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Earth: Is groundwater depletion in the Central Valley causing the Sierra Nevada to grow faster?


A NASA Earth Observatory image shows the Sierra Nevada Mountains in California.

Study also correlates aquifer withdrawals with activity on San Andreas Fault

Staff Report

FRISCO —After crunching the numbers from a global earth-monitoring network, University of Nevada, Reno scientists day rapid depletion of groundwater in California’s Central Valley is accelerating uplift of the Sierra Nevada Mountains.

The draining of the aquifer causes upward flexing of the earth’s surface, including the surrounding mountains. The groundwater subsidence is also linked with seismic activity along the San Andreas fault, the researchers reported in the journal Nature. Continue reading

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Biodiversity: Feds agree to study pesticide impacts to rare frogs in California


USGS sampling found that Pacific chorus frogs in many remote Sierra Nevada locations are contaminated by pesticides and fungicides used in agricultural production in California’s Central Valley. Photo courtesy USGS.

Court settlement may ultimately help protect endangered amphibians

By Summit Voice

FRISCO — In a classic case of government do-nothingism, federal agencies have known for years that pesticides are killing rare California frogs — but have failed to act to protect the amphibians from the poisons.

But that should change soon, as a federal court this week approved a deal that requires the U.S. Fish and Wildlife Service to prepare detailed environmental studies on the effects of seven common pesticides: Glyphosate, malathion, simazine, pendimethalin, permethrin, methomyl and myclobutanil.

The studies, called biological opinions in government jargon, will evaluate and disclose how the use of those chemicals affects California’s red-legged frogs when they’re used in and near the frog’s aquatic and upland habitats. Continue reading

Environment: Frogs up and down the Sierra Nevada are tainted with pesticides from the Central Valley


USGS sampling found that Pacific chorus frogs in many remote Sierra Nevada locations are contaminated by pesticides and fungicides used in agricultural production in California’s Central Valley. Photo courtesy USGS.

Study even finds trace remnants of DDT, banned 40 years ago

By Summit Voice

FRISCO — Frogs in remote Sierra Nevada backcountry ponds are contaminated with traces of pesticides, including a byproduct of DDT, which was banned more than 40 years ago, showing how long some pollutants can persist in the environment.

The chemicals are heavily used in California’s Central Valley, one of the most productive agricultural regions in the world, and transported via wind, dust and precipitation to the High Sierra. Continue reading

NASA mission targets more accurate snowpack data


NASA Airborne Snow Observatory measurements of snow water equivalent (top image) and snow albedo, or reflectivity (bottom image) for the Tuolumne River Basin in California’s Sierra Nevada on April 21, 2013. The snow water equivalent measured the total water contained as snow in the basin on that date at 375 million cubic meters, or enough to fill the Rose Bowl about 1,180 times. The albedo map expresses the percentage of sunlight reflected back to space by the snow. The lower the albedo, the faster the snowmelt rate and runoff. Image credit: NASA/JPL-Caltech.

Aerial surveys with high-tech instruments will create detailed snow maps, yielding better runoff forecasts

FRISCO — Data from an ambitious new NASA aerial program could help resource managers get a jump on global warming, with more precise and timely snowpack measurements.

By Summit Voice

NASA’s Airborne Snow Observatory began it’s three-year demonstration mission in April, with weekly flights over the Tuolumne River Basin in California’s Sierra Nevada and monthly flights over Colorado’s Uncompahgre River Basin. Scientists involved in the program hope to start covering the entire Upper Colorado River Basin.

The data is already paying off for power companies and water managers, who can use real-time updates to allocate water resources more efficiently, for storage, irrigation and municipal supplies.

Most snowpack measurements are currently collected via ground-based surveys and from automated SNOTEL sites. Airborne mapping can cover more ground and gather data from areas without observation stations, resulting in more accurate forecasts. Continue reading

Biodiversity: Sierra Nevada frogs proposed for listing


Recovery efforts for Sierra Nevada yellow-legged frogs may get a boost from a proposed endangered species listing. Photo courtesy U.S. Fish and Wildlife Service.

Endangered Species Act protection could help stem decline and boost recovery efforts

By Summit Voice

SUMMIT COUNTY — After suffering decades of decline  from habitat destruction, disease, predation by nonnative trout, pesticides and climate change, native Sierra Nevada amphibians may get some measure of protection under the Endangered Species Act.

The U.S. Fish and Wildlife Service last week proposed listing Sierra Nevada yellow-legged frogs and Yosemite toads. The agency also proposed protection for a population of mountain yellow-legged frogs that lives in the southern Sierra Nevada. The plan also includes an initial proposal to designate more than 2 million acres of critical habitat.

