Changing Mountains

Colorado’s environment is changing. Indications are everywhere, from devastating wildfires to small furry creatures scampering across mountain rocks. And researchers at Colorado universities are at the forefront of efforts to find answers to a host of issues affecting the West, not only catastrophic events such as the floods of fall 2013, but also less obvious areas such as dust that’s settling on mountain glaciers. Here’s a look at a handful of those issues:

Pikas

Pikas, the small furry animals related to rabbits, are holding their own in the southern Rockies, despite declining in areas such as the Great Basin in Nevada.

A four-year study by Liesl Erb, who has her Ph.D. from the department of ecology and evolutionary biology at the University of Colorado Boulder, showed that of 69 historical sites in the Rockies, pikas still inhabited 65 of them, although some in lower population densities.

Erb calls pikas, which live above 9,000 feet, “an indicator species for the effects of global change on not just alpine ecosystems, but some of the important resources for humans as well. Snowpack is the source of our water resources, so they’re really living at our headwaters, sounding an alarm that there is a problem here. We see them as an indicator of our water resources, an indicator of changes to our ecosystem.”

Pikas, which can die of heat stroke if held at temperatures of 78 degrees, live in broken rocks known as talus. They don’t hibernate in the winter. Instead, they eat vegetation they collect and store in the rocks.
Erb’s study suggests that pikas can withstand higher temperatures better if the vegetation they eat has more nutrition.

Erb expects that changes in temperature and precipitation will change types of vegetation as well.
Future studies will focus on genetics to see if some pika populations are better adapted to deal with changes in temperature.

“In the face of climate change, they probably will decline in certain areas,” Erb says. “But we have a lot of regions of Colorado that still get a lot of snow and because of that snow, have a diverse plant community. They have cooler temperatures in the summer. We are hopeful that some parts of Colorado could sustain the populations, but we are losing them in some places here.”

Forest fires and mountain pine beetles

Climate change, forest conditions and the relentless mountain pine beetle outbreak have all played a role in the devastating wildfires such as High Park and Hayman over the past few years.

Monique Rocca, an associate professor in the Department of Ecosystem Sciences and Sustainability at Colorado State University, is studying the forest conditions before and after the 2012 High Park fire.

High Park provides a unique opportunity to study the effects of the pine beetle outbreak and how it might have contributed to the fire’s severity, Rocca said.

High-resolution aerial photos of the area being taken by the National Ecological Observatory Network in Boulder will provide valuable information about the location of  patches of still-green trees, the location of the beetle outbreaks, as well as where the needles were still on the trees and where they had fallen.

“The time between a tree dying from beetles and the fire matters a lot, because areas that still had red needles on the trees would burn more severely,” Rocca said. “Once the needles had fallen, we would expect fire severity to decrease. But there would be more litter on the forest floor.”

The effects of the beetle outbreak on the fire also are likely to affect regeneration. If the trees were dead before the fire, more seeds might have burned, meaning fewer seeds to grow new trees.

There also has been severe erosion in the burn area, contributing to a water-quality problem in the Poudre River.
The beetle outbreak has likely affected what the forests will look like in the future. On the west side of Rocky Mountain National Park, half of the lodge-pole pines were killed by beetles. The other half, mostly saplings and seedlings, which are not susceptible to pine beetles, survived and are plentiful enough to regenerate that part of the forest, regardless of whether there are new seeds.

But in areas where spruce and fir or aspen trees are underneath the dead lodge-poles, the forest is likely to grow into aspen and fir and spruce stands. “That could help buffer against a future beetle outbreak,” Rocca said.

The beetle outbreak has now moved into ponderosas in the lower elevations.

Climate change could play a role in future wildfires. Warmer winters will result in less snowpack, and warmer springs result in snowpack melting faster. Warmer summers mean drier conditions. And all those factors contribute to a longer fire season.

Dust

Dust storms in Colorado and other parts of the West have increased over the past 17 years, reaching as high as the snowpack in the Rocky Mountains and causing soil erosion and air-quality problems.

A University of Colorado Boulder study published in the journal Aeolian Research used calcium deposition, which is found in wind erosion of soils, for dust measurements and found that the amount had increased over the 17 years.

Dust particles on snowpack cause the snowpack to melt faster, which can lead to earlier spring runoff and quicker evaporation.

Researchers think the dust is coming from Arizona, New Mexico and Utah, primarily caused by drier soil from drought, construction activity, oil and gas exploration, road building and even off-road vehicles.

