Life Sciences Commons^™

Oystershell Scale (Hemiptera: Diaspididae) Population Growth, Spread, And Phenology On Aspen In Arizona, Usa, Connor D. Crouch, Richard W. Hofstetter, Amanda M. Grady, Nylah N.S. Edwards, Kristen M. Waring

Aspen Bibliography

Oystershell scale (OSS; Lepidosaphes ulmi L.) is an invasive insect that threatens sustainability of aspen (Populus tremuloides Michx.) in the southwestern United States. OSS invasions have created challenges for land managers tasked with maintaining healthy aspen ecosystems for the ecological, economic, and aesthetic benefits they provide. Active management is required to suppress OSS populations and mitigate damage to aspen ecosystems, but before management strategies can be implemented, critical knowledge gaps about OSS biology and ecology must be filled. This study sought to fill these gaps by addressing 3 questions: (i) What is the short-term rate of aspen mortality in …

Assessment Of Carbon Productivity Dynamics In Aspen Stands Under Climate Change Based On Forest Inventories In Central Siberia, Andrey Andreevich Vais, Valentina Valerievna Popova, Alina Andreevna Andronova, Viktor Nikolaevich Nemich, Artem Gennadievich Nepovinnykh, Pavel Vladimirovich Mikhaylov

Aspen Bibliography

The aim of the present research was to study the dynamics of growth and conditions of aspen stands under climate change, according to different periods of forest inventory. The study was conducted in modal aspen forests growing in the subtaiga/forest steppe region of Central Siberia. Aspen forests grow intensively at young age, which allows them to realize maximum carbon sequestration potential. The research was based on forest inventory data from 1972, 1982, 2002, and 2021 (the study was conducted on a limited territory). There was a steady increase in temperatures in the growing season from 1982 to 2002. The amount …

Spatial And Temporal Variation Of Epigaeic Beetle Assemblages (Coleoptera, Carabidae, Staphylinidae) In Aspen-Dominated Mixedwood Forests Across North-Central Alberta, H. E. James Hammond, Sergio García-Tejero, Greg R. Pohl, David W. Langor, John R. Spence

Aspen Bibliography

Epigaeic beetle assemblages were surveyed using continuous pitfall trapping during the summers of 1992 and 1993 in six widely geographically distributed locations in Alberta’s aspen-mixedwood forests prior to initial forest harvest. Species composition and turnover (β-diversity) were evaluated on several spatial scales ranging from Natural Regions (distance between samples 120–420 km) to pitfall traps (40–60 m). A total of 19,885 ground beetles (Carabidae) representing 40 species and 12,669 rove beetles (non-Aleocharinae Staphylinidae) representing 78 species was collected. Beetle catch, species richness, and diversity differed significantly among the six locations, as did the identity of dominant species. Beetle species composition differed …

Impacts Of Climate And Insect Herbivory On Productivity And Physiology Of Trembling Aspen (Populus Tremuloides) In Alaskan Boreal Forests, Melissa A. Boyd, Logan T. Berner, Patricia Doak, Scott J. Goetz, Brendan M. Rogers, Diane Wagner, Xanthe J. Walker, Michelle C. Mack

Aspen Bibliography

Climate change is impacting forested ecosystems worldwide, particularly in the Northern Hemisphere where warming has increased at a faster rate than the rest of the globe. As climate warms, trembling aspen (Populus tremuloides) is expected to become more successful in northern boreal forests because of its current presence in drier areas of North America. However, large-scale productivity decline of aspen has recently been documented throughout the United States and Canada as a result of drought and insect outbreaks. We used tree ring measurements (basal area increment (BAI) and stable carbon isotopes (δ 13C)) and remote sensing indices …

Tree Species Richness Enhances Stand Productivity While Stand Structure Can Have Opposite Effects, Based On Forest Inventory Data From Germany And The United States Of America, Laura Zeller, Jingjing Liang, Hans Pretzsch

Faculty & Staff Scholarship

Background: In recent studies, mixed forests were found to be more productive than monocultures with everything else remaining the same.

Methods: To find out if this productivity is caused by tree species richness, by a more heterogeneous stand structure or both, we analyzed the effects of forest structure and tree species richness on stand productivity, based on inventory data of temperate forests in the United States of America and Germany.

