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标题：Carbon Isotope Discrimination in Diverging Growth Forms of Saxifraga oppositifolia in Different Successional Stages in a High Arctic Glacier Foreland
其他标题：Carbon Isotope Discrimination in Diverging Growth Forms of Saxifraga oppositifolia in Different Successional Stages in a High Arctic Glacier Foreland
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作者：Atsushi Kume ; Yukiko S. Bekku ; Yuko T. Hanba 等
期刊名称：Arctic, Antarctic, and Alpine Research
印刷版ISSN：1523-0430
电子版ISSN：1938-4246
出版年度：2003
卷号：35
期号：3
页码：377-383
DOI：10.1657/1523-0430(2003)035[0377:CIDIDG]2.0.CO%3B2
摘要：We investigated carbon isotope discrimination of two morphs of Saxifraga oppositifolia and other plant species in a glacier foreland in the High Arctic at Ny-Ålesund, Svalbard, Norway. At this site, soil conditions vary considerably along with the progress of primary succession within a small area. We compared growth forms and δ 13 C values, which reflect long-term leaf gas exchange characteristics, of plants growing in different successional stages with different soil conditions. Even though the soil mass water content (water mass/dry mass) increased from 10% to 140% with the progress of succession, the water and nitrogen content of the soil had negligible effects on the δ 13 C values of the observed species. The δ 13 C values were determined mainly by species and growth forms. We compared two morphs of S. oppositifolia , the prostrate form (P-form) and the cushion form (C-form), on the same riverbank in the glacier foreland. Regardless of the successional stage, the δ 13 C values of the C-form were about 2‰ more negative than those of the P-form. The ground cover area per plant mass (GA) of the C-form was less than 30% that of the P-form, and the product of GA and stomatal conductance appears to be an important factor in the relationship between transpiration and photosynthesis of a whole plant. We suggest that the relationship between GA and the root mass fraction is a crucial factor affecting the water utilization in high arctic environments. We also examined the relationship between life form and water utilization for other phototrophs, including lichens, mosses, narrow-leaved grasses, perennials, and shrubs.