► Climate warming will lead to colonisation (winners) and extinction (losers) events. ► We quantified the potential winners and losers in Swiss small standing waterbodies. ► The proportion of losers ...was smaller than the proportion of winners. ► A resilience index further prioritizes the species along an extinction risk gradient. ► The potential threat from climate warming is not reflected by the current Red Lists.
Climate warming is affecting the biodiversity all around the world, resulting in the expansion or contraction of the geographical range of species, and leading to colonisation (winners) and extinction (losers) events in ecosystems. It is crucial for the conservation of biodiversity to identify these potential winners and losers.
We focus here on small standing waterbodies in Switzerland and on five taxonomic groups: vascular plants, snails, beetles, dragonflies and amphibians. We first assessed the sensitivity of each species to climate warming through their thermal preferences, using current altitudinal and latitudinal distribution, as a surrogate for temperature. We then evaluated the resilience of species to perturbations through five ecological and biogeographical criteria applicable to the perturbation “warming”: dispersal ability, degree of habitat specialisation, geographical extent in the study area, future trend in geographical extent, and future trend of habitat availability for species.
Potential winners and losers of a warming climate could be quantified through their thermal preferences. The proportion of potential losers ranged from zero species for snails to 33% of the regional species pool for dragonflies. The set of potential winners was much larger, ranging from 53% for amphibians to 61% for dragonflies. A multimetric index combining the five resilience criteria enabled the further prioritisation of the species along a gradient of extinction risk.
This potential threat from climate warming is not reflected by the current Red Lists of dragonflies and amphibians, suggesting that conservation management could gain from a complementary label indicating the degree of sensitivity to warming.
Eutrophication remains a major stress for freshwater biodiversity. Its deleterious consequences on biodiversity are well documented for large waterbodies. However, the impact of eutrophication may ...differ in smaller waterbodies, such as ponds and small lakes, which generally support naturally high levels of nutrients in lowlands. Furthermore, this response could depend on the scale considered, from local (individual waterbody, alpha diversity) to regional (the network of waterbodies, gamma diversity). It is also unclear whether the richness of threatened species responds in the same way as the richness of the whole assemblage. The present study investigates local‐ and regional‐scale consequences of eutrophication on taxonomic richness (all taxa) and conservation value (threatened taxa) in temperate lowland small waterbodies. Five taxonomic groups were investigated: macrophytes, gastropods, water beetles, adult dragonflies and amphibians, in a set of natural waterbodies and a set of enriched waterbodies covering a large nutrient gradient from mesotrophic to hypertrophic conditions. Globally, our study did not reveal consistent, systematic responses to eutrophication. For macrophytes, the richness and conservation value suffered from eutrophication at both local and regional scales. In contrast, for amphibians and gastropods, eutrophication did not impair biodiversity at the local nor the regional scale. Dragonflies and water beetles showed intermediate situations, with an impairment by eutrophication varying according to the type of waterbodies considered. At the regional scale, each trophic status, even the nutrient richest, brought an original contribution to biodiversity. Synthesis and applications. The management of eutrophication for small lowland waterbodies has to be considered differently than for lakes. For an individual waterbody (the local scale), nutrient enrichment is not necessarily a major impairment and its impact depends on the taxonomic group considered. Conversely, at the landscape scale, eutrophication is a major pressure on small waterbody biodiversity, especially because nutrient‐rich small waterbodies are dominant in the landscape. Therefore, conservation efforts should integrate the notion of pond regional networks or ‘pondscapes’, where the regional biodiversity is supported by a mosaic of trophic conditions, and promote the presence of less rich waterbodies.
Disturbance is a central factor shaping composition, structure, and dynamics of local communities. Drying is a disturbance that occurs in aquatic ecosystems globally and can strongly influence their ...communities. Although the effects of drying may depend on ecosystem connectivity and the dispersal abilities of resident species, there have been no comparisons of community responses to drying between lentic and lotic ecosystems across different climates. Here, we predicted that drying would have stronger effects on aquatic communities in isolated lentic ecosystems than in dendritic lotic ecosystems, owing to the higher hydrological connectivity of the latter, and that drying would have stronger effects on passive than on active dispersers, because of the potentially higher recolonizing ability of the latter. We tested these predictions by comparing alpha diversity, phylogenetic relatedness, and beta diversity for active and passive dispersers, in both ecosystem types across five climatic regions. Drying caused greater declines in alpha diversity in lentic than in lotic ecosystems. Communities that experienced drying were more similar to one another than those of perennial sites, and this pattern was especially pronounced in lentic ecosystems. In contrast, drying did not influence the contributions of turnover and richness gradients to beta diversity. Additionally, dispersal mode did not influence community responses to drying. Relatively weaker effects of drying in lotic compared to lentic systems were likely due to the hydrological connectivity among perennial and temporary river sites, which may facilitate dispersal of organisms to escape drying and recolonize rewetted sites. Collectively, our results suggest that habitat connectivity may ameliorate (and fragmentation may worsen) the impacts of drying disturbance. This is an important finding in light of increasing drying and concomitant aquatic habitat fragmentation under global change.
Wetlands often form an important component in the urban matrix, where they are largely disseminated. Despite the abundance of these urban waterbodies, little is known about the spread of alien ...aquatic plant species in cities. Ponds are frequent in urban parks and domestic gardens where terrestrial alien plant species are common. Therefore, urban ponds are likely to support many aquatic alien species which might disperse to the natural environment. To investigate this potential, we collected data from 178 ponds in a large European city (Geneva, Switzerland), across an urbanization gradient. 17% (23 taxa) of the aquatic flora appears to be non-native, including five species at high risk of invasion. A large proportion of the waterbodies (43%) supported at least one alien taxa. Through the development of a risk assessment tool, the “Geneva-Aquatic Weed Risk Assessment system”, a risk map was created which revealed several alien species hotspots situated in the urban environment, but also in rural areas, including in protected wetlands. This risk mapping included the dispersal potential distance of species around these risk hotspots, and showed that most areas of dispersal seem to be relatively small. Ponds are target sites for deliberate introduction but they tend to be hydrologically isolated in the urban matrix, and these ‘islands’ therefore present a relative low risk of a wider dissemination of alien species. This risk is nevertheless expected to sharply increase in future. Introduction by humans is likely to be the main source of new alien aquatic plants, and so management should primarily aim to prevent the introduction of these species. Sites supporting alien species should also be monitored and, if possible, the species presenting a risk should be eradicated. Sites supporting alien species should also be monitored and, if possible, the species presenting a risk eradicated.
Climate change is expected to affect communities worldwide. Many studies focus on responses at the regional level and show an increase in species richness. However, less is known about the ...consequences of climate change at the local scale (in ecosystems). Small waterbodies, such as ponds, could play an important role for the assessment of the impact of future changes in climate at the local level. We evaluated here the potential changes due to climate warming in the species richness for various groups (plants, snails, beetles, dragonflies, amphibians) across 113 lowland and high altitude ponds in Switzerland. We modelled the relationships between species richness and environmental variables (including temperature) and predicted species richness changes for the end of the century (2090-2100; using the A2 IPCC scenario). Temperature rise could significantly increase pond species richness. For the five taxonomic groups pooled, species richness would potentially increase from 41 to 75 (+83%) in lowland ponds. In presently species-poor high altitude ponds, the potential increase would be particularly marked, with a proportional increase (+150%; from 14 to 35 species) almost double that in lowland areas. A strong increase in species richness also resulted from models including changes in additional variables, such as landuse or water quality. Future reductions in water quality (e.g. increase in nutrients) may limit the predicted increase in lowland species richness or, conversely, result in a greater increase in species richness in high altitude areas. Nutrient enrichment is shown to affect the taxonomic groups differentially, with plant species richness the most negatively influenced. Climate warming could therefore affect species richness of temperate ponds not only regionally, but also at the local, within ecosystems-scale; species richness could increase markedly in temperate regions, and especially so at higher altitude.
