Life Sciences Commons^™

Conditions Inside Fisher Dens During Prescribed Fires; What Is The Risk Posed By Spring Underburns?, Craig M. Thompson, Kathryn L. Purcell

USDA Forest Service / UNL Faculty Publications

The use of spring prescribed fires to reduce accumulated fuel loads in western forests and facilitate the return of natural fire regimes is a controversial topic. While spring burns can be effective at reducing fuel loads and restoring heterogeneous landscapes, concerns exist over the potential impacts of unnaturally timed fires to native species. To protect native wildlife from disturbance during critical periods, limited operating periods (LOPs) are often implemented. However when LOPs for multiple species are combined into an integrated management plan, very few time windows for implementing prescribed fires remain. The use of spring burns is often effectively eliminated, …

Riparian Trees And Aridland Streams Of The Southwestern United States: An Assessment Of The Past, Present, And Future, D. Max Smith, Deborah M. Finch

USDA Forest Service / UNL Faculty Publications

Riparian ecosystems are vital components of aridlands within the southwestern United States. Historically, surface flows influenced population dynamics of native riparian trees. Many southwestern streams has been altered by regulation, however, and will be further affected by greenhouse warming. Our analysis of stream gage data revealed that decreases in volume of annual discharge and mean peak discharge and a shift to earlier peak discharge will occur in the Southern Rockies region of Colorado, New Mexico, and Utah. These changes will likely decrease rates of reproduction and survival of cottonwood (Populus fremontii and Populus deltoides ssp. wislizenii), Goodding's willow …

Review Of Broad-Scale Drought Monitoring Of Forests: Toward An Integrated Data Mining Approach, Steven P. Norman, Frank H. Koch, William W. Hargrove

USDA Forest Service / UNL Faculty Publications

Efforts to monitor the broad-scale impacts of drought on forests often come up short. Drought is a direct stressor of forests as well as a driver of secondary disturbance agents, making a full accounting of drought impacts challenging. General impacts can be inferred from moisture deficits quantified using precipitation and temperature measurements. However, derived meteorological indices may not meaningfully capture drought impacts because drought responses can differ substantially among species, sites and regions. Meteorology-based approaches also require the characterization of current moisture conditions relative to some specified time and place, but defining baseline conditions over large, ecologically diverse regions can …

A Forest Vulnerability Index Based On Drought And High Temperatures, David Mildrexler, Zhiqiang Yang, Warren B. Cohen, David M. Bell

USDA Forest Service / UNL Faculty Publications

Increasing forest stress and tree mortality has been directly linked to combinations of drought and high temperatures. The climatic changes expected during the next decades – large increases in mean temperature, increased heat waves, and significant long-term regional drying in the western USA – will likely increase chronic forest stress and mortality. The aim of this research is to develop and apply a new forest vulnerability index (FVI) associated with drought and high temperatures across the Pacific Northwest region (PNW; Oregon and Washington) of the USA during the MODIS Aqua era (since 2003). Our technique incorporates the alterations to canopy …

Contributing Factors For Drought In United States Forest Ecosystems Under Projected Future Climates And Their Uncertainty, Charles H. Luce, James M. Vose, Neil Pederson, John Campbell, Connie Millar, Patrick Kormos, Ross Woods

USDA Forest Service / UNL Faculty Publications

Observations of increasing global forest die-off related to drought are leading to more questions about potential increases in drought occurrence, severity, and ecological consequence in the future. Dry soils and warm temperatures interact to affect trees during drought; so understanding shifting risks requires some understanding of changes in both temperature and precipitation. Unfortunately, strong precipitation uncertainties in climate models yield substantial uncertainty in projections of drought occurrence. We argue that disambiguation of drought effects into temperature and precipitation-mediated processes can alleviate some of the implied uncertainty. In particular, the disambiguation can clarify geographic diversity in forest sensitivity to multifarious drivers …

Improved Bulk Density Of Bamboo Pellets As Biomass For Energy Production, Zhijia Liu, Bingbing Mi, Zehui Jiang, Benhua Fei, Zhiyong Cai, Xing'e Liu

USDA Forest Service / UNL Faculty Publications

To the best of our knowledge, there is the lack of sufficient information concerning bamboo pellets. In the preliminary research, bamboo pellets showed a low bulk density which could not meet requirement of Pellet Fuels Institute Standard Specification for Residential/Commercial Densified (PFI). To improve its bulk density, pellets were manufactured using mixtures of bamboo and pine particles and the properties were investigated. It was found that adding pine particles to bamboo particles was an effective way to improve bulk density of bamboo pellets. When adding 40% pine particles to bamboo particles, bulk density of pellets increased from 0.54 …

