Forest Sciences Commons^™

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

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: 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

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: 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 …

The Linkages Between Photosynthesis, Productivity, Growth And Biomass In Lowland Amazonian Forests, Yadvinder Malhi, Christopher E. Doughty, Gregory R. Goldsmith, Daniel B. Metcalfe, Cécile A.J. Girardin, Toby R. Marthews, Jhon Del Aguila-Pasquel, Luiz E.O.C. Aragão, Alejandro Araujo-Murakami, Paulo Brando, Antonino C.L. Da Costa, Javier E. Silva-Espejo, Filio Farfán Amézquita, David R. Galbraith, Carlos A. Quesada, Wanderley Rocha, Norma Salinas-Revilla, Divino Silvério, Patrick Meir, Oliver L. Phillips

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Understanding the relationship between photosynthesis, net primary productivity and growth in forest ecosystems is key to understanding how these ecosystems will respond to global anthropogenic change, yet the linkages among these components are rarely explored in detail. We provide the first comprehensive description of the productivity, respiration and carbon allocation of contrasting lowland Amazonian forests spanning gradients in seasonal water deficit and soil fertility. Using the largest data set assembled to date, ten sites in three countries all studied with a standardized methodology, we find that (i) gross primary productivity (GPP) has a simple relationship with seasonal water deficit, but …

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

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: 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 …

Seed Priming With Cacl2 And Ridge Planting For Improved Drought Resistance In Maize, Muhammad Bismillah Khan, Mubshar Hussain, Abid Raza, Shahid Farooq, Khawar Jabran

Turkish Journal of Agriculture and Forestry

Drought-induced losses in crop output have forced the scientific community to develop efficient management strategies to cope with the adversities of drought stress. This field trial was done to assess the role of seed priming techniques and planting methods for improving drought resistance in Pakistani hybrid maize in 2011. Maize seeds were soaked in an aerated solution of CaCl2 (osmopriming; $\Psi$s -1.25 MPa) and distilled water (hydropriming), while untreated dry seeds were taken as controls. Primed and untreated seeds were sown on either ridges or a flat seedbed and were subjected to drought at vegetative and tasseling stages. Drought was …

Tipping Point Of A Conifer-Based Ecosystem Under Severe Drought, Kaicheng Huang, Chuixiang Yi, Donghai Wu, Tao Zhou, Xiang Zhao, William J. Blanford, Suhua Wei, Hao Wu, Du Ling, Zheng Li

Publications and Research

Drought-induced tree mortality has recently received considerable attention. Questions have arisen over the necessary intensity and duration thresholds of droughts that are sufficient to trigger rapid forest declines. The values of such tipping points leading to forest declines due to drought are presently unknown. In this study, we have evaluated the potential relationship between the level of tree growth and concurrent drought conditions with data of the tree growth-related ring width index (RWI) of the two dominant conifer species (Pinus edulis and Pinus ponderosa) in the Southwestern United States (SWUS) and the meteorological drought-related standardized precipitation evapotranspiration index …

Evaluation Of Drought Tolerance Of Winter Bread Wheat Genotypes Underdrip Irrigation And Rain-Fed Conditions, Jamala Mursalova, Zeynal Akparov, Javid Ojaghi, Mahammad Eldarov, Savaş Belen, Nurberdi Gummadov, Alexey Morgounov

Turkish Journal of Agriculture and Forestry

To evaluate the genetic diversity in 48 winter bread wheat genotypes originating from different countries, an experiment based on randomized complete block design with 4 replications was carried out in drip irrigation and rain-fed conditions at the field station of the Transitional Zone Agricultural Research Institute, Eskişehir, Turkey in 2011 and 2012. Based on grain yield under rain-fed and irrigated conditions, drought tolerance indices, i.e. stress susceptibility index (SSI), stress tolerance index (STI), tolerance index (TOL), mean productivity (MP), and geometric mean productivity (GMP), were calculated to identify genotypes with better yield and drought tolerance. Analysis of variance indicated that …

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 …

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 …

Transcriptomic Analysis Of Tomato Lines Reveals Putative Stress-Specific Biomarkers, Monther Taha Sadder, Abdullah Alsadon, Mahmoud Wahb-Allah

Turkish Journal of Agriculture and Forestry

Different abiotic stresses recruit dedicated signaling and regulatory genes in plants. Genome-wide stress-specific biomarkers were investigated in tomatoes. Three major abiotic stresses were compared: drought, heat, and salinity. For each stress type, 2 different tomato lines were included: susceptible and tolerant. Gene expression was examined by hybridizing to an available tomato microarray. Several stress responsive genes were upregulated in tolerant as well as in susceptible lines for each stress. Comparative analysis of gene expression in response to stress (drought, heat, or salinity) resolved a number of common biomarkers, while other groups of putative biomarkers were associated with each abiotic stress. …

Genotypic Variability For Tuber Yield, Biomass, And Drought Tolerance In Jerusalem Artichoke Germplasm, Ruttanachira Ruttanaprasert, Poramate Banterng, Sanun Jogloy, Nimitr Vorasoot, Thawan Kesmala, Rameshwar S. Kanwar, Carl Corley Holbrook, Aran Patanothai

Turkish Journal of Agriculture and Forestry

Jerusalem artichoke could be an alternative feedstock for bioenergy during times when there are shortages of other raw materials for the ethanol industry. However, insufficient water under rainfed conditions is a major cause of Jerusalem artichoke losses. Genetic variation for drought tolerance is an essential prerequisite for the development of Jerusalem artichoke cultivars with improved drought tolerance. The objectives of this study were to determine the effects of drought stress on tuber dry weight and biomass and to investigate the genotypic variability in Jerusalem artichoke germplasm. The line-source sprinkler technique was used to compare moisture responses of a range of …

Characterization For Drought Resistance At Early Stages Of Wheat Genotypes Based On Survival, Coleoptile Length, And Seedling Vigor, Ali̇ Öztürk, Si̇nan Bayram, Kami̇l Hali̇loğlu, Murat Aydin, Özcan Çağlar, Sancar Bulut

Turkish Journal of Agriculture and Forestry

In order to develop genotypes having a stable higher yield, it is necessary to characterize genetic resources based on drought adaptation, determine the suitable genotypes, and use them in breeding programs. This study was carried out in greenhouses, plant growth chambers, and research farms of the Faculty of Agriculture at Atatürk University. A total of 64 certified and local bread wheat genotypes were used to test survival after drought, coleoptile length, and seedling vigor. There were significant differences with respect to the selection parameters in this study. Seedling survival ranged from 18.5% to 51.1% and coleoptile lengths were 39–74 mm. …

Tolerance And Avoidance Responses To Salinity And Water Stresses In Calotropis Procera And Suaeda Aegyptiaca, Ali Hassan Ibrahim

Turkish Journal of Agriculture and Forestry

This study was designed to evaluate the response of 2 wild shrubs, Calotropis procera and Suaeda aegyptiaca, to salinity (100% seawater), drought, and waterlogging stresses. The 90-day-old plants were subjected to the stress treatments for 3 weeks, and growth and some physiological parameters were evaluated. The total plant dry mass of C. procera plants was reduced by 40%, whereas S. aegyptiaca was not significantly affected by salinity stress. Water deficit and waterlogging stresses significantly reduced the total dry mass of both species. Under all conditions, the root/shoot ratio in C. procera was 3-fold higher than in S. aegyptiaca. All applied …

Review Of The Potential Effects Of Climate Change On Quaking Aspen (Populus Tremuloides) In The Western United States And A New Tool For Surveying Aspen Decline, Toni L. Morelli, Susan C. Carr

Aspen Bibliography

We conducted a literature review of the effects of climate on the distribution and growth of quaking aspen (Populus tremuloides Michx.) in the Western United States. Based on our review, we summarize models of historical climate determi- nants of contemporary aspen distribution. Most quantitative climate-based models linked aspen presence and growth to moisture availability and solar radiation.

We describe research results pertaining to global climate change effects on aspen distribution and vigor. In addition, we present potential interactive effects related to climate change and natural disturbances and insect and pathogen outbreaks. Finally, we review the phenomenon of sudden aspen decline …

Slides: The Spotted Owl Controversy: An Example Of The Esa's Dominant Role In Federal Land Use Planning, Norman D. James

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: Norman D. James, Director, Fennemore Craig, PC (Phoenix, AZ)

17 slides

Slides: Celebrating Flpma: Land Use Planning At The Blm, Marcilynn Burke

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: Marcilynn Burke, BLM Deputy Director - Programs and Policy, U.S. Dept. of the Interior, (Washington, D.C.)

30 slides

Plant Water Relations And Photosynthetic Activity In Three Tunisian Chickpea (Cicer Arietinum L.) Genotypes Subjected To Drought, Abdelmajid Krouma

Turkish Journal of Agriculture and Forestry

Chickpea (Cicer arietinum L.) is an important food crop grown under rainfed conditions in Mediterranean regions in which drought is a major limiting factor for production. In these areas little attention is given to legumes, and efforts to identify drought-tolerant genotypes are primarily focused on major cereal crops. In the current study a greenhouse experiment was conducted to assess the effects of drought stress on plant growth, photosynthesis, and water relations in 3 Tunisian chickpea genotypes (Cicer arietinum L.). Drought was applied, and soil humidity was maintained at 30% of field capacity (stressed plants) or 100% of field capacity (control …

Slides: Rethinking Western Water Law: Restoring The Public Interest In Western Water Law, Mark Squillace

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

Presenter: Mark Squillace, Director, Natural Resources Law Center, University of Colorado Law School

20 slides

Slides: Economic Incentives For Demand Reduction, Christopher Goemans

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

Presenter: Christopher Goemans, Department of Agriculture & Resource Economics, Colorado State University

17 slides

Slides: Delta Overview, Leo Winternitz

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

Presenter: Leo Winternitz, The Nature Conservancy, California Water Program, Sacramento, CA

17 slides

Slides: Groundwater Declines, Climate Change And Approaches To Adaptation, Katharine Jacobs

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

Presenter: Katharine Jacobs, Director of the Arizona Water Institute, University of Arizona

37 slides

Agenda: Western Water Law, Policy And Management: Ripples, Currents, And New Channels For Inquiry, University Of Colorado Boulder. Natural Resources Law Center, Western Water Policy Program

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

In many pockets of the American West, stresses and demands on water resources are overwhelming our capacity to effectively manage change and accommodate the diversity of interests and values associated with our limited water resources.

This event will offer an opportunity for lawyers, policymakers, and water professionals to engage the experts on the challenges and emerging solutions to the most pressing water policy and management issues of the day.

Slides: Unquenchable, Robert Glennon

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

Presenter: Robert Glennon, Morris K. Udall Professor of Law and Public Policy, James E. Rogers College of Law, University of Arizona

56 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

Slides: Finding Flows: Fish Still Need Water Everyday, Melinda Kassen

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

Presenter: Melinda Kassen, Director of the Western Water Project, Trout Unlimited

12 slides

Currents In Water Resources Law And Policy: How Is “Prior” Coping With New Stresses? [Outline], A. Dan Tarlock, David H. Getches

The Future of Natural Resources Law and Policy (Summer Conference, June 6-8)

3 pages.

Includes bibliographical references

"A. Dan Tarlock, Distinguished Professor of Law and Director, Program in Environmental and Energy Law, Chicago-Kent College of Law"

"David H. Getches, Dean and Raphael J. Moses Professor of Natural Resources Law, University of Colorado Law School"

Slides: Summary: Sources Of Stress And The Changing Context Of Natural Resources Law And Policy In The New West, William R. Travis

The Future of Natural Resources Law and Policy (Summer Conference, June 6-8)

Presenter: Dr. William R. Travis, Department of Geography, University of Colorado at Boulder

43 slides

Effect Of Early Season Drought Stress On Growth Characteristics Of Sugar Beet Genotypes, Rahim Mohammadian, M. Moghaddam, Hassan Rahimian, S. Y. Sadeghian

Turkish Journal of Agriculture and Forestry

This study was conducted to determine the effects of early season drought stress on some plant characteristics of 9 sugar beet genotypes in the Khorasan Agricultural and Natural Resource Research Station, NE Iran. The experimental design was a split plot with a randomized complete block arrangement. Leaf area index, leaf dry weight, shoot dry weight and root dry weight decreased under drought stress compared to non-stress conditions. The decrease was more pronounced as the rate of stress increased. Leaf area index was more affected by water stress than was leaf weight (losses of leaf area indices were 14.1% and 66.6% …

Variation In Isoprene Emission From Quercus Rubra: Sources, Causes, And Consequences For Estimating Fluxes, Jennifer L. Funk, Clive G. Jones, Dennis W. Gray, Heather L. Throop, Laura A. Hyatt, Manuel T. Lerdau

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Isoprene is the dominant volatile organic compound produced in many forest systems. Uncertainty in estimates of leaf level isoprene emission rate stems from an insufficient understanding of the patterns and processes controlling isoprene emission capacity in plant leaves. Previous studies suggest that variation in isoprene emission capacity is substantial; however, it is not known at what scale emission capacity is the most variable. Identifying the sources of variation in emission capacity has implications for conducting measurements and for model development, which will ultimately improve emission estimates and models of tropospheric chemistry. In addition, understanding the sources of variation will help …

Environmental Stress Effects On Vigor, Mortality, And Growth In Northern Hardwood Forests Along A Pollution-Climate Gradient, Neil W. Macdonald, John A. Witter, David R. Reed, Andrew J. Burton, Kurt S. Pregitzer, Hal O. Liechty

Peer Reviewed Publications

Concern exists over the effects of interacting environmental stresses on the ecological integrity of temperate forests. Coincidence of sensitivity to drought, increasing occurrence of defoliation, and elevated pollutant deposition has produced speculation that northern hardwood forests may be susceptible to the increased climatic stresses projected for the Great Lakes region. The objective of our study was to examine relationships among environmental stress factors, vigor, mortality, and growth in northern hardwood forests located along a pollution-climate gradient in the Great Lakes region. Between 1987 and 1993, we quantified climatic variables, pollutant deposition, insect defoliation, and tree vigor and growth at five …