Ponds are now widely recognized to contribute significantly to regional freshwater biodiversity. Therefore, tools to easily and rapidly assess biological quality specifically for these aquatic ...habitats have been increasingly requested by conservation planners and nature managers. In close association with practitioners, we developed such a method for Switzerland; the pond biodiversity index "IBEM". The IBEM-Index is based on the assessment of the taxonomic richness of 5 groups: aquatic vegetation, Gastropoda, Coleoptera, adult Odonata and Amphibia. No abundance data are necessary and genus level identification is required for all groups except Amphibia (species level). The sampling methodology is a stratified random strategy and allows the use of richness estimators to transform the observed taxonomic richness (S sub(obs)) into true taxonomic richness (S sub(true)). As the IBEM assessment follows the methodology presented in the Water Framework Directive, it is based on the calculation of the ratio of true taxonomic richness (S sub(true)) to reference-based predicted richness (S sub(ref)). Each of the five taxonomic groups is assessed separately and the overall biological quality of any given pond (i.e. the IBEM-Index) is the average of the five ratios. This score is later converted into one of five quality classes for each pond: bad (0 to 0.2), poor (> 0.2 to 0.4), moderate (> 0.4 to 0.6), good (> 0.6 to 0.8), and high (> 0.8 to 1). In this paper, the implementation of the IBEM-Index is described in detail. The sampling methodologies are developed (for the biodiversity and the environmental variables) as well as the assessment methodology. Finally, two examples are presented in detail, for a "good" quality pond and for a "bad" quality pond. The method implementation also includes a website (http://campus.hesge.ch/ibem) which allows the online calculation of the index, and provides support for both sampling and assessment methodologies to users. The IBEM-Index is a rapid assessment method which gives an overall value of pond biodiversity in terms of taxa richness and can be used, for example, in regional screenings or site monitoring in Switzerland. Moreover, as biodiversity is generally recognized as a good indicator of global ecological quality, the IBEM-Index can also be used to investigate ecosystem quality.Original Abstract: Esta ampliamente reconocido que las pequenas masas de agua (charcas) contribuyen de forma significativa a la biodiversidad regional de las aguas dulces. Por tanto, las herramientas que de manera rapida facil evaluen especificamente la calidad biologica de estos habitats acuaticos estan siendo requeridas cada vez mas por profesionales de la gestion y conservacion del medio natural. En estrecha colaboracion con estos profesionales, se ha desarrollado un metodo de este tipo para Suiza; el indice de biodiversidad de charcas "IBEM". El Indice-IBEM se basa en la evaluacion de la riqueza taxonomica de 5 grupos: vegetacion acuatica, gasteropoda, coleopteros, odonatos (adultos) y anfibios. No son necesarios datos de abundancia y se requiere un nivel identificacion de genero para todos los grupos excepto para los anfibios (nivel de especie). Se usa un muestreo aleatorio estratificado que permite obtener estimadores para transformar la riqueza taxonomica observada (S sub(obs)) en riqueza taxonomica real (S sub(true)). La evaluacion IBEM sigue la metodologia de la Directiva Marco del Agua, que se basa en el calculo de la relacion entre la riqueza taxonomica real (S sub(true)) y la riqueza esperable en un estado de referencia (S sub(ref)). Cada uno de los cinco grupos taxondmicos se evalua por separado y la calidad biologica de una charca determinada (Indice-IBEM) es la media de los cinco coeficientes. Este resultado es posteriormente asignado a una de las cinco clases de calidad: malo (0 a 0.2), deficiente (> 0.2 a 0.4), moderado (> 0.4 a 0.6), bueno (> 0.6 to 0.8), y muy bueno (> 0.8 a 1). En este articulo, se describe detalladamente la aplicacion del indice IBEM y se desarrollan las metodologias de muestreo (para la biodiversidad y las variables ambientales) y de valoracion utilizadas. Por ultimo, se presentan con detalle dos ejemplos, una charca con "buena" calidad y otra con "mala" calidad. Se incluye tambien una pagina web (http://campus.hesge.ch/ibem), que permite el calculo del indice a traves de internet y sirve de apoyo a los usuarios en las metodologias de muestreo y de valoracion. El indice IBEM es un metodo de evaluacion rapida que da un valor general de la diversidad biologica de una charca en terminos de riqueza de taxones y se puede utilizar, por ejemplo, a nivel regional o en el seguimiento de una localidad, en Suiza. Ademas, como la biodiversidad es un buen indicador de la calidad ecologica global, el indice IBEM tambien se puede usar para evaluar el estado del ecosistema.
