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
 Wind Erosion and Water Conservation Research: Lubbock, TX
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                                    Software
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Plains Area Lubbock, Texas Cropping Systems Research Laboratory Wind Erosion and Water Conservation Research 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
                                            Bell, Colinitem
                                            Acosta-Martinez, Veronicaitem
                                            TISSUE, DAVID - Texas Tech Universityitem
                                            ZAK, JOHN - Texas Tech University
  Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 10/16/2011
                                    Publication  Date: 10/19/2011
                                    Citation: Bell, C.W., Acosta Martinez, V., Tissue, D., Zak, J. 2011. Understanding Soil Microbial Community Structural and Functional Responses to Climate Change[abstract]. American Society of Agronomy, Crop Science Society of America, Soil Science Society of America Annual Meeting. October 16-19, 2011, San Antonio, TX.Interpretive Summary:
                                Technical Abstract: Global climate models (GCM) predict increased temperature and precipitation variability across arid regions in North America within the next century, resulting in fewer rain events of greater magnitude. Increased inter-pulse periods (dry days between rain events) along with increased temperature will increase evapotranspiration stress and reduce soil moisture availability. Reductions in soil moisture can lead to declines in soil microbial biomass and diversity, subsequently altering microbial ecosystem processes that facilitate decomposition and nutrient cycling in this region. While many studies have addressed soil-microbial responses to short-term changes in precipitation magnitudes, few efforts have assessed microbial response to long-term shifts in seasonal precipitation. This research examined soil microbial and nutrient properties as affected by GCM predictions of 25% increased seasonal shifts in rainfall over a 7-year period (2002-2008) in a Chihuahuan Desert grassland. We hypothesized that over time, these minor but realistic increases in soil moisture would produce cumulative changes in soil microbial communities (species assemblage and functional attributes). Our results demonstrated clear shifts in microbial community dynamics by the third year of this study. Microbial community structural responses (identified using fatty acid methyl ester (FAME) analysis) revealed increased abundances of saprophytic, arbuscular mycorrhiza, and gram-negative bacteria within plots subjected to 25% seasonal rainfall additions when compared to ambient (control) conditions. Microbial function (enzyme activity) also demonstrated increases; as ß-Glucosidase and phosphodiesterase activity (involved in cellulose degradation and phosphorus mineralization, respectively) was elevated in plots subjected to minor shifts in seasonal precipitation during this same period. Our findings suggest that microbial community structure and function is linked to climate. Furthermore, different microbial community-assemblages occur as a result of varying seasonal precipitation scenarios; but provide similar ecosystem functional contributions at varying degrees. Consequently, the ability of soil microbial communities to maintain functional resilience may be reduced in this desert grassland ecosystem.


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