priority" and "non-priority" habitats is desirable., SCOPUS: ar.j, info:eu-repo/semantics/published

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 validated for two periods of eight hydrological years each to assess whether the duration of the pond wet phase (hydroperiod) significantly deviated from an expected pattern driven by rainfall and evapotranspiration. The model output indicated a satisfactory performance for all simulations. This approach provided two main conclusions: a) a long-term increasing trend in water losses on the pond water balance which has not been followed by a corresponding decreasing trend in rainfall, and b) these water losses were highest in the pond located at < 1 km to the pumping area and lowest in the pond located at a further distance (5.6 km) and at a lower altitude. Our results suggest that, in the long run, a small groundwater abstraction rate has exerted a high hydrological pressure on the closest pond to the pumping area.

We investigated the influence of different combinations of natural aquatic invertebrate communities and the biological insecticide Bacillus thuringiensis var israelensis (Bti) on the establishment of larval populations of mosquitoes in temporary ponds in the field. The study involved two experiments so called “Bti and community” and “community density” experiments respectively. In the “Bti and community” part, three treatments were tested: added aquatic invertebrate community alone (“com”), Bti alone (“Bti”), and a combination of added invertebrate community and Bti (“comBti”). The “community density” experimentincluded three setups, all treated with Bti but having different densities of aquatic invertebrate communities (that is, “low”, “medium” and “high”). The two species of mosquitoes that established in the ponds were Anopheles spp. and Culex spp. In both experiments and after 24 h following the application of Bti, larval abundance of these mosquitoes decreased by about 78 to 99% in the setups where the biological pesticide was used. However, the recovery of mosquito larvae in these ponds was fast, and the most important in low community density conditions (“Bti” and “low”), moderate in medium community density (“medium”) and did not occur in high community density (“high” and “comBti”). By contrast with the combined treatment of invertebrate community and Bti (“comBti”), the abundance of mosquito larvae in the setup treated with invertebrate community alone (“com”) showed an increase during some days and then a progressive decrease until the end of the experiment. These results suggest that the treatment with Bti alone was efficient but only for a short time as recovery occurred; the addition of community alone was efficient in a longer term whereas the combination of Bti and added community was efficient in both the short and longer terms. This implies that the efficacy of larval control of mosquitoes by Bti was improved with high community density.

Eggs of the Western 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 (SW Spain) 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 (< 1.5 km), prompted us to elucidate the possible links between the reduction in pond hydroperiod over past decades (1989–2008) and the decrease of groundwater pH-buffering capacity. The average hydroperiod had decreased by 4 months since 1998–99 in the pond where the extensive egg mortality had occurred. The total alkalinity, and the Mg2 + concentration had also significantly declined in the shallow water-table since 1998–99, from an average of 8.56 to 0.32 meq l− 1, and of 3.57 to 1.15 meq l− 1, respectively. This decline of the shallow groundwater buffering capacity could turn this pond more susceptible to the inorganic acidity associated with pyrite oxidation as the sediment S content was often above 0.03%. The initial ratio of S/Ca + Mg in the summer dry sediment was a good predictor of pore-water pH on re-wetting after desiccation (r2 = 0.802, p < 0.01). Therefore, this ratio can give some anticipation to mitigate the impact of acidity on toad hatching before these temporary ponds are reflooded on the next wet season. Our results suggest that the long-term damage to pond water levels can trigger a potential risk of soil acidification in the presence of iron-sulphide minerals.

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.