Due to legal requirements, nature managers increasingly have to carry out assessments of biodiversity for conservation purposes. For ponds, a type of waterbody now widely recognized as an important ...reservoir for freshwater biodiversity, standardized bioassessment methods are needed, but still rare. We produced such a tool for small lowland waterbodies in Switzerland: the Pond Biodiversity Index ("IBEM"). This Index is the adaptation of a method used by researchers for assessing the biodiversity in ponds, PLOCH, which does not currently meet the requirements for routine use by nature managers because it is too expensive and requires a high skill level in taxonomic identification. A method intended for practitioners has to be simple, standardized, cheap, adjustable, and consistent with the legislative framework. In order to fulfill these requirements, the theoretical and practical aspects of IBEM were developed with a group of representative end users including nature conservation managers, consultants, governmental organizations and taxonomic experts. To develop the method, we used a species dataset from 63 Swiss lowland ponds which included five taxonomic groups: aquatic plants, aquatic Gastropoda, aquatic Coleoptera, adult Odonata and Amphibia. The following topics were addressed: (i) the number and type of taxonomic groups which should be used for producing the index (is it possible to use surrogates?) (ii) the level of identification for each taxonomic group (species? genus? family?) (iii) the sampling strategy (sampling technique, number of replicates), (iv) the calculation of a unique index and the strategy for assessing its score, and (v) the transfer of this new method to end users. The new method IBEM uses all five taxonomic groups, because a subset of groups did not produce reliable assessments of pond biodiversity. Identification to genus level is required for four groups (aquatic plants, aquatic Gastropoda, aquatic Coleoptera, adult Odonata) and species level for Amphibia. The sampling methodology is based on the stratified random strategy used in the PLOCH method, but with a slight modification in the number of samples per pond. The assessment follows the methodology adopted by the European Water Framework Directive, and the ratio of the observed richness to a reference-based predicted richness is translated into one of five quality categories for each pond. The final index is the mean of the five assessment scores. To facilitate the implementation of the IBEM method, a website (http://campus.hesge.ch/ibem) enables online calculation of the index, and provides instructions on both sampling and assessment methodologies. Furthermore, training courses are organized by the authors of the method for end users.Original Abstract: Debido a requerimientos legales, es cada vez mas necesario que los gestores del medio ambiente lleven a cabo evaluaciones de la biodiversidad dirigidas a la conservacion de la naturaleza. Para las charcas, pequenas masas de agua ampliamente reconocidas como importantes reservorios de diversidad bioldoica acuatica, los metodos normalizados de bio-evaluacion son necesarios, pero aun escasos. Para esta tipologia de pequenas masas de agua situadas a baja altitud en Suiza, se ha elaborado el indice de Biodiversidad de charcas ("IBEM"). Este indice es la adaptacion de un metodo utilizado por los investigadores para evaluar la diversidad biologica en charcas, PLOCH, que no cumplia los requisitos para un uso rutinario por parte de los gestores del medio natural por ser demasiado caro y requerir un alto nivel de experiencia en la identificacion taxonomica. Un metodo destinado a estos profesionales tiene que ser sencillo, estandarizado, econdmico, ajustable y en consonancia con el marco legislativo. Con el fin de cumplir estos requisitos, los aspectos teoricos y practicos de IBEM se han desarrollado con un grupo representativo de posibles usuarios, incluyendo gestores conservadores, consultores, organizaciones gubernamentales y expertos en taxonomia. Para desarrollar el metodo, se ha utilizado una base de datos de 63 charcas Suizas, situadas en altitudes bajas, que incluye cinco grupos taxondmicos: plantas acuaticas, gasteropodos acuaticos, coleopteros acuaticos, odonatos adultos y anfibios. Se han estudiado los siguientes aspectos: (i) el numero y tipo de grupos taxonomicos que se deben utilizar (es posible el uso de sustitutos?) (ii) nivel de identificacion para cada grupo taxonomico (especie, genero, familia?) (iii) estrategia de muestreo (tecnica, numero de replicas), (iv) calculo de un indice unico y procedimiento para la asignacion de valores y (v) la transferencia de este metodo a los posibles usuarios. El nuevo metodo IBEM utiliza los cinco grupos taxonomicos, ya que un subconjunto de ellos no produciria evaluaciones fiables de la diversidad biologica de la charca. La identificacion a nivel de genero es necesaria para cuatro de estos grupos (plantas acuaticas, gasteropodos acuaticos, coleopteros acuaticos, y odonatos adultos) y para los anfibios es necesario el nivel de especie. El muestreo sigue un diseno aleatorio estratificado, utilizado en el metodo PLOCH, pero con una ligera modificacion en el numero de muestras por charca. La evaluacion sigue la metodologia adoptada por la Directiva Marco de Aguas, y la relacion entre la riqueza observada y la del estado de referencia se traduce en una de las cinco categorias de calidad para cada charca. El indice final es la media de las cinco puntuaciones de la evaluacion. Para facilitar la aplicacion del metodo IBEM, un sitio web (http://campus.hesge.ch/ibem) permite calculo del indice a traves de la red y proporciona instrucciones tanto de las metodologias de muestreo como de la valoracion. Ademas, los autores han organizado cursos de formacion sobre el metodo para los usuarios.
