From Climate Change and Energy to Fires and Fish:
About 4,000 people are expected to attend the annual meeting of the Ecological Society of America in Portland, Ore., Aug. 5-10. The theme of this year’s conference is “Life on Earth: Preserving, Utilizing and Sustaining our Ecosystems.”
The Mostly Fowl Effects of Climate Change on Bird Distribution: Climate change will not affect all bird species equally, according to preliminary USGS research. Its impacts – and whether climate change will help or harm the species – will depend in great part on the species’ natural history and habitat needs. In this study, researchers focused on six western and southwestern bird species, and through modeling, forecasted how much climate change will likely affect the distribution of these species over the next century under different climate scenarios. The research suggested that three of the six bird species will suffer moderate to large losses in habitat and range (pinyon jay, pygmy nuthatch and Williamson’s sapsucker), two will enjoy large increases ( gray vireo and black-throated sparrow), and one may experience only minor declines (Virginia’s warbler). The pygmy nuthatch was forecasted to experience the greatest declines in habitat and range (81 percent), whereas the gray vireo will likely experience the greatest gains (58 percent). This research will help resource managers plan more effectively for climate change effects on wildlife. This presentation, Forecasting climate impacts on select birds in the Western United States, will be in Room B115 on Aug. 7 at 2:50 p.m. Contact: James Hatten, jhatten@usgs.gov, 509-439-2276.
Fight, Flight, or Nothing Much at All? Do Wolves Make Elk Skinnier? A new study is casting doubt on the popular notion that large mammalian predators shape ecosystems through the predator-avoidance behavior of their prey. Small-scale studies of invertebrates and amphibians have often shown that the risk of being killed by a predator can impact the behavior of prey animals strongly enough to reduce their foraging rates, nutrition and reproductive success. But recent results from the vast Yellowstone landscape, where re-introduced wolves hunt elk, have bucked this expectation. In this study, researchers simultaneously tracked the movements of wolves and the foraging behavior, body-fat levels and pregnancy of elk to determine whether wolves slow elk reproduction through fear alone. Although the presence of nearby wolves clearly affected elk behavior, these effects were not strong enough to make elk skinnier. When wolves were within one kilometer (.62 miles) of the prey, elk movement rates and vigilance increased slightly, but their habitat use did not change. Even in areas with particularly high wolf predation risk, individual elk experienced 1-km wolf encounters infrequently, thereby limiting the potential cumulative effects of wolves on elk behavior. These preliminary results echo the recent finding from other study systems that widely ranging, active-hunting predators such as wolves produce weaker risk cues and anti-predator behaviors among their prey, pointing to stalking predators (such as big cats) as likely carrying stronger ecosystem impacts. These research findings are especially relevant because the states of the Greater Yellowstone Ecosystem – Montana, Idaho, and soon Wyoming – are starting to manage wolf populations with an eye on their impacts on elk populations. This presentation, Spatial and temporal context limit the effect of wolves on elk behavior, will be in Room C120 on Aug. 9 at 4:40 p.m. Contact: Arthur Middleton, amiddle2@uwyoedu, 307-460-0880, or Matt Kauffman, mkauffman@usgs.gov, 307-766-6404.
Climatic Stress Increases Forest Fire Severity across the Western United States: A growing concern over current warming trends in the western United States is increased wildfire probabilities, leading to tree deaths (and subsequent losses of carbon, watershed integrity and wildlife habitat). The situation may be made worse if trees respond to increasing temperatures and droughts by becoming increasingly sensitive to fire. Research by USGS Western Ecological Research Center forest ecologist Phillip van Mantgem suggests that drought may pre-condition trees to die from fire. Dr. van Mantgem will present multiple independent data sets that document this climate-fire relationship, including long-term fire effects data from across the western United States. Can climate change increase fire severity independent of fire intensity? will be in Room E143 on Aug. 9 at 3:20 p.m. Contact Phil van Mantgem, pjvanmantgem@usgs.gov, 707-825-5189.
When Spring Comes Early — or Late — Migratory Moose Get Moving: Moose – and perhaps other short-distance migrants – may be fairly adaptable to changes to the start of the growing season caused by climate change, according to preliminary USGS research. Migratory ungulates, such as moose and deer, time their migrations to coincide with forage availability. However, as climate change leads to food plants leafing out earlier in the year, mismatches can occur if migrants arrive on their summering grounds after forage plants have reached their optimal stage. In this study, researchers evaluated factors that influenced the timing of spring and fall migration of GPS-collared moose in the Greater Yellowstone Ecosystem. Individual moose in this study were very loyal to their summer ranges, returning to them year after year, whereas they were less picky about their winter ranges. The main finding of the study is that moose reliably began their spring migrations depending on the elevation of their summering habitat. Migrants headed for lower elevation habitats left their winter ranges as much as 60 days earlier in the spring than those destined for higher elevations. Since it is well known that spring arrives late in the high mountains, these findings suggest that moose are timing their spring migrations so that they arrive in their summering grounds when their forage plants are most nutritious. The research indicates that relatively short-distance migratory taxa like moose are fairly adept at tracking the timing of spring across their individual summer ranges, which may allow them to better adapt to such phenological changes caused by climate change. This presentation, Moose Migrations Track Summer Range Phenology: Implications for Trophic Mismatch will be in Room A103 on Aug. 9 at 1:30 p.m. Contact Matt Kauffman, mkauffman@usgs.gov, mkauffm1@uwyo.edu, 307-766-6404.
