18 Mar 2014:
Wildflower Season in Rockies
Is 35 Days Longer as Climate Warms
A warming climate has extended the wildflower season in the Rocky Mountains by 35 days since the 1970s,
according to a 39-year study of more than two million blooms. The bloom season, which used to run from late May to early September, now lasts from late April to late
Crested Butte, Colorado
September, the researchers say. Previous, less extensive studies seemed to indicate most wildflowers simply shift their bloom cycles to earlier in the year, but new findings
published in the Proceedings of the National Academy of Sciences
show that the changes are more complex, with the flowers reaching peak bloom sooner and flowering later in the year. The shift in the timing of blooms could have a major impact on pollinating insects and migratory birds. For example, hummingbirds that summer in the Rocky Mountains time their nesting so that their eggs hatch at peak bloom, when there is plenty of flower nectar for hungry chicks. As the bloom season lengthens, the plants are not producing more flowers. The same number of blooms is spread out over more days, so at peak bloom there may be fewer flowers and less food for hummingbirds, the researchers say.
An e360 Interview with Wendell Berry:
Strong Voice for Local Farms and the Land
Author Wendell Berry wrote about and practiced “sustainable agriculture” long before the term was widely used. His early writings in the 1970s, in which he argued against industrial agriculture and for small-scale, local-based farming, strongly influenced the U.S.
© Counterpoint Press
environmental movement. At age 79, Berry still speaks eloquently about the importance of local communities and of caring for the land, while warning about the destructive potential of industrialization and technology. In an interview with Yale Environment 360
, he talked about his Kentucky farm and why he has remained there, why sustainable agriculture faces an uphill battle, and why strong rural communities are important. “A deep familiarity between a local community and a local landscape is a dear thing, just in human terms,” Berry said. “It’s also, down the line, money in the bank, because it helps you to preserve the working capital of the place.”
Read the interview.
03 Mar 2014:
Harsh Winter Causing Large
Die-off of Invasive Insects, Researchers Say
As a frigid winter takes a toll on the United States and Canada, invasive insect populations are also taking a hit. The U.S. Forest Service estimates that up to 80 percent
of emerald ash borers, which have been decimating ash tree populations, were killed by long
Emerald ash borer
stretches of bitter cold in the the upper Midwest this year. Several other insect pests, many of which have migrated northward because of milder winters in recent years, also are faring poorly this winter, including corn earworms and gypsy moths. Researchers remain skeptical, however, that the die-offs will have lasting effects on pest populations. Emerald ash borers in Chicago, for example, survived the sub-zero weather because Chicago temperatures fell only to -17 degrees F, rather than Minnesota's -20 degrees F, which seems to be a critical temperature threshold for the pests.
27 Feb 2014:
Pine Forest Aerosols Play
Significant Role in Climate, Study Says
Pine forest vapors form small aerosol particles that may significantly cool the climate by reflecting the sun's energy back into space, according to new findings
. Scientists have known for decades that gases from pine
Hyytiälä pine forest in Finland
trees can form particles that grow from just 1 nanometer in diameter to 100 nanometers in about a day. The new research, published in Nature
, shows the rapid growth of these particles relies on a chemical chain reaction among pine-scented molecules and atmospheric ozone and oxygen. The growing particle then grabs others like it, eventually snowballing into a 100-nanometer particle — one that's large enough to condense water vapor, prompt cloud formation, and, ultimately, influence climate. Boreal or pine forests give off the largest amount of these compounds, so the finding is especially relevant for the northern parts of North America, Europe, and Russia. But other types of forests emit similar vapors, and the scientists think these may undergo similar rapid chemical reactions.
