Life Sciences Commons^™

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 …

Housing Development Erodes Avian Community Structure In U.S. Protected Areas, Eric M. Wood, Anna M. Pidgeon, Volker C. Radeloff, David Helmers, Patrick D. Culbert, Nicholas S. Keuler, Curtis H. Flather

USDA Forest Service / UNL Faculty Publications

Protected areas are a cornerstone for biodiversity conservation, but they also provide amenities that attract housing development on inholdings and adjacent private lands. We explored how this development affects biodiversity within and near protected areas among six ecological regions throughout the United States. We quantified the effect of housing density within, at the boundary, and outside protected areas, and natural land cover within protected areas, on the proportional abundance and proportional richness of three avian guilds within protected areas. We developed three guilds from the North American Breeding Bird Survey, which included Species of Greatest Conservation Need, land cover affiliates …

Temporal Fluctuation Scaling In Populations And Communities, Michael Kalyuzhny, Yishai Schreiber, Rachel Chocron, Curtis H. Flather, Ronen Kadmon, David A. Kessler, Nadav M. Shnerb

USDA Forest Service / UNL Faculty Publications

Taylor’s law, one of the most widely accepted generalizations in ecology, states that the variance of a population abundance time series scales as a power law of its mean. Here we reexamine this law and the empirical evidence presented in support of it. Specifically, we show that the exponent generally depends on the length of the time series, and its value reflects the combined effect of many underlying mechanisms. Moreover, sampling errors alone, when presented on a double logarithmic scale, are sufficient to produce an apparent power law. This raises questions regarding the usefulness of Taylor’s law for understanding ecological …

Quantitative Analysis Of Woodpecker Habitat Using High-Resolution Airborne Lidar Estimates Of Forest Structure And Composition, James E. Garabedian, Robert Mcgaughey, Stephen E. Reutebuch, Bernard R. Parresol, John C. Kilgo, Christopher E. Moorman, M. Nils Peterson

USDA Forest Service / UNL Faculty Publications

Light detection and ranging (LiDAR) technology has the potential to radically alter theway researchers and managers collect data onwildlife–habitat relationships. To date, the technology has fostered several novel approaches to characterizing avian habitat, but has been limited by the lack of detailed LiDAR-habitat attributes relevant to species across a continuum of spatial grain sizes and habitat requirements. We demonstrate a novel three-step approach for using LiDAR data to evaluate habitat based on multiple habitat attributes and accounting for their influence at multiple grain sizes using federally endangered red-cockaded woodpecker (RCW; Picoides borealis) foraging habitat data fromthe Savannah River Site (SRS) …

Nitrogen And Carbon Dynamics In Prairie Vegetation Strips Across Topographical Gradients In Mixed Central Iowa Agroecosystems, Marlin Perez-Suarez, Michael J. Castellano, Randall Kolka, Heidi Asbjornsen, Matthew J. Helmers

USDA Forest Service / UNL Faculty Publications

Reductions of nitrogen (N) export from agricultural lands because of changes in specific N stocks andfluxes by incorporation of small amounts of prairie vegetation strips (PVS) are poorly understood. Theprimary objective of this study was to evaluate the effect of the presence and topographical position of PVSon soil and plant carbon (C) and N stocks relative to annual crop and native prairie vegetation. The studywas implemented within three small adjacent watersheds, treated with one of the following cover types:(1) 100% row-crop agriculture (CROP); (2) 20% prairie vegetation (PVS) distributed along the contouracross three topographical positions: upslope, sideslope and footslope position; …

Changing Forest Water Yields In Response To Climate Warming: Results From Long-Term Experimental Watershed Sites Across North America, Irena F. Creed, Adam T. Spargo, Julia A. Jones, Jim M. Buttle, Mary B. Adams, Fred D. Beall, Eric G. Booth, John L. Campbell, Dave Clow, Kelly Elder, Mark B. Green, Nancy B. Grimm, Chelcy Miniat, Patricia Ramlal, Amartya Saha, Stephen Sebestyen, Dave Spittlehouse, Shannon Sterling, Mark W. Williams, Rita Wrinkler, Huaxia Yao

