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林业科学 ›› 2019, Vol. 55 ›› Issue (5): 1-10.doi: 10.11707/j.1001-7488.20190501

• 论文与研究报告 • 上一篇    下一篇

环剥对毛白杨树干表面CO2通量及其温度敏感性的影响

张茜茜1, 杨庆朋2, 刘亮1, 王清涛3, 李菲1, 郭丽丽1, 郝立华1, 曹旭1, 范晓懂1, 梁伟佳1, 郑云普1   

  1. 1. 河北工程大学水利水电学院 邯郸 056038;
    2. 中国科学院沈阳应用生态研究所 中国科学院森林生态与管理重点实验室 沈阳 110016;
    3. 河北工程大学园林与生态工程学院 邯郸 056038
  • 收稿日期:2018-06-29 修回日期:2018-10-28 出版日期:2019-05-25 发布日期:2019-05-20
  • 基金资助:
    国家自然科学基金项目(31570402,31400418);河北省自然科学基金项目(C2016402088);河北省高等学校青年拔尖人才计划项目(BJ2016012);河北省引进留学人员资助项目(CN201702);河北省研究生创新能力资助项目(CXZZSS2019070);河北省创新能力提升计划科技研发平台建设专项(18965307H);中国博士后科学基金项目(2014M561044,2016T90128)。

Effects of Girdling on Stem CO2 Efflux and Its Temperature Sensitivity of Populus tomentosa

Zhang Xixi1, Yang Qingpeng2, Liu Liang1, Wang Qingtao3, Li Fei1, Guo Lili1, Hao Lihua1, Cao Xu1, Fan Xiaodong1, Liang Weijia1, Zheng Yunpu1   

  1. 1. School of Water Conservancy and Hydroelectric Power, Hebei University of Engineering Handan 056038;
    2. Key Laboratory of Forest Ecology and Management, Chinese Academy of Sciences Institute of Applied Ecology, Chinese Academy of Sciences Shenyang 110016;
    3. School of Landscape and Ecological Engineering, Hebei University of Engineering Handan 056038
  • Received:2018-06-29 Revised:2018-10-28 Online:2019-05-25 Published:2019-05-20

摘要: [目的]探明光合产物供应状况对树干表面CO2通量及其温度敏感性的影响机制。[方法]以10年生毛白杨人工林为研究对象,采用随机区组试验设计,通过环剥改变林木的光合产物供应状况,连续监测环剥点上部(AG)和下部(BG)的树干表面CO2通量(Es)和树干温度(Tstem)并拟合其温度敏感性(Q10),同时测定AG和BG非结构性碳水化合物含量的动态变化,比较生长季和非生长季的Es及其Q10对底物变化的不同响应。[结果]1)相比于对照树木(NG),环剥处理30天后,环剥导致生长季AG的Es升高57%和BG的Es降低43%,但在非生长季NG、AG和BG的Es差异不明显。2)环剥降低生长季AG和BG的可溶性糖浓度29%和15%,而非生长季环剥导致AG和BG的可溶性糖浓度分别降低15%和增加10%。3)不同季节EsTstem均存在较好的指数函数关系,但环剥会降低AG和BG的TstemEs变化解释率。4)环剥提高生长季和非生长季AG的温度敏感性(Q10)和树干基础呼吸速率(R15),但却同时降低BG的Q10R15。[结论]环剥阻断了光合产物的输入,从而改变树体环剥点上、下部的可溶性糖含量,最终导致环剥点上部的树干表面CO2通量及其温度敏感性上升,而环剥点下部的树干表面CO2通量及其温度敏感性下降。毛白杨树干表面CO2通量及其温度敏感性对环剥的响应在不同季节(生长季和非生长季)存在明显差异。

关键词: 光合产物供应, 树干呼吸, 树干温度, 可溶性糖, 人工林

Abstract: [Objective] This study aimed to investigate the mechanism of photosynthate supply on stem CO2 efflux and its temperature sensitivity of tree trunk surface, which is not only critical for understanding the carbon cycling processes of forest ecosystem, but also provides theoretical basis for forest and plantation management under global climate change.[Method] In this study, 10-year-old Populus tomentosa plantation was taken as the research object, and a random block experiment was conducted with three plots (30 m×30 m)in Chinese white poplar (P. tomentosa) plantation in northern China. A girdling experiment on the tree stems was operated to change the supply of photosynthate. The stem CO2 efflux (Es) and stem temperature (Tstem) of Chinese white poplar were measured to examine the effects of photosynthates supply on the temperature sensitivity (Q10) of Es above girdle (AG) and below girdle (BG). Meanwhile, the dynamic changes of nonstructural carbohydrates in stem tissue were measured for comparing different responses of Es and Q10 to substrate supply in growing and non-growing seasons.[Result] 1) Es of AG was increased by 57% and Es of BG was decreased by 43% in growing season after the 30-day girdling treatment, whereas no obvious difference in Es was detected among NG, AG, and BG in non-growing season. 2) Soluble sugar contents of the AG and BG in growing season were decreased by 29% and 15%, respectively. Similarly, the soluble sugar content of AG was also decreased by 15%, but the soluble sugar content of BG was increased by 10% in non-growing season. 3) We also found exponential relationships between Es and stem temperature in both growing and non-growing seasons, but the R squares (R2) of the exponential relationship between Tstem and Es at AG and BG were decreased under stem girdling treatment. 4) Both the Q10 and stem basal respiration rate (R15) at AG were increased, while those of BG were decreased under stem girdling treatment.[Conclusion] Stem girdling blocked the import of photosynthates, and thus altered the soluble sugar contents of AG and BG. Stem girdling resulted in increases in the Es and Q10 at AG, but led to decreases in the Es and Q10 at BG. The responses of stem CO2 efflux and its temperature sensitivity to stem girdling were obviously different between growing season and non-growing season.

Key words: Photosynthates supply, stem respiration, stem temperature, soluble sugar, plantation

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