20 Feb 2014:
Global Forest Watch Tool
Allows 'Near-Real Time' Forest Monitoring
A new online tool
called Global Forest Watch employs a trove of high-resolution NASA satellite imagery and large amounts of computing power to help governments, conservation organizations, and concerned citizens monitor deforestation in "near-real
time." Organized by the World Resources Institute (WRI), Global Forest Watch
uses satellite data to track changes in forest cover since 2000. It's the first tool with the capability of monitoring forests on a monthly basis, potentially allowing groups to take action against deforestation while it's in progress. Businesses committed to eliminating deforestation from supply chains can also use the tool to verify that vendors are not engaging in practices that harm forests. A custom alert feature can also notify a user when there are signs of deforestation in a region the user has selected. "Businesses, governments and communities desperately want better information about forests," said WRI president Andrew Steer. "Now, they have it."
18 Feb 2014:
Website Allows Whistleblowers
To Report Wildlife and Forest Crimes
A new whistleblower site
offers people a secure and anonymous way to report incidents of poaching, wildlife trafficking, and illegal logging around the world. The site is called WildLeaks, a nod to the well-known WikiLeaks site, and it's backed by the California-based Elephant Action League. Users can upload documents, video, or images detailing the crimes, and submissions will be encrypted so data and identities remain secure. The aim
is to provide a safe way for citizens to report these illegal activities so that local and federal governments can take action. Prosecuting wildlife crimes and illegal logging is often a low priority in countries where some of the worst offenses occur; moreover, local government corruption often deters people from reporting such crimes, organizers say. "We [will] work to transform this information into a verified and actionable item, a point for launching an investigation or sharing it with the media or, when possible, with selected and trusted law enforcement officers, always aiming at exposing wildlife crimes and bringing the responsible individuals to justice," said the WildLeaks project leader.
13 Feb 2014:
Australian Bushfire Has Grown
To Size of Melbourne, NASA Image Shows
A fire rivaling the size of the city of Melbourne is raging in southeastern Australia, as a NASA satellite image taken at night earlier this week shows. The Snowy River Complex Fire
, which is burning mountain forests near a
remote national park, is one of three bushfires that flared up last weekend. Fueled by strong winds combined with a heat wave and prolonged dry conditions, the three fires have consumed more than 180,000 hectares (695 square miles), about 100,000 (390 square miles) of which burned in the Snowy River Complex. That fire's dense, opaque smoke is visible from space during night and day, and satellite images show the smoke plume stretching across the Tasman Sea to New Zealand. The Snowy River blaze includes fires that ignited on February 9, as well as fires that were started by lightning in January. Though stunningly large in this view, they do not pose much of a threat to people or infrastructure.
07 Feb 2014:
Documented in Remote Forest in Congo
Researchers have documented a huge population of chimpanzees in the Democratic Republic of Congo — a community of perhaps tens of thousands of individuals with its own unique customs and behaviors, the Guardian reports
. The so-called "mega-culture," which spans 50,000 square kilometers of virtually untouched
Chimps are thriving in a remote Congo forest.
forest, is thought to be the largest population of chimps in Africa and one of the last remaining continuous populations of chimpanzees in the wild, the scientists report
in the journal Biological Conservation
. The researchers first reported on this community in 2007, but their new survey includes detailed videos of the thriving population and its unique behaviors, which include feasting on leopards, using tools to harvest giant African snails and swarming insects, and building ground nests far more frequently than other chimps. While the find is heartening in terms of chimpanzee conservation, the researchers and wildlife advocates fear the population could be decimated by habitat loss and poachers, who stand to make huge profits in the bushmeat trade.
06 Feb 2014:
Maps Show Tropical Corridors
Important to Wildlife As Climate Changes
A new set of maps
highlights the importance of habitat corridors in helping wildlife deal with the effects of climate change and deforestation. The series of maps shows more than 16,000 habitat corridors
— swaths of
land that connect forests or protected areas and allow animals to move between them — in tropical regions of Africa, Southeast Asia, and South America. High-resolution data on biodiversity, endemism, and vegetation density allowed the researchers, led by Patrick Jantz of the Woods Hole Research Center, to determine which corridors are most important for maintaining biodiversity under changing climate conditions. The maps also highlight which corridors are most important for sequestering carbon and averting carbon emissions associated with deforestation. Researchers hope the findings will help guide wildlife protection plans and serve as a framework prioritizing the conservation of habitat corridors.
