21 Aug 2013:
Thai Monkeys May Abandon
Stone Tools Due to Human Disruptions
Human disturbances in Thailand’s Laem Son National Park may be causing Burmese long-tailed macaques to abandon their use of stone tools, say researchers studying the primates
. The only monkeys in Asia to use
stone tools — and one of only three non-human primates worldwide to do so — these Burmese macaques have learned to use coastal rocks to crack the hard-shelled crabs, snails, and oysters that make up their diet. Habitat loss to rubber and oil palm farming, competition with humans for food sources, and threats from domestic dogs are forcing the macaques to change their foraging habits, researchers from Singapore’s Nanyang Technological University report. The monkeys are also showing signs of acclimating to humans and becoming dependent on human food sources.
15 Aug 2013:
Plants in U.S. Southwest
Moving Higher as the Climate Warms
Numerous plant species on a mountain in the southwestern U.S. are migrating to higher elevations
as the climate gets warmer and drier, according to a new
University of Arizona
An alligator juniper on Mount Lemmon
study. After comparing the results of a recent survey of 27 plants found on Mount Lemmon, a 9,157-foot peak near Tucson, Ariz., with a similar survey conducted in 1963, researchers at the University of Arizona found that three-quarters of the plants have shifted their range “significantly” upslope in the last five decades. In some cases, researchers found that the plants had moved upward by as much as 1,000 feet, into a much narrower elevation range than where the plants existed in the early 1960s. Writing in the journal Ecology and Evolution
, the researchers note that the lowermost boundary for 15 of the species has shifted upslope.
02 Aug 2013:
Prolonged Heat Wave Leaves
Russian Arctic Vulnerable to Wildfires
An enduring high-pressure weather system over the Russian Arctic has led to a prolonged heat wave, creating conditions for another surge in wildfires
a year after a particularly extreme wildfire season. NASA
scientists say that a so-called “blocking high” system — in which rain-bearing systems are blocked from moving west to east — has caused temperatures to reach 90 degrees F (32 degrees C) in the northern city of Norlisk, where daily highs in July typically average 61 degrees F (16 degrees C). Using satellite data, NASA produced a map that vividly depicts the land surface temperature anomalies in the region during the week of July 20-27, with temperatures soaring as high as 37 degrees F above normal. A separate satellite image shows smoke billowing from several fires burning in one of the areas, in the Khanty-Mansiyskiy and Yamal-Nenetskiy districts. According to scientists, the Siberian fires are burning in areas far north of where summer wildfires typically occur.
30 Jul 2013:
Return of Yellowstone Wolves
Triggers Surge in Grizzly's Prized Berries
The reintroduction of wolves at Yellowstone National Park has caused a cascade of ecological effects that has led to the regrowth of berries
, an important food source for the park’s grizzly bears, scientists say. Writing in the
Journal of Animal Ecology
Yellowstone National Park
Grizzly bear at Yellowstone Park
, scientists from Oregon State University and the University of Washington report that the percentage of fruit found in bear scat has nearly doubled during the month of August in recent years. According to researchers, this reflects a recovery of berry bushes triggered in large part by the wolves, which have reduced overbrowsing by the park’s elk herds. The removal of wolves for most of the 20th century triggered the demise of the park’s young aspen and willow trees, as well as berry-producing shrubs, scientists say. According to the report, berries may be so important to the health of bear populations that their recovery could mean a lifting of the species’ “threatened” status under the Endangered Species Act
25 Jul 2013:
Mapping of Oil Palm Genome
Could Boost Productivity of Key Crop
Scientists say they have identified the gene responsible for the yield of oil palm crops, a discovery that could boost the productivity of the world’s top source of
vegetable oil and help reduce the size of oil palm plantations in the world’s tropical regions. Writing in the journal Nature
, Malaysian and U.S. researchers describe the mapping of the genome of the oil palm, whose products are used in everything from food to cosmetics to biofuels. According to the scientists, the so-called “shell gene” controls “how the thickness of its shell correlates to fruit size and oil yield
.” The fruit of the African palm oil tree comes in three varieties
: a thick-shelled dura, a shell-less pisifera, and a thin-shelled tenera, which produces a greater oil yield. According to scientists, the shell gene plays a key role in a mutation that produces the more commercially productive tenera variety.
