Importance of permafrost as a source of water for plants in east Siberian taiga
Importance of permafrost as a source of water for plants in east Siberian taiga
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DOI：
10.1046/j.1440-1703.2002.00506.x
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发表时间：
2002-07
影响因子：
2
通讯作者：
A. Sugimoto;Nao Yanagisawa;D. Naito;N. Fujita;T. Maximov
中科院分区：
文献类型：
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作者：
A. Sugimoto;Nao Yanagisawa;D. Naito;N. Fujita;T. Maximov
1997-1999年在俄罗斯雅库茨克附近的Spasskaya Pad试验林观测了植物水（树液水）的稳定氧同位素比率。落叶松（Larix gmelinii）树液水的δ18O在每年叶片展开后很快减小，表明初夏已利用了融雪水。在夏季中后期，植物利用的水源在湿润夏季和严重干旱夏季之间存在明显差异。1999年8月（湿夏）落叶松水分δ18O值较高（−17.8 ~−16.1‰），1998年8月（干旱夏）δ18O值较低（−20.4 ~−19.7‰）。这些结果表明，植物在潮湿的夏季利用雨水，而在干旱的夏季则利用冻土融水。永久冻土的一个重要作用是在严重干旱的夏季为植物提供直接的水源；另一个作用是保持土壤中多余的水分直到下一个夏天。如果这个永久冻土系统受到未来全球变暖的干扰，西伯利亚东部独特的单型落叶松林可能会在一个严重干旱的夏季受到严重破坏。
Stable oxygen isotope ratios of plant water (sap water) were observed at Spasskaya Pad experimental forest near Yakutsk, Russia in 1997–1999. The δ18O of sap water in larch trees (Larix gmelinii) decreased soon after leaf unfolding every year, indicating that snowmelt water was used in the beginning of summer. During mid to late summer, a clear difference in the water source used by plants was observed between wet summers and severe drought summers. The δ18O values of water in larch trees were high (−17.8 to −16.1‰) in August 1999 (wet summer), but low (−20.4 to −19.7‰) in August 1998 (drought summer). These results indicated that plants used rainwater during a wet summer, but meltwater from permafrost was used by plants during a drought summer. One important role of permafrost is to provide a direct source of water for plants in a severe drought summer; another role is to keep surplus water in the soil until the next summer. If this permafrost system is disturbed by future global warming, unique monotypic stands of deciduous larch trees in east Siberia might be seriously damaged in a severe drought summer.