The physical-chemical features of four temporary shallow ponds and their invertebrate fauna were studied during the summer months of three consecutive years. Invertebrate sampling was conducted by suction of pond water with a pump. From the physical-chemical point of view, the study ponds were heliotopic, mesotrophic and mesopoikilohaline microlimnotopes. Their thermal stratification is monomic-tic, with few degrees of difference in water temperature between surface and bottom. The chemical characteristics of pond water were in between those of freshwater and truly saline ponds. The study ponds exhibited high content of phosphate, Ca, and sulfate content, followed by fluoride, Fe, K, Mg, Cl, nitrate, and total suspended solids. They were low in bicarbonate and CN content. Apparently, the geochemical properties of the surrounding mountains play a role in the hydrochemistry of these water bodies. Total abundance per taxon was mostly low. We recorded five higher taxa. Cladocerans (e.g., Alona spp.), followed by dipterans (e.g., chironomid flies), and copepods (e.g., cyclopoids and harpactoids) were the dominant groups. Less abundant groups were amphipods (e.g., Hyperia spp.), and ostracods (e.g., Cyprididae). Some of the taxa reported in this work are recorded for first time in this type of habitat. Nevertheless, given the habitat characteristics, studies at finer taxonomic resolution are needed to search for site-specific genera or species. We obtained lower taxono-mic richness compared to lotic systems found in the area. This result may be due to differences in the dynamics of abiotic conditions observed between the two habitats. The variability in abundance among ponds was high for most of the recorded taxa. This variability may be a reflection of the general condition of the wet pasture we studied, suggesting that the ponds are important sources of the high biodiversity found in these landscape units. As the wet pastures of the area are networked, also contribute t, Durante los meses de verano de tres años consecutivos se estudiaron las características fisicoquímicas de cuatro pozas efímeras, de poca profundidad y su fauna de invertebrados. El muestreo de los invertebrados se llevó a cabo por succión del agua con una máquina de bombeo. Desde el punto de vista fisicoquímico, las pozas estudiadas resultaron ser microlimnotopos heliotópicos, mesotróficos y mesopoikilohalinos. Su estratificación térmica resultó ser de carácter monomíctico, con pocos grados de diferencia térmica entre la superficie y el fondo. Se encontró que sus características químicas las sitúan entre hábitats dulceacuícolas y verdaderamente salinos. Las pozas mostraron alto contenido de fosfato, Ca y sulfato, seguido por los niveles de fluoruro, Fe, K, Mg, Cl y nitrato. El contenido de los sólidos totales suspendidos fue igualmente alto. Por el contrario, el contenido de bicarbonato y CN fue bajo. Al parecer, las propiedades geoquímicas de las montañas que rodean a la vega juegan un papel importante en la hidroquímica de estos cuerpos de agua. En general, las abundancias totales por taxón fueron bajas. Se registraron cinco taxones superiores. Cladóceros (e.g., Alona spp.), seguido por los dípteros quironómidos y los copépodos ciclopoideos y harpacticoideos fueron los grupos dominantes. Grupos menos abundantes fueron los anfípodos (e.g., Hyperia spp.) y los ostrácodos Cyprididae. Algunos de los taxones reportados en este trabajo se registran por primera vez en este tipo de hábitat. Sin embargo, debido a sus características, se necesitan estudios con una resolución taxonómica más fina con el fin de dilucidar la presencia de géneros o especies propias de estos sistemas. En comparación con los cuerpos lóticos encontrados en la zona, las pozas arrojaron una menor riqueza taxonómica. Este resultado puede deberse a diferencias en la dinámica de las condiciones abióticas observadas entre los dos hábitats. La variabilidad entre pozas, asociada a la abundancia, fue alta p

The study ponds are part of a peatland located in the Elqui river basin of the Andes. They turned out to be heliotropic (homoeother-mic), mesotrophic and mesopoikilohaline microlimnotopes. The ponds showed high content of dissolved metals, mainly Ca (mean ~205 mg/l), Na (~60 mg/l), Mg (~60 mg/l) and K (~13 mg/l), and the inorganic non-metals sulfate (~976 mg/l), chloride (~34.2 mg/l), phosphate (~23 mg/l), bicarbonate (~11 mg/l) and nitrate (~3.3 mg/l). Excluding Hg, Se and nitrite, trace elements were represented by Al, As, Cd, CN, Cu, Cr, Fe, Ba, Be, Co, Zn, Mo, Ni, Pb, Li, Ag, and V. The cationic pattern of ponds was Ca > Na > Mg > K >Mn; whereas the anionic pattern was sulfate > chloride > phosphate > carbonate > Fl. Although we did not study, the hydrochemical characteristics of these water bodies seem to reflect the characteristics of the geological substrate of the mountains through which the water drains into the peatland., Las pozas estudiadas forman parte de una vega ubicada en el piso altoandino de la hoya hidrográfica del río Elqui. Estas resultaron ser microlimnotopos heliotópicos (homeotérmicos), mesotróficos y mesopoikilohalinos. Las pozas mostraron niveles elevados de metales disueltos, principalmente Ca (promedio: ~205 mg/l), Na (~60 mg/l), Mg (~60 mg/l) y K (~13 mg/l), y los inorgánicos no metálicos sulfato (~976 mg/l), cloruro (~34,2 mg/l), fosfato (~23 mg/l), bicarbonato mg/l) y nitrato (~3,3 mg/l). Excluyendo Hg, Se y nitrito, las pozas presentaron niveles traza de Al, As total, Cd, CN, Cu, Cr, Fe, Ba, Be, Co, Zn, Mo, Ni, Pb, Li, Ag y V. El patrón catiónico de las pozas fue Ca > Na > Mg > K > Mn; a su vez, el patrón aniónico fue sulfato > cloruro > fosfato > carbonato > Fl. Aunque no fue estudiado por nosotros, las características hidroquímicas de estos cuerpos de agua parecen reflejar las características del sustrato geológico de las montañas por medio del que el agua fluye hacia la vega.

