Crustacean and rotifer seasonality in a Mediterranean temporary pond with high biodiversity (Lavajo de Abajo de Sinarcas, Eastern Spain)

A follow-up study was made of planktonic and periphytic crustaceans and rotifers during two hydroperiods of consecutive years in a Mediterranean temporary pond. The pond is relatively large with quite long hydroperiods in wet years (6-8 months) and it has a very rich community (4 large branchiopods, 12 cladocerans, 9 copepods, 36 rotifers). Three phases in faunal composition, quite consistent fram year to year, were distinguished: (1) Filling phase in autumn-winter is dominated by anos­tracans (endemic Branchipus cortesi, with low proportions of Branchipus schaefferi) and diaptomids, two univoltine species (Hemidiaptomus ingens inermis, Diaptomus cyaneus intermedius) and one muItivoltine (Mixodiaptomus laciniatus atlantis). (2) Middle phase in spring dominated by cladocerans (Ceriodaphnia n.sp., Simocephalus vetulus, Ephemeroporus pinthoni­cus, Chydorus sphaericus, Alona azorica) in this phase is also abundant the conchostracan Maghrebestheria maroccana and the notostracan Triops cancriformis. A shift toward insects occurs in the later part of this phase. (3) Desiccation phase in sum­mer with lower diversity (Moina micrura, Alona rectangula and cyclopoids). Rotifers showed a low contribution to biomass and were more important in the middle phase. These phases are also marked by an increase of nutrients and phytoplankton chlorophyll in the filling and desiccation phases and a decrease of these variables in the middle phase, resulting in phytoplank­ton cIearance and greater water transparency, concurrent with macrophyte growth. Interannual variability was outstanding in shaping these phases. The year 2007 was preceded by a wetter autumn, whereas 2008 was preceded by a very dry autumn thus, in this second year the main hydroperiod was shorter and the first phase was merged with the middle phase. In this shorter hydroperiod the open water microinvertebrate community reached lower biomass but attained a similar diversity since rotifers became relatively more abundant and richer in species than in the 2007 main hydroperiod, when the community was fully dominated by crustaceans.Se ha estudiado la estacionalidad de las comunidades de crustáceos y rotiferos planctónicos y perifíticos en una charca tempo­ral mediterránea en varios hidroperiodos durante dos años consecutivos. La charca tiene una extensión relativamente grande con un hidroperiodo largo en años húmedos (7-8 meses) y alberga una gran riqueza de especies (4 grandes branquiópodos, 12 cladóceros, 9 copépodos, 36 rotiferos). Basándonos en los cambios en la composición de esta fauna, se diferencian tres fases que se repiten de año en año, estas fases son: (1) Fase de llenado en otoño-invierno, dominada por anostráceos (princi­palmente por el endémico Branchipus cortesi, con una baja proporción de Branchipus schaefferi) y diaptómidos, dos especies univoltinas (Hemidiaptomus ingens inermis y Diaptomus cyaneus intermedius) y una multivoltina (Mixodiaptomus laciniatus atlantis). (2) Fase intennedia en primavera, dominada por cladóceros (Ceriodaphnia n.sp., Simocephalus vetulus, Ephe­meroporus pinthonicus, Chydorus sphaericus, Alona azorica), destacan también en esta fase la presencia del concostráceo Maghrebestheria maroccana y el notostráceo Triops cancriformis. Los rotiferos contribuyen poco a la biomasa y son algo más importantes en esta fase intermedia. En la última parte de esta fase se produce un cambio hacia una mayor presencia de insectos. (3) Fase de desecación en verano que corresponde con una menor diversidad (Moina micrura, Alona rectangula y ciclópidos). Las fases de llenado y desecación se caracterizan también por un aumento de nutrientes y clorofila fitoplantónica mientras que en la fase intermedia su concentración es menor, aumentando la transparencia del agua y el desarrollo de los macrófitos. La variabilidad interanual determina la configuración de estas fases. El año 2007 fue precedido por un otoño húmedo mientras que 2008 fue precedido por un otoño muy seco, por lo que en este segundo año el hidroperiodo principal fue muy corto fusionándose la primera fase con la intermedia y la biomasa de microinvertebrados en aguas abiertas fue mucho menor que en el hidroperiodo del 2007, sin embargo se alcanzaron valores similares de diversidad debido a una relativamente mayor abundancia y riqueza de especies de rotiferos con respecto al hidroperiodo del 2007, en el que dominaron plenamente los crustáceos

