#ForestHealth — #ClimateChange — water supply in the #West #ActOnClimate #Wildfire #aridification

Here’s a in-depth look wildfire in Colorado and the west from Mark Jaffee writing for The Colorado Sun. Click through for the article and the photos. Here’s an excerpt:

The heat of a warming planet, like an artist’s palette knife on a canvas, etches its way across Western forests, slowly altering ecosystems that have flourished for centuries.

A firefighting helicopter flies in the foreground while the Spring Creek Fire (August 2018) rages behind it. Photo credit: El Paso County

Stevens-Rumann, a 33-year-old assistant forestry professor at Colorado State University, was [on site to observe the aftermath of the Spring Fire to measure and mark what comes next. In all likelihood, the ponderosa pine forest that had been there would not return.

Aspen and scrub oak have already sprouted, but all the pine trees and their cones were destroyed. No pine saplings poke through the charred soil.

Across the Rockies and even into the Sierra Nevada and the Pacific Northwest’s Cascades, forests are changing or simply vanishing. Wildfire has played a big role. Insect infestations have also had a hand, as has drought.

Behind it all is one driving force — climate change. Scientists charting the fate of forests see it, whether they are entomologists or botanists or wildfire ecologists like Stevens-Rumann. The heat of a warming planet, like an artist’s palette knife on a canvas, etches its way across Western forests, slowly altering ecosystems that have flourished for centuries.

“We are really moving out of a climate that is suitable for forests,” Stevens-Rumann said. “Old trees can persist, but when change comes in a disturbance like a wildfire and the ecosystem resets, the forests don’t come back.”

The transformation isn’t quite that simple. Lower elevation forests, like those along the Front Range, are most at risk, but as the forest rises into the mountains, the nature of the woods may change with spruce, fir and pine competing for survival even as new pests push into those higher, and now warmer and drier, mountain reaches.

“As ecosystems change, there are going to be winners and losers,” said Thomas Veblen, a biogeographer and distinguished professor at the University of Colorado. “The regulator function of the forest could diminish … leading to more runoff and flash floods. With a reduction of the forest canopy, we are going to see the potential for greater erosion. The question is how much of the forest will fail to regenerate.”

Fire changes the forest’s composition

Colorado’s Front Range has had five ecotones — shifts in plant and animal communities — from grasslands at 5,500 feet above sea level to alpine tundra at 11,300 feet.

“When we go to higher elevations under warming temperatures, we do expect the species from lower elevations to do better after a fire or other disturbance,” Veblen said.

After six years as a forest firefighter in an elite hotshot crew, Stevens-Rumann, curious about what happens after the fire is out, became a wildfire ecologist.

In a study of 1,485 sites that burned in 52 wildfires in forests from Colorado to northern Idaho, a team led by Stevens-Rumann found tree regeneration was significantly reduced at the sites that burned after 2000.

Fewer than half the spots had signs of growing back with a density of trees similar to the pre-fire forest, and nearly one-third of the sites had no trees at all.

These forests ranged from lower elevation dry conifer forests, containing ponderosa pine and Douglas fir, to moister conifer forests of Engelmann spruce and lodgepole pine. The highest elevation forests in the study were around 9,000 feet.

The researchers measured the site temperatures and moisture, and classified the areas by the severity of the burn.

It appeared that the hotter and drier the site, the less chance of a forest coming back. “There is an ecotone shift already underway,” Stevens-Rumann said. “We may see aspen and scrub oak replace pine and at higher elevations, maybe pine replace fir.”

This is happening across the Front Range. An analysis of five Front Range forest fires between 1996 and 2003 — Bobcat Gulch, Overland, High Meadow, Buffalo Creek and Hayman — found that 23% of the forest cover has been lost.

“Below 8,200 feet, we saw little generation; above 8,200 feet, where it tends to be cooler and moister, we saw more,” said Marin Chambers, a researcher at the Colorado Forest Restoration Institute and the study’s lead author.

Savage wildfires disrupt the trees’ lifecycle

At the site of the 2002 Hayman Fire — the largest in the state’s history, consuming 135,114 acres northwest of Colorado Springs — the most intensely burned areas have come back as grasslands.

The problem, Chambers explained, is that while fire releases the seeds of pine cones, they do not travel very far. And the hotter, drier and more open sites where they land are less hospitable.

Fire has been an essential component of the pine forest ecosystem. The pine and fir trees are “serontinous” — depending on fire to release their seeds and simultaneously clear an ashy, nutrient-rich bed for new seedlings.