En aquest estudi, s’han quantificat els fluxos de carboni en diferents basses temporals de l’illa de Menorca. Les basses s’han comportat com a emissores de diòxid de carboni (CO2) cap a l’atmosfera durant totes les fases del cicle hidrològic, amb fluxos de CO2 comparables als de sistemes lacustres no temporals, si bé els fluxos de metà són de menor importància. Destaca l’important paper de la fase seca d’aquests sistemes com a emissora de CO2. Les seccions no inundades de les basses han mostrat una elevada activitat de processament de carboni, emetent CO2 a intensitats significativament superiors a les observades des de la columna d’aigua.In this study, we evaluated the carbon fluxes in a set of temporary ponds in the island of Menorca. The ponds were net emitters of carbon dioxide (CO2) towards the atmosphere during the different phases of their hydrologic cycles. The measured CO2 fluxes were comparable to those from non-temporary lacustrinesystems, although methane presented lower values. We stress the relevant role of the dry phase of these systems as a net CO2 emitter. The non-flooded sections of the ponds showed a strong carbon processing activity, emitting CO2 at significantly higher intensity than the water column.

The study ponds are part of a peatland located in the Elqui river basin of the Andes. They turned out to be heliotropic (homoeother-mic), mesotrophic and mesopoikilohaline microlimnotopes. The ponds showed high content of dissolved metals, mainly Ca (mean ~205 mg/l), Na (~60 mg/l), Mg (~60 mg/l) and K (~13 mg/l), and the inorganic non-metals sulfate (~976 mg/l), chloride (~34.2 mg/l), phosphate (~23 mg/l), bicarbonate (~11 mg/l) and nitrate (~3.3 mg/l). Excluding Hg, Se and nitrite, trace elements were represented by Al, As, Cd, CN, Cu, Cr, Fe, Ba, Be, Co, Zn, Mo, Ni, Pb, Li, Ag, and V. The cationic pattern of ponds was Ca > Na > Mg > K >Mn; whereas the anionic pattern was sulfate > chloride > phosphate > carbonate > Fl. Although we did not study, the hydrochemical characteristics of these water bodies seem to reflect the characteristics of the geological substrate of the mountains through which the water drains into the peatland., Las pozas estudiadas forman parte de una vega ubicada en el piso altoandino de la hoya hidrográfica del río Elqui. Estas resultaron ser microlimnotopos heliotópicos (homeotérmicos), mesotróficos y mesopoikilohalinos. Las pozas mostraron niveles elevados de metales disueltos, principalmente Ca (promedio: ~205 mg/l), Na (~60 mg/l), Mg (~60 mg/l) y K (~13 mg/l), y los inorgánicos no metálicos sulfato (~976 mg/l), cloruro (~34,2 mg/l), fosfato (~23 mg/l), bicarbonato mg/l) y nitrato (~3,3 mg/l). Excluyendo Hg, Se y nitrito, las pozas presentaron niveles traza de Al, As total, Cd, CN, Cu, Cr, Fe, Ba, Be, Co, Zn, Mo, Ni, Pb, Li, Ag y V. El patrón catiónico de las pozas fue Ca > Na > Mg > K > Mn; a su vez, el patrón aniónico fue sulfato > cloruro > fosfato > carbonato > Fl. Aunque no fue estudiado por nosotros, las características hidroquímicas de estos cuerpos de agua parecen reflejar las características del sustrato geológico de las montañas por medio del que el agua fluye hacia la vega.

