Ghosts of Forests Past: Bark Beetles Kill Lodgepole Pines, Affecting Entire Watersheds

NSF Discovery posted this pine beetle story on June 27, 2013. It's part eleven in a series on the National Science Foundation's Science, Engineering, and Education for Sustainability (SEES) Investment.

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Sustainability: Water - Dead Trees & Dirty Water in the Rockies

NBC Learn has just published the “Sustainability: Water” collection live to their websites.

You can see the full collections at:
NBC LEARN Collection page:

This collection will be a great teaching and learning resource for middle and high school students and the general public for years to come. In addition, this collection adds to the incredible body of high-quality educational content that NBC Learn and the National Science Foundation have co-produced over the past four years – nearly 140 stories, in all!

Connecting the Pine Beetle Dots

Mines News posted an article, Connecting the Pine Beetle Dots. This article appears in the 2013-14 edition of Mines' research magazine, "Energy and the Earth."

Posted: June 14, 2013 By Todd Neff

Forests across the Mountain West have gone orange and faded to gray. Since about the turn of the millennium, the mountain pine beetle’s appetite for lodgepole has killed off some four million acres of trees in Colorado and Wyoming alone. That the larvae of an insect the size of a grain of rice can bring such destruction is in itself a wonder of nature.

The changes go far beyond appearance, and while questions about the effects of so many dead trees on forest fires may be the most obvious, some of the beetles’ biggest impacts lie downstream. Pine beetles are shrinking the snowpack, hastening runoff and parching summer soil. The bugs have affected everything from the molecular habits of soil metals to the makeup of soil microbes. They have changed the chemistry of forest earth and increased the loads of carcinogens flowing through water treatment plants.

It’s more than a provincial concern of cabin dwellers and ski condo owners. Mountain runoff into the Colorado and Platte rivers alone sustains 30 million people and 1.8 million acres of irrigated farmland. With a warming climate, the deep freezes that once killed off pine beetles will be fewer, threatening more frequent, longer lasting epidemics affecting the region in ways science is only beginning to grasp. But science will soon catch up. A Mines-led team of hydrologists, microbiologists, geochemists, numerical modelers and social scientists is sharpening the picture of pine beetle impacts below a given dead tree and connecting how those changes trickle out to watersheds and the people who depend on them.

A five-year, $3 million National Science Foundation grant and $375,000 in Colorado state matching funds are fueling the effort. Mines Associate Professor Reed Maxwell, who specializes in hydrological modeling, serves as principal investigator. His Mines office is big and sparse. Its notable features include a high-end road bike outfitted with commuter lights, a wall clock whose arms at noon point to the cube root of 1728, and a 28-square-foot whiteboard, mostly empty on this day.

“The water quality in, say, Lake Granby has a lot to do with a watershed area that’s heavily beetle impacted,” Maxwell said. “We want to move from tree to plot to hillslope to watershed scale. That’s one of the big tasks in our grant, and we’re developing the models from scratch. They aren’t really out there.”

There are plenty of hypotheses, supported — but also contradicted — by a growing number of studies. Combined, the story goes something like this: Pine beetles kill trees, which drop their needles and load the soil with carbon as they break down. Their denuded branches let more snow into the ground, but they also stop less sunlight and block less wind, accelerating melting and runoff. The water moves through the hillslope and watershed faster. That influences how fast it reacts chemically, which in turn affects carbon balance, metal absorption and microbial makeup. At larger scales, the flow paths and speeds of rivulets, creeks and rivers change, too. The sum of the impacts shifts water quality, quantity and timing to new equilibriums, Maxwell said.

But no one knows for sure, which is why the team of eight faculty, eight graduate students and two postdoctoral researchers from Mines and Colorado State University has much to do.

