| Summary: | Knowledge of the effects of logging on amphibians in British Columbia is
limited. The long-toed salamander, Ambystoma macrodactylum, is a pond-breeding
species with a relatively widespread distribution in the province. I
examined the effects of removing canopy cover on long-toed salamanders in
both aquatic and terrestrial habitats. The study was conducted at the Opax
Mountain Silvicultural Systems Research Area, near Kamloops, B.C.
I compared the relative abundance of breeding salamanders in ponds with
canopy cover conditions ranging from completely open to natural levels of
canopy cover. Similar comparisons were made for juvenile salamanders
emerging from breeding ponds. Capture rates of breeding salamanders were
positively related to canopy cover index, and were higher in more permanent
ponds. The same pattern was observed for emerging juvenile salamanders at
one of the two replicate sites, Mud Lake. The relationship was different at the
second site, Opax, where capture rates were negatively related to canopy cover
index. Emergence of juveniles tended to start earlier at ponds at the Mud Lake
site compared to those at Opax. Juvenile salamanders emerged earlier from
more open ponds at the Opax site, but not at the Mud Lake site. Differences in
effects between sites may result from the shorter growing season at the higher
elevation Opax site, which would place constraints on the number of larvae that
obtain a large enough size to reach metamorphosis. Higher temperatures in
ponds that receive more sunlight would allow faster larval growth, thus increasing
the number of emerging juvenile salamanders.
The effect of reduced canopy cover on long-toed salamanders in
terrestrial habitats was examined by comparing their relative abundance in 1.7-
ha patch cut areas with that in uncut forested controls. The experiment was set
up in a split-plot design, with volume of downed wood (high or low) as the split-plot
factor. Very low capture rates at one of the two replicate sites limited my
ability to detect differences between treatments. The pattern observed at the
Mud Lake site suggests that activity of long-toed salamanders may be restricted
in patch cuts during the summer.
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