The physical-chemical features of four temporary shallow ponds and their invertebrate fauna were studied during the summer months of three consecutive years. Invertebrate sampling was conducted by suction of pond water with a pump. From the physical-chemical point of view, the study ponds were heliotopic, mesotrophic and mesopoikilohaline microlimnotopes. Their thermal stratification is monomic-tic, with few degrees of difference in water temperature between surface and bottom. The chemical characteristics of pond water were in between those of freshwater and truly saline ponds. The study ponds exhibited high content of phosphate, Ca, and sulfate content, followed by fluoride, Fe, K, Mg, Cl, nitrate, and total suspended solids. They were low in bicarbonate and CN content. Apparently, the geochemical properties of the surrounding mountains play a role in the hydrochemistry of these water bodies. Total abundance per taxon was mostly low. We recorded five higher taxa. Cladocerans (e.g., Alona spp.), followed by dipterans (e.g., chironomid flies), and copepods (e.g., cyclopoids and harpactoids) were the dominant groups. Less abundant groups were amphipods (e.g., Hyperia spp.), and ostracods (e.g., Cyprididae). Some of the taxa reported in this work are recorded for first time in this type of habitat. Nevertheless, given the habitat characteristics, studies at finer taxonomic resolution are needed to search for site-specific genera or species. We obtained lower taxono-mic richness compared to lotic systems found in the area. This result may be due to differences in the dynamics of abiotic conditions observed between the two habitats. The variability in abundance among ponds was high for most of the recorded taxa. This variability may be a reflection of the general condition of the wet pasture we studied, suggesting that the ponds are important sources of the high biodiversity found in these landscape units. As the wet pastures of the area are networked, also contribute t, Durante los meses de verano de tres años consecutivos se estudiaron las características fisicoquímicas de cuatro pozas efímeras, de poca profundidad y su fauna de invertebrados. El muestreo de los invertebrados se llevó a cabo por succión del agua con una máquina de bombeo. Desde el punto de vista fisicoquímico, las pozas estudiadas resultaron ser microlimnotopos heliotópicos, mesotróficos y mesopoikilohalinos. Su estratificación térmica resultó ser de carácter monomíctico, con pocos grados de diferencia térmica entre la superficie y el fondo. Se encontró que sus características químicas las sitúan entre hábitats dulceacuícolas y verdaderamente salinos. Las pozas mostraron alto contenido de fosfato, Ca y sulfato, seguido por los niveles de fluoruro, Fe, K, Mg, Cl y nitrato. El contenido de los sólidos totales suspendidos fue igualmente alto. Por el contrario, el contenido de bicarbonato y CN fue bajo. Al parecer, las propiedades geoquímicas de las montañas que rodean a la vega juegan un papel importante en la hidroquímica de estos cuerpos de agua. En general, las abundancias totales por taxón fueron bajas. Se registraron cinco taxones superiores. Cladóceros (e.g., Alona spp.), seguido por los dípteros quironómidos y los copépodos ciclopoideos y harpacticoideos fueron los grupos dominantes. Grupos menos abundantes fueron los anfípodos (e.g., Hyperia spp.) y los ostrácodos Cyprididae. Algunos de los taxones reportados en este trabajo se registran por primera vez en este tipo de hábitat. Sin embargo, debido a sus características, se necesitan estudios con una resolución taxonómica más fina con el fin de dilucidar la presencia de géneros o especies propias de estos sistemas. En comparación con los cuerpos lóticos encontrados en la zona, las pozas arrojaron una menor riqueza taxonómica. Este resultado puede deberse a diferencias en la dinámica de las condiciones abióticas observadas entre los dos hábitats. La variabilidad entre pozas, asociada a la abundancia, fue alta p

