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Biological Aspects Of Mountain Pine Beetle In Lodgepole Pine Stands Of Different Densities In Colorado, Usa, Jose Negron Dec 2018

Biological Aspects Of Mountain Pine Beetle In Lodgepole Pine Stands Of Different Densities In Colorado, Usa, Jose Negron

USDA Forest Service / UNL Faculty Publications

Research Highlights: The biology of mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, in Colorado’s lodgepole pine forests exhibits similarities and differences to other parts of its range. Brood emergence was not influenced by stand density nor related to tree diameter. The probability of individual tree attack is influenced by stocking and tree size. Findings have implications for understanding MPB as a disturbance agent and for developing management strategies. Background and Objectives: MPB causes extensive tree mortality of lodgepole pine, Pinus contorta Douglas ex Loudon, across the western US and Canada and is probably the most studied bark beetle in North …


Improving Ecological Restoration To Curb Biotic Invasion—A Practical Guide, Qinfeng Guo, Dale G. Brockway, Diane L. Larson, Deli Wang, Hai Ren Nov 2018

Improving Ecological Restoration To Curb Biotic Invasion—A Practical Guide, Qinfeng Guo, Dale G. Brockway, Diane L. Larson, Deli Wang, Hai Ren

USDA Forest Service / UNL Faculty Publications

Common practices for invasive species control and management include physical, chemical, and biological approaches. The first two approaches have clear limitations and may lead to unintended (negative) consequences, unless carefully planned and implemented. For example, physical removal rarely completely eradicates the targeted invasive species and can cause disturbances that facilitate new invasions by nonnative species from nearby habitats. Chemical treatments can harm native, and especially rare, species through unanticipated side effects. Biological methods may be classified as biocontrol and the ecological approach. Similar to physical and chemical methods, biocontrol also has limitations and sometimes leads to unintended consequences. Therefore, a …


Short Communications: First Tracking Of Individual American Robins (Turdus Migratorius) Across Seasons, Alex E. Jahn, Susannah B. Lerman, Laura M. Phillips, Thomas B. Ryder, Emily J. Williams Sep 2018

Short Communications: First Tracking Of Individual American Robins (Turdus Migratorius) Across Seasons, Alex E. Jahn, Susannah B. Lerman, Laura M. Phillips, Thomas B. Ryder, Emily J. Williams

USDA Forest Service / UNL Faculty Publications

The American Robin (Turdus migratorius) is one of the most widespread, common bird species in North America; yet, very little is known about its migratory connectivity, migration timing, and migratory routes. Using archival GPS tags, we tracked the movements of 7 individual robins from 3 breeding populations in the United States. Four robins captured in Denali National Park and Preserve, Alaska, overwintered in Texas, Nebraska, Oklahoma, and Montana, up to 4,500 km from the capture location. One robin captured in Amherst, Massachusetts, overwintered in South Carolina 1,210 km from the capture location, whereas 2 robins captured in Washington, D.C., spent …


Tamm Review: Reforestation For Resilience In Dry Western U.S. Forests, Malcolm P. North, Jens T. Stevens, David F. Greene, Michelle Coppoletta, Eric E. Knapp, Andrew M. Latimer, Christina M. Restaino, Ryan E. Tompkins, Kevin R. Welch, Rob A. York, Derek J.N. Young, Jodi N. Axelson, Tom N. Buckley, Becky L. Estes, Rachel N. Hager, Jonathan W. Long, Marc D. Meyer, Steven M. Ostoja, Hugh D. Safford, Kristen L. Shive, Carmen L. Tubbesing, Dana Walsh, Chhaya M. Werner, Peter Wyrsch, Heather Vice Sep 2018

Tamm Review: Reforestation For Resilience In Dry Western U.S. Forests, Malcolm P. North, Jens T. Stevens, David F. Greene, Michelle Coppoletta, Eric E. Knapp, Andrew M. Latimer, Christina M. Restaino, Ryan E. Tompkins, Kevin R. Welch, Rob A. York, Derek J.N. Young, Jodi N. Axelson, Tom N. Buckley, Becky L. Estes, Rachel N. Hager, Jonathan W. Long, Marc D. Meyer, Steven M. Ostoja, Hugh D. Safford, Kristen L. Shive, Carmen L. Tubbesing, Dana Walsh, Chhaya M. Werner, Peter Wyrsch, Heather Vice

USDA Forest Service / UNL Faculty Publications

The increasing frequency and severity of fire and drought events have negatively impacted the capacity and success of reforestation efforts in many dry, western U.S. forests. Challenges to reforestation include the cost and safety concerns of replanting large areas of standing dead trees, and high seedling and sapling mortality rates due to water stress, competing vegetation, and repeat fires that burn young plantations. Standard reforestation practices have emphasized establishing dense conifer cover with gridded planting, sometimes called 'pines in lines', followed by shrub control and pre-commercial thinning. Resources for such intensive management are increasingly limited, reducing the capacity for young …


On-Road Emissions Of Ammonia: An Underappreciated Source Of Atmospheric Nitrogen Deposition, Mark E. Fenn, Andrzej Bytnerowicz, Susan L. Schilling, Dena M. Vallano, Erika S. Zavaleta, Stuart B. Weiss, Connor Morozumi, Linda H. Geiser, Kenneth Hanks Jan 2018

On-Road Emissions Of Ammonia: An Underappreciated Source Of Atmospheric Nitrogen Deposition, Mark E. Fenn, Andrzej Bytnerowicz, Susan L. Schilling, Dena M. Vallano, Erika S. Zavaleta, Stuart B. Weiss, Connor Morozumi, Linda H. Geiser, Kenneth Hanks

USDA Forest Service / UNL Faculty Publications

We provide updated spatial distribution and inventory data for on-road NH3 emissions for the continental United States (U.S.) On-road NH3 emissions were determined from on-road CO2 emissions data and empirical NH3:CO2 vehicle emissions ratios. Emissions of NH3 from on-road sources in urbanized regions are typically 0.1– 1.3 t km−2 yr−1 while NH3 emissions in agricultural regions generally range from 0.4–5.5 t km−2 yr−1, with a few hot spots as high as 5.5–11.2 t km−2 yr−1. Counties with higher vehicle NH3 emissions than from agriculture …


Ecological-Economic Assessment Of The Effects Of Freshwater Flow In The Florida Everglades On Recreational Fisheries, Christina Estela Brown, Mahadev G. Bhat, Jennifer S. Rehage, Ali Mirchi, Ross Boucek, Victor Engel, Jerald S. Ault, Pallab Mozumder, David Watkins, Michael Sukop Jan 2018

Ecological-Economic Assessment Of The Effects Of Freshwater Flow In The Florida Everglades On Recreational Fisheries, Christina Estela Brown, Mahadev G. Bhat, Jennifer S. Rehage, Ali Mirchi, Ross Boucek, Victor Engel, Jerald S. Ault, Pallab Mozumder, David Watkins, Michael Sukop

USDA Forest Service / UNL Faculty Publications

This research develops an integrated methodology to determine the economic value to anglers of recreational fishery ecosystem services in Everglades National Park that could result from different water management scenarios. The study first used bio-hydrological models to link managed freshwater inflows to indicators of fishery productivity and ecosystem health, then link those models to anglers' willingness-to-pay for various attributes of the recreational fishing experience and monthly fishing effort. This approach allowed us to estimate the foregone economic benefits of failing to meet monthly freshwater delivery targets. The study found that the managed freshwater delivery to the Park had declined substantially …