植物生态学报 ›› 2017, Vol. 41 ›› Issue (9): 964-971.DOI: 10.17521/cjpe.2017.0015

• 研究论文 • 上一篇    下一篇

川西亚高山云杉林冬季土壤呼吸对雪被去除的短期响应

杨开军, 杨万勤, 谭羽, 贺若阳, 庄丽燕, 李志杰, 谭波, 徐振锋*()   

  1. 四川农业大学生态林业研究所, 四川省林业生态工程重点实验室, 成都 611130
    四川农业大学高山森林生态系统定位研究站, 长江上游生态安全协同创新中心, 成都 611130
  • 收稿日期:2016-05-24 修回日期:2017-08-26 出版日期:2017-09-10 发布日期:2017-10-23
  • 通讯作者: 徐振锋
  • 基金资助:
    国家自然科学基金(31570601、31570445和31500509)和中国博士后科学基金(2014T70880)

Short-term responses of winter soil respiration to snow removal in a Picea asperata forest of western Sichuan

Kai-Jun YANG, Wan-Qin YANG, Yu TAN, Ruo-Yang HE, Li-Yan ZHUANG, Zhi-Jie LI, Bo TAN, Zhen-Feng XU*()   

  1. Key Laboratory of Ecological Forestry Engineering of Sichuan Province, Institute of Ecology & Forestry, Sichuan Agricultural University, Chengdu 611130, China;
    Long-Term Research Station of Alpine Forest Ecosystems and Collaborative Innovation Center of Ecological Security in the Upper Reaches of Yangtze River, Sichuan Agricultural University, Chengdu 611130, China
  • Received:2016-05-24 Revised:2017-08-26 Online:2017-09-10 Published:2017-10-23
  • Contact: Zhen-Feng XU

摘要:

季节性雪被是高寒森林冬季土壤呼吸的重要调控因子, 气候变化导致的季节性雪被减少可能对高寒森林冬季土壤呼吸产生显著影响。该研究采用人工去除雪被的方法, 研究雪被去除对川西亚高山云杉(Picea asperata)人工林冬季土壤呼吸的影响。结果表明: 与对照相比, 雪被去除加大了土壤温度波动, 使冬季土壤表层和5 cm平均温度分别降低了1.12和0.34 ℃, 冻融循环次数分别增加了39和12次; 冬季平均土壤呼吸速率和土壤碳排放通量分别为0.52 μmol·m-2·s-1和88.44 g·m-2, 雪被去除使冬季平均土壤呼吸速率和碳排放通量分别降低了21.02%和25.99%, 雪被效应主要发生在雪被初期; 冬季土壤呼吸与土壤温度存在显著的指数关系, 雪被去除显著降低了冬季土壤呼吸温度敏感性。未来气候变化所引发的季节性雪被减少可能会降低川西亚高山森林冬季土壤碳排放, 从而对亚高山森林土壤碳动态产生深远影响。

关键词: 亚高山森林, 季节性雪被, 雪被去除, 土壤呼吸, 温度敏感性, 森林碳汇

Abstract:

Aims Seasonal snow cover is one of the most important factors that control winter soil respiration in the cold biomes. The warming-induced decreases in snowpack could affect winter soil respiration of subalpine forests. The aim of this study was to explore the effects of snow removal on winter soil respiration in a Picea asperata forest.Methods A snow removal experiment was conducted in a P. asperata forest stand in western Sichuan during the winter of 2015/2016. The snow removal treatment was implemented using wooden roof method. Soil temperatures, snow depth and soil respiration rate were simultaneously measured in plots of snow removal and controls during the experimental period.Important findings Compared to the control, snow removal increased the fluctuations of soil temperatures. The average daily temperature of the soil surface and that at 5 cm depth were 1.12 °C and 0.34 °C lower, respectively, and the numbers of freeze-thaw cycles of the soil surface and that at 5 cm depth were increased by 39 and 12, respectively, in plots of snow removal than in the controls. The average rate of winter soil respiration and CO2 efflux were 0.52 μmol·m-2·s-1 and 88.44 g·m-2, respectively. On average, snow removal reduced soil respiration rate by 21.02% and CO2 efflux by 25.99%, respectively. More importantly, the snow effect mainly occurred in the early winter. The winter soil respiration rate had a significant exponential relationship with soil temperature. However, snow removal significantly reduced temperature sensitivity of the winter soil respiration. Our results suggest that seasonal snow reduction associated with climate change could inhibit winter soil respiration in the subalpine forests of western Sichuan, with significant implications for the carbon dynamics of the subalpine forests.

Key words: subalpine forest, seasonal snowpack, snow removal, soil respiration, temperature sensitivity, forest carbon sink