For the past two years, the professor, who’s affiliated with the Sierra Nevada Research Institute, has worked with student researchers at remote sites in the mountains. They manipulate the snowpack to see the effects of early snowmelt on the forest, from how it affects the nutrients in the soil and plant growth, to how greenhouse gases are emitted from the soil.
It’s all with the goal of designing better predictive tools, and they’ve gotten some surprising results.
Although Hart thought they’d find that the earlier the snowmelt, the more carbon dioxide would be released from the microorganisms in the soil – contributing to even more global warming –it appears to be just the opposite.
“The emissions are actually slowed down,” Hart said.
The researchers also found that earlier snowmelt has a longer-lasting effect than they had theorized – drier soil persisted for much of the summer growing season, impacting the forest plants’ growing season.
In Hawaii, Hart also studies the effects of climate change on the soils in the rain forests, and while he doesn’t have to worry about soil drying out there, he said studying the contrast between the two different ecosystems is fascinating and contributes to the global knowledge about climate change.
“We need to understand how warmer temperatures are affecting the ecosystems we live in – the crops, water availability, birds and animals – everything,” Hart said.
To manipulate the snowmelt, Hart and the other researchers, including his postdoctoral student Joey Blankinship, have tried different methods, from spreading black cloth over areas of snowpack, thinking it will pull in warmth (it actually slowed the melt) to spreading bags of black sand over the snow.
It took a few tries to come up with the method that warms the snow at rates that simulate those caused by global warming in the Sierra, so they can evaluate the effects of an earlier snowmelt on the forests.
They visited the remote sites more often in the spring and less often in the summer, relying on snowmobiles to get in and out.
Having wrapped up the data-gathering this summer, they will analyze all the information and prepare reports on what they’ve found. One research paper is being revised now, and the next one should be coming soon.
Then, Hart said, it’s a matter of deciding what to do next – expand the research to bigger sites? Move on to a new area? One project he’d like to get involved with is an international research network being formed to look at climate change in high-elevation ecosystems all over the world. The researchers will share data and create predictive models to see what’s happening globally.
“It’s a scary trajectory we’ve got the planet on. The rate of change in the climate is unprecedented. It is undeniable that we live in a warmer world, and we need to better understand the consequences of this warming on the sustainability of our planet,” Hart said. “We can’t wait until nature just shows us what happens – by then it will be too late.”