If recent studies are any indication, the pine beetle plot will have many twists. Mines hydrological engineering PhD student Kristin Mikkelson spent three summers doing field work in Pennsylvania Gulch near Breckenridge and Keystone Gulch, focused on testing surface waters for copper and zinc. Dissolved organic carbon, more abundant with all the fallen pine needles, latches onto metals and keeps them mobile, boosting their soil concentrations and, one would think, the volume of metals flowing in surface waters. But while soil concentrations of metals have indeed been higher, Mikkelson said, “We’re not seeing it in the surface water.”

Another curiosity relates to municipal water quality. In a separate Mikkelson-led study, published in Nature Climate Change in October 2012, she and Mines colleagues reported that higher concentrations of organic carbon from pine needle pulses react with chlorine-based disinfectants in water treatment plants and produce more carcinogenic disinfectant byproducts. The study compared water treatment plants in five pine-beetle-impacted watersheds with four controls and linked increases in disinfectant byproducts with the degree of pine beetle infestation. The surprise, Mikkelson said, was that one class of disinfectant byproducts, known as trihalomethanes, spiked while others, haloacetic acids, didn’t.

“When we saw the jump in only the one, it was clear that the pine beetle epidemic is not only changing the amount of organic carbon, but also its composition,” she said.

Mikkelson is following up with experiments in which she percolates artificial rainwater presoaked with brown pine needles through columns of soil. “We’re measuring how that organic carbon is changing as it goes through the columns — what parts are partitioning and sorbing into the soil and which metals they’re grabbing.”

That effort complements Mines hydrology PhD student Lindsay Bearup’s work. In a Berthoud Hall lab, Bearup pulled a one-gallon Ziploc® bag from a refrigerator. Its dirt would find its way into jars, and then vials.

“I have jars and jars of dirt – really exciting!” she joked.

Bearup had collected it from a site north of Bear Lake in Rocky Mountain National Park. After hiking the eight miles in, she had filled bags of dirt beneath trees in various states of beetle impact – some green and untouched, some orange, some gray. In the lab, she had put single grams of soil into 50 milliliter falcon tubes and added chemicals to determine how organic fractions differed and what metals were present. This information, combined with water captured in a rain gauge (to determine precipitation volume and stable isotopes) and other data, may help explain the surface water metal mystery, among other things.

“I’m looking at where metals are associated with soils,” she said. “It’s interesting because organic matter is changing as trees die.”

Those changes probably affect the microbial communities in forest soils, added Jonathan Sharp, a Mines assistant professor who focuses on the intersection of microbiology, geology and hydrology. With the pine beetle work, Sharp is guiding graduate students as they work to determine microbial makeup in soil based on DNA analysis. The theory is that, as trees die, microbial ecosystems face a pulse of needles and lifeless root systems and will evolve accordingly. That, in turn, could ultimately affect the transport of metals and water quality.

“We’re trying to look from the millimeter scale all the way up to the watershed,” Sharp said.

Maxwell’s modeling work will incorporate the team’s fieldwork, as well as data from partners at the U.S. Geological Survey and the University of Colorado, to bridge these scales. One aim is to put new information in the hands of water managers and policymakers. Part of the project, Maxwell said, will involve partnering with water municipalities in Colorado and southern Nevada to help them understand how pine beetles may be affecting the quality of their inflows and how they might adjust their water treatment regimes.

“We’re seeing real water quality changes,” Maxwell said. “At best, this is going to mean an increase in water bills.”

John McCray, a co-investigator and head of Mines' Department of Civil and Environmental Engineering, says the project’s combination of field work, chemical and DNA analysis, and computer modeling could help answer questions well beyond those posed by the pine beetle.

“The processes we’re looking at really have to do with any sort of change in mountain and forest hydrology,” McCray said. “Those could be changes due to fire, development or climate change.”

It’s good that the work’s happening now, he added. “Pine beetles appear to have significant effects on hydrology and water quality, and we’ve only had a limited window in which to study this.”

This article appears in the 2013-14 edition of Mines' research magazine, "Energy and the Earth."

The pine beetle devastation in Colorado. A close up of the pitch tubes is shown on the right.

PHD Students Lindsay Bearup (left) and Kristin Mikkelon (right)

2013 RMSAWWA/RMWEA Joint Annual Conference

We will have a session at the AWWA conference on September 8-11, 2013 at Keystone, Colorado.

Impacts of Tree Mortality from Mountain Pine Beetle Infestation upon Water Quality and Supply
In addition to changes in temperature, precipitation patterns, and snow accumulation and melt, ecological perturbations resulting from anthropogenic climate change such as the ongoing mountain pine beetle (MPB) epidemic have already dramatically impacted the Rocky Mountains. It is currently estimated that pine trees are dying in over 4 million acres of forests in Colorado and Wyoming infected by the MPB. The visual impact of dying and dead forests is stunning, but the invisible changes to the water cycle in vital watersheds in the Rocky Mountain west, including the Platte and Colorado River headwaters, may be a longer lasting legacy of the MPB. The objective of this National Science Foundation project is to determine potential water resource changes resulting from the MPB epidemic by defining and quantifying feedbacks between changes in climate, forested ecosystems altered by MPB impacts, biogeochemical processes and resource management practices. Beetle-killed trees will alter hydrologic and biogeochemical processes that govern water quantity and quality in forested headwater catchments, coupled with natural resources management options that can potentially affect downstream water user demands and ecological and human health needs. This five-year project addresses two main questions: (1) How will land cover change from beetle-killed forests and forest management practices affect local, watershed, and regional-scale surface and groundwater resources? (2) Can the MPB outbreaks significantly alter water quality parameters that include aesthetics, concentrations of heavy metals (i.e., Zn, Cu), and potential formation of disinfection byproducts? The outcomes of this project are to provide an improved scientific basis for managing watershed ecosystems in the Platte and Colorado River basins, thus helping to ensure safe and reliable water resources to more than 30 million residential users, and improve understanding of the water supply and quantity challenges for MPB-impacted areas across the Rocky Mountain West. The goals of this technical session are to introduce this project to the local water provider community and present the first-year findings of this project.


NBC Learn, the educational division of NBC News

The crew from NBC Learn were here on April 4-5, 2013 to do the Mountain Pine Beetle Story. This story is one of ten they are producing in conjunction with the National Science Foundation called Sustainability: Water, which is part one in a three part series on sustainability.

They were interested in the Mountain Pine Beetle infestation in Colorado; focusing specifically on how the bugs will affect the water supply.

NBC crew with Reed Maxwell and Lindsay Bearup

Crew setting up for John Stednick's interview at watershed location

Lindsay Bearup at Locky Mountain National Park field site and at CSM aboratory 

Niki Budnick from NBC Universal interviewing Reed Maxwell on campus    


Pine-Beetle-Ravaged Forests Could Pollute Drinking Water

Written By: Tiffany Stecker, ClimateWire

Trees killed by the mountain pine beetle epidemic in Colorado could lead to the contamination of the drinking water supply by a known carcinogen, a study has found.

Levels of cancer-causing trihalomethanes (THM) in water treatment facilities have increased on average by 2 parts per billion per year in areas of the state struck by mountain pine beetles, reaching an average of 70 ppb by 2011, according to a study published yesterday in Nature Climate Change.

In some facilities, concentrations were as high as 111 ppb. U.S. EPA limits THM concentrations in drinking water to 80 ppb.

"It's a bit of a concern that levels at treatment facilities are getting awfully close or surpassing EPA standards," said Kristin Mikkelson, lead author of the study and a researcher in hydrological engineering at the Colorado School of Mines. The scientists relied on water quality data from the state Department of Public Health and Environment, as well as nine water treatment facilities.

As trees die off, they decompose and release carbon into waterways and soil. This carbon reacts with chlorine disinfectants in water treatment plants to form water disinfection byproducts, some of which include THM.

