Understanding the drought and deluge in California

Environmental studies professor Michael Loik talks about how the current weather system is impacting the state’s ecology.

February 21, 2017


Professor Michael Loik
Undergraduates Kelly Rush (left) and Hanna Inman (right) are sampling biodiversity under experimental drought shelters for the UCSC Drought Experiment at the UCSC Arboretum. This is one of seven sites Loik coordinates for the UCSC Drought Experiment. Other sites include the Seymour Marine Discovery Center, the Natural Reserves, and Marshall Field on the UCSC Upper Campus. The research is part of the California Drought Experiment and the International Drought Experiment. Photo: Michael Loik
One of the Mammoth Lakes under drought conditions in the summer of 2015. "They will look a lot different this year," says Loik. Photo: Michael Loik

After a record-breaking drought in California, came record-breaking rain storms to the golden state.

“Some have wondered whether this is a hint of future weather conditions,” says environmental studies professor Michael Loik about the extreme meteorological maelstroms California is experiencing. 

For over 20 years, Loik has studied the impact of weather patterns on ecological processes. He’s worked in the Sierra Nevada and Rocky Mountains, as well as all four of the US deserts to explore how weather patterns affect the west’s varied and eclectic ecosystems.

Currently, Loik is conducting several research projects about the consequences of climate change, including an initiative with the UC Natural Reserves about the effects of a drought across the state and another project near Mammoth Lakes in the Sierra Nevada that examines how natural habitats respond to and recover from drought and deluge.

Loik has a B.Sc. and M.Sc. in biology and botany from the University of Toronto and a Ph.D. in biology from the University of California Los Angeles. He joined the Environmental Studies Department at UC Santa Cruz in 1998 and teaches courses on the ecological forecast for global warming and climate change ecology.

Compared to your previous research about El Niño storm seasons, what makes this particular weather pattern so unique?

Michael Loik (ML): Right now we are on track to have the wettest winter in the weather records, wetter even than the 1982-1983 El Nino that was devastating for California. This comes only two years after a 1-in-1200 year drought. So this could really cause a one-two punch to California’s forests, deserts, grasslands and agricultural ecosystems. However, our preliminary findings suggest that trees and shrubs in the Sierra Nevada that survived the worst of California’s drought were conducting photosynthesis and growing at rather normal levels last year.

What are some of the damages of a deluge right after a drought?

ML: Trees during the drought were affected by a lack of water, which meant they could not feed themselves by photosynthesis, which means they could not properly protect themselves from attack by insects and diseases. So they have been quite weakened for multiple reasons, resulting in damaged root systems. This means that trees after the drought are more likely to topple over in saturated soils and the high winds during all of these storms, compared to trees with healthy root systems.

What will recovery look like?

ML: In the short-term, we are seeing a return of photosynthesis and growth to levels that we measured over many years prior to the drought.

In the long-term, I expect that Mammoth Lakes and the rest of California will see a legacy of the drought in the form of higher fire risk from all the dead and dying trees that didn’t survive the drought, beetles, and fungal disease.

Your lab studies mitigation and adaptation. Considering the recent extreme weather swings, how can people mitigate or adapt accordingly? 

ML: There are lots of different ways. For example, deluge grows vegetation and drought causes it to dry to fire fuel. So homeowners can reduce climate change impacts right in their own backyard by keeping property clear of non-native plants and by removing so-called ladder fuels that allow fire to travel from grasses near the ground into tree canopies.  

How unusual is this weather pattern? Will it continue?

ML: In combination, the drought followed by the deluge this winter is probably a 1-in-120,000 year event. There is no way to know if we will continue to experience extreme droughts and deluges of this magnitude. But we do know that California is in a state of perpetual drought that is punctuated by relatively brief periods of abundant rain and snow in the mountains. The big question is whether the recent drought and this year’s wet winter is a harbinger of a “new normal” for California weather in the future.

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