Frogs can’t beat the heat

Image by Zach Chan

Research out of SFU has shown that hot and dry summers with minimal snowpack are putting pressure on the wetland ecosystems  among the Pacific Northwest mountains.

A study co-authored by SFU biology professor Wendy Palen, a long-time researcher of amphibians in the region, has developed and demonstrated a new method to project climate-induced changes in the mountain wetlands — and the projections do not look promising for the future of these delicate ecosystems or our amphibian friends.

The study collected data from 121 wetland sites and measured multiple environmental variables to learn more about the types of mountain wetlands that were sampled and the variety of life that they sustain.

Palen explained, “This year we’ve seen that the lack of winter snowpack and high summer temperatures have resulted in massive breeding failures and the death of some adult frogs.” While the ecosystems provide habitats for a wide range of plant and animal species, amphibians are one of the hardest hit groups because of their life cycles.

Mountain wetlands are categorized by how much water they lose throughout the year. This is because changes in the water level will influence the way the environments are used in the ecosystem: as watering holes, breeding grounds, and permanent habitats.

Based on the projections from the study, 58 per cent of wetlands that are currently only dry in the late summer are expected to become ephemeral (seasonal) wetlands; these do not stay wet long enough during the year to sustain animal populations.

Therefore, many fast-growing species of amphibians that depend on these climate-vulnerable ponds will be put at risk. According to Palen, “More years like 2015 do not bode well for the frog.” The Cascades frog is at a particular risk and is currently being evaluated for listing under the endangered species act.

These projection models will serve as a first step towards filling a gap in wetland research, conservation, and assessment. Using the new techniques developed for this study, land managers will be able to gather important information to track and predict the impacts of climate change on not only the amphibians, but all the other life that depend on these oases in the mountain to survive.