Two things, however, have altered the natural cycle. First, a century of fire suppression — think Smokey the Bear — has prevented regeneration, creating forests of mostly large, old trees. Additionally, it has built up dead wood on the forest floor that aids fires to burn more intensely when they do happen.

Black Forest Fire June 2013 via CBS Denver

And now those fires are coming more quickly and more savagely. Since 2000, there has been vastly more acreage burned in Colorado than in the three previous decades, with peaks of more than 300,000 acres scorched in 2003 and about 160,000 acres destroyed in 2013.

Across the West, about 20 million acres burned between 1979 and 2015. The average fire season grew by 26 days, a 41% increase, and high-fire-potential days increased by 17, according to a study by John Abatzoglou, a University of Idaho geographer.

Abatzoglou measured drought conditions and water availability, as well as temperature, and estimated that climate change contributed to about half the forest fire acreage as heat parched the forests, creating more dry fuel.

The analysis also found that significant declines in spring rains in the southwestern U.S. during the period from 1979-2015 and in summer precipitation in the Northwest add to the fire problem.

Another Abatzoglou study projects the shortening of the snowpack season except for in the high Rockies and parts of the Uinta and Bighorn ranges in Utah and Wyoming, as well as more precipitation falling as rain rather than snow.

How much hotter has it been? The average observed summer temperature in Colorado between 2005 and 2009 was nearly 67 degrees Fahrenheit — the hottest it has been in a century, up almost 2.5 degrees since 1989, according to the National Oceanic and Atmospheric Administration.

The temperature itself poses an ecological Rubicon. A study of 177 burn sites from 21 forest fires in the northern Rockies documented the same phenomenon Stevens-Rumann saw: fewer trees growing in the lower elevation patches and no trees at about one-third of the sites, with grasses, sedges and a wild, purple evening primrose called fireweed taking root.

The study also calculated that at summer average temperatures above 63 degrees, fir tree regeneration would be “minimal.” Ponderosa pine is slightly more heat tolerant at temperatures up to 66 degrees, the study said…

So much is at stake. And it’s not about the view.

There is much more at stake in the fate of the high-country forests than just a majestic view. The snowpack that falls in the woods, and is essential to nourishing the forest, and it is also the main source of drinking water for the state.

“Every person in Colorado gets a touch of the forest ecosystem every day when they open up the tap,” West said. But thinner forests would lead the dwindling snowpack to run off more quickly.

Even without the spruce beetle, the high-elevation forests are under threat. In a study of Colorado Front Range forests between 9,500 feet and 11,150 feet, researchers found a decrease in new spruce and fir as a result of declining snowpack and rising summer temperatures.

Above-average snowpack was found to be a key in the establishment of new Engelmann spruce and subalpine fir, according to one of Veblen’s studies. Conversely, declining snowpack along with cooler, wetter summers was related to a decrease in the number of fir and spruce establishment events from 1975.

A study of high-elevation areas in Rocky Mountain National Park warned that these ecosystems were “at higher risk of species redistribution as they are more insular and experience more rapid changes than environments at lower elevations.”

In some places, climate change is pushing forests higher or farther. In Alaska’s Noatak National Preserve, boreal forests have moved as much as 300 feet north onto what was formerly treeless tundra.

In Yosemite National Park researchers have found whitebark and lodgepole pines pushing into montane meadows as high at 10,000 feet.

Air pollution from straw burning near a residential area. The traditional practice of open burning of rice straw produces large amounts of smoke creating a thick cloud over fields. Photo: Ali Mohammadi, distributed via imaggeo.egu.eu

From Colorado State University (Mary Guiden):

Researchers suggest new approach needed to address Anthropocene risk

A team of international researchers led by Colorado State University is calling for a new approach to understanding environmental risks in the Anthropocene, the current geological age in which humans are a dominant force of change on the planet.

Patrick Keys, a research scientist in the School of Global Environmental Sustainability at CSU, is the lead author of “Anthropocene risk,” a perspective paper published July 22 in Nature Sustainability that suggests adopting a holistic approach to understanding environmental risks. Keys said the team hopes that the article is “productively provocative.”

“The Anthropocene is a time of rapid global change – socially, environmentally, and geophysically,” he said. “Typical notions of neatly and cleanly delineating complex environmental risks are changing in unexpected ways. It’s becoming clear that a more holistic perspective, including social history, power relations, and environmental ethics may be important components of Anthropocene risks.”

As an example, Keys said it’s a common belief that the civil war in Syria has been driven by drought and climate change. While those two factors more than likely played a role in what led to the civil war, it also ignores other aspects such as incentives by Syrian government officials that kept farmers on agriculturally precarious land for decades. Keys said those incentives made it possible for drought and climate change to have such an impact.