05 Feb 2014:
Vast Forests and Frequent
Fires Were Key Causes of Ancient Warming
The release of volatile organic compounds from forests and smoke from wildfires had a far greater impact on global warming 3 million years ago than ancient atmospheric levels of carbon dioxide, a new study finds
. During the mid-Pliocene epoch, forests covered a much larger percentage of the planet, releasing large amounts of volatile organic compounds, according to Nadine Unger of the Yale School of Forestry & Environmental Studies. Those compounds are precursors to ozone and organic aerosols, which are both potent greenhouse gases. The dark foliage of the planet's abundant forests also absorbed large amounts of solar energy, another reason why the Pliocene was a relatively warm era even though atmospheric levels of CO2 were not exceptionally high. The research — based on earth-system modeling that used a supercomputer capable of processing 52 trillion calculations per second — provides evidence that dynamic atmospheric chemistry played an important role in past warm climates, underscoring the complexity of climate change, the authors write in Geophysical Research Letters
18 Dec 2013:
Mapping Course and Software
Make Forest Monitoring Widely Accessible
Citizen scientists interested in tracking the health of the planet's forests have a new tool at their disposal. New software that uses satellite technology to map and
monitor changes in forested areas is being made available to the public
through a free online course. Users who complete the course, hosted by Stanford University
, can receive a license to operate the software, called CLASlite. CLASlite, or the Carnegie Landsat Analysis System lite, is a highly automated system for converting satellite imagery from its original, raw format into maps that can be used to detect deforestation, logging, and other disruptions. It was developed by Carnegie researcher Greg Asner to help governments, nongovernmental organizations, and academic institutions conduct high-resolution mapping and monitoring of forests
. "We are making the science of forest monitoring broadly available to people who want and need to participate in tracking and managing the health of their forests," said Asner.
29 Nov 2013:
Wide Mangrove Destruction
Is Documented Along Coast of Myanmar
Rapid agricultural expansion destroyed nearly two-thirds of the mangrove forests
in Myanmar’s Ayeyarwady Delta between 1978 and 2011, increasing the region’s vulnerability to cyclones and typhoons, according to a new study. Using remote sensing imagery
and field data, researchers from Myanmar and Singapore said that the dense mangrove cover in the Ayeyarwady Delta declined from 2,623 square kilometers to 1,000 square kilometers in that 33-year period. The main cause was agriculture expansion and the researchers said that if rates of destruction continue at their current pace the delta’s mangroves could be completely deforested by 2026. Reporting in the journal Global Environmental Change
, the scientists said the loss of mangroves in the Ayeyarwady Delta could put the region at greater risk of major storms such as Cyclone Nargis, which killed 138,000 people in Myanmar in 2008. But the researchers said the destruction could be slowed if Myanmar creates coastal protected areas.
26 Nov 2013:
Updated Conservation List
Finds Forest Giraffes on Brink of Extinction
In an updated list released today, the International Union for the Conservation of Nature (IUCN) noted some significant successes and failures in global wildlife
Okapi, or forest giraffe
conservation efforts. A major success story is the leatherback sea turtle
, whose Atlantic population has recovered enough for the species to be considered only vulnerable, rather than critically endangered. The IUCN attributed the leatherback rebound to better protection of nesting beaches and reduced fisheries bycatch. The updated Red List contains more somber news, though, for the blue-tongued forest giraffe
, the national symbol of the Democratic Republic of the Congo. The striped-legged forest giraffe, a species of okapi, is on the brink of extinction due mainly to the long, ongoing civil war in that country, which has led to increased poaching and loss of habitat. The Red List's ranks of threatened species have grown by 352 species since this summer
, Mongabay reports, with roughly 21,000 species now listed as threatened.
15 Nov 2013:
Groundbreaking Mapping Project
Depicts Forest Change Around the Globe
Scientists from Google, U.S. universities, and federal agencies have for the first time produced a high-resolution global map showing in striking detail the extent of deforestation across the globe.
