气候变化领域集成服务门户(CCPortal): Temperature thresholds for the onset of xylogenesis in alpine shrubs on the Tibetan Plateau

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DOI	10.1007/s00468-016-1436-z
	Temperature thresholds for the onset of xylogenesis in alpine shrubs on the Tibetan Plateau
	Li, Xiaoxia; Rossi, Sergio; Liang, Eryuan; Julio Camarero, J.
通讯作者	Liang, EY (通讯作者)
发表日期	2016
ISSN	0931-1890
EISSN	1432-2285
起始页码	2091
结束页码	2099
卷号	30 期号:6
英文摘要	The threshold minimum air temperature driving xylem growth of alpine Rhododendron aganniphum is lower than that commonly observed at the treeline of conifers. Understanding how alpine shrubs grow and which environmental factors drive their biomass gain could help to functionally differentiate trees and shrubs. The cambium is the main meristem responsible for wood formation in trees and shrubs. Thus, a better knowledge of cambium growth dynamics in alpine shrubs would allow explaining why shrubs displace trees above the treeline. Here, we aim to investigate the timings and dynamics of xylogenesis and to identify the thermal thresholds controlling the onset of xylem growth of Rhododendron aganniphum, a tall shrub growing above the alpine treeline on the Tibetan Plateau. Timings of xylogenesis and radial growth rates were assessed from anatomical observations of the developing xylem during three growing seasons (2011, 2012, and 2013). The threshold temperature at which xylogenesis had a 0.5 probability of being active was calculated with logistic regressions. The onset of xylogenesis was observed between mid and late June, whereas the end of xylogenesis lasted from mid to late September. Overall, the duration of xylem growth lasted 88-101 days, and 94 % of the ring was formed from June to August. The threshold for the onset of xylem growth was observed at 2.0 +/- 0.6 A degrees C for the minimum air temperature, lower than that commonly observed for treeline conifers (ca. 6 A degrees C). This low thermal threshold allows alpine shrubs to have a growing season long enough to complete xylem production and maturation during the warmest summer months. Our results suggest that the time required to complete xylogenesis is critical to understand why shrubs displace trees above the treeline.
关键词	CAMBIAL ACTIVITY CLIMATIC SIGNALS GROWING-SEASON SCOTS PINE SMITH FIR GROWTH TREE CONIFERS MOUNTAINS PERSPECTIVE
英文关键词	Rhododendron; Alpine shrub; Xylem growth; Wood formation; Cambial activity; Minimum air temperature; Short growing season
语种	英语
WOS研究方向	Forestry
WOS类目	Forestry
WOS记录号	WOS:000387723300017
来源期刊	TREES-STRUCTURE AND FUNCTION
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/258824
推荐引用方式 GB/T 7714	Li, Xiaoxia,Rossi, Sergio,Liang, Eryuan,et al. Temperature thresholds for the onset of xylogenesis in alpine shrubs on the Tibetan Plateau[J]. 中国科学院青藏高原研究所,2016,30(6).
APA	Li, Xiaoxia,Rossi, Sergio,Liang, Eryuan,&Julio Camarero, J..(2016).Temperature thresholds for the onset of xylogenesis in alpine shrubs on the Tibetan Plateau.TREES-STRUCTURE AND FUNCTION,30(6).
MLA	Li, Xiaoxia,et al."Temperature thresholds for the onset of xylogenesis in alpine shrubs on the Tibetan Plateau".TREES-STRUCTURE AND FUNCTION 30.6(2016).