Name: 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
Photo from Corkran and Thoms (1996)
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
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
Chazal, A. C., and P. H. Niewiarowski. 1998. Responses of mole salamanders
to clearcutting: using field experiments in forest management. Ecological
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.