USDA Forest Service / UNL Faculty Publications

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment’s change in actual ET divided by P …

Recovery Of Wolverines In The Western United States: Recent Extirpation And Recolonization Or Range Retraction And Expansion?, Kevin S. Mckelvey, Keith B. Aubry, Neil J. Anderson, Anthony P. Clevenger, Jeffrey P. Copeland, Kimberley S. Heinemeyer, Robert M. Iman, John R. Squires, John S. Waller, Kristine L. Pilgrim, Michael K. Schwartz

USDA Forest Service / UNL Faculty Publications

Wolverines were greatly reduced in number and possibly extirpated from the contiguous United States (U.S.) by the early 1900s. Wolverines currently occupy much of their historical range in Washington, Idaho, Montana, and Wyoming, but are absent from Utah and only single individuals are known to occur in California and Colorado. In response, the translocation of wolverines to California and Colorado is being considered. If wolverines are to be reintroduced, managers must identify appropriate source populations based on the genetic affinities of historical and modern wolverine populations. We amplified the mitochondrial control region of 13 museum specimens dating from the late …

Performance Of Species Richness Estimators Across Assemblage Types And Survey Parameters, Gordon C. Reese, Kenneth R. Wilson, Curtis H. Flather

USDA Forest Service / UNL Faculty Publications

Aim A raw count of the species encountered across surveys usually underestimates species richness. Statistical estimators are often less biased. Nonparametric estimators of species richness are widely considered the least biased, but no particular estimator has consistently performed best. This is partly a function of estimators responding differently to assemblage-level factors and survey design parameters. Our objective was to evaluate the performance of raw counts and nonparametric estimators of species richness across various assemblages and with different survey designs.

Location We used both simulated and published field data.

Methods We evaluated the bias, precision and accuracy of raw counts and …

A New Metric For Quantifying Burn Severity: The Relativized Burn Ratio, Sean A. Parks, Gregory K. Dillon, Carol Miller

USDA Forest Service / UNL Faculty Publications

Satellite-inferred burn severity data have become increasingly popular over the last decade for management and research purposes. These data typically quantify spectral change between pre-and post-fire satellite images (usually Landsat). There is an active debate regarding which of the two main equations, the delta normalized burn ratio (dNBR) and its relativized form (RdNBR), is most suitable for quantifying burn severity; each has its critics. In this study, we propose and evaluate a new Landsat-based burn severity metric, the relativized burn ratio (RBR), that provides an alternative to dNBR and RdNBR. For 18 fires in the western US, we compared the …

Climate Change And North American Rangelands: Assessment Of Mitigation And Adaptation Strategies, Linda A. Joyce, David D. Briske, Joel R. Brown, H. Wayne Polley, Bruce A. Mccarl, Derek W. Bailey

USDA Forest Service / UNL Faculty Publications

Recent climatic trends and climate model projections indicate that climate change will modify rangeland ecosystem functions and the services and livelihoods that they provision. Recent history has demonstrated that climatic variability has a strong influence on both ecological and social components of rangeland systems and that these systems possess substantial capacity to adapt to climatic variability. Specific objectives of this synthesis are to: 1) evaluate options to mitigate greenhouse gas emissions and future climate change; 2) survey actions that individuals, enterprises, and social organizations can use to adapt to climate change; and 3) assess options for system transformation when adaptation …

Forest Recovery Patterns In Response To Divergent Disturbance Regimes In The Border Lakes Region Of Minnesota (Usa) And Ontario (Canada), Brian R. Sturtevant, Brian R. Miranda, Peter T. Wolter, Patrick M.A. James, Marie-Josée Fortin, Philip A. Townsend

USDA Forest Service / UNL Faculty Publications

The persistence of landscape-scale disturbance legacies in forested ecosystems depends in part on the nature and strength of feedback among disturbances, their effects, and subsequent recovery processes such as tree regeneration and canopy closure. We investigated factors affecting forest recovery rates over a 25-year time period in a large (6 million ha) landscape where geopolitical boundaries have resulted in important land management legacies (managed forests of Minnesota, USA; managed forests of Ontario, Canada; and a large unmanaged wilderness). Stand-replacing disturbance regimes were quantified across management zones, both inside and outside a central ecoregion, using a time series of classified land …

