Invasive species


Tapping Crowds to Track California’s Weeds

Help map the spread of invasive plants with a smartphone app

Artichoke thistle flower in Wildcat Canyon Regional Park. Citizens with smartphones can help in a statewide weed-mapping initiative.

If you have a sharp eye for invasive plants – and a smartphone – you can help a Bay Area non-profit in its effort to document the distribution and spread of invasive plants across California.

The Berkeley-based California Invasive Plant Council, or Cal-IPC, has found that weeds cost the state at least $82 million annually in terms of increased erosion and flooding, degraded agricultural land and reduced water supplies.

California is hardly alone. A 2005 study by researchers from Cornell University put the nationwide cost of battling invasive weeds at a staggering $120 billion [PDF].

Climate change is making the issue even more complex, says Doug Johnson, Cal-IPC’s executive director, who is trying to better understand how non-native plants may respond and how they may gain advantage over native plants during prolonged bouts of warming or cooling. Continue reading

Climate Change Could Mean Cloudy Future for Lake Tahoe

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

Spring Comes Sooner, Some Species Suffer


Spring in the United States comes ten days sooner than it did just 20 years ago, according to scientists on a media call Tuesday.   This phenomenon, known as “spring creep” (or “season creep“), may be good news for flip-flop fans, but it doesn’t always work out well for native species in certain habitats.  According to Reuters, scientists on the call (which was sponsored by the Union of Concerned Scientists) explained that when spring comes earlier, it doesn’t just bring warm weather sooner — it actually throws off the balance of entire ecosystems by encouraging the spread of invasive species, many of which are better able to adapt to the changing conditions than are native plants and animals.  In the American West, warmer weather is already shrinking the habitat of the American pika, and more of it could make wildfires more frequent and intense.