Pronghorn Habitat Suitability In The Texas Panhandle, Nathan P. Duncan, Samantha S. Kahl, Shawn S. Gray, Christopher J. Salice, Richard D. Stevens

USDA Forest Service / UNL Faculty Publications

Habitat quality is an important factor that can greatly affect wildlife populations. Pronghorn (Antilocapra americana) habitat in the Texas Panhandle, USA has been lost through growth of human settlements and agricultural lands. We determined the most pertinent environmental variables affecting habitat selection using multiple methods, including a search of peer-reviewed literature, expert opinion ranking, and habitat suitability modeling. We determined quality and extent of pronghorn habitat in the Texas Panhandle using the MAXENT modeling environment to build a presence-only habitat suitability model based on global positioning system (GPS) locations collected via aerial surveys. Our habitat suitability model indicated …

Pyrodiversity Promotes Avian Diversity Over The Decade Following Forest Fire, Morgan W. Tingley, Viviana Ruiz-Gutierrez, Robert L. Wilkerson, Christine A. Howell, Rodney B. Siegel

USDA Forest Service / UNL Faculty Publications

An emerging hypothesis in fire ecology is that pyrodiversity increases species diversity.We test whether pyrodiversity—defined as the standard deviation of fire severity—increases avian biodiversity at two spatial scales, and whether and how this relationship may change in the decade following fire. We use a dynamic Bayesian community model applied to a multi-year dataset of bird surveys at 1106 points sampled across 97 fires in montane California. Our results provide strong support for a positive relationship between pyrodiversity and bird diversity. This relationship interacts with time since fire, with pyrodiversity having a greater effect on biodiversity at 10 years post-fire than …

Ecosystem Services Of Woody Crop Production Systems, Ronald S. Zalesny Jr., John A. Stanturf, Emile S. Gardiner, James H. Perdue, Timothy M. Young, David R. Coyle, William L. Headlee, Gary S. Bañuelos, Amir Hass

USDA Forest Service / UNL Faculty Publications

Short-rotation woody crops are an integral component of regional and national energy portfolios, as well as providing essential ecosystem services such as biomass supplies, carbon sinks, clean water, and healthy soils. We review recent USDA Forest Service Research and Development efforts from the USDA Biomass Research Centers on the provisioning of these ecosystem services from woody crop production systems. For biomass, we highlight productivity and yield potential, pest susceptibility, and bioenergy siting applications. We describe carbon storage in aboveground woody biomass and studies assessing the provision of clean and plentiful water. Soil protection and wildlife habitat are also mentioned, in …

Timber Talk, Vol. 53, No .4, November 2015

Timber Talk: Nebraska Forest Industry Newsletter

In This Issue

Lumber Market News ...........................1

Hardwood Lumber Price Trends—Green..................................2

Hardwood Lumber Price Trends—Kiln Dried...........................2

Sun-dried Lumber.................................3

NFS Forest Products Program...............4

Milling Railroad Ties in Nebraska........4

A Closer Look at Edgers........................5

Nebraska Forest Industry Spotlight......7

The Trading Post....................................8

Landscape Position Influences Microbial Composition And Function Via Redistribution Of Soil Water Across A Watershed, Zhe Du, Diego Andrés Riveros-Iregui, Ryan T. Jones, Timothy R. Mcdermott, John E. Dore, Brian L. Mcglynn, Ryan E. Emanuel, Xu Li

Department of Civil and Environmental Engineering: Faculty Publications

Subalpine forest ecosystems influence global carbon cycling. However, little is known about the compositions of their soil microbial communities and how these may vary with soil environmental conditions. The goal of this study was to characterize the soil microbial communities in a subalpine forest watershed in central Montana (Stringer Creek watershed within the Tenderfoot Creek Experimental Forest) and to investigate their relationships with environmental conditions and soil carbonaceous gases. As assessed by tagged Illumina sequencing of the 16S rRNA gene, community composition and structure differed significantly among three landscape positions: high upland zones (HUZ), low upland zones (LUZ), and riparian …

