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Es和Tstem均存在较好的指数函数关系,但环剥会降低AG和BG的Tstem对Es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Q10和R15。【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。
【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 ( T stem ) 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 E s 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 E s 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 E s and stem temperature in both growing and non-growing seasons,but the R squares ( R2 ) of the exponential relationship between T stem and E s 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 photosyntha
作者
张茜茜
杨庆朋
刘亮
王清涛
李菲
郭丽丽
郝立华
曹旭
范晓懂
梁伟佳
郑云普
Zhang Xixi;Yang Qingpeng;Liu Liang;Wang Qingtao;Li Fei;Guo Lili;Hao Lihua;Cao Xu;Fan Xiaodong;Liang Weijia;Zheng Yunpu(School of Water Conservancy and Hydroelectric Power,Hebei University of Engineering Handan 056038;Key Laboratory of Forest Ecology and Management,Chinese Academy of SciencesInstitute of Applied Ecology,Chinese Academy of Sciences Shenyang 110016;School of Landscape and Ecological Engineering,Hebei University of Engineering Handan 056038)
出处
《林业科学》
EI
CAS
CSCD
北大核心
2019年第5期1-10,共10页
Scientia Silvae Sinicae
基金
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)
关键词
光合产物供应
树干呼吸
树干温度
可溶性糖
人工林
Photosynthates supply
stem respiration
stem temperature
soluble sugar
plantation
