Amphibians were trapped for 6 weeks in the autumn of 2003 at 6 sites in the Malcolm Knapp Research Forest. These 6 sites were in riparian areas adjacent to small streams, divided amongst 2 controls, 2 clear-cut sites, and 2 sites with 30 m reserves. The sites that received harvesting did so in 1998, and the changes in abundance of amphibians have been followed since. All 9 native species that should occur at the research forest have been found at most sites, in addition to the non-native green frog. In 2003 211 individuals across all species were trapped during the 6 week period across all sites. The most common of the species across all sites were the northwestern salamander, red-backed salamander, and the tailed frog (in order of abundance). The rate of capture in 2003 was the lowest in 6 years of trapping, probably reflecting the very protracted dry conditions of last year and late onset of rain. Year-to-year variation in numbers is relatively high, but there are still patterns associated with forest harvesting. Numbers of northwestern salamanders remain highest at the two control sites relative to the harvested sites. In contrast, red-backed salamander abundances remain higher at the harvesting sites than the control, although, they were also lower at the control sites prior to harvesting, so this probably reflects a site effect. Site-to-site and inter-annual variation remain high relative to the variation due to treatments, indicating the need for long-term data for species such as these to determine the consequences of harvesting and the efficacy of using riparian reserves to protect putatively sensitive wildlife species.
John S. Richardson, Tatiana Lee.
Richardson, John S.. 2004. Amphibian populations as indicators of integrity and recovery from riparian harvesting in a coastal forest. Forest Investment Account (FIA) - Forest Science Program. Forest Investment Account Report. FIA2004MR213