Timber Talk, Vol. 53, No. 3, September 2015

Timber Talk: Nebraska Forest Industry Newsletter

In This Issue

Lumber Market News ...........................1

Hardwood Lumber Price Trends—Green..................................2

Hardwood Lumber Price Trends—Kiln Dried...........................2

Open for Business..................................3

U.S. Pumps out More Pellets.................4

Should I Buy a Sawmill.........................5

Nebraska Forest Industry Spotlight......7

The Trading Post....................................8

Timber Sales...........................................8

Carbon Storage Potential Of Windbreaks On Agricultural Lands Of The Continental United States, William Ballesteros Possu

School of Natural Resources: Dissertations, Theses, and Student Research

Agricultural production systems face major challenges under climate change scenarios in terms of expected negative impacts on productivity and persistence of the crops. Greenhouse gases from agriculture continue to rise although not as fast as from other fossil fuel-based human activities. Windbreaks perform several ecosystems functions that improve the local and regional capacity of crop systems to increase yields and offer environmental services by minimizing the negative effects of extreme weather events. Windbreaks also represent an important means of mitigating greenhouse gas emissions. This is predominantly accomplished by the windbreak trees storing carbon (C) in their above and belowground woody …

Timber Talk, Vol. 53, No. 2, June 2015

Timber Talk: Nebraska Forest Industry Newsletter

In This Issue

Lumber Market News ...........................1

Hardwood Lumber Price Trends—Green..................................2

Hardwood Lumber Price Trends—Kiln Dried...........................2

Top Ten Family Forestry Issues.............3

Hardwood Floors with a Zip.................5

Nebraska Forest Industry Spotlight......7

The Trading Post....................................8

Timber Sales...........................................8

Timber Talk, Vol. 53, No. 1, February 1, 2015

Timber Talk: Nebraska Forest Industry Newsletter

In This Issue

Lumber Market News ...........................1

Hardwood Lumber Price Trends—Green...................................2

Hardwood Lumber Price Trends—Kiln Dried...........................2

Innovation Treats Firewood for Safe Transport...................................3

Tax Tips for Landowners for the 2014 Tax Year.............................4

Nebraska Forest Industry Spotlight......6

Utilization of Small-Diameter Material...................................................7

The Trading Post.....................................8

Monthly Land Cover-Specific Evapotranspiration Models Derived From Global Eddy Flux Measurements And Remote Sensing Data, Yuan Fang, Ge Sun, Peter Caldwell, Steven G. Mcnulty, Asko Noormets, Jean-Christophe Domec, John King, Zhiqiang Zhang, Xudong Zhang, Guanghui Lin, Guangsheng Zhou, Jingfeng Xiao, Jiquan Chen

USDA Forest Service / UNL Faculty Publications

Evapotranspiration (ET) is arguably the most uncertain ecohydrologic variable for quantifying watershed water budgets. Although numerous ET and hydrological models exist, accurately predicting the effects of global change on water use and availability remains challenging because of model deficiency and/or a lack of input parameters. The objective of this study was to create a new set of monthly ET models that can better quantify landscape-level ET with readily available meteorological and biophysical information. We integrated eddy covariance flux measurements from over 200 sites, multiple year remote sensing products from the Moderate Resolution Imaging Spectroradiometer (MODIS), and statistical modelling. Through examining …

Alternative Timing Of Carbaryl Treatments For Protecting Lodgepole Pine From Mortality Attributed To Mountain Pine Beetle, Christopher J. Fettig, A Steve Munson, Kenneth E. Gibson

USDA Forest Service / UNL Faculty Publications

Carbaryl is regarded among the most effective, economically viable, and ecologically-compatible insecticides available for protecting conifers from bark beetle attack in the western United States. Treatments are typically applied in spring prior to initiation of bark beetle flight for that year. We evaluated the efficacy of spring and fall applications for protecting individual lodgepole pine, Pinus contorta Dougl. ex Loud, from mortality attributed to mountain pine beetle, Dendroctonus ponderosae Hopkins, the most notable forest insect pest in western North America. Both spring and fall treatments of 2.0% a.i. carbaryl (Sevin® SL) were efficacious for two field seasons, while results from …

Long-Term Droughtiness And Drought Tolerance Of Eastern Us Forests Over Five Decades, Matthew P. Peters, Louis R. Iverson, Stephen N. Matthews