The proposal are the result of a 2011 agreement between the Center for Biological Diversity and the USFWS to speed up endangered species protection decisions for 757 imperiled animals and plants around the country. So far, 56 species have been fully protected and another 96 have been proposed for protection under the settlement agreement.  Continue reading

Illegal pot farmers killing rare wildlife in California

Between 80 and 90 percent of dead fishers in study area found with traces of rodenticides

Marijuana growing on national forest land near Winter Park Ski Area.

A rare fisher. Photo courtesy U.S. Forest Service.

By Summit Voice

SUMMIT COUNTY —While comic book characters like the Fabulous Furry Freak Brothers may live up to the stereotype of Earth-loving hippies, the reality of pot-growing on public lands is far uglier.

In a new study, UC Davis researchers found that rat poison deployed by illegal marijuana growers is killing rare forest mammals like the fisher, which makes its home in some of California’s most remote backcountry terrain.

Fishers in California, Oregon and Washington have been declared a candidate species for listing under the federal Endangered Species Act.

“I am really shocked by the number of fishers that have been exposed to significant levels of multiple second-generation anticoagulant rodenticides,” said pathologist Leslie Woods of the UC Davis California Animal Health and Food Safety Laboratory System, which conducted the necropsies. Continue reading

Study confirms ancient California megadroughts

100 to 200 year dry spells not uncommon

Fallen Leaf Lake, California.

By Summit Voice

SUMMIT COUNTY — With the central Sierra Nevada in drought conditions, researchers with the University of Nevada, Reno and their partners at Scripps Institution of Oceanography in San Diego are warning that the region is no stranger to megadroughts, often lasting several hundred years.

The best-known of those is the Medieval megadrought, between 800 to 1250 A.D. when annual precipitation was less than 60 percent of normal. The Reno-Tahoe region is now about 65 percent of annual normal precipitation for the year, which doesn’t seem like much, but imagine if this were the “norm” each and every year for the next 200 years. Continue reading

California researchers say chorus frogs are carriers of deadly chytrid fungus that’s wiped out 200 frog species

Known for its distinctive "ribbit" call, this noisy frog is a potent carrier of a deadly amphibian disease, according to new research published March 12, 2012, in the journal PLoS One. The research was led by Vance Vredenburg, assistant professor of biology at San Francisco State University. PHOTO BY JOYCE GROSS

New research may help treat or prevent the disease in endangered amphibians

By Summit Voice

SUMMIT COUNTY— New studies of common Pacific chorus frogs may help scientists stem the spread — or at least better understand — a deadly fungus that has already wiped out more than 200 frog species worldwide, and has pushed Colorado’s boreal toad close to brink.

San Francisco State University biologists working in the Sierra Nevada found that the disease is widespread among among the frogs, but the species rarely shows symptoms, making it a highly effective carrier.

“We found that the vast majority of Pacific chorus frogs don’t die or show symptoms even with surprisingly high levels of infection,” said Natalie Reeder, who conducted the research for her master’s thesis at SF State. “They are able to go about life as normal, moving over land and carrying the disease to new locations.” Continue reading

Global warming: Sierra chipmunks take genetic hit

Some alpine mammals are taking a genetic hit from global warming. PHOTO BY BOB BERWYN.

Startling changes documented in just a few decades

By Summit Voice

SUMMIT COUNTY — Chipmunks in the High Sierra have taken a startling genetic hit from global warming, according to University of California Berkeley scientists, who say that climate change has shifted the species’ range upward by about 1,600 feet.

The chipmunks have retreated to higher and cooler ground as the average temperature in the Yosemite region has increased by about 5.4 degrees during the past century. Their habitat has become more fragmented, resulting in smaller, more isolated populations, which are becoming genetically impoverished. Continue reading

Biodiversity: Marten numbers dwindling in Sierra Nevada


Logging may be fragmenting old-growth habitat

By Summit Voice

SUMMIT COUNTY — Martens, small but fierce mammal predators at home in old-growth Sierra Nevada forests, may be in serious decline, according to research published last week in the Journal of Wildlife Management.

Biologists from Oregon State University and the U.S. Forest Service estimated that detection rates of marten have declined by 60 percent compared to historical surveys in the 1980s – and one possible cause, they say, is habitat loss from logging.

Previous research  demonstrated that marten populations had become increasingly fragmented in northeastern California. The latest study offers an explanation for the pattern.

Martens also are considered an “indicator” species that reflect beneficial conditions for other animals that occupy old forests. Continue reading


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