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 samples of 22 ponds, during two successive years (2005-2007). The exotic weevil was present in 21% of the sampled ponds where the host plant, A. filiculiodes, was not detectable. Because A. filiculoides can reach high densities in an adjacent area of marsh, we suggest that the occurrence of the exotic weevil in these ponds is a consequence of dispersal from nearby marshes. Our study demonstrates that S. rufinasus adults can occur at relatively high densities in ponds where the host plant is not present, suggesting that such apparently “host-free” sites may act as stepping stones for the spread of this species, La presencia de la especie de gorgojo exótico Stenopelmus rufinasus (Coleoptera: Curculionidae) está íntimamente rela- cionada con la planta acuática exótica Azolla filiculoides. En este estudio se registró por primera vez la presencia de S. rufinasus en el Parque Nacional de Doñana (SO España) tras realizar un muestreo de macroinvertebrados en 91 lagunas que incluye muestreos mensuales de 22 de las mismas durante dos años consecutivos (2005-2007). El gorgojo exótico estuvo presente en el 21% de las lagunas muestreadas a pesar de que su supuesto hospedador, A. filiculiodes, no fue detectado. Dado que A. filiculiodes puede alcanzar grandes densidades en la marisma adyacente, sugerimos que la presencia del gor- gojo exótico en las lagunas temporales se debe a su dispersión desde la marisma. Este estudio demuestra que individuos adultos de S. rufinasus pueden aparecer con densidades relativamente altas en lagunas donde su hospedador potencial no está presente, lo que sugiere que estos sitios libres de hospedador podrían actuar como zonas de paso para la dispersión de la especie

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 their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas.

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 their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas.

Small water bodies, such as temporary ponds, have a high carbon processing potential. Nevertheless, despite the global occurrence of these systems, the carbon effluxes from such water bodies have been largely overlooked. In this study, we examined the intra- and intersystem variability of carbon dioxide (CO2) effluxes from a set of Mediterranean temporary ponds during the flooding phase, a hot-spot for biogeochemical cycling in temporary systems. The CO2 effluxes showed higher variability among the various sections of each pond (i.e., inundated, emerged-unvegetated and emerged-vegetated) than among the ponds. The emerged-vegetated sections showed the highest CO2 effluxes per unit area and tended to drive the total effluxes at the whole-ecosystem scale. The mean CO2 efflux (121.3 +/- 138.1 mmol m(-2) d(-1)) was in the upper range for freshwater ecosystems. The CO2 effluxes were not related to catchment properties but rather to the organic content of the sediments, especially in the emerged sections of the ponds. Our results indicate that temporary ponds, especially their emerged sections, are important sources of CO2 to the atmosphere, highlighting the need to include the dry phases of these and other temporary aquatic systems in regional carbon budgets.

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 their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas., Las características hidrológicas y geomorfológicas pueden ser de gran utilidad para la clasificación de humedales. Las lagunas temporales del manto eólico de Doñana se pueden clasificar en función de las cinco áreas geomorfológicas en que se encuentran. Nuestra hipótesis se basa en que las lagunas de estas áreas difieren en las características de sus suelos, lo cual puede explicar también las diferente composición de las comunidades de macroinvertebrados, anfibios y plantas que las habitan. Las lagunas del sur de Doñana se diferenciaron de las del norte principalmente en la distancia a la capa freática. Se realizó una ordenación de las lagunas a partir de un análisis multivariante de las características del suelo que resultó consistente con la segregación norte-sur. Se observó una mayor segregación en las comunidades de plantas acuáticas en este gradiente norte-sur, que se explica en función de las concentraciones de carbonatos y de otros iones principales en el suelo de las lagunas. Las lagunas localizadas en áreas de ecotono (marisma-arenas y arenas estabilizadas-arenas móviles) resultaron ser las de mayor riqueza de anfibios y macroinvertebrados. Esto podría deberse a que estas áreas contienen las lagunas de mayor duración, siendo los únicos medios inundados en épocas de sequía, y al alto número de lagunas temporales que presentan, favoreciendo la conectividad y heterogeneidad de ambientes.

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 their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas.

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 their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas.

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 their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas.