Energy and Ecosystems in the West: Striving to Strike a Delicate Balance. With its diverse mix of energy resources, the Rocky Mountain West is an active region for energy production in the United States. Many energy-rich areas also include other resource values — such as wildlife, habitat and water resources — of federal, state, and local interest. As energy production in this region increases, developers and land managers alike need to better understand the patterns and processes associated with energy development and its potential effects on ecosystems. Project lead Zack Bowen provides a broad overview of energy resource trends in the Rocky Mountain West, including wind energy and the use of hydraulic fracturing to develop unconventional hydrocarbon resources. Research, technical assistance and objective, systematic methods are critically needed to evaluate the cumulative effects of energy development, including identifying tradeoffs, balancing multiple demands and examining the potential outcomes of management alternatives on ecosystems, from local to landscape scales. Trends and issues associated with energy development in the West will be in the Portland Ballroom 253 on Aug. 7 at 3:45 p.m. Contact Zack Bowen, bowenz@usgs.gov, 970-493-7014.
To Be or Not To Be: Species Adaptation to Climate Change: The pace of climate change has quickened beyond earlier estimates. In fact, parts of the Rocky Mountains have warmed 1.8 times the global average and scientists are documenting complex and often subtle mountain ecosystem vulnerabilities. For example, temperature-sensitive native bull trout will travel to montane headwaters in search of cooler waters. This will restrict their distribution to higher elevations where genetic isolation can occur and open up their home range to invasive species such as lake trout. For land-dwelling species such as the snowshoe hare, earlier spring snowmelt makes the species more vulnerable to predators because they are still transitioning from their white pelage. However, researchers are seeing resilience as well. The capacity of some organisms to change what they do according to varying environmental conditions, known as behavioral plasticity, has allowed them to adapt to changing climates and ecosystem processes. Resiliency is being enhanced by protection of critical habitats such as the North Fork of the Flathead River, a transboundary effort between the United States and Canada. These examples of species’ vulnerability and adaptation will be presented in the talk, The indirect human influence on western mountain environments: Vulnerabilities and resiliencies, in Portland Ballroom 253 on Aug. 7 at 1:30 p.m. Contact: Dan Fagre, dan_fagre@usgs.gov, 406-888-7922.
Predicting the Future: Where Fools Rush In: Rocky Mountain Futures: An Ecological Perspective (2002, Island Press) addressed cumulative ecological effects of human activity in the Rocky Mountains. Contributors described how mountain ecosystems have changed from past human use and projected how ecosystems might look in the future, given then-current drivers and trends. However, the past 10 years have seen unprecedented rates of social-ecological change from climate change, technological advances in fossil fuel and renewable energy extraction, and a stagnant global economy. This presentation compares then and now, examining how rapidly changing global forces supersede or are superimposed on local decisions. If scientists wish to contribute to effective place-based natural resource management, more consideration must be given to social and technological short- and long-term scenarios of the forces that shape the future. This presentation, Only fools and newcomers predict the future: The hubris of forecasting, will be in Portland Ballroom 253 on Aug. 7 at 4:35 p.m. Contact: Jill Baron, jill_baron@usgs.gov, 970-491-1968.
Climate and Fires in Different Subregions of California: When wildfires sweep through news media and current events, there is a tendency to describe them broadly as “wildfires in the western U.S.” The truth requires far more nuance. In this talk, USGS Western Ecological Research Center fire ecologist Jon Keeley discusses the subregions of California and contrasts the relationship between fire activity over the past 100 years and changes in climate and in human demography. Surprisingly, in both forested and non-forested subregions, the decade with the highest area burned was the 1920s. In some subregions, the area burned has declined continuously up until the present whereas in other subregions there has been a steady rise in fire activity since the 1970s, with the current decade approaching 1920s level of burning. A subregional analysis of climate / fire interactions in California will be in Room B114 on Aug. 10 at 8:20 a.m. Contact: Jon Keeley, jon_keeley@usgs.gov, 559-565-3170.
