Tag Archives: Ecosystems

The Science

How Much Carbon Do California’s Forests Hold?

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It’s a tough number to nail down, but a federal program is zeroing in on it

Trees, grasses and freshwater aquatic systems all play a part in the carbon cycle.

The U.S. Geological Survey is developing a series of reports on how much carbon and other greenhouse gases the nation’s ecosystems hold. Trees and plants, soils and rivers, farms and wetlands all sequester carbon to greater or lesser extents. But how much? And how might that number change in the future? That’s the crux of the USGS study, which was initiated by the Energy Independence and Security Act of 2007 [page 223 of the PDF]. (There’s a simultaneous study, also by the USGS, to assess geologic carbon sequestration).

The national assessment will include details on greenhouse gas sequestration nationwide: how much carbon is stored now, how that carbon sink might be altered by different land use scenarios in the future (for example, increased or decreased logging, urbanization, wetland restoration efforts or agriculture), plus impacts from other sources, such as wildfire and climate change.

Continue reading How Much Carbon Do California’s Forests Hold? →

The Science

Climate Change Could Mean Cloudy Future for Lake Tahoe

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New threats to lake’s clarity are emerging just as restoration funding is drying up

Climate change and invasive species threaten Lake Tahoe just as restoration funding dwindles.

Over the last 15 years, more than a billion dollars has been spent to protect Lake Tahoe’s clear waters from runoff and erosion. Now, new threats to lake’s clarity are emerging, just as restoration funding is drying up.

Researchers from UC Davis are hot on the trail of one of those threats. On a recent late summer morning, Katie Webb and a team from UC Davis’s Tahoe Environmental Research Center went looking for it on a boat near South Lake Tahoe.

Hear the radio version of this story Wednesday on The California Report. Continue reading Climate Change Could Mean Cloudy Future for Lake Tahoe →

Get Involved, The Science

Time for “Creosote Bush” National Park?

It’s not time to rename Joshua Tree just yet, says the author of a new study.

Climate change is threatening the Joshua trees in Joshua Tree National Park all right, according to a new report. But unlike the findings of recently-published study,  this report finds the park’s iconic, spiky namesake is unlikely to completely vacate the premises over the next century.

The new report was funded in part by Joshua Tree National Park, and its author Cameron Barrows, a researcher at UC Riverside’s Center for Conservation Biology, says that he conducted it partly in response to the recent study by Ken Cole of the USGS, which found that the trees would likely be gone from the park within the next 90 years.

“I facetiously say if that was to happen, we’d have to rename the park ‘Creosote Bush National Park’ or something like that,” said Barrows.  “It would be really sad if that’s the case.”
Continue reading Time for “Creosote Bush” National Park? →

The Science

Joshua Trees Losing Ground, Fast

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Joshua trees, the spiky desert-dwellers that are so iconic to Southern California’s dry country that they got a national park named after them, will likely disappear from 90% of their current range by the end of the century, according to a new study by scientists at the US Geological Survey.

Ecologist Ken Cole, the study’s lead author, said that means no more Joshua Trees in Joshua Tree National Park, which is currently in the southernmost part of the species’ range. It also means elimination of the trees across wide swathes of other parts of Southern California as well as Nevada and Arizona.

Cole and his team used climate models, field work, and the fossil record to project the future distribution of Joshua trees. They compared the projected increase in temperatures for the Southwest (four degrees Celsius, according to a “middle of the road” IPCC scenario) to a similar rapid increase in temperatures nearly 12,000 years ago, at the end of the ice age.

Using fossil sloth dung and packrat midden, the scientists reconstructed how Joshua trees responded to that warming. (Sloths, which are now extinct in the region, and packrats, ate the Joshua tree fruit, spreading the seeds and leaving them behind for the scientists to track.) Continue reading Joshua Trees Losing Ground, Fast →

The Science

California’s Giant Carbon Sponge

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The forests in the state provide water, habitat for animals, lumber and tourism dollars, and they sequester carbon. (Photo: Molly Samuel)

For decades the federal government has touted the nearly 200 million acres of national forests and grasslands under its control as a “land of many uses.” But one “use” that’s seldom discussed is as a huge repository for carbon.

But clearly it’s on the minds of officials and scientists as the Forest Service seeks comments on its proposed new planning rule. National Forests and Grasslands are managed individually, but the planning rule guides how those management plans are developed. This new one is replacing a Planning Rule from 1982. Continue reading California’s Giant Carbon Sponge →

Government & Business, Water

What Will Your Water Cost?

