No abstract

No abstract

No abstract

ABSTRACT1. In 1986 work began which led to the foundation of Pond Conservation, the UK NGO which promotes the conservation of ponds and other freshwater habitats. In 1989 the organization initiated the UK National Pond Survey (NPS) to provide baseline data on the biota and physico-chemical characteristics of ponds.2. Survey data have been used to demonstrate the importance of small water bodies for freshwater plants and animals, to establish techniques for assessing the ecological status of ponds and to provide the basis for a new national pond monitoring network in the UK.3. Comparisons with extensive river and lake datasets show that, at a UK level, ponds support slightly more macroinvertebrate species than rivers, and more uncommon species. They support similar numbers of wetland plants to lakes. Farmland ponds generally have lower site diversity than rivers; however, in terms of regional diversity they make a greater contribution than other aquatic habitats.4. Although ponds are an important biodiversity resource, studies have shown that ponds outside nature reserves are significantly degraded: thus ponds in the lowlands supported only half the number of wetland plant species that would be expected in minimally impaired ponds.5. The environmental factors most highly correlated with species number and rarity in minimally impaired ponds were area, isolation, pH (and the related chemical measures alkalinity, calcium, conductivity) and abundance of vegetation.6. Studies of degraded ponds showed strong negative relationships between potentially damaging environmental factors (e.g. intensive land use, nutrient levels) and species richness and rarity.7. Although considerable progress has been made in characterizing the plant and invertebrate assemblages of ponds, comparatively little is known about the way ponds function or how they are affected by management. Given the importance of ponds in maintaining aquatic biodiversity at the landscape scale, further research is needed on ponds in the catchment context.

No abstract

No abstract

No abstract

There is growing awareness in Europe of the importance of ponds, and increasing understanding of the contribution they make to aquatic biodiversity and catchment functions. Collectively, they support considerably more species, and specifically more scarce species, than other freshwater waterbody types. Ponds create links (or stepping stones) between existing aquatic habitats, but also provide ecosystem services such as nutrient interception, hydrological regulation, etc. In addition, ponds are powerful model systems for studies in ecology, evolutionary biology and conservation biology, and can be used as sentinel systems in the monitoring of global change. Ponds have begun to receive greater protection, particularly in the Mediterranean regions of Europe, as a result of the identification of Mediterranean temporary ponds as a priority in the EU Habitats Directive. Despite this, they remain excluded from the provisions of the Water Framework Directive, even though this is intended to ensure the good status of all waters. There is now a need to strengthen, develop and coordinate existing initiatives, and to build a common framework in order to establish a sound scientific and practical basis for pond conservation in Europe. The articles presented in this issue are intended to explore scientific problems to be solved in order to increase the understanding and the protection of ponds, to highlight those aspects of pond ecology that are relevant to freshwater science, and to bring out research areas which are likely to prove fruitful for further investigation.