Are Pine Bark Beetles Affecting Water Quality? Pine forests in northern Colorado and southern Wyoming recently experienced the most severe mountain pine beetle epidemic in recorded history. More than 3.6 million acres of land have been affected; in total, the epidemic is more than ten times the size of previous epidemics in the region. One major concern among resource managers is possible degradation of drinking water quality as a result of this epidemic. The goal of this study was to investigate possible changes in soil and water chemistry in Grand County, Colo., in response to the epidemic, and to identify controlling factors on stream-water nutrients and carbon in areas affected by the mountain pine beetle. Among other findings, USGS scientists and partners noted an increase in soil moisture and soil nitrogen in areas beneath trees killed by the mountain pine beetle, reflecting reduced evapotranspiration and increased litter accumulation in the study area. Researchers found that particulate forms of nutrients in streams had increased, but dissolved forms had not. Spatial patterns in dissolved nutrients were more strongly controlled by basin slope, precipitation, and forest cover than by pine beetles. Possible explanations for these findings will be explored in the presentation Responses of soil and water chemistry to mountain pine beetle induced tree mortality in Grand County, Colorado, USA,” which will be in Room A105 on Aug. 9 at 10:30 a.m. Contact David Clow, dwclow@usgs.gov, or 303-236-6881.
How the Fish Grows: Are Movement Patterns in Humpback Chubs Related to Size? The federally endangered humpback chub is now limited to only six populations in the Colorado River Basin and its tributaries. A large, but previously unknown proportion of adult chub migrate seasonally into tributaries for spawning, returning to the main Colorado River afterward with surprising location fidelity. Less is known about the movement of young chubs between tributaries and the main Colorado River, however, juveniles are thought to be more vulnerable to decisions made by resource managers. Consequently, USGS researchers and their colleagues at the University of Florida developed model to quantify movement rates and their dependency on individual size of the chub. These models also allow researchers to compare survival and growth rates between sampling location. They found that movement rates of chub vary significantly depending on their size. They also found evidence that the survival and growth rates may vary between chub that live in the Lower Colorado River, a tributary, and those that live in the main-stem. This presentation, Movement and growth in humpback chub: using multistate models for inference from a mixed batch and individual tag dataset, will be in the Portland Ballroom 258 on August 7 at 9:50 a.m. For more information, contact Charles Yackulic, cyackulic@usgs.gov, 928-864-8684.
Increased Nitrogen Affecting Ecosystems of the Four Corners? Nitrogen deposition in the western United States is increasing, and these increases can significantly affect terrestrial ecosystems by altering the composition of plants; in particular, by increasing the likelihood of exotic plant invasion and the frequency of fires. In this study, researchers examined how increased nitrogen deposition in the Four Corners region could affect plant and soil communities and biogeochemical cycling in and near Mesa Verde and Arches National Parks. In Mesa Verde NP, where nitrogen deposition rates are higher than Arches NP, additional increases in nitrogen resulted in declines in nitrogen fixation rates. This may be good news for the Park’s resource managers because elevated nitrogen concentrations can increase exotic plant invasion. Thus, lowered nitrogen fixation inputs could mean less total nitrogen entering soils. In contrast, in Arches NP, small amounts of added nitrogen actually stimulated nitrogen fixation rates, while larger amounts suppressed fixation. Taken together, these data suggest that nitrogen deposition has the potential to affect biogeochemical cycles and ecosystem performance of the Four Corners region, and that – through interactions with multiple processes – human-caused nitrogen inputs may significantly alter dryland plant and soil function. This and other USGS research could help resource managers make more effective land management decisions. Nitrogen deposition in drylands: how anthropogenic nitrogen inputs affect coupled biogeochemical cycles in the Four Corners Region, U.S.A., will be in Room B114 on Aug. 7 at 9:20 a.m. Contact: Sasha Reed, screed@usgs.gov, 435-719-2334.
Increased Temperatures May Reduce Growth of a Dominant Bunchgrass: Average annual temperature for the southwestern United States is expected to increase 2-4oC by 2100. While this increase seems modest, even small temperature increases can negatively affect vegetation in already warm dryland communities. USGS researchers examined whether a +2oC increase in temperature would adversely affect growth of Indian ricegrass, a prominent bunchgrass in the Southwest USA. They found that elevated temperatures significantly reduced net photosynthesis in the grass, thought the effect was greatest in the spring when the plants are most active. The decrease in spring photosynthesis resulted in a significant decline in growth, reproductive output and soil respiration. Overall, these findings suggest that a +2oC increase in temperature can substantially and negatively affect growth and carbon cycling associated with this bunchgrass. This and other USGS research will help resource managers make more effective land-management decisions in preparing for climate change effects on ecosystems they manage. Increased temperature negatively affects carbon assimilation and growth of Achantherum hymenoides bunchgrass, will be in Room F151 on Aug. 8 at 3:20 p.m. Contact: Timothy Wertin, 435-719-2334.
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