Li Biao, Wu Xiaodong, Dong Xingfeng, Man Haoran, Liu Chao, Zou Siyuan, He Jianxiang, Zang Shuying
Heilongjiang Province Key Laboratory of Geographical Environment Monitoring and Spatial Information Service in Cold Regions, Harbin Normal University, Harbin, China.
Heilongjiang Province Collaborative Innovation Center of Cold Region Ecological Safety, Harbin, China.
Front Plant Sci. 2024 Oct 4;15:1444811. doi: 10.3389/fpls.2024.1444811. eCollection 2024.
Global warming has caused the gradual degradation of permafrost, which may affect the vegetation water uptake from different depths. However, the water utilization strategies of different vegetation species during the thawing stages of permafrost regions need further study. To elucidate these differences, we selected the permafrost region in Northeast China as study area. We analyzed the water uptake from different depths of , a deciduous coniferous tree, var. , an evergreen tree, and , a deciduous broadleaf tree, using stable isotopes of xylem water, soil water, and precipitation from June to October 2019. The results showed that primarily used shallow soil water (0-40 cm) with the highest proportion at 64.1%, generally used middle soil water (40-110 cm) with the highest proportion at 55.7%, and mainly used middle (40-110cm) and deep soil water (110-150 cm) with the highest proportion at 40.4% and 56.9%. The water sources from different depths exhibited more frequent changes in , indicating a higher water uptake capacity from different soil depths. mainly uptakes water from shallow soils, suggesting that the water uptake of this species is sensitive to permafrost degradation. This study revealed the water uptake strategies from different depths of three tree species in a permafrost region, and the results suggested that water uptake capacity of different tree species should be considered in the prediction of vegetation changes in permafrost regions under a warming climate.
全球变暖导致多年冻土逐渐退化，这可能会影响不同深度植被对水分的吸收。然而，多年冻土区不同植被物种在解冻阶段的水分利用策略仍需进一步研究。为了阐明这些差异，我们选择中国东北的多年冻土区作为研究区域。我们利用2019年6月至10月木质部水、土壤水和降水的稳定同位素，分析了落叶针叶树兴安落叶松、常绿树红皮云杉和落叶阔叶树白桦不同深度的水分吸收情况。结果表明，兴安落叶松主要利用浅层土壤水（0 - 40厘米），最高比例为64.1%；红皮云杉一般利用中层土壤水（40 - 110厘米），最高比例为55.7%；白桦主要利用中层（40 - 110厘米）和深层土壤水（110 - 150厘米），最高比例分别为40.4%和56.9%。不同深度的水源在兴安落叶松中表现出更频繁的变化，表明其从不同土壤深度吸收水分的能力更强。白桦主要从浅层土壤吸收水分，表明该物种的水分吸收对多年冻土退化敏感。本研究揭示了多年冻土区三种树种不同深度的水分吸收策略，结果表明，在气候变暖条件下预测多年冻土区植被变化时，应考虑不同树种的水分吸收能力。