Results: Having accounted for effects such as tree size and stand density, we found that: (I) tree species richness increased stand productivity in both countries while the effect of tree …

Altered Spring Phenology Of North American Freshwater Turtles And The Importance Of Representative Populations, Fredric J. Janzen, Luke A. Hoekstra, Ronald J. Brooks, David M. Carroll, J Whitfield Gibbons, Judith L. Greene, John B. Iverson, Jacqueline D. Litzgus, Edwin D. Michael, Steven G. Parren, Willem M. Roosenburg, Gabriel F. Strain, John K. Tucker, Gordon R. Ultsch

Faculty & Staff Scholarship

Globally, populations of diverse taxa have altered phenology in response to climate change. However, most research has focused on a single population of a given taxon, which may be unrepresentative for comparative analyses, and few long-term studies of phenology in ectothermic amniotes have been published. We test for climate- altered phenology using long-term studies (10–36 years) of nesting behavior in 14 populations representing six genera of freshwater turtles (Chelydra, Chrysemys, Kinosternon, Malaclemys, Sternotherus, and Trachemys). Nesting season initiation oc- curs earlier in more recent years, with 11 of the populations advancing phenology. The onset of nesting for nearly all populations …

Toward An Improved Conceptual Understanding Of North American Tree Species Distributions, Paige E. Copenhaver-Parry

Faculty Publications - Department of Biological & Molecular Science

Species distributions have often been assumed to represent climatic limitations, yet recent evidence has challenged these assumptions and emphasized the potential importance of biotic interactions, dispersal limitation, and disturbance. Despite significant investigation into these factors, an integrated understanding of where and when they may be important is lacking. Here, we review evidence for the factors underlying the historical and contemporary distributions of North American tree species and argue that a cohesive conceptual framework must be informed by an understanding of species ecological and evolutionary history. We further demonstrate that available evidence offers little indication of a significant, independent influence of …

The Variation Of Productivity And Its Allocation Along A Tropical Elevation Gradient: A Whole Carbon Budget Perspective, Yadvinder Malhi, Cécile A. J. Girardin, Gregory R. Goldsmith, Christopher E. Doughty, Norma Salinas, Daniel B. Metcalfe, Walter Huaraca Huasco, Javier E. Silva-Espejo, Jhon Del Aguilla-Pasquell, Filio Farfán Amézquita, Luiz E.O.C. Aragão, Rossella Guerrieri, Françoise Yoko Ishida, Nur Bahar, William Farfan-Rios, Oliver L. Phillips, Patrick Meir, Miles Silman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

• Why do forest productivity and biomass decline with elevation? To address this question, research to date generally has focused on correlative approaches describing changes in woody growth and biomass with elevation.
  
  
• We present a novel, mechanistic approach to this question by quantifying the autotrophic carbon budget in 16 forest plots along a 3300 m elevation transect in Peru.
  
  
• Low growth rates at high elevations appear primarily driven by low gross primary productivity (GPP), with little shift in either carbon use efficiency (CUE) or allocation of net primary productivity (NPP) between wood, fine roots and canopy. The lack of trend in …

Not Only Climate: Interacting Drivers Of Treeline Change In Europe, Dominik Kulakowski, Ignacio Barbeito, Alejandro Casteller, Ryszard J. Kaczka, Peter Bebi

Geography

Treelines have long been recognized as important ecotones and likely harbingers of climate change. However, over the last century many treelines have been affected not only by global warming, but also by the interactions of climate, forest disturbance and the consequences of abrupt demographic and economic changes. Recent research has increasingly stressed how multiple ecological, biophysical, and human factors interact to shape ecological dynamics. Here we highlight the need to consider interactions among multiple drivers to more completely understand and predict treeline dynamics in Europe.

Wildland Fire Deficit And Surplus In The Western United States, 1984-2012, Sean A. Parks, Carol Miller, Marc-Andrè Parisien, Lisa M. Holsinger, Solomon Z. Dobrowski, John Abatzoglou

Forest Management Faculty Publications

Wildland fire is an important disturbance agent in the western US and globally. However, the natural role of fire has been disrupted in many regions due to the influence of human activities, which have the potential to either exclude or promote fire, resulting in a "fire deficit" or "fire surplus," respectively. In this study, we developed a model of expected area burned for the western US as a function of climate from 1984 to 2012. We then quantified departures from expected area burned to identify geographic regions with fire deficit or surplus. We developed our model of area burned as …

Linking Remote Sensing And Various Site Factors For Predicting The Spatial Distribution Of Eastern Hemlock Occurrence And Relative Basal Area In Maine, Usa, Kathleen Dunckel, Aaron Weiskittel, Greg Fiske, Steven A. Sader, Erika Latty, Amy Arnett

Publications

Introduced invasive pests are perhaps the most important and persistent catalyst for changes in forest composition. Infestation and outbreak of the hemlock woolly adelgid (Adelges tsugae; HWA) along the eastern coast of the USA, has led to widespread loss of hemlock (Tsuga canadensis (L.) Carr.), and a shift in tree species composition toward hardwood stands. Developing an understanding of the geographic distribution of individual species can inform conservation practices that seek to maintain functional capabilities of ecosystems. Modeling is necessary for understanding changes in forest composition, and subsequent changes in biodiversity, and one that can be implemented at the species …

Negative Feedbacks On Bark Beetle Outbreaks: Widespread And Severe Spruce Beetle Infestation Restricts Subsequent Infestation, Sarah J. Hart, Thomas T. Veblen, Nathan Mietkiewicz, Dominik Kulakowski