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Report: Big changes needed to avert “widespread environmental and economic losses” in California

Grand illusion? Water rushes over the spillway at Nicasio Reservoir in Marin County. (Photo: Craig Miller)

A high-profile team of experts is calling for a major overhaul of the way California manages its water. In a 500-page report from the non-partisan Public Policy Institute of California, the authors say decades of well-intended water policies simply haven’t worked, leaving the state vulnerable to major crises, including water shortages, catastrophic floods, decline & extinction of native species, deteriorating water quality, and further decline of the Sacramento-San Joaquin Delta.

“Our system has been dying a death by a thousand cuts,” says co-author Ellen Hanak, an economist and policy analyst at the PPIC. Hanak says that the state’s water management efforts have been “incremental” and “piecemeal,” with little success to show for it. Continue reading What Will Your Water Cost? →

Get Involved

Why the Pros Need “Citizen Science”

iNaturalist Update: A biologist’s take on the potential for citizen science in a changing climate

(Photo: Richard Morgenstein)

Last month I went out to Jasper Ridge Biological Preserve near Stanford, where Scott Loarie and Ken-ichi Ueda showed me and about a dozen docents how to use the new iNaturalist iPhone app, which Ueda created. The aim of the app is to make recording and sharing of accurate field observations incredibly simple. It’s still in testing mode and not yet available to the public. “Citizen scientists” can already upload their digital photos and share them with an online community of naturalists around the world, at the iNaturalist website.

This week I spoke with Healy Hamilton, who directs the Center for Applied Biodiversity Informatics at the California Academy of Sciences. Below are some excerpts from our interview about climate change, citizen science, and iNaturalist: Continue reading Why the Pros Need “Citizen Science” →

Get Involved, The Science

Citizen Science: The iPhone App

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A new iPhone app aims to make recording and sharing observations of the natural world fast, easy, and could eventually help bring climate models into better focus.

Ken-ichi Ueda and Scott Loarie demonstrating the new iNaturalist iPhone app at Stanford’s Jasper Ridge Biological Preserve (Photo: Richard Morgenstein)

At Jasper Ridge, a biological preserve and study area on the Stanford campus, a dozen of the preserve’s docents gathered this week to learn about a new iPhone application that could ultimately help scientists study how ecosystems are adapting to climate change.

The new app, called iNaturalist, is the mobile version of a citizen-science website by the same name.  The iPhone app is still in testing and not yet available, but the website, iNaturalist.org, is already an active online community of citizen-scientists around the world who use the site to record and share their sightings. Continue reading Citizen Science: The iPhone App →

The Science

Climate Warms, Trees Head Downhill?

Near Tioga Pass, Yosemite (Photo: Gretchen Weber)

As the climate warms, plants and animals will need to move uphill to more hospitable climes, right?  Some are — but it turns out that in other cases, the process seems to have shifted into reverse.

According to a new study published in the journal Science, some plants in Northern California are actually moving downhill in response to climate change.   Aided by historical data, researchers from UC Davis and the University of Montana determined that between 1930 and 2000, many California species shifted downward an average of 260 feet.

The reason, according to UC Remote Sensing scientist Jonathan Greenberg, is increased precipitation, which, in some cases is overriding temperature as the main driver for species distribution.

“These wetter conditions are allowing plants to exist in warmer locations than they were previously capable of,” said Greenberg in a press release about the study.

NPR’s Richard Harris has more on the study and on what it could signal for California’s changing ecosystems.

The Science

If You’re a Tree, Timing is Everything

Scientists come up with a way to handicap a key harbinger of spring

Photo: R.A. Howard from the USDA-NRCS PLANTS Database

Bud burst, when the buds on a tree begin to open up, marks the end of winter dormancy and the beginning of a tree’s growing season. Timing’s important: If a tree buds too early, it may be susceptible to a late frost. Too late, and it misses out on some or all of its growing season. As the climate warms, this delicate timing can go awry.

Scientists at the US Forest Service’s Pacific Northwest Research Station in Portland, Oregon, have developed a model to predict bud burst. They used Douglas firs in their experiments but also surveyed research on about 100 other species, so they expect to be able to adjust the model for other plants and trees.

Both cold and warm temperatures affect the timing, and different combinations yield different outcomes — not always intuitive. With plenty of hours of cold temperatures, trees need fewer warm hours to burst. So earlier spring warmth will drive bud burst earlier. If a tree isn’t exposed to enough cold, though, it needs more warmth to burst. So under the most dramatic climate change scenarios, warmer winters could actually mean a later bud burst.

Genes play a roll, too. The researchers experimented with Douglas firs from across Oregon, Washington, and California. Trees from colder or drier environments showed earlier burst. Trees descended from those lines could fare better in places where their warmer-and-wetter-adapted cousins live now.

The team, led by research forester Connie Harrington, hopes to use the model to predict how trees will respond under various climate projections. With that information, land managers can decide where and what to plant, and, if necessary, plan assisted migration strategies.