Relaciones entre las aportaciones a la zona regable del río Jucar y la conductividad de la Albufera de Valencia

Las aportaciones a la zona regable del río Júcar condicionan la conductividad de la Albufera porque recibe las aguas sobrantes de riego. Se ha observado una relación inversa entre ambas variables. La demanda de agua para otras zonas pretende satisfacerse a partir del trasvase de los sobrantes de riego basándose en una mejora de la eficiencia del regadío. Estas actuaciones deben realizarse sólo cuando se aseguren previamente las aportaciones necesarias para mantener la calidad del lago.The water inflows to the irrigation area of the Júcar river determine the conductivity of the Albufera because it receives the surplus irrigation water. It has been observed an inverse relationship between both variables. The water demands for other regions is sought by transferring the surplus irrigation water based on an improvement of the irrigation efficiency. These actions must be carried out only after having ensured a sufficient quantity of water inflow to maintain the quality of the lake

Pond conservation: from science to practice

In Europe, ponds are an exceptionally numerous and widely distributed landscape feature forming a major part of the continental freshwater resource and contributing significantly to freshwater biodiversity conservation. This has been reflected by a growing scientific concern over the first few years of the twenty-first century and is evidenced by an increasing number of academic publications on pond related topics, particularly those relating to biodiversity. It is essential, however, that this expanding scientific knowledge is widely disseminated to those involved with pond management and is then rapidly translated into action. Inevitably, the task of transferring science to practice remains a significant challenge. As a first step towards meeting this challenge the European Pond Conservation Network (EPCN), at its biennial meeting in 2008 in Valencia (Spain), made this the main theme of the conference together with two special workshops further encouraging exchanges between scientists, practitioners and policy makers. The papers selected for this special issue of Hydrobiologia (from over 120 communications presented) are all from the conference. They represent a diverse collection of themes from across the continent and North Africa and present new and original insights into topics as wide ranging as: pond biodiversity; human disturbance; landscape ecology; ecological assessment and monitoring; practical management measures; ecological restoration; hydrology and climate change; invasive species and threatened species. In all cases, the papers demonstrate an overriding need for the development of a tight link between scientific knowledge and management. Furthermore, scientific advances have to be beneficial for on the ground management and, vitally, have to be disseminated, communicated and implemented into local, national and international policy. As such, national and international networks (such as the EPCN) have a central role to play and have to develop a robust information and communication strategy which will enable the dissemination of best practice materials and advice across the continent and beyond. The work contained in this volume represents a step in the right direction and will help to ensure that ponds remain a characteristic and highly visible feature of the European landscape in the twenty-first centur

Relaciones entre las aportaciones a la zona regable del río Jucar y la conductividad de la Albufera de Valencia.

Las aportaciones a la zona regable del río Júcar condicionan la conductividad de la Albufera porque recibe las aguas sobrantes de riego. Se ha observado una relación inversa entre ambas variables. La demanda de agua para otras zonas pretende satisfacerse a partir del trasvase de los sobrantes de riego basándose en una mejora de la eficiencia del regadío. Estas actuaciones deben realizarse sólo cuando se aseguren previamente las aportaciones necesarias para mantener la calidad del lago. The water inflows to the irrigation area of the Júcar river determine the conductivity of the Albufera because it receives the surplus irrigation water. It has been observed an inverse relationship between both variables. The water demands for otherregions is sought by transferring the surplus irrigation water based on an improvement of the irrigation efficiency. These actions must be carried out only after having ensured a sufficient quantity of water inflow to maintain the quality of the lak

Macroinvertebrates assemblages on reed beds, with special attention to Chironomidae (Diptera), in Mediterranean shallow lakes

