Individual study: Changes in dewpond numbers and amphibian diversity over 20 years on chalk downland in Sussex, England
Beebee T. (1997) Changes in dewpond numbers and amphibian diversity over 20 years on chalk downland in Sussex, England. Biological Conservation, 81, 215-219
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
A replicated, before-and-after study in 1977–1996 of ponds on chalkland in England, UK (Beebee 1997) found that pond restoration and creation resulted in increased occupancy by amphibians but not species richness/pond. In 1996, 69% of ponds were used compared to 55% in 1977. Species richness was similar in 1977 and 1996 (all ponds: 1.1; used ponds: 1.9 vs 1.6 species). Occupancy increased from 1977 to 1996 for common frogs Rana temporaria (4 vs 9 ponds) and toads Bufo bufo (2 vs 4). However, occupancy decreased for smooth newts Triturus vulgaris (14 vs 10), palmate newts Triturus helveticus (6 vs 3) and great crested newts Triturus cristatus (9 vs 3). Despite restoration, 17 of 33 original ponds were lost by 1996. However, a higher proportion of surviving ponds (n = 26) were in good condition in 1996 (58%) compared with 1977 (24%). Ponds were within a 150 km2 area. Eleven of 33 ponds had been restored since 1977 and 13 created. Ponds were surveyed in spring 1995 or 1996 for species presence by egg counts, torchlight surveys and netting and trapping for newts.
Create ponds for amphibians
A replicated before-and-after study in 1977–1996 of 13 created ponds on chalkland in England, UK (Beebee 1997) found that five amphibian species colonized ponds. Six of 13 new ponds were occupied by common frogs Rana temporaria (46%) and three (23%) by common toads Bufo bufo, which constituted 67% and 75% of their total 1996 distributions (total ponds: 26). Great crested newts Triturus cristatus colonized only one new pond, smooth newts Triturus vulgaris colonized four (only 40% of distribution) and palmate newts Triturus helveticus did not colonize created ponds. Thirteen ponds had been created since 1977, within a 150 km2 area. Ponds were surveyed in spring 1995 or 1996 for species presence by egg counts, torchlight surveys, netting and newt trapping.