Month: April 2017

Shared from LA Times: Click the Link below to see the whole article.

The trees that shade, cool and feed people from Ventura County to the Mexican border are dying so fast that within a few years it’s possible the region will look, feel, sound and smell much less pleasant than it does now.

“We’re witnessing a transition to a post-oasis landscape in Southern California,” says Greg McPherson, a supervisory research forester with the U.S. Forest Service who has been studying what he and others call an unprecedented die-off of the trees greening Southern California’s parks, campuses and yards.

Botanists in recent years have documented insect and disease infestations as they’ve hop-scotched about the region, devastating Griffith Park’s sycamores and destroying over 100,000 willows in San Diego County’s Tijuana River Valley Regional Park, for example. McPherson’s is the first survey to quantify and assess the big picture.

It’s not a pretty one.

His initial estimate is that just one particularly dangerous menace — the polyphagous shot hole borer beetle — could kill as many as 27 million trees in Los Angeles, Orange, Riverside and San Bernardino counties, including parts of the desert.

That’s roughly 38% of the 71 million trees in the 4,244 square mile urban region with a population of about 20 million people.

And that insect is just one of the imminent threats.

“Many of the trees we grow evolved in temperate climates and can’t tolerate the stress of drought, water restrictions, higher salinity levels in recycled water, wind and new pests that arrive almost daily via global trade and tourism, local transportation systems, nurseries and the movement of infected firewood,” he said.

If as many trees as projected die, the cost to remove and replace them could be about $36 billion, he said.

But Southern Californians would face many other costs.

“Catastrophic loss of our canopy,” McPherson said, “would have consequences for human health and well-being, property values, air-conditioning savings, carbon storage, the removal of pollutants from the air we breathe, and wildlife habitat.”

Jerrold Turney, plant pathologist for Los Angeles County, likened the surge in urban tree mortality to “watching a train wreck in slow motion.”

“It’s heartbreaking,” he said, “to see trees dying in such dramatic numbers in famously lush cities like Pasadena, Alhambra and Arcadia: sycamores, all the maples, olives, liquidambers, flower plums, myrtles, oleanders and oaks.”

Mark Hoddle, director of UC Riverside’s Center for Invasive Species, said that the tree loss is “starting to cascade across the urban landscape.”

“Without shade trees, water temperatures will rise and algae will bloom in riparian areas, for instance,” Hoddle said. “As a result, fish, frog and native insect populations will diminish, along with the pleasure of hiking, because there’ll be nothing to look at but dead boughs of trees.”

“And,” he added, “there will be no miraculous recovery of these urban ecosystems after the beetles are done with them.”

Among the hardest-hit native species of urban trees are California sycamores, typically found along streams and commonly used as shade and street trees in places such as Griffith Park and along downtown’s Wilshire Boulevard.

“Here’s the sad news about sycamores,” said Akif Eskalen, a plant pathologist at the University of California, Riverside. “If we cannot control the shot hole borer, it will kill all the sycamores in California. And when they’re done with sycamores, they’ll move to other trees.”

By 2012, pathologists knew that the shot hole borer was transmitting a fatal fungal disease to 19 species of trees in Southern California, he said. Since then, scientists have identified 30 additional host species.

http://www.latimes.com/local/california/la-me-dying-urban-trees-20170403-story.html

 

This was sent to us by Connie Young, Co-Chairperson Fresno Earth Day Event:

This is a photo of a barrio of the town of Mocoa, the Colombian town that was inundated by mud last weekend.  The significance of the photo is that this particular barrio suffered relatively little damage and no one was hurt there  —  because of the presence of deliberate plantings of trees around the neighborhood.  Officials are already studying what happened with an eye to better conservation of the ecosystem of the river basin and, of course, flood prevention.

Denver, CO / Arlington, VA (October 31, 2016) – A new study from The Nature Conservancy finds that an investment in tree planting of just US $4 per resident in some of the world’s largest cities could improve the health of tens of millions of people by reducing air pollution and cooling city streets.

Released at the American Public Health Association annual meeting, the “Planting Healthy Air” study applies well-established research into how trees clean and cool the air locally at a global scale to identify those places where an investment in tree planting can make the biggest impact on people’s lives.

The Conservancy partnered with the C40 Cities Climate Leadership group to develop the study, with the aim of providing urban leaders with the data they need to demonstrate that investments in tree planting can improve public health in their cities.