A Polygon-Based Modeling Approach To Assess Exposure Of Resources And Assets To Wildfire, Matthew P. Thompson, Joe Scott, Jeffrey D. Kaiden, Julie W. Gilbertson-Day

USDA Forest Service / UNL Faculty Publications

Spatially explicit burn probability modeling is increasingly applied to assess wildfire risk and inform mitigation strategy development. Burn probabilities are typically expressed on a per-pixel basis, calculated as the number of times a pixel burns divided by the number of simulation iterations. Spatial intersection of highly valued resources and assets (HVRAs) with pixel-based burn probability estimates enables quantification of HVRA exposure to wildfire in terms of expected area burned. However, statistical expectations can mask variability in HVRA area burned across all simulated fires. We present an alternative, polygon-based formulation for deriving estimates of HVRA area burned. This effort enhances investigations …

A National Approach For Integrating Wildfire Simulation Modeling Into Wildland Urban Interface Risk Assessments Within The United States, Jessica R. Haas, David E. Calkin, Matthew P. Thompson

USDA Forest Service / UNL Faculty Publications

Ongoing human development into fire-prone areas contributes to increasing wildfire risk to human life. It is critically important, therefore, to have the ability to characterize wildfire risk to populated places, and to identify geographic areas with relatively high risk. A fundamental component of wildfire risk analysis is establishing the likelihood of wildfire occurrence and interaction with social and ecological values. A variety of fire modeling systems exist that can provide spatially resolved estimates of wildfire likelihood, which when coupled with maps of values-at-risk enable probabilistic exposure analysis. With this study we demonstrate the feasibility and utility of pairing burn probabilities …

The Influence Of Vertical And Horizontal Habitat Structure On Nationwide Patterns Of Avian Biodiversity, Patrick D. Culbert, Volker C. Radeloff, Curtis H. Flather, Josef M. Kellndorfer, Chadwick D. Rittenhouse, Anna M. Pidgeon

USDA Forest Service / UNL Faculty Publications

With limited resources for habitat conservation, the accurate identification of high-value avian habitat is crucial. Habitat structure affects avian biodiversity but is difficult to quantify over broad extents. Our goal was to identify which measures of vertical and horizontal habitat structure are most strongly related to patterns of avian biodiversity across the conterminous United States and to determine whether new measures of vertical structure are complementary to existing, primarily horizontal, measures. For 2,546 North American Breeding Bird Survey routes across the conterminous United States, we calculated canopy height and biomass from the National Biomass and Carbon Dataset (NBCD) as measures …

Keeping It Wild: Mapping Wilderness Character In The United States, Steve Carver, James Tricker, Peter Landres

USDA Forest Service / UNL Faculty Publications

A GIS-based approach is developed to identify the state of wilderness character in US wilderness areas using Death Valley National Park (DEVA) as a case study. A set of indicators and measures are identified by DEVA staff and used as the basis for developing a flexible and broadly applicable framework to map wilderness character using data inputs selected by park staff. Spatial data and GIS methods are used to map the condition of four qualities of wilderness character: natural, untrammelled, undeveloped, and solitude or primitive and unconfined recreation. These four qualities are derived from the US 1964 Wilderness Act and …

Wildlife Population And Harvest Trends In The United States A Technical Document Supporting The Forest Service 2010 Rpa Assessment, Curtis H. Flather, Michael S. Knowles, Martin F. Jones, Carol Schilli

USDA Forest Service / UNL Faculty Publications

The Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974 requires periodic assessments of the condition and trends of the nation’s renewable natural resources. Data from many sources were used to document recent historical trends in big game, small game, migratory game birds, furbearers, nongame, and imperiled species. Big game and waterfowl have generally increased in population and harvest trends. Many small upland and webless migratory game bird species have declined notably in population or harvest. Considerable declines in fur harvest since the 2000 RPA Assessment have occurred. Among the 426 breeding bird species with sufficient data to estimate …

