کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
9447830 | 1305563 | 2005 | 15 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Drought stress and fluctuating asymmetry in Quercus undulata leaves: confounding effects of absolute and relative amounts of stress?
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
فرآیندهای سطح زمین
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چکیده انگلیسی
One of the most general types of stress experienced by plants is water-limitation, which becomes particularly pronounced during periods of drought. We evaluated fluctuating asymmetry (FA) in Quercus undulata leaves for two subsequent dry years: 2001, when precipitation was 25% below average, and 2002, when precipitation was 65% below average, from a plot receiving ambient water and one in which water was excluded. In the first and less severe drought year, ambient-water trees had a slightly higher index of FA than the water-exclusion trees, contrary to expectations. However, in the second and much more extreme drought year, water-exclusion trees exhibited greater FA as expected, but in additional observations water-supplement trees exhibited by far the greatest amount of FA, contrary to expected. Further data on plant water potential confirmed that degree of plant stress corresponded to plot treatments: water exclusion>ambient water>water supplement. Stable carbon isotope ratios indicated that trees on the water-supplement plots were less stressed than ambient-water and water-exclusion trees, and leaf size was much greater for water-supplement trees than ambient-water or water-exclusion trees. We hypothesize that the complexity of the results could be due to the confounding effects of relative vs. absolute stress.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Arid Environments - Volume 62, Issue 2, July 2005, Pages 235-249
Journal: Journal of Arid Environments - Volume 62, Issue 2, July 2005, Pages 235-249
نویسندگان
J.M. Fair, D.D. Breshears,