The project — which relied heavily on expertise from the computing
center Google Earth Engine — documents a loss of 888,000 square miles of forest between 2000 and 2012, along with a gain of 309,000 square miles of new forest. The rate of deforestation is equal to losing 68,000 soccer fields of forest every day for the past 13 years, or 50 soccer fields every minute, says the World Resources Institute
. Brazil, once responsible for a majority of the world's tropical forest loss, is now the global leader in scaling back forest destruction, cutting its deforestation rate in half over the past decade, researchers report in Science
. Over the same period, Indonesia has more than doubled its annual rate of forest loss, despite a supposed 2011 Indonesian government moratorium on new logging licenses.
06 Nov 2013:
Disturbed Tropical Forests
Are Slow to Regain Plant Biodiversity
In tropical forests that are regrowing after major disturbances, the ability to store carbon recovers more quickly than plant biodiversity, researchers from the U.K. have found
. However, even after 80 years, recovering forests store less carbon than old-growth
A regrowing tropical forest in Brazil
forests, according to a study published in the Proceedings of the Royal Society B.
This is likely because regenerating forests are often dominated by small, fast-growing trees and it may take centuries for larger trees, which hold more carbon, to become established, according to scientists from the Center for Ecology & Hydrology and Bournemouth University, who studied more than 600 recovering tropical forests. Tree species that are hallmarks of old-growth forests were rare or missing in the regrowing forests, the study showed. Since regenerating forests are often located far from old-growth forests and surrounded by farmland, it may be difficult for animals to move seeds between the forests, which may account for the lower plant biodiversity, researchers said.
22 Oct 2013:
Southern Amazon Rainforest
In Danger as Dry Season Expands, Study Says
The dry season in the southern part of the Amazon rainforest is lasting three weeks longer than it did 30 years ago, putting the forest at higher risk for fires and tree mortality, according to new research from the University of Texas
. The most likely culprit is global
warming, says lead researcher Rong Fu. Even if future wet seasons become wetter, rainforest soil can only hold so much water, Fu explained. That water must sustain the forest throughout the entire dry season, and as the dry season lengthens the rainforest becomes increasingly stressed, vegetation growth slows, and the risk of fire rises. During a severe drought in 2005, the Amazon actually released a large amount of carbon dioxide into the atmosphere, rather than acting as a net carbon sink. Should dry seasons continue to expand, conditions like those in 2005 could become the norm, accelerating the buildup of CO2 in the atmosphere, the researchers wrote in the Proceedings of the National Academy of Sciences
11 Oct 2013:
Agricultural Ammonia Emissions
Threatening U.S. National Parks, Study Finds
Ammonia emissions from agricultural fertilizers are threatening sensitive ecosystems in U.S. national parks, a study led by Harvard researchers
has found. Thirty-eight national parks are seeing nitrogen deposition levels at or above the threshold for ecological damage,
Great Smoky Mountains N.P.
the study says. In natural ecosystems, excess nitrogen can disrupt nutrient cycling in soil
, cause algal overgrowth, and make aquatic environments acidic. While some of that nitrogen comes in the form of nitrogen oxides (NOx) from power plants and vehicle exhaust, existing air quality regulations and new clean energy technologies are helping reduce NOx emissions. Ammonia emissions from agricultural operations, however, are expected to climb as demand for food and biofuels surges. Daniel Jacob, who led the study, said that because ammonia is volatile, only 10 percent of the nitrogen makes it into the food, with much of it escaping through the atmosphere and being deposited across the landscape. According to the report, published in Atmospheric Chemistry and Physics
, hardwood trees, such as those shown above, are most sensitive to excess nitrogen in eastern temperate forests, while in western national parks lichens appear to suffer first.
