Retain connectivity between habitat patches
Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 1
Background information and definitions
Habitat destruction and fragmentation are important factors in the decline of amphibian populations. Small patches of habitat support smaller populations and if individuals are unable to move to other suitable areas of habitat, populations become isolated. This can make them more vulnerable to extinction. On a smaller scale, amphibians often occupy two distinct types of habitat, aquatic and terrestrial. They therefore require suitable habitat to enable them to migrate between these different areas. A study found that as the amount of connecting habitat decreased, so did the diversity of amphibian species with aquatic larvae (Becker et al. 2007). Retaining corridors of native vegetation between suitable habitat patches may help to maintain amphibian populations.
Studies investigating the effect of restoring connectivity are discussed in ‘Habitat restoration and creation – Restore habitat connectivity’ and ‘Threat: Transportation and service corridors – Install culverts or tunnels as road crossings’.
Becker C.G., Fonseca C.R., Haddad C.F.B., Batista R.F. & Prado P.I. (2007) Habitat split and the global decline of amphibians. Science, 318, 1775–1777.
Supporting evidence from individual studies
A before-and-after study in 1998–1999 of pine plantations and surrounding native forest in New South Wales, Australia (Lemckert, Brassil & Towerton 2005) found that retaining native vegetation corridors helped maintain populations of eight of 13 frog species over 20 years. Eight of the species that had been present in 1980–1984 were recorded within native forest remnants and plantations in 1998–1999. Five species were not found, but two new species were observed. Numbers of species or individuals captured did not increase significantly with corridor width or distance to continuous native vegetation. Species diversity and abundance did not differ between sites that bordered pine or were surrounded by pine (>450 m from native forest). Following a wildfire in 1983, pines were replanted and native vegetation strips (20 m to over 100 m wide) regenerated. Strips were originally retained along drainlines linking native forest remnants. Twenty-four breeding sites within and around the forest were surveyed four times between November 1998 and December 1999. Call and visual surveys were undertaken.Study and other actions tested