Macroinvertebrates associated to reed-beds (Phragmites australis) in six shallow natural water bodies along the 220 km of coast of the Comunidad Valenciana (Spain) were studied. These sites were selected to reflect different trophic states, but also, and due to the natural variability of mediterranean wetlands, they greatly differ in salinity and hydroperiod. To unify the sampling, reed bed was chosen to provide data from a habitat common to all wetlands, including the most eutrophic ones where submerged macrophytes have disappeared due to water turbidity. Individual submerged stems of Phragmites australis were sampled along with the surrounding water. The animal density found refers to the available stem surface area for colonization. Forty-one taxa were recorded in total, finding Chironomidae to be the most important group, quantitatively and qualitatively. In freshwater sites it was observed an increase in macroinvertebrate's density at higher trophic states. Nevertheless each studied region had a different fauna. The PCA analysis with macroinvertebrate groups distinguished three types of environment: freshwaters (characterized by swimming insect larvae, collectors and predators, oligochaetes and Orthocladiinae), saline waters (characterized by crustaceans and Chironominae) and the spring pool, which shares both taxa. Chironomids were paid special attention for being the most abundant. A DCA analysis based on the relative abundance of Chironomids reveals salinity as the main characteristic responsible for its distribution, but trophic state and hydrological regime were also shown to be important factors.Se han estudiado los macroinvertebrados asociados a la vegetación de carrizo (Phragmites australis) en seis lagunas someras a lo largo de los 220 km de costa de la Comunidad Valenciana (España). Las lagunas se eligieron de manera que se contemplasen diferentes estados tróficos, pero además y reflejando la natural variabilidad de los humedales mediterráneos, presentan importantes diferencias en cuanto al hidroperiodo y la salinidad. Para unificar el muestreo, se eligió el carrizo por ser un elemento común en todos los humedales, incluso los más eutróficos en los que los macrófitos sumergidos han desaparecido debido a la turbidez del agua. Para cada muestra se toma individualmente la parte sumergida de una planta de Phragmites australis junto con el agua circundante. La densidad de animales encontrados se refiere a superficie colonizable del tallo de la planta. En total se han encontrado 41 taxones, siendo Chironomiidae el grupo más importante tanto cuantitativa como cualitativamente. En las lagunas de agua dulce, se observó un aumento de la densidad de macroinvertebrados en los niveles tróficos mayores. Sin embargo cada zona de estudio tiene una fauna diferente. El análisis PCA de los grupos de macroinvertebrados diferencia tres tipos de ambientes: aguas dulces (caracterizados por larvas nadadoras de insectos recolectores y depredadores, oligoquetos y orthocladinos), aguas salobres (caracterizadas por la presencia de crustáceos y Chironomiinae) y el "ullal" o surgencia de agua que comparte taxones de los dos grupos anteriores. Se ha prestado especial atención al grupo de quironómidos por ser los más abundantes. Un análisis DCA basado en la abundancia relativa de las especies de quironómidos, muestra la salinidad como la principal característica responsable de su distribución, siendo luego el estado trófico y el régimen hidrológico factores también importantes

Preface: conservation of european ponds-current knowledge and future needs

Ponds are common elements of the landscape with an important role in the global processes of biosphere and biodiversity preservation. Recent research indicates that ecological characteristics of ponds are different from other inland water systems, but scientific knowledge is still insufficient and poor compared to lakes and rivers. Therefore, whilst indicators and conservation tools have been developed for most aquatic systems, there is also a gap between existing basic information on pond ecology and applied research. The European Pond Conservation Network (EPCN) with the aim of strengthening the links between basic and applied research and pond management organized its 3rd biennial meeting in Valencia (Spain) with the theme "Pond conservation: from science to practice". We present a selection of papers from this conference, which cover the three main topics of the sessions: (1) Management and conservation in practice, (2) Pond ecology at different scales and (3) Temporary ponds. The articles presented develop techniques for assessing the ecological status of this type of ecosystems, evidence the importance of ponds in a global scale, indicate that their conservation must take into account their spatial arrangement in networks, discuss environmental factors that are relevant to biodiversity conservation and provide information on different research areas such as biogeochemical processes, evolution of aquatic biota and community ecology