“Trees can have a significant local impact on pollution levels and temperatures,” said Rob McDonald, lead scientist for global cities at The Nature Conservancy and the study’s primary author. “Urban trees can save lives and are just as cost-effective as more traditional solutions like putting scrubbers on smokestacks or painting roofs white.”

(ALL RIGHTS) November 2015. The Brightside Organization, The Nature Conservancy, UPS and Brown-Forman partnered to plant 150 trees along West Broadway from 20th Street to the end at Shawnee Park in Louisville, Kentucky. Photo credit: © The Nature Conservancy (Devan King)

The challenges facing cities are significant, but trees can be an important part of the solution:

• Every year, more than 3 million people die from the effects of fine particulate matter – air pollution so small that it can enter the bloodstream and lungs, causing such ailments as asthma, heart disease and stroke. In cities, much of this pollution comes from the burning of fossil fuels, including in car engines. Trees can remove as much as a quarter of the particulate matter pollution within a few hundred yards, and when planted in the right places, can offer a very effective barrier, filtering bad air and protecting local residents.
• Urban heat is already the deadliest type of weather-related disaster facing the world, and the impacts will only increase as our climate continues to change. In France in 2003, a summer heat wave killed approximately 11,000 people in one week, so many that the Paris city morgue was overwhelmed and the bodies had to be stored at a vegetable market. The most vulnerable to deadly heat waves are elderly people without access to air conditioning. Trees can cool their immediate vicinity by as much as 2 degrees C, offering a means of protecting people from the impacts of a changing climate.

The Conservancy’s Planting Healthy Air study found that an annual global investment of US $100 million in tree planting could provide 77 million people with cooler cities and 68 million people with measurable reductions in particulate matter pollution.

Cities with high population density, high levels pollution and heat, and a low cost of planting trees showed the highest return on investment, with countries like India, Pakistan and Bangladesh topping the global rankings. But the data also shows neighborhoods in every city that offer a high potential benefit to residents from tree planting.

Trees are the only solution that both clean and cool the air, while simultaneously offering other benefits, including urban green space for residents, habitat for wildlife and carbon sequestration. Tree planting is a solution that mayors and other municipal leaders around the globe can implement to improve the lives of residents within their communities, reducing air pollution and slowing climate change.

“Trees alone cannot solve all of the world’s urban air and heat challenges, but they’re an important piece of the solution,” McDonald said.

Shared from the Washington Post: Click the link below to see the whole article!

By Chelsea Harvey November 2, 2016

Yet another study has reaffirmed the idea that living near nature is good for human health — and can even save lives. A new paper, published Monday by the Nature Conservancy, suggests that planting trees in cities can result in cooler temperatures and reduced air pollution for millions of urban residents. The paper was released at the annual meeting of the American Public Health Association, but it has not been published in a peer-reviewed journal.

The study indicates that a global investment of $3.2 billion throughout 245 of the world’s largest cities — that’s about $4 per resident — could reduce pollution-related mortalities by anywhere from 2.7 to 8.7 percent, saving up to 36,000 lives every year. This level of investment could also reduce temperatures on the hottest days of the year for millions of people, save up to 48 billion kilowatt-hours of electricity annually and avoid up to 13 million tons of carbon dioxide emissions each year.

“Cities usually think of trees just as aesthetic ornamentation,” said lead study author Rob McDonald, lead scientist for The Nature Conservancy’s Global Cities program. “But we wanted to show there’s a lot of benefits. Cities should be thinking about their public health goals as connected to and integrated with their urban goals.”

Previous research has already shown that trees are capable of both cooling and cleaning the air in urban spaces. They provide shade and are able to redirect some of the sun’s energy into their own biological processes, lowering the ambient temperature. And they can remove harmful particulate matter from the air around them.

These are important benefits, both in terms of economics and human health. Previous research estimates that exposure to particulate matter leads to about 3 million premature deaths around the world each year. Excessive heat can also lead to heat stroke and even death, declines in productivity and spikes in air conditioning-related energy use.

The new study focused on 245 cities around the world, which are home to about 910 million people, relying on previous research to assess the impact of trees on ambient temperature and air pollution. The paper suggests that existing urban trees already reduce air pollution by at least 1 microgram of fine particulate matter per cubic meter for about 52 million people worldwide. And more than 68 million people are benefiting from a reduction in summer temperature of up to 3.6 degrees Celsius, thanks to the trees.

https://www.washingtonpost.com/news/energy-environment/wp/2016/11/02/how-planting-trees-in-cities-can-save-thousands-of-lives/?utm_term=.e890a9d80f74