USDA Forest Service / UNL Faculty Publications

Droughts can influence forest composition directly by limiting water or indirectly by intensifying other stressors that affect establishment, growth, and mortality. Using community assemblages of eastern US tree species and drought tolerance characteristics assessed from literature, we examine recent drought conditions in relation to the spatial distribution of species and their tolerance to drought. First we calculate and compare a cumulative drought severity index (CDSI) for the conterminous US for the periods 1960–1986 and 1987–2013 using climate division Palmer Drought Severity Index (PDSI) values and a gridded self-calibrated PDSI dataset. This comparison indicates that drought conditions in the East tend …

Scarification And Gap Size Have Interacting Effects On Northern Temperate Seedling Establishment, John L. Willis, Michael B. Walters, Kurt W. Gottschallk

USDA Forest Service / UNL Faculty Publications

After decades focused on promoting economically valuable species, management of northern temperate forests has increasingly become focused on promoting tree species diversity. Unfortunately, many formerly common species that could contribute to diversity including yellow birch (Betula alleghaniensis Britton.), paper birch (Betula papyrifera Marsh), eastern hemlock (Tsuga canadensis L.), and eastern white pine (Pinus strobus L.) are now uncommon in the seedling layer, raising concerns about our ability to use these species to increase diversity. In this study, two related seed addition experiments conducted in 45 variably-sized harvest gaps (unharvested to 6500 m^2) in adjacent mesic northern hardwood stands, Emmet County, …

Biological Invasion Hotspots: A Trait-Based Perspective Reveals New Sub-Continental Patterns, Basil V. Iannone Iii, Kevin M. Potter, Qinfeng Guo, Andrew M. Liebhold, Bryan C. Pijanowski, Christopher M. Oswalt, Songlin Fei

USDA Forest Service / UNL Faculty Publications

Invader traits (including plant growth form) may play an important, and perhaps overlooked, role in determining macroscale patterns of biological invasions and therefore warrant greater consideration in future investigations aimed at understanding these patterns. To assess this need, we used empirical data from a national-level survey of forest in the contiguous 48 states of the USA to identify geographic hotspots of forest plant invasion for three distinct invasion characteristics: invasive species richness, trait richness (defined as the number of the five following plant growth forms represented by the invasive plants present at a given location: forbs, grasses, shrubs, trees, and …

Effects Of Drought On Forests And Rangelands In The United States: A Comprehensive Science Synthesis, James M. Vose, James S. Clark, Charles H. Luce, Toral Patel-Weynand

USDA Forest Service / UNL Faculty Publications

This assessment provides input to the reauthorized National Integrated Drought Information System (NIDIS) and the National Climate Assessment (NCA), and it establishes the scientific foundation needed to manage for drought resilience and adaptation. Focal areas include drought characterization; drought impacts on forest processes and disturbances such as insect outbreaks and wildfire; and consequences on forest and rangeland values. Drought can be a severe natural disaster with substantial social and economic consequences. Drought becomes most obvious when large-scale changes are observed; however, even moderate drought can have long-lasting impacts on the structure and function of forests and rangelands without these obvious …

Nebraska Statewide Forest Action Plan - 2015, Scott Josiah, John Erixson

Nebraska Forest Service: Publications

The Nebraska Forest Action Plan identifies strategic goals based on national objectives collaboratively crafted by both the National Association of State Foresters and the USFS State & Private Forestry Program. The strategic goals and actions identified in this document serve as a blueprint for focusing private, state and federal resources in areas of Nebraska where they will be most effective.

On Underestimation Of Global Vulnerability To Tree Mortality And Forest Die-Off From Hotter Drought In The Anthropocene, Craig D. Allen, David D. Breshears, Nate G. Mcdowell

United States Geological Survey: Staff Publications

Patterns, mechanisms, projections, and consequences of tree mortality and associated broadscale forest die-off due to drought accompanied by warmer temperatures—‘‘hotter drought’’, an emerging characteristic of the Anthropocene—are the focus of rapidly expanding literature. Despite recent observational, experimental, and modeling studies suggesting increased vulnerability of trees to hotter drought and associated pests and pathogens, substantial debate remains among research, management and policy-making communities regarding future tree mortality risks. We summarize key mortalityrelevant findings, differentiating between those implying lesser versus greater levels of vulnerability. Evidence suggesting lesser vulnerability includes forest benefits of elevated [CO2] and increased water-use efficiency; observed and modeled increases …

Managing Threats To The Urban Forest: From Dutch Elm Disease To Emerald Ash Borer - Learning From Experience, Christopher J. Borman

Doctor of Plant Health Program: Dissertations and Student Research

The urban forest provides important essential services to all municipalities; however, its value is often overlooked. The urban forest contributes to energy savings, environmental benefits, psychological well-being, and social benefits. Managing the urban forest in a sustainable manner is important if we wish to benefit from these services well into the future. Reliable management techniques have been created through previous experiences with pests, and these should be utilized and improved for use on urban forests.

