‘Unprecedented’ Tree Die-Off Hits Southern California

Wednesday, April 26, 2017

By Marissa Cabrera, Maureen Cavanaugh

Dead trees in the Cleveland National Forest in San Diego County are pictured ...

Credit: Cleveland National Forest

Above: Dead trees in the Cleveland National Forest in San Diego County are pictured in this undated photo. They are a casualty of the goldspotted oak borer beetle.

GUEST: Greg McPherson, supervisory research forester, U.S. Forest Service

Researchers from the U.S. Forest Service are documenting what they are calling an unprecedented die-off of trees in urban areas across Southern California.

Sycamores, willows, avocado and citrus trees are dying because of the drought, pests and disease infestations.

Greg McPherson, a supervisory research forester with the Forest Service, estimates that a pest called the polyphagous shot hole borer beetle alone could kill 27 million trees across the region. That is about 40 percent of the area’s 70 million urban trees.

McPherson joined Midday Edition Wednesday to talk about the environmental and economic impacts of California’s tree die-off. Read more and listen to the podcast HERE

Additional 27 Million Trees Have Died in California in the Last Year

Wednesday, December 13, 2017

By Marissa Cabrera, Maureen Cavanaugh

Dead trees in the Cleveland National Forest in San Diego County are pictured ...

Credit: Cleveland National Forest

Above: Dead trees in the Cleveland National Forest in San Diego County are pictured in this undated photo. They are a casualty of the goldspotted oak borer beetle.

More trees are dying in California’s forests.

A new U.S. Forest Service survey found that another 27 million trees died since November 2016. That brings the total number of dead trees to a record 129 million since 2010.

Read more and listen to the podcast HERE

These maps show the progression of tree mortality across ...

Photo credit: U.S. Forest Service

These maps show the progression of tree mortality across California from 2014-2017.

The lingering effects of California’s drought and bark beetles are largely to blame for the dying trees. But there are signs that the rate of the tree die-off is slowing.

RELATED: Fixing California’s Tree Die-Off May Take Decades

Stephanie Gomes, with the U.S. Forest Service’s tree mortality task force, discusses Wednesday on Midday what the department is doing to address the health of California’s forests.

US cities losing 36 million trees a year, researchers find

Scientists warn of environmental threats rising from trend that is ‘likely to continue unless policies are altered’

CITIES IN THE UNITED STATES ARE INCREASINGLY SEEING CONCRETE in place of greenery as urban areas lose an estimated 36m trees annually, according to a study from the Forest Service.

Tree cover in urban areas has declined at a rate of around 175,000 acres per year, while impervious cover – such as roads and buildings – has increased significantly across the country. An estimated 40% of new impervious surfaces were in areas where trees used to grow, the study found.

The total loss of tree cover reached 1% across cities and surrounding areas in the five years between 2009-2014. As four-fifths of Americans live in urban areas, it has serious environmental, social and economic ramifications, warned researchers.

 

Trees add beauty, health benefits and significant energy savings in urban environments. Left, an urban park near the U.S. Capitol.

 

“Understanding where these losses are occurring and the magnitude of change will hopefully facilitate informed discussions on how much tree cover communities want to have in the coming years, and on the roles of urban trees in sustaining environmental quality and human health and wellbeing,” said David Nowak, co-author of the study, published in the journal Urban Forestry and Urban Greening.

Urban forests moderate climate and reduce carbon emissions, improving the quality of air and water. Properly placed around buildings, trees can save energy by reducing the need for air conditioning by 30% and for heating by up to 50%. They also mitigate rainfall runoff, offering vital barriers in flood-prone cities. The estimated loss of these benefits – including carbon storage, pollution reduction, altered energy use in buildings – is valued at $96m (£71m) per year.

Urban trees also have social advantages, such as improving people’s mental and physical health.

“Trees in urban areas help ward off pollution, providing a long list of benefits for people and the planet,” said Rolf Skar, forest campaign director for Greenpeace USA. “This news proves once again that we need to prioritise adding more green spaces to our cities.” Read more>

Rebecca Latta on CBS News: Drought-Damaged Trees can Topple in Heavy Rain

CBS news interviewed arborist Rebecca Latta on how the combination of drought and a sudden heavy rain can damage trees. An unusual number of trees came down across the region last month, following heavier-than-usual rain and wind, the result of trees weakened by parched soils from an extended period of drought.

Latta warns that homeowners should examine their trees regularly for any unusual signs, such as mushroom growth near roots, oozing sap, branch dieback or broken branches. All of these are signs that something could be wrong with the tree, and a certified arborist should be called. “It’s important to keep your trees maintained by an expert,” she said.

Tree Die-Off in Santa Monica Mountains due to Drought, Heat


California’s drought has caused many thousands of native oaks, sycamores, alders and willows to die at Topanga State Park, one of the largest urban parks in the U.S. The view along the park’s hiking trails has changed dramatically in the last few years as it has throughout the Santa Monica Mountains. A senior conservation biologist for the Resource Conservation District of the Santa Monica Mountains attributes the dead trees to the effects of climate change on the region.