气候变化领域集成服务门户(CCPortal): Seed-based treeline seedlings are vulnerable to freezing events in the early growing season under a warmer climate: Evidence from a reciprocal transplant experiment in the Sergyemla Mountains, southeast Tibet

CCPortal

DOI	10.1016/j.agrformet.2013.12.004
	Seed-based treeline seedlings are vulnerable to freezing events in the early growing season under a warmer climate: Evidence from a reciprocal transplant experiment in the Sergyemla Mountains, southeast Tibet
	Shen, Wei; Zhang, Lin; Liu, Xinsheng; Luo, Tianxiang
通讯作者	Luo, TX (通讯作者)
发表日期	2014
ISSN	0168-1923
EISSN	1873-2240
起始页码	83
结束页码	92
卷号	187
英文摘要	Seedling mortality is important to the formation and dynamics of alpine treeline. There is a need to understand the mechanisms governing seedling mortality at and above treelines under a warmer climate. We tested the hypothesis that under a warmer climate, seed-based treeline seedlings are especially vulnerable to freezing events in the early growing season. Using space-for-time substitution, we conducted a 5-yr reciprocal transplant experiment for >10 yr-old seedlings of seed-based fir and root-sprouting juniper between north-facing and south-facing slopes of a valley with elevations of 4200-4600 m in the Sergyemla Mountains, and additional experiments of seed germination and younger seedling transplants (with ages of 3-5 yr) at and above the fir treeline. Between both slopes, annual precipitation was similar but annual mean air-temperature above the treeline differed by 2.0 degrees C, being comparable to the temporal difference of 2.3 degrees C between the warmest and coldest years and the unchanged trend of precipitation during 1960-2008 at Nyingchi station nearby the study sites. The frequency, intensity and duration of growing-season freezing events were much higher under the warmer climate on the south-facing slope. Across years and non-forested sites above both treelines, annual mean air-temperature was well correlated with the early-season (April-June) freezing events. In pooled data across years and sites, annual mortality increased in fir seedlings but varied little in juniper seedlings with increasing freezing events in the early growing season. Similar patterns were also found in their annual growth rates. Partial correlation analysis indicated that the early-season freezing event was the major limiting factor determining annual mortality of fir seedlings, while that of juniper seedlings varied little with all the microclimate factors. Harsh environments above the treeline did not limit fir seed germination. The finding that the early-season freezing events under a warmer climate increased fir seedling mortality can explain the cause for the unique distribution pattern of fir and juniper treelines on opposite slopes of a valley in southeast Tibet, and suggests an explanation for the phenomenon that the world's highest fir-treeline position did not advance with climatic warming in past 200 years. (C) 2013 Elsevier B.V. All rights reserved.
关键词	PINUS-SYLVESTRIS ALPINE TEMPERATURE PATTERNS GROWTH FROST REGENERATION CONSTRAINTS VARIABILITY RECRUITMENT
英文关键词	Alpine treeline; Climate change; Frost; Mortality; Seedling; Transplant
语种	英语
WOS研究方向	Agriculture ; Forestry ; Meteorology & Atmospheric Sciences
WOS类目	Agronomy ; Forestry ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000331489100008
来源期刊	AGRICULTURAL AND FOREST METEOROLOGY
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/258274
推荐引用方式 GB/T 7714	Shen, Wei,Zhang, Lin,Liu, Xinsheng,et al. Seed-based treeline seedlings are vulnerable to freezing events in the early growing season under a warmer climate: Evidence from a reciprocal transplant experiment in the Sergyemla Mountains, southeast Tibet[J]. 中国科学院青藏高原研究所,2014,187.
APA	Shen, Wei,Zhang, Lin,Liu, Xinsheng,&Luo, Tianxiang.(2014).Seed-based treeline seedlings are vulnerable to freezing events in the early growing season under a warmer climate: Evidence from a reciprocal transplant experiment in the Sergyemla Mountains, southeast Tibet.AGRICULTURAL AND FOREST METEOROLOGY,187.
MLA	Shen, Wei,et al."Seed-based treeline seedlings are vulnerable to freezing events in the early growing season under a warmer climate: Evidence from a reciprocal transplant experiment in the Sergyemla Mountains, southeast Tibet".AGRICULTURAL AND FOREST METEOROLOGY 187(2014).