Interpretation Of Gypsy Moth Frontal Advance Using Meteorology In A Conditional Algorithm, K. L. Frank, P. C. Tobin, H. W. Thistle Jr., Laurence S. Kalkstein

USDA Forest Service / UNL Faculty Publications

The gypsy moth, Lymantria dispar, is a nonnative species that continues to invade areas in North America. It spreads generally through stratified dispersal where local growth and diffusive spread are coupled with long-distance jumps ahead of the leading edge. Longdistance jumps due to anthropogenic movement of life stages is a well-documented spread mechanism. Another mechanism is the atmospheric transport of early instars and adult males, believed to occur over short distances. However, empirical gypsy moth population data continue to support the possibility of alternative methods of longrange dispersal. Such dispersal events seemed to have occurred in the mid- to …

Carbon Benefits From Protected Areas In The Conterminous United States, Daolan Zheng, Linda S. Heath, Mark J. Ducey

USDA Forest Service / UNL Faculty Publications

Background: Conversion of forests to other land cover or land use releases the carbon stored in the forests and reduces carbon sequestration potential of the land. The rate of forest conversion could be reduced by establishing protected areas for biological diversity and other conservation goals. The purpose of this study is to quantify the efficiency and potential of forest land protection for mitigating GHG emissions.

Results: The analysis of related national-level datasets shows that during the period of 1992–2001 net forest losses in protected areas were small as compared to those in unprotected areas: -0.74% and −4.07%, respectively. …

A Wildfire Risk Assessment Framework For Land And Resource Management, Joe H. Scott, Matthew P. Thompson, David E. Calkin

USDA Forest Service / UNL Faculty Publications

Wildfires can result in significant, long-lasting impacts to ecological, social, and economic systems. It is necessary, therefore, to identify and understand the risks posed by wildland fire, and to develop cost-effective mitigation strategies accordingly. This report presents a general framework with which to assess wildfire risk and explore mitigation options, and illustrates a process for implementing the framework. Two key strengths of the framework are its flexibility— allowing for a multitude of data sources, modeling techniques, and approaches to measuring risk—and its scalability, with potential application for project, forest, regional, and national planning. The specific risk assessment process we introduce …

Integrating Biodiversity And Drinking Water Protection Goals Through Geographic Analysis, James D. Wickham, Curtis H. Flather

USDA Forest Service / UNL Faculty Publications

Aim Biodiversity and drinking water share a common interest in land conservation. Our objective was to identify where that common interest occurs geographically to inform conservation planning.

Location The study focused on 2112 eight-digit hydrologic units (watersheds) occurring in the conterminous United States.

Methods Data on aquatic-dependent species occurrence, drinking water intakes, protected land status and land cover change were compiled for each watershed. We compared these four datasets after defining ‘hotspots’ based on attribute-specific thresholds that included (1) the 90th percentile of at-risk aquatic biodiversity, (2) with and without drinking water intakes, (3) above and below the median percentage …

Marine Vertebrates From The Hartland Shale (Upper Cretaceous: Upper Cenomanian) In Southeastern Colorado, Usa, Matthew Nagrodski, Kenshu Shimada, Bruce A. Schumacher

USDA Forest Service / UNL Faculty Publications

The Hartland Shale Member of the Greenhorn Limestone was deposited in the middle of the Late Cretaceous Western Interior Seaway of North America. Rock samples rich in micro-vertebrate fossils were collected from the lower part of the Hartland Shale (ca. 94.6 Ma: early Late Cenomanian) in southeastern Colorado, USA. Through acid treatment of the rock samples, 25 marine vertebrate taxa are identified including chondrichthyans, osteichthyans, and a reptile. Chondrichthyans are represented by seven species: Ptychodus anonymus, Squalicorax curvatus, Carcharias saskatchewanensis, Archaeolamna kopingensis, Cretoxyrhina mantelli, Cretomanta canadensis, and Rhinobatos incertus. Osteichthyan fishes consist of 17 taxa: Micropycnodon kansasensis, cf. Palaeobalistum …

Fish And Other Aquatic Resource Trends In The United States A Technical Document Supporting The Forest Service 2010 Rpa Assessment, Andrew J. Loftus, Curtis H. Flather

