U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Derner, Justinitem
                                            Hendrickson, Johnitem
                                            Frank, Albertitem
                                            Morgan, Jackitem
                                            THUROW, T - UNIVERSITY OF WYOMINGitem
                                            HART, R - USDA-ARS, RETIRED
  Submitted to: Western Range Science Seminar Proceedings: The Range: Progress & Potential
                                    Publication Type: Proceedings
                                    Publication Acceptance Date: 1/19/2003
                                    Publication  Date: 1/19/2003
                                    Citation: DERNER, J.D., HENDRICKSON, J.R., FRANK, A.B., MORGAN, J.A., THUROW, T.L., HART, R.H. DROUGHT EFFECTS ON RANGELAND ECOSYSTEMS. WESTERN RANGE SCIENCE SEMINAR PROCEEDINGS: THE RANGE: PROGRESS & POTENTIAL. 2003.Interpretive Summary: Drought, defined as the period when soil moisture availability drops to a level that adversely affects production from agricultural lands, influences the structure and function of rangelands. Drought modifies the structure of rangelands by changing vegetation composition as some plants can escape drought, other reduce water loss or maintain adequate water uptake through an extensive root system, and others tolerate drought by changing the chemical composition of internal fluids. The rate of plant recovery following relief from drought conditions is influenced by the management of these plants during drought. For example, substantial reductions in the number of grazing animals during drought conditions will accelerate recovery of plants following relief from drought. Drought modifies the function of rangelands by influenceing biomass production and the ability of these lands to effectively store carbon in soils from the atmosphere. Understanding how individual plants respond to drought and how ecological processes on rangelands are affected by drought will increase our ability to predict how management can maintain desired plant communities.
                                Technical Abstract: Rangeland ecosystems are event-driven, and water events are typically considered most important. Thus, understanding the dimensions of drought (duration, severity, and extent) becomes pivotal to understanding rangelands. Strong relationships between precipitation and forage production have been determined for fall precipitation and/or soil moisture as well as early spring precipitation. Because many rangelands in the Northern Great Plains are comprised of both warm- and cool-season plants, changes in the precipitation regime may alter species composition. Much of the classical work evaluating vegetation compositional responses to drought was accomplished by pioneers of rangeland ecology (e.g., Weaver, Albertson) through their monitoring efforts before, during and after the Dust Bowl years of the 1930s. One of the key lessons of this work is that the early identification of the onset of drought is critical for reducing stocking rates and preventing further rangeland degradation from loss of vegetation and soil erosion. More recently, drought research on rangeland ecosystems has addressed key ecological processes, with such efforts aimed at increasing our understanding of the functional impact of drought. Carbon flux data from a shortgrass prairie indicate that this rangeland was net sink for atmospheric carbon in non-drought years. However, severe drought in 2002 resulted in this rangeland being a net source of carbon. Additionally, grazing exacerbated carbon losses during this drought with the greatest carbon losses associated with rangeland that was heavily-grazed (targeted 75% utilization). Integration of individual plant responses with ecosystem-level processes will likely increase our predictive ability regarding management efforts to 1) maintain desired plant communities or 2) transition to another plant community.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov