植物生态学报 ›› 2008, Vol. 32 ›› Issue (5): 1061-1071.DOI: 10.3773/j.issn.1005-264x.2008.05.011

• 研究论文 • 上一篇    下一篇

川西亚高山林线交错带糙皮桦和岷江冷杉幼苗物候与生长对模拟增温的响应

徐振锋1, 胡庭兴1,*(), 张远彬2, 鲜骏仁1, 王开运2,3   

  1. 1 四川农业大学林学园艺学院,四川雅安 625014
    2 中国科学院成都生物研究所,成都 610041
    3 华东师范大学上海市城市化生态过程和生态恢复重点实验室,上海 200062
  • 收稿日期:2007-11-22 接受日期:2008-04-22 出版日期:2008-11-22 发布日期:2008-09-30
  • 通讯作者: 胡庭兴
  • 作者简介:*(hutx001@yahoo.com.cn)
  • 基金资助:
    国家自然科学基金重大项目(90511008);国家自然科学基金重大项目(90202010);四川省科技攻关项目资助项目(05SG023-009);上海市城市化生态过程和生态恢复重点实验室开放基金(20070010)

RESPONSES OF PHENOLOGY AND GROWTH OF BETULA UTILIS AND ABIES FAXONIANA IN SUBALPINE TIMBERLINE ECOTONE TO SIMULATED GLOBAL WARMING, WESTERN SICHUAN, CHINA

XU Zhen-Feng1, HU Ting-Xing1,*(), ZHANG Yuan-Bin2, XIAN Jun-Ren1, WANG Kai-Yun2,3   

  1. 1Faculty of Forestry, Sichuan Agricultural University, Ya’an, Sichuan 625014, China
    2Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
    3Shanghai Key Laboratory of Urbanization Processes and Ecological Restoration, East China Normal University, Shanghai 200062, China
  • Received:2007-11-22 Accepted:2008-04-22 Online:2008-11-22 Published:2008-09-30
  • Contact: HU Ting-Xing

摘要:

采用开顶式生长室(Open-top chamber, OTC)模拟增温对植被影响的研究方法, 研究了川西亚高山林线交错带糙皮桦(Betula utilis)和岷江冷杉(Abies faxoniana)幼苗物候及生长特性对模拟增温的响应。结果表明, 温度升高使岷江冷杉幼苗芽开放时间显著提前(15.2 d); 糙皮桦春季芽物候期变化不显著, 而落叶时间明显推迟(19.7 d), 叶寿命延长(22.8 d)。与对照(CK)相比, OTC内糙皮桦叶面积和岷江冷杉叶片长度及两者侧枝生长速率都显著加快。模拟增温对两物种基径相对生长速率都表现为正效应, 增温对两物种枝叶特性及分布格局表现为不同程度的正效应、负效应或无影响。不同功能型两物种对模拟增温响应方式存在一定程度差异。

关键词: 林线交错带, 糙皮桦, 岷江冷杉, 物候, 生长, 开顶式生长室

Abstract:

Aims Betula utilis andAbies faxoniana are two typical, important plants in timberline ecotone in subalpine regions of western Sichuan, China. Their responses in phenology, growth and leaf and branch traits to simulated global warming can be studied using the open-top chamber (OTC) method. The main purposes of our experiment are to determine how two species change their phenology, whether shoot growth is enhanced and whether responsive patterns of deciduous and evergreen species are consistent. We reported the second year’s responses of plants to the OTC treatment.

Methods During the 2007 growing season, we observed phenological events (bud break, leaf expansion and defoliation) and measured branch and leaf growth rates, traits and distribution patterns. Microclimate data between OTCs and control plots (CK) were automatically recorded at 15-minute intervals. We analyzed phenological events, leaf area, branch length, etc. for OTCs and CKs by the Mann-Whitney U-test. Specific leaf area (SLA) was analyzed by the Wilcoxon’s signed ranks test.

Important findings Air temperature at vegetation height (1.2 m) increased by 2.9 oC during the growing season, and soil temperature at 5 cm depth did not differ between OTC and CK throughout the growing season. Abies faxonianashowed earlier bud break in the OTC, and B. utilishad extended foliage period and individual leaf longevity in the OTC. Elevated temperature resulted in higher leaf and branch growth rates and basal diameter relative growth rates for both species. There were significant differences in SLA and leaf size for B. utilisbetween the OTC and the CK. Different responses (positive, negative or no effects) were found in branch length, branch number and leaf distribution pattern for both species. Therefore, evergreen conifer and deciduous broad-leaved species differ in their responses to warming.

Key words: ecotone in timberline, Betula utilis, Abies faxoniana, phenology, growth, open-top chamber