18 Jul 2013:
Malaysian Borneo Plundered
As 80 Percent of Rainforests Are Logged
The first comprehensive, satellite-based assessment of industrial logging practices in Malaysian Borneo has shown that more than 80 percent of the region’s forests have been heavily impacted by logging
. Reporting in the journal PLOS One
, researchers from Australia,
New Guinea, and the U.S. say that Malaysian Borneo — which just 30 years ago was considered one of the wildest places on Earth — now has been eaten away by 226,000 miles of roads that have enabled companies to legally and illegally log most of the territory, which consists of the Malaysian states of Sabah and Sarawak. At best, only 17,500 square miles of forest ecosystems remain intact, the study said. “The extent of logging in Sabah and Sarawak documented in our work is breathtaking,” said study co-author Phil Shearman of the University of Papua New Guinea.
15 Jul 2013:
Map Shows Possible Link
Between Warmer Springs and Large Fires
An interactive tool produced by the group Climate Central illustrates how rising temperatures and reduced snowpack in the western U.S. have corresponded with an increase in wildfires
in recent decades. Based on
federal wildfire data from 1970 to 2012, the graphic shows how large fires in some western states — including Arizona, Colorado, and Idaho — have doubled or even tripled in four decades, a period when the average spring and summer temperatures in 11 states increased by more than 1.5 degrees F. According to the Climate Central analysis, Arizona has experienced the highest average increase in spring temperatures, about 1 degree F, which has likely been a key factor in the steep increase in fires covering more than 1,000 acres. Another key factor has been the decrease in mountain snowpack. During several seasons, unusually low amounts of spring snow caused extended droughts that helped drive more big fires.
27 Jun 2013:
New Bird Species Identified
In Crowded Outskirts of Phnom Penh
A team of scientists in Cambodia has identified a new species of lowland tailorbird
recently captured in the densely populated outskirts of Phnom Penh. Originally
An adult male Cambodia tailorbird
caught and photographed in 2009 during a routine sampling for avian influenza, the small wren-sized bird was initially misidentified as a known type of tailorbird until the photographs caught the attention of scientist Simon Mahood of the Wildlife Conservation Society. Following genetic analysis of other individuals collected in the region, scientists confirmed that the bird — which has white cheeks, a rich cinnamon-colored crown, and distinct vocal characters — was indeed a new species. According to an article co-authored by Mahood in Forktail
, a journal of the Oriental Bird Club, the so-called Cambodia tailorbird (Orthotomus chaktomuk
) is known to exist only in a dense, lowland scrub ecosystem that is declining in size and quality.
21 Jun 2013:
Illegal Fires in Sumatra
Send Dangerous Pollution to Singapore
Billowing smoke from illegal fires on the Indonesian island of Sumatra has engulfed Singapore this week, pushing air pollution to record levels
consecutive days. The smoke, which is captured in a new NASA satellite image
, has created an acrid blanket of smog across the region and historic levels of air pollution. According to government officials, Singapore's air pollution index reached 401 on Friday, a level considered hazardous for breathing. Before this week, the previous high was 226. The smoke has been blowing east toward southern Malaysia and Singapore
from Sumatra, where farmers set illegal fires to clear land for new crops during the mid-year dry season. The fires are yet another sign of the large-scale deforestation taking place on Sumatra.
14 Jun 2013:
Nicaragua Approves New Canal
Linking Atlantic and Pacific Oceans
Nicaragua has approved plans to build a $40 billion cross-country canal
linking the Atlantic and Pacific oceans, a project that would rival the Panama Canal but is raising major concerns about impacts on regional
water supplies and the environment. Lawmakers yesterday granted Hong-Kong-based HK Nicaragua Canal Development Investment Co. a 50-year concession to study, and possibly construct, a 180-mile canal that advocates say would better accommodate the massive cargo ships and supertankers needed to handle the increased trade between Asia and the Americas. Major questions remain, however, about whether the canal will ever be built. Environmental advocates warn that water needed to operate the massive infrastructure project would deplete the region’s freshwater supplies.
06 Jun 2013:
Carbon Emissions in Brazil
Dropped 39% from 2005 to 2010, Report Says
Greenhouse gas emissions in Brazil fell by nearly 39 percent from 2005 to 2010
, largely because of reductions in the amount of forest loss, according to a new government report. Overall, Brazil emitted the equivalent of 1.25 billion tons of carbon dioxide in 2010, which was more than 10 percent lower than 1990 levels. About 76 percent of the reductions were the product of a dramatic decline in deforestation across the Amazon and surrounding savannahs, according to the government inventory. That decline was driven by the country’s conservation policies, including stricter enforcement of land use laws, expansion of protected regions, and stronger local incentives to achieve environmental goals. For the first time, agriculture accounts for the largest share of emissions. In fact, rising emissions from agriculture and the energy sector threaten to offset improvements achieved through reduced forest loss, experts warn.
02 May 2013:
Five Southeast Asian Nations
Have Lost One-Third of Forests in 33 Years
Thailand, Vietnam, Laos, Cambodia, and Vietnam have lost one-third of their forests since 1980
and could be left with only 10 to 20 percent of their original forest cover by 2030, according to a review of satellite data by WWF. The conservation group warned that if present trends continue only 14 percent of the greater Mekong region’s remaining forest cover will consist of contiguous habitat capable of sustaining viable populations of many wildlife species, such as tigers and Asian elephants. The WWF researchers calculated that since 1980, Thailand and Vietnam have lost 43 percent of their forests, Laos and Burma have lost 24 percent, and Cambodia has lost 22 percent. Since 1973, areas of core, undisturbed forest — defined as having at least 3.2 square kilometers of uninterrupted forest — have declined from 70 percent to 20 percent of the region. Peter Cutter, landscape conservation manager with WWF-Greater Mekong, said the region is at a crossroads and that to preserve its remaining forests and biodiversity it must expand protected areas and better safeguard those that already exist.
Interview: Telling the Life Story of
Ginkgo, the Oldest Tree on Earth
Botanist Peter Crane sees the ginkgo as more than just a distinctive tree with foul-smelling fruits and nuts prized
Ginkgo leaves in autumn
for reputed medicinal properties. To Crane, author of a new book, Ginkgo
, the tree is an oddity in nature because it is a single species with no known living relatives; a living fossil that has been essentially unchanged for more than 200 million years; and an inspiring example of how humans can help a species survive. In an interview with Yale Environment 360
, Crane, dean of the Yale School of Forestry & Environmental Studies, talks about what makes the ginkgo unique and what makes it smell, how its toughness and resilience has enabled it to thrive as a street tree, and what the ginkgo’s long history says about human life on earth. The ginkgo, which co-existed with the dinosaurs, “really puts our own species — let alone our individual existence — into a broader context,” says Crane. Read the interview
23 Apr 2013:
Conservation of Forests
Can Prevent Malaria Spread, Study Says
The conservation of woodlands and biodiversity can actually help prevent the spread of malaria
in tropical forests, a new study says. Using a mathematical model of different conditions in a forest region of southeastern Brazil, scientists found that the circulation of the parasite Plasmodium vivax
— which is associated with 80 million to 300 million malaria cases worldwide — is likely to decrease in less developed forests where populations of non-malarial mosquitoes and warm-blooded animals are abundant. While no malaria cases have been reported in 30 years within the biodiverse study area, located in the Atlantic Forest, researchers say a primary malaria mosquito is found nearby. According to their study, published in the journal PLoS Neglected Tropical Diseases
, the findings suggest that malarial and non-malarial mosquito populations are likely to compete for blood feeding, and that the animals act as “dead-end reservoirs” of the malaria parasite. “These aspects of biodiversity that can hinder malaria transmission are services provided by the forest ecosystem,” Gabriel Zorello, an epidemiologist at the University of Sao Paulo and lead researcher of the study, told ScieDev.Net.
10 Apr 2013:
New Satellite-Based System Will
Track Illegal Deforestation in Real Time
A coalition of organizations has unveiled a digital tool its developers say will help governments, environmental groups, and local communities monitor illegal logging in the world’s forest regions in close to real time. Using satellite technology, data sharing, and a global network of local contributors, the so-called Global Forest Watch 2.0 system will enable users to track forest loss that has occurred within the last 30 days
and allow local forest managers to upload geo-referenced photographs to support data on deforestation. Developed by the World Resources Institute (WRI) and other contributors — including Google, the University of Maryland, and the United Nations Environment Program — the technology was unveiled this week at a UN forum on forests and will be available next month
. WRI hopes the system will allow government leaders and companies to make more timely forest management decisions
05 Mar 2013:
African Forest Elephant
Populations Fell 62 Percent in a Decade
Populations of forest elephants in central Africa plummeted by more than 60 percent from 2002 to 2011
, with dwindling habitat and an acceleration in poaching driving the elephants toward extinction, according to a
new study. An international team of 60 scientists found that while elephants historically ranged across a 772,000-square-mile region in Cameroon, Central African Republic, the Democratic Republic of Congo, Gabon and the Republic of Congo, they now exist in just 25 percent of that area, said John Hart, scientific director for the Lukuru Foundation and co-author of the study published in the journal PLoS ONE
. The decade-long survey, which involved the work of many local conservation staff members who walked more than 8,000 miles conducting censuses, is the largest ever conducted on forest elephants. According to the survey, the remaining 100,000 forest elephants are increasingly scarce in regions with high human populations, heavy poaching, and weak governance.
20 Feb 2013:
Camera Trap in Amazon
Gives Stunning Glimpse of Species Diversity
Using footage from a camera trap trained on a single “colpa” salt lick in the remote jungle of the western Amazon, a Peru-based conservationist has captured a rare glimpse into the region’s robust biodiversity,
documenting an array of species, some of which are threatened, in an area now targeted by loggers, miners, and other developers. During a four-week period, Paul Rosolie’s camera collected footage of dozens of species
, including a troop of howler monkeys, a giant anteater, and a host of big cats — including jaguars, pumas, and ocelots — constantly on the hunt for prey. In a short film, Rosolie, a field director at a research station for Tamandua Expeditions, documents a wide array of wildlife in a region of the lower Las Piedras River in Peru.
Interview: Perils and Rewards
Of Protecting Congo’s Gorillas
It is difficult to imagine a more dangerous place to be a conservationist than the Democratic Republic of Congo, which for decades has been ravaged by war and civil
Virunga National Park/gorillacd.org
Emmanuel de Merode
strife that has left several million people dead. But it is against this backdrop that Emmanuel de Merode has waged a five-year struggle to protect Congo’s Virunga National Park, the oldest national park in Africa and home to one of the last sizeable populations of mountain gorillas. De Merode is the chief warden of Virunga, a UNESCO World Heritage site that encompasses nearly 2 million acres of forests, mountains, savannahs, and iconic wildlife. Since 1996, more than 150 Virunga park rangers have been killed in the line of duty, with two murdered last October. In an interview with Yale Environment 360
, de Merode discusses the challenges of protecting the mountain gorillas in a war-torn nation, the remarkable survival of the gorillas amid this strife, and how restoring order inside Virunga National Park could play a role in bringing peace to Congo.
Read the interview
11 Dec 2012:
NASA Visualization Captures
Record Year for Wildfires in the U.S.
This year has been an unusually severe one for wildfires in the U.S., with more than 9.1 million acres of land burned through the end of November, federal officials say. The total affected area, which is depicted in a new NASA map, is already the third-largest since records were first kept
in 1960, and will likely break previous
records by year’s end. The most intense fires occurred in the western U.S., where several major fires during the early summer — sparked by a combination of drought, light winter snow pack, and the long-term effects of climate change — forced evacuations in some areas. In the visualization, which shows all fires that occurred between Jan. 1 and Oct. 31, areas of yellow and orange indicate larger and more intense fires, while many of the less intense fires, shown in red, represent prescribed burns started for brush clearing or agriculture and ecosystem management. The visualization was based on data collected by NASA satellites.
07 Dec 2012:
Populations of Large, Old Trees
Are Dying Off Worldwide, Report Says
Populations of large, old trees, which provide critical ecosystem services, are declining across the planet
and could eventually disappear altogether in some regions, according to a report by three leading ecologists. Writing in the journal Science
, the scientists say the loss of large trees is occurring in all kinds of forests and at all altitudes, from Yosemite National Park in the U.S., to African savannahs, to Amazon rainforests and northern boreal forests. The losses are being driven by numerous factors, including land clearing, agricultural expansion, human-designed fire regimes, logging, invasive species, and climate change. “We are talking about the loss of the biggest living organisms on the planet, of the largest flowering plants on the planet, of organisms that play a key role in regulating and enriching our world,” said Bill Laurance
, a scientist at James Cook University in Australia, who coauthored the report.
05 Dec 2012:
African Lion Populations
Plummet as Habitat Disappears, Study Says
More than two-thirds of Africa’s lions have disappeared over the last 50 years as the continent’s once-vast savannah regions have been lost to human
A lion in South Africa
development, a new study has found. Using high-resolution satellite images from Google Earth and human population data, Duke University researchers calculated that about 75 percent of the original savannah has been lost since 1960
, driven by land-use changes and deforestation. On the entire continent, they found, there are now just 67 remaining pockets of savannah suitable for lion habitat; only 10 of those areas would be considered lion “strongholds.” Overall, lion populations have dropped from 100,000 to roughly 32,000 in just five decades, according to the study published in the journal Biodiversity and Conservation
. Continued habitat loss projected over the coming decades could put these populations at increased risk, the study said.
29 Nov 2012:
China is Largest Importer
Of Illegally Harvested Timber, Report Says
China has become the world’s leading importer of illegally harvested timber, even as the growing economic giant has made strides in protecting its own forests, according to a new report
. Drawing on its own investigative research and the work of Interpol, the London-based Environmental Investigation Agency (EIA) estimates that China now imports about $4 billion in illegal timber
annually to meet rising demand for construction materials and furniture. According to the report, more than half of China’s raw timber imports are now coming from nations with “a high risk of illegal logging and poor forest governance,” including Cambodia, Laos, and Madagascar. Meanwhile, the report said, the Chinese government has taken critical steps in preserving and re-growing its own forests. “China is now effectively exporting deforestation around the world,” said EIA's Faith Doherty.
27 Nov 2012:
Pine Beetle Attacks Cause
Temperature Rise in Canadian Forests
The decimation of trees by mountain pine beetles in British Columbia has caused air temperatures in affected areas to climb by an average of 1 degree Celsius
during the summer months, according to a new study.
A mountain pine beetle
In an analysis of satellite and forest data collected between 1999 and 2010, scientists from the University of Toronto and University of California, Berkeley calculated that areas hit hardest by widespread pine beetle infestations
have experienced even sharper temperature increases of several degrees Celsius, as regions are increasingly deprived of the natural cooling effect of trees. Since water evaporation through leaves prevents some of the sun’s radiation from heating the ground surface, the widespread loss of trees causes the temperature increases, said Holly Maness, a UC Berkeley researcher and co-author of the study, published in Nature Geoscience
16 Oct 2012:
Increasingly Severe Droughts
Could Transform U.S. Forests, Study Says
Severe drought conditions in the southwestern U.S. in recent years could become normal in the years to come, a shift that could trigger increased tree mortality and ultimately transform the region’s forests
, a new study says. In an analysis of tree-ring data from conifer trees dating back to A.D. 1000, a team of scientists concluded that while the region endured several “mega-droughts” over the last 1,000 years, the long-term drought that began in the late-1990s could end up being the worst yet and may portend even drier periods in the future. After modeling the level of stress caused by droughts on forests — and considering other factors caused by these changes, including bark-beetle outbreaks and wildfires — the researchers calculated that tree mortality over the next four decades will be worse than at any time over the last 1,000 years. “With increasing drought stress, our forests of tomorrow will hardly resemble our forests of yesterday,” said Henri Grissino-Mayer, a geography professor at the University of Tennessee, Knoxville and one of the authors of the study
published in the journal Nature Climate Change
12 Oct 2012:
New Disney Paper Policy
Promises Responsible Use and Sourcing
The Walt Disney Co., the world’s largest publisher of children’s books, has announced a dramatic shift in how the company will use and source paper
, vowing to minimize the amount of paper it uses overall and eliminate its purchase of irresponsibly harvested timber products. In an announcement, the multinational media company, which had been under pressure from forest activists, said it would increase its use of recycled paper and paper products certified by the Forest Stewardship Council and will avoid products coming from what it called “high conservation-value” and “high carbon-value” forests. In addition, executives say they will work with the Rainforest Action Network (RAN) and other groups to identify "regions with poor forest management and high rates of deforestation,” including Indonesia, where rampant deforestation for pulp and paper products is decimating rainforests. The policy shift comes two years after RAN launched a campaign against Disney, citing evidence that its publishing arm, which produces 50 million books and 30 million magazines annually, was using hardwood pulp likely sourced in Indonesia rainforests
10 Oct 2012:
U.S. Supreme Court Refuses
Chevron Challenge of Ecuador Damages
The U.S. Supreme Court has refused to hear Chevron Corp.’s challenge
of an $18.2 billion judgment issued by an Ecuadorian court over large-scale damages caused by oil drilling in the Amazon. The Supreme Court decision is the latest development in a long legal battle that led to a ruling last year by an Ecuadorean court that Chevron had to pay the damages for massive oil dumping by Texaco, which Chevron acquired in 2001. Chevron was challenging a ruling by the 2nd U.S. Circuit Court of Appeals in New York that would have effectively opened the way for worldwide enforcement of the judgment against Chevron. An Ecuadorean court found that an oil consortium run by Texaco dumped billions of gallons of oil and toxic sludge in the Amazon rainforest
from 1964 through 1992, badly polluting water supplies and causing health problems among some of the 30,000 plaintiffs in the Lago Ario region. Chevron vowed to continue to fight the Ecuadorean court’s decision, which it called “fraudulent” and tainted by judicial misconduct. Chevron contends that the decision is not enforceable under New York law.
08 Oct 2012:
Indonesian Palm Oil Is
Growing Source of CO2 Emissions
The rapid expansion of palm oil plantations in the world’s tropical regions, particularly Indonesian Borneo, is becoming an increasingly significant source of global carbon emissions
, a new study says. Writing in the journal Nature Climate Change
, researchers from Stanford and Yale universities project that the continued expansion of plantations will add more than 558 million metric tons of carbon dioxide into the atmosphere by 2020 — an amount greater than all of Canada’s current fossil fuel emissions. Much of the expansion in recent decades has occurred in Indonesia, particularly on the island of Borneo, also known as Kalimantan. According to researchers, the loss of forest for palm oil plantations in Kalimantan led to the emission of more than 140 million metric tons of CO2 in 2010 alone, or the equivalent of the annual emissions of 28 million vehicles. About 80 percent of planting leases remained undeveloped in 2010, the study says. If all these leases are developed, more than one-third of Kalimantan’s lowlands outside of protected areas would be covered with palm oil plantations.
05 Oct 2012:
Northern Conifers Are Younger
As a Result of Extreme Climate Shifts
Extreme climate cycles in the Northern Hemisphere over millions of years altered the evolutionary history of the hemisphere’s conifer trees
, encouraging the formation of new species that are millions of years younger than their counterparts in the Southern
Hemisphere, according to a new study. In an analysis of the fossil remains and genetic makeup of 489 of the world’s roughly 600 living conifer species, scientists found that while the majority of conifers belong to ancient lineages, most of those found in the Northern Hemisphere emerged in just the last 5 million years. Scientists suggest that the migration of trees species and changes to range sizes in response to glacial cycles resulted in isolated populations and the introduction of new species. “Extreme climatic shifts through time may have favored the replacement of older lineages with those better adapted to cooler and drier conditions,” said Andrew Leslie, a Yale researcher and co-author of the study, published in the Proceedings of the National Academy of Sciences
. In the Southern Hemisphere, meanwhile, fragmented habitats and mild, wetter habitats likely helped the older conifers survive with greater diversity.
01 Oct 2012:
Organized Crime Groups Drive
Increase in Illegal Logging, Report Says
Illegal logging accounts for 15 to 30 percent of the global logging trade
, with an increasing number of illegal operations in the world’s tropical regions being driven by organized crime, a new report says. According to the report
, released by the United Nations Environment Program (UNEP) and INTERPOL, the illegal logging trade is now worth between $30 billion and $100 billion each year and is undermining global efforts to protect forests in the world’s most important tropical regions, including the Amazon, central Africa, and Southeast Asia. “Illegal logging is not on the decline, rather it is becoming more advanced as cartels become better organized, including shifting their illegal activities in order to avoid national and local police efforts,” wrote Achim Steiner and Ronald Noble, the heads of UNEP and INTERPOL, respectively. In the Brazilian state of Pará, for example, illegally obtained permits allowed logging cartels to steal an estimated 1.7 million cubic meters of forest in 2008. A year later, Brazilian investigators uncovered a scam involving 3,000 companies illegally exporting logged timber as allegedly “eco-certified” wood.
17 Sep 2012:
Forest Mortality in U.S. Declines
As Beetles Run Out of Food, Report Says
Tree deaths caused by insect infestation and disease in the western U.S. declined significantly last year
, largely because mountain pine beetles have devoured so many
A mountain pine beetle
forests that they are running out of food, according to a report by the U.S. Forest Service
. Researchers reported that about 6.4 million acres of forest died nationally in 2011, compared with 9.2 million acres in 2010 and a peak mortality of 11.8 million acres in 2009. Scientists say about 60 percent of the mortality was caused by one pest, the mountain pine beetle, a native insect that has decimated lodgepole and ponderosa pine forests across western North America because warmer winters are not killing off beetle larvae. While the researchers say a critical factor in the decline has been a reduced number of available lodgepoles, they say ponderosa pine and high-elevation white bark pine remain at risk. The greatest forest mortality was reported in Colorado, Montana, Idaho, and Wyoming. “Native insects and diseases run in cycles, and right now we are grateful the trend is downward,” said U.S. Forest Service Chief Tom Tidwell. He added, however, that forests still face significant threats, including from climate change and new invasive species.