Amphibians: trends in numbers
Habitat loss, acidification and the effects of water draw-down have led to a decline in the number of species of amphibians. In recent years the more common species have remained stable.
Trends
Despite conservation measures such as the construction of ponds, many species of amphibian have declined in recent decades. Important causes of this are habitat loss, the acidification of pools and fens, fragmentation and the effects of water draw-down. Since 1987 the more common amphibian species have, on average, remained stable. No significant changes have been observed for any single species, but the time series is still short.
Some of these species are included in the Habitats Directive.
Technical note
The Species Group Trend Index (SGTI) is the average index (the benchmark year (= 100) is 1997) for the alpine newt, warty newt, smooth newt, common toad, natterjack, moor frog, common frog and some species of green frog that are difficult to distinguish.
The data are from the Ecological Monitoring Network's national amphibian monitoring network.
References
- RAVON-Werkgroep Monitoring (2002). Meetnet Amfibieën. Mededelingen nr. 10.
