Alana Hilton

Department of Forest Sciences
3041-2424 Main Mall, UBC
Vancouver, B.C. V6T 1Z4

Position: M.Sc. Candidate

Study Topic: Effects of forest harvesting on northwestern salamanders: An experimental approach.

Comparative studies suggest that amphibians are negatively affected by forest harvesting, with smaller population sizes and lower species richness in harvested areas (Petranka, 1994). Few experimental studies have been done to directly demonstrate the effect of silvicultural practices on amphibian populations (Chazal and Niewiarowski, 1998). For my Master’s thesis, I propose to use an experimental approach to determine the effects of forest harvesting on a common salamander species, the northwestern salamander.

Northwestern salamanders are a pond-breeding species that are terrestrial in the non-breeding season. Mature adults perform a seasonal breeding migration to ponds during the late winter/early spring, and return to their terrestrial habitat after breeding is completed. Metamorphosed juvenile northwestern salamanders emerge from their natal ponds during rainy nights in the summer months, and mature in the surrounding terrestrial habitat.

My experiment will take place at the Malcolm Knapp Research Forest in Maple Ridge B. C., and it will be modeled on that of Chazal and Niewiarowski (1998). Twenty-four 7m x 7m field enclosures will be built on 2 recent clearcut sites and 3 adjacent second-growth forested sites. The experiment will have two replicated treatments, clearcut and food/water addition, each with a control. Soil temperature, leaf litter moisture, soil moisture, rainfall and air temperature will be recorded for enclosures at each site.

The study will consist of two trials. In the first trial, 25 individually marked, weighed and measured adult salamanders will be introduced to each enclosure. Adults will live in the enclosures for 3-4 months. Pitfall trapping will be done within each enclosure twice throughout the study and at the conclusion to record changes in weight and estimate survival rates. Adults will be trapped out of the enclosures at the end of the trial. In the second trial, 25 individually marked, weighed and measured juvenile salamanders will be introduced to the enclosures. Juveniles will also remain in the enclosures for 3-4 months, and their growth rates and ages at maturity will be recorded, in addition to survival rates.

This research will increase understanding of the microhabitat factors that could be affecting salamanders in harvested areas. This knowledge is essential for the proper management of less abundant amphibian species.

Chazal, A. C., and P. H. Niewiarowski. 1998. Responses of mole salamanders to clearcutting: using field experiments in forest management. Ecological Applications. 8:1133-1143.
Petranka, J. W. 1994. Response to impact of timber harvesting on salamanders. Conservation Biology. 8:302-304.

Other Interests: Between graduating with my B.Sc. from SFU and starting my Master’s, I spent 5 years working in the biology field. The majority of my work has involved research on spotted owls in B. C. I performed call-playback inventories, radio-tagging, radio-telemetry, and leg banding of spotted owls in the Vancouver and Kamloops Forest Regions. I also spent time analyzing spotted owl radio-telemetry data for the Ministry of Water, Land and Air Protection. In 2000, my husband (Shawn) and I started a consulting company called Panorama Wildlife Research. We have worked with B.C. Conservation Foundation, Ministry of Water, Land and Air Protection, and various other consulting companies in the Vancouver area. Shawn is still involved in spotted owl and barred owl research through our company. Other biology-related work that I have been involved in include construction monitoring, electrofishing, habitat assessments, small mammal trapping, small mammal radio-telemetry, and vegetation surveys.