Geography

Understanding disturbance interactions and their ecological consequences remains a major challenge for research on the response of forests to a changing climate. When, where, and how one disturbance may alter the severity, extent, or occurrence probability of a subsequent disturbance is encapsulated by the concept of linked disturbances. Here, we evaluated 1) how climate and forest habitat variables, including disturbance history, interact to drive 2000s spruce beetle (Dendroctonus rufipennis) infestation of Engelmann spruce (Picea engelmannii) across the Southern Rocky Mountains; and 2) how previous spruce beetle infestation affects subsequent infestation across the Flat Tops Wilderness in northwestern Colorado, which experienced …

Slides: Climate Change And Public Lands: Examples From National Parks, Stephen Saunders

The Past, Present, and Future of Our Public Lands: Celebrating the 40th Anniversary of the Public Land Law Review Commission’s Report, One Third of the Nation’s Land (Martz Summer Conference, June 2-4)

Presenter: Stephen Saunders, President, The Rocky Mountain Climate Organization (Denver, CO)

40 slides

Population Trends In Northern Spotted Owls: Associations With Climate In The Pacific Northwest, Elizabeth M. Glenn, Robert G. Anthony, Eric D. Forsman

USDA Forest Service / UNL Faculty Publications

We used reverse time capture-mark-recapture models to describe associations between rate of population change (λ) and climate for northern spotted owls (Strix occidentalis caurina) at six long-term study areas in Washington and Oregon, USA. Populations in three of six areas showed strong evidence of declining populations, while populations in two additional areas were likely declining as well. At four areas, λ was positively associated with wetter-than-normal conditions during the growing season, which likely affects prey availability. Lambda was also negatively associated with cold, wet winters and nesting seasons, and the number of hot summer days. The …

Relationship Of Climate And Growth Of Quaking Aspen (Populus Tremuloides) In Yellowstone National Park, Erik S. Jules, Allyson L. Carroll, Matthew J. Kauffman

Aspen Bibliography

Quaking aspen is a widespread tree that is in decline across wide areas of western North America, and is predicted to experience a large range shift if future climate predictions are realized. The purpose of our study was to determine what climate factors have influenced aspen growth in Yellowstone National Park, USA, and to determine whether these climatic influences vary across a heterogeneous landscape. We extracted increment cores from 10-12 aspen in each of 16 stands spread across a 1,526 km2 area. Using ring widths, we created a182-year standardized chronology from 1821 to 2003 A.D. composed of 151 series. We …

Slides: Market-Based Stream Flow Restoration And Mitigation, Amanda Cronin

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Amanda Cronin, Washington Water Trust, Seattle, WA

23 slides

Slides: Climate Change And The Death Of Stationarity: A New Era For Western Water?, Stephen T. Gray

Western Water Law, Policy and Management: Ripples, Currents, and New Channels for Inquiry (Martz Summer Conference, June 3-5)

Presenter: Steven T. Gray, Wyoming State Climatologist, University of Wyoming, Laramie, WY

48 slides

Research Report No. 33, Climate And Growth, Christopher C. Brown, Hershel C. Reeves, J. David Lenhart

Informal Project Reports

Growth of loblolly pine (Pinus taeda L.) plantations in East Texas is influenced by many factors - soil, genetics , insects, diseases, associated vegetation and climate - to list a few items. Insights into the role that these factors contribute to the production of wood might assist East Texas plantation managers in establishing, growing and harvesting planted trees.

Aspen Ecosystem Properties In The Upper Great Lakes, David H. Alban, D.A. Perala, M.F. Jurgensen, M.E. Ostry, J.R. Probst

Aspen Bibliography

No abstract provided.

The Arctic National Wildlife Refuge: A Case Study In Reconciling Nationally Significant Wildlife Protection, Wilderness And Mineral Potential, Guy R. Martin

The Public Lands During the Remainder of the 20th Century: Planning, Law, and Policy in the Federal Land Agencies (Summer Conference, June 8-10)

28 pages.

Contains 10-page chronology, 1867-1987.

Seasonal Climates At The Cedar-Sauk Field Station, David Miller

Field Station Bulletins

The climate of the Cedar-Sauk Field Station in its annual cycle can be described in terms of (a) energy inputs and their consequences, (b) water inputs and budget, and (c) weather phenomena. All these aspects of climate express a marked seasonality between long, snowy, and cold winters, and fully developed, warm summers. Let us look first at the energy factors in its climate.

Climate And Plant Growth In Certain Vegetative Associations, Arthur W. Sampson

Aspen Bibliography

The relation of climate to the growth and development of vegetation is of profound importance in both practical and experimental agriculture. It is extremely useful to know the cause of successful growth and establishment, or of partial success or failure, of various species in different plant associations and under widely contrasted climatic conditions. The climatic requirements of various plant types are largely responsible for the results obtained in the case of experimental seedings and plantings of most species. Once the adverse climatic factors are definitely known, failures with plants may be largely avoided by the judicious selection of sites or …