American elm (Ulmus americana L.) was once a major component of the urban forests of North America. In 1927, Dutch elm disease (DED) was …

Timber Talk, Vol. 52, No. 4, November 1, 2014

Timber Talk: Nebraska Forest Industry Newsletter

In This Issue

Lumber Market News ...........................1

Hardwood Lumber Price Trends—Green..................................2

Hardwood Lumber Price Trends—Kiln Dried...........................2

Wood is Good........................................3

Simple Steps for Double Your Firewood Profits................................4

Homemade Log Forwarder...................5

Nebraska Forest Industry Spotlight......6

The Trading Post....................................8

Timber Sales...........................................8

Timber Talk, Vol. 52, No. 3, September 1, 2014

Timber Talk: Nebraska Forest Industry Newsletter

In This Issue

Lumber Market News ...........................1

Hardwood Lumber Price Trends—Green..................................2

Hardwood Lumber Price Trends—Kiln Dried...........................2

Band Saws for Small Sawmills..............3

Sawmills Can Make More than Lumber.............................................5

Nebraska Forest Industry Spotlight......6

The Trading Post....................................8

Timber Sales...........................................8

Diversity Of Bacteria Carried By Pinewood Nematode In Usa And Phylogenetic Comparison With Isolates From Other Countries, Diogo Neves Proença, Luís Fonseca, Thomas Powers, Isabel M.O. Abrantes, Paula V. Morais

Department of Plant Pathology: Faculty Publications

Pine wilt disease (PWD) is native to North America and has spread to Asia and Europe. Lately, mutualistic relationship has been suggested between the pinewood nematode (PWN), Bursaphelenchus xylophilus the causal nematode agent of PWD, and bacteria. In countries where PWN occurs, nematodes from diseased trees were reported to carry bacteria from several genera. However no data exists for the United States. The objective of this study was to evaluate the diversity of the bacterial community carried by B. xylophilus, isolated from different Pinus spp. with PWD in Nebraska, United States. The bacteria carried by PWN belonged to Gammaproteobacteria …

2014 Greatplants Gardener, Jan Riggenbach, Rachel Anderson, Ryan Armbrust, Laura Armbrust, Bob Henrickson, Louise Lynch, Doug Golick

Nebraska Statewide Arboretum Publications

One of the goals of the GreatPlants program is to promote tough plants for the landscape, plants that are more resilient in the extreme weather of the Great Plains. With so many plants to choose from, it can be overwhelming for gardeners to decide what to plant. We hope GreatPlants can be your guide to some staggeringly beautiful—and long-lived—plants.

Soils Of Temperate Rainforests Of The North American Pacific Coast, Dunbar N. Carpenter, James G. Bockheim, Paul F. Reich

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Temperate rainforests have high conservation and natural resource value, but the soils of this bioregion have not previously been studied as a unit. Here we examine the soils of North America's Pacific coastal temperate rainforests, utilizing databases from the United States Natural Resources Conservation Service and the Canadian Centre for Land and Biological Resources Research to (i) identify the soil taxa, (ii) evaluate the soil properties, and (iii) compare soils in temperate and tropical rainforests. There are strong climate gradientswithin these temperate rainforests,with the mean temperature declining from 11.7 °C to 6.1 °C and the mean annual precipitation increasing from …

Development And Evaluation Of High Resolution Simulation Tools To Improve Fire Weather Forecasts, Brian K. Lamb, Jason M. Forthofer, Peter R. Robichaud

JFSP Research Project Reports

Fire weather forecasts rely on numerical weather simulations where the grid size is 4 km x 4 km or larger. In areas of complex terrain, this model resolution will not capture the details of wind flows associated with complicated topography. Wind channeling in valleys, wind speed-up over mountains and ridges, and enhanced turbulence associated with rough terrain and tall forest canopies are poorly represented in current weather model applications. A number of numerical wind flow models have been developed for simulating winds at high resolution; however, there are limited observational data available at the spatial scales appropriate for evaluating these …