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
 Water Management and Systems Research: Fort Collins, CO
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                                    Software
                People

                    Staff Listing
                                    Careers


        


                    Publications
                    NewsSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Plains Area Fort Collins, Colorado Center for Agricultural Resources Research Water Management and Systems 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
                                            Gleason, Seanitem
                                            BLACKMAN, CHRIS - Macquarie Universityitem
                                            COOK, ALICIA - Macquarie Universityitem
                                            LAWS, CLAIRE - Macquarie Universityitem
                                            WESTOBY, MARK - Macquarie University
  Submitted to: Tree Physiology
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 12/1/2013
                                    Publication  Date: 2/1/2014
                                    Citation: Gleason, S.M., Blackman, C.J., Cook, A.M., Laws, C.A., Westoby, M. 2014. Whole-plant capacitance, embolism resistance and slow transpiration rates all contribute to longer desiccation times in woody angiosperms from arid and wet habitats. Tree Physiology. 34(3):275-84.Interpretive Summary: High levels of drought stress can damage the water transporting tissues in plants (xylem), yet little is understood about which plant traits (e.g., water storage, evaporation rates from leaves, etc.) have most influence in delaying the onset of dysfunction during periods of drought. We examined three traits contributing to longer desiccation times in excised shoots of 11 species from two sites of contrasting aridity: (i) the amount of water released from plant tissues (storage tissues inside the plant); (ii) the minimum level of water stress preceding damage; and (iii) the rate of evaporation from leaves. The time required for species to reach acute levels of stress varied markedly, ranging from 1.3 h to nearly 3 days. Water released from storage tissues, minimum stress preceding damage, and evaporation rates all contributed significantly to longer desiccation times, explaining 28, 22 and 50% of the variation in the time required to reach acute stress. Interestingly, these three traits were nearly independent to one another, suggesting that they do not represent alternative strategies, but likely trade off with other traits not measured in this study.  The majority of water lost during desiccation (60–91%) originated from leaves, suggesting that leaves are an important source of water during desiccation.
                                Technical Abstract: Low water potentials in xylem can result in damaging levels of cavitation, yet little is understood about which hydraulic traits have most influence in delaying the onset of hydraulic dysfunction during periods of drought. We examined three traits contributing to longer desiccation times in excised shoots of 11 species from two sites of contrasting aridity: (i) the amount of water released from plant tissues per decrease in xylem water potential (W'); (ii) the minimum xylem water potential preceding acute water stress (defined as P50L; water potential at 50% loss of leaf conductance); and (iii) the integrated transpiration rate between the points of full hydration and P50L (Wtime). The time required for species to reach P50L varied markedly, ranging from 1.3 h to nearly 3 days. W', P50L and Wtime all contributed significantly to longer desiccation times, explaining 28, 22 and 50% of the variance in the time required to reach P50L. Interestingly, these three traits were nearly orthogonal to one another, suggesting that they do not represent alternative hydraulic strategies, but likely trade off with other ecological strategies not evaluated in this study. The majority of water lost during desiccation (60–91%) originated from leaves, suggesting an important role for leaf capacitance in small plants when xylem water potentials decrease below -2 MPa.


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