Five facilities in Dillon, Winter Park, Kremmling, Steamboat Springs and Granby -- serving areas with forests affected by the beetles -- were used in the experimental group. Four other facilities in Colorado were used in the control group.

A legacy from an epidemic

Comparing data from before 2008 and after, the researchers found that levels of total THM increased by nearly one-third. Although the pine beetle outbreak began in 2004 and 2005 in Colorado, it takes three to five years for the pine needles to drop on the forest floor and begin degrading.

Levels of THM tend to be highest in late summer, after the season in which more trees die from pine beetle infestations.

"We don't know if this is going to occur over the longer term or if it will occur in other places," Mikkelson said, or whether it will have human health implications in the long term.

Last year, the pine beetle epidemic killed about 3.8 million acres of trees across the Western states, according to the Forest Service, a drop from a peak of nearly 9 million acres in 2009. The Forest Service expects the epidemic to continue to shrink as the declining number of pine trees leaves beetles without food. Rising temperatures due to climate change have been identified as a factor in exploding pine beetle populations.

A spokesman from the Colorado Department of Public Health and Environment did not comment directly on the findings of the study but said the department had not changed its water monitoring program to look for an increase in organic carbon or water disinfection byproducts like THM.

"Chlorination of organic matter in the water does create [disinfection byproducts]" said Mark Salley, communications director for the department. "However, much of the organic matter can [or] is filtered out by public water systems before the chlorination step."

Mikkelson will expand her research to investigate how rising levels of organic carbon react with metals in soil.

For orginial article click here.


Mines Awarded NSF Grant to Research Pine Beetle Devastation Impact on Water Resources

GOLDEN, Colo., Oct. 30, 2012 – A study by Colorado School of Mines researchers demonstrates beetle-killed trees in Colorado’s forests are affecting the quality of municipal drinking water in the region. The study was recently published online in Nature Climate Change.

In “Water-quality impacts from climate-induced forest die-off” by Mines graduate student Kristin Mikkelson and faculty members Eric Dickenson, Reed Maxwell, John McCray and Jonathan Sharp, the research notes higher contaminant levels of harmful disinfection by-products and total organic carbon at water-treatment facilities using mountain-pine-beetle-infested source waters than those using water from control watersheds.

The study stresses the need to include water quality to the list of potential impacts as climate change continues to alter ecosystem dynamics.

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Mines Awarded NSF Grant to Research Pine Beetle Devastation Impact on Water Resources

A five year, $3 million National Science Foundation Water Sustainability and Climate program grant has been awarded to Colorado School of Mines researchers to examine the impact of the pine beetle devastation on vital watersheds in the Rocky Mountain west. The project will be led by Mines in collaboration with research partners from Colorado State University.

Researchers estimate beetle-killed trees will alter hydrologic and biogeochemical processes that govern water quantity and quality in forested headwater catchments, potentially affecting downstream user demands and challenging ecological and human health. This study’s findings will help towns and cities in the American west manage water rates and effectively improve watershed health.

According to principal investigator Reed Maxwell, Mines associate professor of hydrology in the Department of Geology and Geological Engineering and director of the Integrated Groundwater Modeling Center, the study will examine the potential water resource changes resulting from the mountain pine beetle epidemic by examining changes in climate, forested ecosystems altered by pine beetle impacts, biogeochemical processes and resource management practices.

Mines will receive $2.3 million from the NSF, research partner Colorado State University will receive $600,000. The Colorado Higher Education Competitive Research Authority is providing $375,000 in matching funds. Co-principal investigators at Mines include Jonathan Sharp, assistant professor of environmental engineering, Alexis Navarre-Sitchler, assistant professor of aqueous geochemistry and Eric Dickenson, assistant research professor of environmental engineering. Collaborative work at CSU will be led by John Stednick, professor of watershed science in the Department of Forest and Rangeland Stewardship, Warner College of Natural Resources, CSU.