Disturbance is a central factor shaping composition, structure, and dynamics of local communities. Drying is a disturbance that occurs in aquatic ecosystems globally and can strongly influence their ...communities. Although the effects of drying may depend on ecosystem connectivity and the dispersal abilities of resident species, there have been no comparisons of community responses to drying between lentic and lotic ecosystems across different climates. Here, we predicted that drying would have stronger effects on aquatic communities in isolated lentic ecosystems than in dendritic lotic ecosystems, owing to the higher hydrological connectivity of the latter, and that drying would have stronger effects on passive than on active dispersers, because of the potentially higher recolonizing ability of the latter. We tested these predictions by comparing alpha diversity, phylogenetic relatedness, and beta diversity for active and passive dispersers, in both ecosystem types across five climatic regions. Drying caused greater declines in alpha diversity in lentic than in lotic ecosystems. Communities that experienced drying were more similar to one another than those of perennial sites, and this pattern was especially pronounced in lentic ecosystems. In contrast, drying did not influence the contributions of turnover and richness gradients to beta diversity. Additionally, dispersal mode did not influence community responses to drying. Relatively weaker effects of drying in lotic compared to lentic systems were likely due to the hydrological connectivity among perennial and temporary river sites, which may facilitate dispersal of organisms to escape drying and recolonize rewetted sites. Collectively, our results suggest that habitat connectivity may ameliorate (and fragmentation may worsen) the impacts of drying disturbance. This is an important finding in light of increasing drying and concomitant aquatic habitat fragmentation under global change.
We developed a method to quantify
cis
-permethrin and
trans
-permethrin and their metabolites in several biological matrices in pregnant rats and foetuses using liquid chromatography coupled with ...tandem mass spectrometry (LC-MS/MS). The objective was to quantify
cis
-permethrin and
trans
-permethrin in faeces, kidney, mammary gland, fat and placenta in mothers and in both maternal and foetal blood, brain and liver. The metabolites
cis
-3-(2,2-dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid (
cis-
DCCA),
trans
-3-(2,2-dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid (
trans
-DCCA) and 3-phenoxybenzoic acid (3-PBA) were measured in blood, liver and urine. Sample preparation was performed by liquid-liquid extraction. A purification step was not carried out except for the more complex biological samples (fat, mammary glands and faeces). Validation parameters including specificity, linearity, matrix effect, limits of quantification (LOQs), accuracy and precision were evaluated. The recoveries of target compounds ranged from 47 to 136%. LOQs were in the range 4 to 80 ng/mL for permethrin isomers and 4 to 800 ng/mL for their respective metabolites. Intra- and inter-batch precision and accuracy in matrix were better than 15%. The validated method was applied in a preliminary toxicokinetic study in pregnant rats with oral dosing of 50 mg/kg permethrin. In pregnant rats, permethrin isomers and their metabolites were quantified in all requested matrices except maternal liver and blood for
trans
-permethrin and
cis
-DCCA respectively. In foetuses,
cis
- and
trans
-permethrin were also quantified, demonstrating that the method is suitable for the analysis of foetal distribution of permethrin in toxicokinetic studies.
The current study concerns the temperature of foodstuffs on sale in refrigerated display cabinets in bakeries, pork butcher's/delicatessens and cheese/dairy shops. The authors propose a single ...criterion to estimate whether storage conditions are satisfactory: foodstuffs must remain at temperatures below or equal to 7 °C to avoid any hazardous bacterial growth. Applying this criterion, 70% of time–temperature profiles are unsatisfactory.
Of the main factors responsible for these excess temperatures, the authors distinguished factors related to the refrigerated display itself from factors related to professional practices. The equipment must be properly designed, used and maintained in order to keep foodstuff temperatures within a range geared to food safety needs.
► Study of foodstuffs temperatures in refrigerated display cabinets. ► 7 °C considered as the maximum acceptable temperature as regards to food safety. ► 70% of the 99 time–temperature collected profiles are unsatisfactory. ► Definition of the main factors responsible for excess temperatures. ► Poor equipment design and poor professional practices are responsible in equal part.
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