A crucial part of California’s ecosystem has almost disappeared. Mountain meadows act like natural reservoirs, storing and cleaning water.
They may also have another benefit – capturing greenhouse gases. Scientists are studying if restoring meadows can play a small part in combating climate change.
When you imagine a meadow, you might think about soggy ground with tall green grasses and a shallow stream running through it. It’s unlikely you’d imagine a place like Bean Meadow, in the Sierra Nevada foothills of Mariposa County.
"Although we have a meadow here right now you can see it's extremely dry, there is no wet component to it at all right now," says Bridget Fithian with the Sierra Foothill Conservancy.
Golden European grasses crunch beneath our feet. Cows graze in the distance.
The Conservancy has embarked on a project to return 39 acres back to what it once was, before people built roads and ditches and turned it into ranchland in the 19th century.
She takes me to the middle of the meadow.
"We’re kind of in a forest now, but we’re actually in a creek channel," says Fithian. "The creek channel should not have gigantic ponderosas growing in it and these huge decadent willows. So basically the wetland area of this property has been totally condensed to this little corridor."
What is supposed to be a shallow stream is 14 feet deep.
"It’s just absurd. It should not look like that here," says Fithian.
A deep stream moves water through the landscape too quickly. This meadow is supposed to capture water from melting snow and slowly release it downstream into the Merced River.
"When you have that slow release, you reduce evaporation and you reduce the temperature of the water,"says Fithian."So you really increase the quality of the water and you increase the quantity."
Wet meadows also have native grasses with robust root structures. That serves another important purpose - sucking carbon dioxide out of the air and storing it in the soil.
“We know that wetlands in general store lots of carbon," says Stephen Hart, an ecology professor at UC Merced. "So if we restore the meadows like this one back to a wetland state, we’re anticipated more carbon will be stored, because less CO2 will be admitted.”
But researchers need to first get a good idea how much greenhouse gas the meadow is emitting now.
Researchers are placing chambers, which look like plastic, upside-down bowls, over patches of grass. They then stick a syringe through the chamber to grab a sample of air inside.
They’ll measure the emissions coming off the meadow now and compare it to the meadow once it’s been restored. Bridget Fithian says restoration requires earthmoving equipment, large tree removal, and the creation of earthen berms that allow water to spread out onto its historic floodplain.
“It’s actually a pretty radical alteration to the landscape," says Fithian. "But what we have right now is radical alteration to the landscape.”
It’s not just Bean meadow that’s been altered. Stephen Hart with UC Merced says most mountain meadows in the Sierra are in sad shape.
“Pretty much all of them are in a state of degradation, loss of ecological function," says Hart. "So if we had the funds to restore them all that would be quite a significant sink – if my hypothesis is correct – for greenhouse gases in the future."
If Hart is right, the restored meadow will capture carbon dioxide, store and clean water, and provide for native habitat. State agencies are betting on it.
The Bean Meadow project was one of 12 wetland restoration projects to receive money from the state’s cap and trade program. Reconstruction of the meadow will begin next fall.