Floods

The fall 2013 floods that swept through the Front Range from Denver to the Colorado-Wyoming border were remarkable on several fronts, said Stephanie Kampf, an associate professor with Colorado State University’s department of Ecosystem Science and Sustainability.

The storm hit a large area for a long period of time — nearly eight days – in the fall, all unusual in Colorado.
Some areas at high elevations recorded more than eight inches of rain, and most fell within two days.
“That’s comparable to the amount of water in the snowpack at its peak accumulation,” Kampf said.

Peak flows were at record levels in the area around Boulder.

The area, the amount of rainfall, the size of the weather system and the period of time it lasted, the high levels of water, the time of year, were all “quite rare. The only thing even similar to this was in 1938,” she said.
Discussions are taking place among various entities about how they can learn to manage floodplains.

“The problem is, we have a lot of activity in these places that can get flooded — roads, houses, infrastructure, ditches. Lessons learned can relate to how we manage potentially flooded areas,” Kampf said.

“But in places like Boulder that got so much rain in such a short period of time, they ended up with flooding in places that have not previously even been identified as floodplains.”

On the engineering side, changes in design could be based on what made it through the flood and what didn’t: roads, bridges, buildings.

But in places such as the Big Thompson Canyon, “when you have a road in such a narrow confined canyon, it’s very difficult to figure out a way that any structure, no matter now strong, could withstand that. There’s going to be a lot of analysis on the engineering side.”

Alpine lakes

Nitrogen deposition in Colorado’s alpine lakes has leveled off, said Jill Baron, co-director of the John Wesley Powell Center for Earth System Analysis and Synthesis at the U.S. Geological Survey.

Nitrogen comes from multiple sources: vehicles, power plants, industry and trains, which are a major source of air pollution. It also comes from ammonia from animal urine and agricultural fertilizer. The nitrogen gets released into the air and then falls in places such as alpine lakes. Nitrogen in the lakes causes changes in algae growth.
If enough nitrogen gets into the lakes, acidification — or acid rain — could occur. “Then it’s not just algae. It becomes plankton and eventually fish that are affected,” she said.

But Baron emphasizes: “We have not found that.”

The nitrogen levels Baron found in her study also are good news because of rules in the Nitrogen Deposition Reduction Plan, which requires that nitrogen levels be reduced to meet a certain level by 2035 to protect air quality. The plan was developed by the National Park Service, Environmental Protection Agency and Colorado Department of Public Health and Environment. If goals aren’t met, regulations could be imposed.

So far, new technology and voluntary emission-reduction efforts are helping, Baron said.

But concerns about the effects of climate change could throw a monkey wrench into the works.

“Even if deposition stays the same, now we have this additional nitrogen that was probably stored in ice and released as it melts,” she said. “And we’re also seeing increasing warming waters, which is changing the environment for the algae.

“All kinds of things could happen because now we have this intersection of climate and nitrogen.”

Colorado River

Reduction in Colorado River flows could result in major changes to a legal compact that has been governing water rights among seven western states since 1922.

A 14-year drought coupled with increased farming, urbanization and recreational use has contributed to a 20 percent decline in the river’s flow, said Brad Udall, director of the Getches-Wilkinson Center for Natural Resources, Energy and the Environment at the University of Colorado Law School in Boulder.

That’s resulted in major decreases in storage in western reservoirs, which previously stored huge amounts of water. Today, the two largest reservoirs in the United States — Lake Mead, located in Nevada and Arizona, and Lake Powell, in Utah and Arizona — have lost half their storage.

“We really haven’t ever seen this,” Udall said.

Historically, the annual flow averages about 15 million acre feet. That’s about 325,000 gallons of water.

“We still have a lot of it. We’re just going to have to think about how to use it efficiently and effectively if the 20 percent decline is going to continue,” he said, adding that in fact, the 20 percent decline is expected to continue to 2050.

The compact requires that the upper basin states – Colorado, Utah, Wyoming and New Mexico — deliver a certain sum of water every 10 years to the lower basin states — Arizona, California and Nevada. But the lower basin has been using water that until now the upper basin hasn’t needed. Given the lower flows, the upper basin may well need to use the water it’s entitled to, and the lower basin will have to figure out how to cut its own use.

High-level discussions among the seven states are under way to deal with the shortages and negotiate use.

“It’s a sensitive topic, but the pressure is on,” Udall said.

on Facebook on LinkedIn