Title: Climate-related genetic variation in drought-resistance of Douglas-fir ( Pseudotsuga menziesii )
Author: Bansal, Sheel; Harrington, Constance A.; Gould, Peter J.; St.Clair, J. Bradley;
Source: Global Change Biology
Publication Series: Scientific Journal (JRNL)
Description: There is a general assumption that intraspecific populations originating from relatively arid climates will be better adapted to cope with the expected increase in drought from climate change. For ecologically and economically important species, more comprehensive, genecological studies that utilize large distributions of populations and direct measures of traits associated with drought-resistance are needed to empirically support this assumption because of the implications for the natural or assisted regeneration of species. We conducted a space-for-time substitution, common garden experiment with 35 populations of coast Douglas-fir (Pseudotsuga menziesii var. menziesii) growing at three test sites with distinct summer temperature and precipitation (referred to as ‘cool/moist’, ‘moderate’, or ‘warm/dry’) to test the hypotheses that (i) there is large genetic variation among populations and regions in traits associated with drought-resistance, (ii) the patterns of genetic variation are related to the native source-climate of each population, in particular with summer temperature and precipitation, (iii) the differences among populations and relationships with climate are stronger at the warm/dry test site owing to greater expression of drought-resistance traits (i.e., a genotype x environment interaction). During midsummer 2012, we measured the rate of water loss after stomatal closure (transpirationmin), water deficit (% below turgid saturation), and specific leaf area (SLA, cm2 g-1) on new growth of sapling branches. There was significant genetic variation in all plant traits, with populations originating from warmer and drier climates having greater drought-resistance (i.e., lower transpirationmin, water deficit and SLA), but these trends were most clearly expressed only at the warm/dry test site. Contrary to expectations, populations from cooler climates also had greater drought-resistance across all test sites. Multiple regression analysis indicated that Douglasfir populations from regions with relatively cool winters and arid summers may be most adapted to cope with drought conditions that are expected in the future.
Keywords: climate change, genecology, minimum conductance, specific leaf area, water deficit
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
XML: View XML
Bansal, Sheel; Harrington, Constance A.; Gould, Peter J.; St.Clair, J. Bradley 2014. Climate-related genetic variation in drought-resistance of Douglas-fir (Pseudotsuga menziesii) . Global Change Biology. 21(2): 947-958.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility