کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
87306 159244 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Increased intrinsic water-use efficiency during a period with persistent decreased tree radial growth in northwestern China: Causes and implications
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک بوم شناسی، تکامل، رفتار و سامانه شناسی
پیش نمایش صفحه اول مقاله
Increased intrinsic water-use efficiency during a period with persistent decreased tree radial growth in northwestern China: Causes and implications
چکیده انگلیسی

To understand how tree growth responds to rising atmospheric CO2 concentration ([CO2]) and climate change in arid and semi-arid regions, it is important to determine how trees in natural forests adjust physiologically to the changing atmospheric environment. Here, we developed an annual-resolution tree-ring stable carbon isotope (δ13C) chronology from the dominant natural spruce (Picea crassifolia) trees in the Xinglong Mountains, in the eastern part of northwestern China, from 1800 to 2009. The climate response recorded in the tree-ring δ13C residuals indicated that insufficient moisture during the previous autumn and the current growing season was the dominant climatic factor that controlled tree-ring carbon isotope discrimination in the semi-arid Xinglong Mountains. By combining the tree-ring δ13C, the atmospheric [CO2] (Ca), and ring width data, and by calculating the variations in leaf intercellular [CO2] (Ci), their ratio (Ci/Ca), intrinsic water-use efficiency (iWUE), and basal area increment (BAI), we found that the Ci/Ca remained mostly constant during the last century whereas Ci and iWUE increased significantly. The increase in iWUE totaled about 40% by the end of the study period. However, after 1998, the trees switched from an active to a passive response to elevated atmospheric [CO2], leading to relatively stable iWUE. Since 1800, tree radial growth did not always parallel the increase in iWUE; the tree growth rate declined during drought periods, and especially during the severe droughts that occurred from 1923 to 1934 and recent decade. This response is a concern for future forest management and conservation under the current climate change scenario.


► We develop a tree-ring δ13C chronology.
► We calculate the variations of intrinsic water-use efficiency and basal area increment.
► Previous autumn and current growing season’s moisture mainly control tree-ring carbon isotope discrimination.
► Significantly increasing in intrinsic water-use efficiency does not promote tree growth.
► Severe droughts decline tree growth obviously.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Forest Ecology and Management - Volume 275, 1 July 2012, Pages 14–22
نویسندگان
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