Small water bodies, such as temporary ponds, have a high carbon processing potential. Nevertheless, despite the global occurrence of these systems, the carbon effluxes from such water bodies have been largely overlooked. In this study, we examined the intra- and intersystem variability of carbon dioxide (CO2) effluxes from a set of Mediterranean temporary ponds during the flooding phase, a hot-spot for biogeochemical cycling in temporary systems. The CO2 effluxes showed higher variability among the various sections of each pond (i.e., inundated, emerged-unvegetated and emerged-vegetated) than among the ponds. The emerged-vegetated sections showed the highest CO2 effluxes per unit area and tended to drive the total effluxes at the whole-ecosystem scale. The mean CO2 efflux (121.3 ± 138.1 mmol m–2 d–1) was in the upper range for freshwater ecosystems. The CO2 effluxes were not related to catchment properties but rather to the organic content of the sediments, especially in the emerged sections of the ponds. Our results indicate that temporary ponds, especially their emerged sections, are important sources of CO2 to the atmosphere, highlighting the need to include the dry phases of these and other temporary aquatic systems in regional carbon budgets.Los pequeños cuerpos de agua como los estanques temporales tienen un elevado potencial para procesar carbono. Sin embargo, a pesar de su presencia global, los flujos de carbono procedentes de estos sistemas han sido muy poco estudiados. En el presente trabajo, se estudió la variabilidad intra- e inter-sistémica de los flujos de dióxido de carbono (CO2) en un conjunto de estanques temporales mediterráneos durante su fase de inundación, un momento en que los ciclos biogeoquímicos en sistemas temporales se intensifican. Las emisiones de CO2 presentaron una mayor variabilidad entre las diferentes secciones dentro de cada estanque (es decir, inundada, emergida-sin vegetación y emergida-vegetada) que entre los diferentes estanque

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 their macroinvertebrate, amphibian, and aquatic plant species assemblages. The study ponds were significantly segregated into southern and northern geomorphological areas based on the depth to the water table. The results of the multivariate ordination of soil variables were consistent with a north-south segregation, which was explained by the carbonate and other main ion concentrations in the pond basins. The ponds located in ecotones (marsh-sand and stable-mobile dunes) were particularly rich in amphibians and macroinvertebrates. This result may be explained because the ponds with the longest permanence of water were located in these areas, which represented the only flooded ponds during droughts. In addition, they also contained a high number of temporary ponds, thus favouring connectivity and environmental heterogeneity in these areas.

Lepidurus arcticus (Pallas, 1793) is a keystone species in High Arctic ponds, which are exposed to a wide range of environmental stressors. This thesis provides information on the ecology of this little studied species by paying particular focus on the sensitivity of L. arcticus to acidification and climate change. Respiration, reproduction, olfaction, morphology, salinity and pH tolerance of the species were studied in the laboratory and several environmental parameters were measured in its natural habitats in Arctic ponds. Current global circulation models predict 2–2.4 °C increase in summer temperatures on Spitsbergen, Svalbard, Norway. The L. arcticus respiration activity was tested at different temperatures (3.5, 10, 16.5, 20, 25 and 30 °C). The results show that L. arcticus is clearly adapted to live in cold water and have a temperature optimum at +10 °C. This species should be considered as stenothermal, because it seems to be able to live only within a narrow temperature range. L. arcticus populations seem to have the capacity to respond to the ongoing climate change on Spitsbergen. Changes can be seen in the species’ reproductive capacity and in the individuals’ body size when comparing results with previous studies on Spitsbergen and in other Arctic areas. Effective reproduction capacity was a unique feature of the L. arcticus populations on Spitsbergen. L. arcticus females reached sexual maturity at a smaller body size and sexual dimorphism appeared in smaller animals on Spitsbergen than anywhere else in the subarctic or Arctic regions. L. arcticus females were able to carry more eggs (up to 12 eggs per female) than has been observed in previous studies. Another interesting feature of L. arcticus on Spitsbergen was their potential to grow large, up to 39.4 mm in total length. Also cannibalistic behaviour seemed to be common on Spitsbergen L. arcticus populations. The existence of different colour morphs and the population-level differences in morphology o, Lepidurus arcticus (Pallas, 1793) on avainlaji arktisissa lammissa, joissa se on altistunut useille ympäristön stressitekijöille. Tutkielmassa selvitetään tämän vähän tutkitun lajin ekologiaa keskittyen lajin herkkyyteen happamoitumiselle ja ilmastonmuutokselle. Lajin hengitysaktiivisuutta, lisääntymistä, hajuaistia, morfologiaa sekä suolan ja pH:n sietoa tutkitiin laboratoriossa ja useita ympäristömuuttujia mitattiin arktisista lammista. Maailmanlaajuinen ilmastomalli ennustaa 2–2,4 °C nousua kesälämpötiloihin Huippuvuorilla Norjassa. L. arcticus lajin hengitysaktiivisuutta mitattiin eri lämpötiloissa (3,5; 10; 16,5; 20; 25 ja 30 °C). Tulokset osoittivat, että L. arcticus on selvästi sopeutunut elämään kylmissä vesissä ja sen lämpötila optimi on 10 °C. L. arcticus lajia tulisi pitää stenotermisenä lajina, koska se näyttää sietävän vain vähäistä lämpötilan vaihtelua. L. arcticus populaatioilla vaikutti olevan kyky reagoida meneillään olevaan ilmastonmuutokseen Huippuvuorilla. Ilmastonmuutoksen aiheuttamia muutoksia voidaan nähdä lajin lisääntymistehokkuudessa ja yksilöiden koossa, kun tuloksia on vertailtu aikaisemmin Huippuvuorilla ja muilla arktisilla ja subarktisilla alueilla tehtyihin tutkimuksiin. Tehokas lisääntyminen oli ainutlaatuinen piirre Huippuvuorten L. arcticus populaatioissa. Naaraat saavuttivat sukukypsyyden pienemmässä koossa ja pystyivät kantamaan enemmän munia (jopa 12 kappaletta) Huippuvuorilla kuin mitä on havaittu minkään muun alueen L. arcticus populaatioissa. Toinen mielenkiintoinen piirre Huippuvuorten L. arcticus yksilöissä oli niiden kyky kasvaa kookkaaksi (jopa 39,4 mm) ja kolmanneksi populaatioissa esiintynyt kannibalismi. Eri värimuotojen olemassaolosta tai populaatioiden välisistä morfologisista eroista ei tiedetty aikaisemmin mitään. Huippuvuorten populaatioista löytyi kaksi päävärityyppiä (yksivärinen ja marmorikuvioinen) sekä useita värityyppien yhdistelmiä. Kolmas mielenkiintoinen löytö oli tieteelle uusi sairaus, joka aktivoitui l

Recent and increasing interest in tempo- rary 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 Don˜ ana National Park (SW Spain). We sampled the pond at four different times—morning, afternoon, evening and night—distinguishing between deep and shallow zones. In our sampling, dip-netting captured a higher number of taxa, and higher abundances of individuals than fyke nets. However, both techniques captured exclusive taxa, not recorded with the other device. Fyke nets distinguished between nocturnal and diurnal macroinvertebrates, and hence are more appropriate to study macroinvertebrate diel activity. We detected nocturnal activity in Gerris thoracicus larvae, and adults of Colymbetes fuscus, Rhantus suturalis, Rhantus hispanicus and Hydrochara flav- ipes. Conversely, larvae of Sympetrum fonscolombei and Notonecta spp., and adults of Notonecta glauca were mainly diurnal. The overall diel activity pattern of the macroinvertebrate assemblage depended on the diel activities of their integrating taxa and stages. Although dip-netting was more appropriate to sample macroinvertebrate assemblages in different micro- habitats, fyke nets better captured nocturnal and fast- swimming invertebrates. Consequently, the joint use of both sampling techniques would capture a better picture of the representative macrofauna of a tempo- rary pond than either one on its own

Aim The imperfect detection of species may lead to erroneous conclusions about species–environment 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 reliability of species detection into regression-based species distribution modelling. Location Don˜ana National Park (south-western Spain). Methods Using species-specific monthly detection probabilities, we estimated the detection reliability as the probability of having detected the species given the species-specific survey time. Such reliability estimates were used to account explicitly for data uncertainty by weighting each absence. We illustrated how this novel framework can be used to evaluate four competing hypotheses as to what constitutes primary environmental control of amphibian distribution: breeding habitat, aestivating habitat, spatial distribution of surrounding habitats and/or major ecosystems zonation. The study was conducted on six pond-breeding amphibian species during a 4-year period. Results Non-detections should not be considered equivalent to real absences, as their reliability varied considerably. The occurrence of Hyla meridionalis and Triturus pygmaeus was related to a particular major ecosystem of the study area, where suitable habitat for these species seemed to be widely available. Characteristics of the breeding habitat (area and hydroperiod) were of high importance for the occurrence of Pelobates cultripes and Pleurodeles waltl. Terrestrial characteristics were the most important predictors of the occurrence of Discoglossus galganoi and Lissotriton boscai, along with spatial distribution of breeding habitats for the last species. Main conclusions We did not find a single best supported hypothesis valid for all species, which stresses the importance of multiscale and multifactor approaches. More im

Nestedness has been widely used to measure the structure of biological communities and occurs when species-poor sites contain subsets of species-rich ones. Here, we examine nested patterns across the macroinvertebrate assemblages of 91 ponds in Doñana National Park, Spain, and explore temporal variation of nestedness and species richness in 19 temporary ponds over 2 years with differing rainfall. Macroinvertebrate assemblages were significantly nested; both pond spatial arrangement and environmental variation being important in driving nested patterns. Despite the nested structure observed, a number of taxa and ponds deviate from this pattern (termed idiosyncratic), by occurring more frequently than expected in species-poor sites, or having assemblages dominated by species largely absent from species-rich sites. Aquatic adults of winged insects, capable of dispersal, were more highly nested than non-dispersing taxa and life-history stages. Idiosyncratic taxa were found in ponds spanning a wide range of hydroperiods, although nestedness was higher in more permanent waterbodies. Monthly sampling demonstrated a gradual increase of species richness and nestedness from pond filling to April-May, when the most temporary ponds started to dry. Although the degree of nestedness of individual pond assemblages varied from month to month, the overall degree of nestedness in the two study years was practically identical despite marked differences in hydroperiod. Our results suggest that differential colonization and environmental variation are key processes driving the nested structure of Doñana ponds, that macroinvertebrate assemblages change in a predictable manner each year in response to cycles of pond wetting and drying, and that connectivity and environmental variability maintain biodiversity in pond networks.

Nestedness has been widely used to measure the structure of biological communities and occurs when species-poor sites contain subsets of species-rich ones. Here, we examine nested patterns across the macroinvertebrate assemblages of 91 ponds in Doñana National Park, Spain, and explore temporal variation of nestedness and species richness in 19 temporary ponds over 2 years with differing rainfall. Macroinvertebrate assemblages were significantly nested; both pond spatial arrangement and environmental variation being important in driving nested patterns. Despite the nested structure observed, a number of taxa and ponds deviate from this pattern (termed idiosyncratic), by occurring more frequently than expected in species-poor sites, or having assemblages dominated by species largely absent from species-rich sites. Aquatic adults of winged insects, capable of dispersal, were more highly nested than non-dispersing taxa and life-history stages. Idiosyncratic taxa were found in ponds spanning a wide range of hydroperiods, although nestedness was higher in more permanent waterbodies. Monthly sampling demonstrated a gradual increase of species richness and nestedness from pond filling to April-May, when the most temporary ponds started to dry. Although the degree of nestedness of individual pond assemblages varied from month to month, the overall degree of nestedness in the two study years was practically identical despite marked differences in hydroperiod. Our results suggest that differential colonization and environmental variation are key processes driving the nested structure of Doñana ponds, that macroinvertebrate assemblages change in a predictable manner each year in response to cycles of pond wetting and drying, and that connectivity and environmental variability maintain biodiversity in pond networks.

Mediterranean temporary ponds are a priority habitat under the European Union Habitats Directive, but those of natural origin are scarce, as many of them have been destroyed or transformed into permanent waters. The aim of this study is to highlight the conservation value of the system of temporary ponds in Do˜nana National Park, where more than 3000 water bodies may be lled during wet years. They are located on soils of aeolian origin where water persistence is favoured by the presence of an argilic semi permeable horizon and by a relic clay-rich sandy layer. Temporary ponds can be classi ed across a wide hydroperiod gradient. Most ponds ll with autumnal or winter rains and persist up to late spring or summer, and only a few may persist through summer. Eight of the 11 amphibian species of this area require temporary ponds for breeding. More than 124 taxa of macroinvertebrates have been recorded, coleopterans (56 taxa) and heteropterans (19 taxa) being the richest taxonomic groups. Several zooplankton species are endemic to this kind of habitats, such as the copepod Dussartius baeticus and the rotifer Lecane donyanensis. Regarding vegetation, at least 55 hydrophytes species were identi ed in the ponds sampled, and also some species endemic to SW Iberian Peninsula (Callitriche regis-jubae, Scorzonera stulosa, Callitriche lusitanica) and others are in relic situation (Hydrocharis morsus-ranae, Thorella verticillato-inundata, Lemna trisulca). The conservation value of these ponds is highlighted by the large variety of protected and/or rare species of ora and fauna, which are favoured by a high pond abundance and connectivity.