气候变化领域集成服务门户(CCPortal): Negative relationship between photosynthesis and late-stage canopy development and senescence over Tibetan Plateau

CCPortal

DOI	10.1111/gcb.16668
	Negative relationship between photosynthesis and late-stage canopy development and senescence over Tibetan Plateau
	Meng, Fandong; Liu, Dan; Wang, Yilong; Wang, Shiping; Wang, Tao
发表日期	2023
ISSN	1354-1013
EISSN	1365-2486
起始页码	3147
结束页码	3158
卷号	29 期号:11
英文摘要	Canopy greening, which is associated with significant canopy structure changes, is the most notable signal of ecosystem changes in response to anthropogenic climate change. However, our knowledge of the changing pattern of canopy development and senescence, and its endogenous and climatic drivers is still limited. Here, we used the Normalized Difference Vegetation Index (NDVI) to quantify the changes in the speed of canopy development and senescence over the Tibetan Plateau (TP) during 2000-2018, and used a solar-induced chlorophyll fluorescence dataset as a proxy for photosynthesis, in combination with climate datasets to decipher the endogenous and climatic drivers of the interannual variation in canopy changes. We found that the canopy development during the early green-up stage (April-May) is accelerating at a rate of 0.45-0.8 x 10(-3) month(-1) year(-1). However, this accelerating canopy development was largely offset by a decelerating canopy development during June and July (-0.61 to -0.51 x 10(-3) month(-1) year(-1)), leading to the peak NDVI over the TP increasing at a rate of only one fifth of that in northern temperate regions, and less than one tenth of that in the Arctic and boreal regions. During the green-down period, we observed a significant accelerating canopy senescence during October. Photosynthesis was found to be the dominant driver for canopy changes over the TP. Increasing photosynthesis stimulates canopy development during the early green-up stage. However, slower canopy development and accelerated senescence was found with larger photosynthesis in late growth stages. This negative relationship between photosynthesis and canopy development is probably linked to the source-sink balance of plants and shifts in the allocation regime. These results suggest a sink limitation for plant growth over the TP. The impact of canopy greening on the carbon cycle may be more complicated than the source-oriented paradigm used in current ecosystem models.
关键词	canopy development carbon allocation photosynthesis senescence source-sink dynamic Tibetan Plateau
英文关键词	SOLAR-INDUCED FLUORESCENCE; LEAF-AREA INDEX; CARBON ALLOCATION; PLANT-GROWTH; CO2; CLIMATE; GRASSLANDS; PATTERNS; IMPACTS; BALANCE
WOS研究方向	Biodiversity Conservation ; Ecology ; Environmental Sciences
WOS记录号	WOS:000950395900001
来源期刊	GLOBAL CHANGE BIOLOGY
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283798
作者单位	Chinese Academy of Sciences; Institute of Tibetan Plateau Research, CAS
推荐引用方式 GB/T 7714	Meng, Fandong,Liu, Dan,Wang, Yilong,et al. Negative relationship between photosynthesis and late-stage canopy development and senescence over Tibetan Plateau[J]. 中国科学院青藏高原研究所,2023,29(11).
APA	Meng, Fandong,Liu, Dan,Wang, Yilong,Wang, Shiping,&Wang, Tao.(2023).Negative relationship between photosynthesis and late-stage canopy development and senescence over Tibetan Plateau.GLOBAL CHANGE BIOLOGY,29(11).
MLA	Meng, Fandong,et al."Negative relationship between photosynthesis and late-stage canopy development and senescence over Tibetan Plateau".GLOBAL CHANGE BIOLOGY 29.11(2023).