08 Oct 2013:
Eighty Percent of Ecosystems
Vulnerable to Climate Change, Study Finds
Climate change could significantly transform up to 86 percent of the planet's land ecosystems under worst-case global warming scenarios, according to researchers at Germany's Potsdam Institute for Climate Impact Research
. That estimate is based on a 4 to 5 degree C temperature increase by the year 2100 — a scenario that is plausible given many nations' reluctance to enact greenhouse gas emissions limits, the researchers say. Even if global temperatures are kept to 2 degrees C above preindustrial levels, 20 percent of natural land ecosystems are at risk of moderate or major changes, especially high-altitude and high-latitude regions. Such changes could include boreal forests being transformed into temperate savannas, trees growing in thawed Arctic tundra, or even a dieback of some of the world's tropical forests. "Essentially, we would be leaving the world as we know it," says Sebastian Ostberg, who led the research. "The findings clearly demonstrate that there is a large difference in the risk of global ecosystem change under a scenario of no climate change mitigation compared to one of ambitious mitigation," he added.
12 Sep 2013:
Migration of Trees Is
Not Keeping Pace with Warming
Most tree species in the U.S. aren't migrating northward as rapidly as predicted in response to climate change, a new study says
. Looking at 65 species across
Kilmer Forest, North Carolina
31 eastern states, the team found no consistent, northward migration of tree species, as many other climate studies have predicted. Rather than shifting northward by dispersing seeds to cooler climates, the researchers found, tree species are responding by speeding up their life cycles. "Most trees are responding through faster turnover," says lead scientist James Clark
of Duke University, "meaning they are staying in place but speeding up their life cycles in response to longer growing seasons and higher temperatures." The results appear in Global Change Biology
Counterpoint: Two Scientists Offer
A Dissenting View on Ascension Island
Ecologists Daniel Simberloff, of the University of Tennessee, and Donald Strong, of the University of California, Davis, have written a critical appraisal of a recent Yale Environment 360
article by Fred Pearce about Ascension Island. In their critique, the two scientists contend that Pearce failed to accurately describe what has occurred on the island and misrepresented the science of restoration ecology. Read more
29 Aug 2013:
Future Wildfire Seasons to Be
Longer, Smokier, Cover More Area
Fire seasons will be three weeks longer, generate twice as much smoke, and cover a larger area of the western U.S. by 2050, a new study from Harvard researchers finds
. The risk of large fires could also increase by a
Petruncio Mike, USFWS
factor of two to three. In general, the biggest driver for future fires in Western states will be temperature, but driving factors can vary from region to region, the researchers say. In the Rockies, for example, moisture in the forest floor is the biggest predictor. Wildfires in the Great Basin region, however, will be more heavily influenced by relative humidity in the previous year. The results, published in Atmospheric Environment
, are based on records of past fire activity, decades of meteorological data, and a set of internationally recognized climate scenarios.
28 Aug 2013:
Illegal Slash-and-Burn Fires
Are Causing Smog Problem in Indonesia
Skies above Indonesia have been blanketed with smog
as wildfires burn throughout its forests. Ignoring
environmental laws, companies are using the practice of slash-and-burn to clear land for palm oil plantations. The illegal fires decimate rainforests and peatlands and fill the air with lethal levels of smoke, as seen in this NASA satellite image taken on August 27. Indonesia's pollution index hit a record-high 401 earlier this month; any reading above 400 is considered life-threatening to the elderly and sick. Palm oil is the world's largest vegetable oil commodity
and demand is rising rapidly, causing massive damage to tropical forests, especially in Southeast Asia.
22 Aug 2013:
Satellite Images of Fire
Help Guide Restoration Projects
The U.S. Forest Service is using NASA satellite images of fires in the American West to help rapidly restore burned areas
before the upcoming rainy season causes floods and washouts that could threaten lives and property.
This image of the Silver Hill fire in New Mexico, which burned 138,000 acres in June, was taken using infrared technology — mounted on NASA’s Landsat satellite — that distinguishes between vegetated and burned areas. The most severely burned areas are depicted in red, followed by areas of moderate-severity burn in yellow and low-severity burn in green. NASA began supplying the Forest Service with images as the fire raged, and in the wake of the fire the Forest Service has undertaken restoration efforts to stabilize the ground and prevent flooding during the rainy season in late summer.
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.