Individual study: A comparison of logging systems and bat diversity in the Neotropics
Clarke F.M., Pio D.V. & Racey P.A. (2005) A comparison of logging systems and bat diversity in the Neotropics. Conservation Biology, 19, 1194-1204
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Use selective harvesting/reduced impact logging instead of clearcutting
A replicated, controlled, site comparison study in 2001–2002 in a lowland tropical forest in Victoria-Mayaro Forest Reserve, Trinidad (Clarke et al 2005) found a significant difference in the numbers of bats per guild between sites that were continuously logged, periodically logged or undisturbed. Fruit-eating bat species were more abundant in continuously logged forest (958 bats captured of 13 species, 87% of total captures) than periodically logged (352 bats captured of nine species, 82% of total captures) or undisturbed forest (282 bats captured of 10 species, 66% of total captures). Gleaning animal-eating species were more abundant in undisturbed forest (71 bats captured of nine species, 17% of total captures) than periodically logged (six bats captured of seven species, 6% of total captures) or continuously logged forest (52 bats captured of eight species, 5% of total captures). The sample sizes of bats in other guilds were too small for comparisons to be made. The number of bat species or species captured per guild did not differ between undisturbed and logged forest. Continuously logged sites had been under open range management from 1954 to 1990 in which trees were cropped continuously with the only control being a girth limit for certain species. The canopy in open range forests is relatively open, allowing pioneer fruit plants to grow. In periodically logged sites, since the 1970’s selected trees (4–8 trees/ha) in blocks of 150–300 ha were felled based on several ecological criteria including value to wildlife. The blocks are logged over one to two years and then closed for 30 years. Undisturbed sites were protected primary forest. Two sites were surveyed in each of the three habitats: primary undisturbed forest, forest under period block management (closed 10–20 years ago) and forest under open range management (closed ten years ago). Bats were captured using mist nets (at ground level and in the forest sub canopy) and harp traps for six hours after sunset at five sampling points spaced 350–750 m apart twice at each site. A total of 1959 bats were caught representing 38 different species.