USDA Forest Service / UNL Faculty Publications

The Forest and Rangeland Renewable Resources Planning Act (RPA) of 1974 requires periodic assessments of the status and trends in the Nation’s renewable natural resources including fish and other aquatic species and their habitats. Data from a number of sources are used to document trends in habitat quality, populations, resource use, and patterns of imperilment among aquatic fauna. Freshwater habitat quality varied widely across the United States. Nationwide, more than half of monitored lakes were ranked in good condition, but the percentage ranged from a high of 91 percent in the upper Midwest to a low of 1 percent in …

Modeling Broad-Scale Patterns Of Avian Species Richness Across The Midwestern United States With Measures Of Satellite Image Texture, Patrick D. Culbert, Volker C. Radeloff, Véronique St-Louis, Curtis H. Flather, Chadwick D. Rittenhouse, Thomas P. Albright, Anna M. Pidgeon

USDA Forest Service / UNL Faculty Publications

Avian biodiversity is threatened, and in order to prioritize limited conservation resources and conduct effective conservation planning a better understanding of avian species richness patterns is needed. The use of image texture measures, as a proxy for the spatial structure of land cover and vegetation, has proven useful in explaining patterns of avian abundance and species richness. However, prior studies that modeled habitat with texture measures were conducted over small geographical extents and typically focused on a single habitat type. Our goal was to evaluate the performance of texture measures over broad spatial extents and across multiple habitat types with …

Monitoring The Invasion Of An Exotic Tree (Ligustrum Lucidum) From 1983 To 2006 With Landsat Tm/Etm + Satellite Data And Support Vector Machines In Córdoba, Argentina, Gregorio I. Gavier-Pizarro, Tobias Kuemmerle, Laura E. Hoyos, Susan I. Stewart, Cynthia D. Huebner, Nicholas S. Keuler, Volker C. Radeloff

USDA Forest Service / UNL Faculty Publications

In central Argentina, the Chinese tree glossy privet (Ligustrum lucidum) is an aggressive invasive species replacing native forests, forming dense stands, and is thus a major conservation concern. Mapping the spread of biological invasions is a necessary first step toward understanding the factors determining invasion patterns. Urban areas may function as propagule sources for glossy privet because it has been used as a landscaping tree for over a century. The objectives of this paperwere to 1)map the patterns of glossy privet expansion from1983 to 2006 using a time series of Landsat TM/ETM+images, and 2) analyze the spatial pattern …

Revisiting The Homogenization Of Dammed Rivers In The Southeastern Us, Ryan A. Mcmanamay, Donald J. Orth, Charles A. Dolloff

USDA Forest Service / UNL Faculty Publications

For some time, ecologists have attempted to make generalizations concerning how disturbances influence natural ecosystems, especially river systems. The existing literature suggests that dams homogenize the hydrologic variability of rivers. However, this might insinuate that dams affect river systems similarly despite a large gradient in natural hydrologic character. In order to evaluate patterns in dam-regulated hydrology and associated ecological relationships, a broad framework is needed. Flow classes, or groups of streams that share similar hydrology, may provide a framework to evaluate the relative effects of dam regulation on natural flow dynamics. The purpose of this study was to use a …

Integrating Landis Model And A Multi-Criteria Decision-Making Approach To Evaluate Cumulative Effects Of Forest Management In The Missouri Ozarks, Usa, Zongbo Shang, Hong S. He, Weimin Xi, Stephen R. Shifley, Brian J. Palik

USDA Forest Service / UNL Faculty Publications

Public forest management requires consideration of numerous objectives including protecting ecosystem health, sustaining habitats for native communities, providing sustainable forest products, and providing noncommodity ecosystem services. It is difficult to evaluate the long-term, cumulative effects and tradeoffs these and other associated management objectives. To demonstrate the capabilities of techniques suitable to support such evaluations we combined a spatially explicit landscape-scale, succession and disturbance model (LANDIS) with wildlife habitat suitability models and a multi-criteria decisionmaking framework to compare four management alternatives across a 700 km² area of the Mark Twain National Forest in Missouri, USA. We estimated the combined, cumulative …