“If we ignore the social and political economic factors that deliver us to this present, we will attribute an event to being caused by the environment when, in fact, that was just one cause or the icing on top of the cake. If we look at things only in the present, we will come up with solutions to a problem defined in the present, but we may not be defining the problem correctly.”

This point of view stems from Guidance for Resilience in the Anthropocene: Investments for Development (GRAID), a program based at the Stockholm Resilience Centre, where five of the paper’s co-authors currently work.

In the paper, the research team explores four different cases outside of Europe and North America to highlight this way of looking at environmental risks and underline why people studying such risks must take a broader approach.

“As the Anthropocene unfolds, navigating new and emerging risks will require considering changes that happen over years, decades, centuries, or even millennia.” Keys said. “In this increasingly interconnected and accelerating world, it’s on us to really educate ourselves about how to interact intelligently and meaningfully to work toward a more sustainable world.”

Tamarisk leaf beetles at work

From The Associated Press (Felicia Fonseca) via Tucson.com:

That the tiny beetles brought to the U.S. from Asia in an experiment to devour invasive, water-sucking tamarisks showed up at the Verde River in central Arizona is no surprise. But it’s further evidence they’re spreading faster than once anticipated and eventually could pervade the Southwest U.S, raising wildfire risks and allowing less time to uproot the tamarisks, also called salt cedars, and replace them with native trees.

Without those efforts, an already highly flammable tree will burn more intensely, and an endangered songbird that nests in tamarisk might not have a home.

The federal program to use the beetles to chew up tamarisk trees began as an experiment in rural Nevada in 2001 and was approved for more widespread use in 2005, as long as they were at least 200 milesfrom Southwestern willow flycatcher territory. It ended in 2010 as the beetles intruded on the birds’ habitat. An unintentional release in southern Utah also helped the insects spread into Arizona.

Johnson believes the quarter-inch beetles hitchhiked to the Verde River on clothing, a backpack or a boat. Normally, they are wind travelers but would have had to catch quite a gust to get to the river from the closest drainage where they’ve been recorded, he said.

Johnson has sent samples to a geneticist in Colorado to determine if the beetles can be traced to a population north of Arizona or a subtropical one from Texas that multiplies quicker.

Arizona once was projected to be too hot for the beetles to survive, but they’ve evolved as they’ve expanded their reach.

Dan Bean with the Colorado Department of Agriculture found even more this summer in far southwestern Arizona along the California border, where temperatures regularly top 100 degrees.

The concern now is the beetles establishing themselves in the Gila, Salt and San Pedro watersheds, which have higher concentrations of flycatcher habitat.

The beetles aren’t known to feast on anything other than tamarisks, though one beetle can’t eat much on its own. In the thousands, they can consume entire trees, Bean said.

Southwestern Willow flycatcher

The tamarisk leaves can grow back within the season, but repeated attacks can be fatal for the trees — a welcome result in places flycatchers don’t live.

Dead tamarisks can litter the ground with leaves and increase wildfire risks.

The trees already are notorious for burning hot and black, and beetle predation would provide more fuel.

Ben Bloodworth works with Rivers Edge West, formerly the Tamarisk Coalition, which has been tracking the beetles’ movement for years.

The group has mapped the beetles along the Green River in Utah, the Rio Grande and Pecos River in New Mexico and Texas, the Arkansas River in Colorado, the Colorado River — a major source of water for 40 million people in seven Western states — and other waterways.

“Eventually the beetles will be throughout the entire Southwest, and really what we need to do is, in areas where it’s appropriate, get in ahead of the beetle (and) plant willows and cottonwoods and other native species that can provide habitat for the willow flycatcher,” Bloodworth said.

The beetles and the songbird have been the subject of legal fights. The Tucson-based Center for Biological Diversity sued the U.S. Department of Agriculture and its Animal and Plant Health Inspection Service in 2013.

The lawsuit alleged the damage caused by the insects through the beetle release program violated the Endangered Species Act, and argued the federal government should be held liable.

As part of a settlement, the USDA released a draft conservation plan in June for the flycatcher, which is found in parts of Arizona, California, Colorado, Nevada, New Mexico, Texas and Utah. Under the plan, the agency would aid existing conservation programs, contribute money and monitor beetle impacts. The public has until Aug. 8 to weigh in.

The beetles would not be in the United States if not for the tamarisk that thrives along riverbeds.

2014 Tamarisk leaf beetle distribution map via the Tamarisk Coalition

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