The dire situation facing amphibians worldwide has received increasing (if still insufficient) attention in recent years and numerous initiatives have now been developed in order to protect this group from further declines and species level extinctions. Such initiatives include captive breeding efforts, habitat restoration and ecological mitigation as well as legal protection status. Legal protection for various species often also translates into the protection of their habitats. For amphibians this most often focuses on their aquatic, breeding sites, which are smaller and easier to identify and manage compared to their terrestrial sites. For pond-breeding amphibians, such actions are a vital step for their conservation as most pond habitats often receive little or no protection and ponds are themselves a rapidly declining habitat in much of Europe. Ponds are also disproportionately species rich compared to other habitats, including freshwater habitats such as streams, rivers or lakes, and ponds are therefore extremely worthy of protection. In this context, the inclusion of ponds as protected sites for amphibians can only be a positive conservation measure. However, given the multiple constraints and pressures to land use as well as a need for an ecosystem approach, conservation efforts should encompass a wider biodiversity context than a single group and as such it is important to know how effective is the protection of important amphibian breeding areas for other biodiversity groups.
Instinctively, many conservation practitioners imagine that a high-quality, diverse pond is most often also an important amphibian breeding site and that managing protected sites for amphibian conservation offers the good wider biodiversity outcomes. Yet, the empirical evidence is mostly lacking, especially at the local, pond level rather than the wider, landscape or “pondscape” scale.
A very recent study from Switzerland has investigated 89 high-quality amphibians breeding sites and tried to understand the level of convergence between amphibians and other associated biodiversity, focusing on aquatic plants, aquatic snails, beetles and dragonflies.
The results of the study showed that amphibians are a poor surrogate group for other aquatic biodiversity groups such as macroinvertebrates and plants in ponds. Even the few existing associations, such as the relationship between the community composition of amphibians and that of dragonflies and damselflies, were weak. In terms of species richness, conservation value and community composition amphibians were a poor indication of the wider biodiversity value of the pond. For species richness, amphibians showed the lowest cross-taxa correlations values of all investigated groups. This might be due to the fact that in Switzerland, as is partly the case in the UK, several amphibian species are often early colonisers, preferring to some degree early succession ponds that have yet to become fully established. Those ponds are however, not the best ones for other aquatic species, although they might become so in time.
As such, although pond protection remains a key feature of amphibian conservation, a wider range of taxonomic groups should be taken into account in conservation planning and for the selection of sites for freshwater biodiversity conservation.
Ilg, C. and Oertli, B. (2016), Effectiveness of amphibians as biodiversity surrogates in pond conservation. Conservation Biology. Accepted Author Manuscript. doi:10.1111/cobi.12802