川西高山-亚高山草地群落特征及稳定性对增温的响应  

Response of Community Characteristics and Stability of Alpine-Subalpine Grassland to Warming in Western Sichuan of China

作　　者：宋扎磋 王腊梅 张莉 陆徐伟 陈程浩 杨燕[4] 索南吉 SONG Zhacuo;WANG Lamei;ZHANG Li;LU Xuwei;CHEN Chenghao;YANG Yan;SUO Nanji(Life Science College,Qinghai Normal University,Xining 810016,China;Forest and Grassland Bureau of Ganzi Tibetan Autonomous Prefecture,Ganzi 626001,Sichuan,China;Chaotian Emergency Management Bureau of Guangyuan City,Guangyuan 628021,Sichuan,China;Chengdu Institute of Mountain Hazards and Environment,Chinese Academy of Sciences&Ministry of Water Resources,Chengdu 610041,China;Academy of Plateau Science and Sustainability,Qinghai Normal University,Xining 810016,China)

机构地区：[1]青海师范大学生命科学学院,西宁810016 [2]甘孜藏族自治州林业和草原局,四川甘孜626001 [3]广元市朝天区应急管理局,四川广元628021 [4]中国科学院、水利部成都山地灾害与环境研究所,成都610041 [5]青海师范大学高原科学与可持续发展研究院,西宁810016

出　　处：《山地学报》2023年第3期348-360,共13页Mountain Research

基　　金：国家自然科学基金(32160285);四川省科技计划引智成果示范推广项目(2022ZHYZ0005);青海省科技厅自然科学基金青年项目(2020-ZJ-952Q)。

摘　　要：川西高山-亚高山区域作为中国长江、黄河上游的重要生态屏障,拥有丰富的生物多样性。川西高山-亚高山草地生态系统对增温变化敏感,但对其草地生态系统群落及其稳定性对增温的响应研究仍存在不足。由于指标选取单一、研究尺度小等研究方法问题,已有研究结论的代表性不足。为了深入了解这一生态系统在不同海拔高度上对气候变暖的响应特征,本研究在贡嘎山东北坡雅家埂峡谷地带,沿海拔3000~4130 m设置4个高山亚高山草地样地,采用两种常用的模拟增温模式(OTC增温和带草皮下移增温)模拟环境温度升高,研究2012—2017年期间,不同海拔梯度上草地物种丰富度、群落高度和盖度、地上净初级生产力对增温的响应特征,以及这些特征变化与群落生物量时间稳定性的关系。结果表明:(1)OTC增温仅在高海拔寒冷样地降低了物种丰富度,不影响中低海拔样地的物种丰富度;下移增温增加了高海拔寒冷样地的物种丰富度,却降低了低海拔温暖样地的物种丰富度;(2)OTC增温仅增加了高海拔寒冷样地的群落高度,下移增温显著增加了所有海拔梯度上的植被高度;(3)在两个中间海拔梯度样地,两种增温模式都降低了杂草类植物盖度,却增加了莎草与禾草的盖度;(4)仅有下移增温显著增加了高海拔寒冷样地的地上净初级生产力,各功能群地上净初级生产力的变化存在海拔差异;(5)位于灌草交错带3850 m样地的群落生物量时间稳定性最高,而位于4130 m的高海拔寒冷样地的群落生物量时间稳定性最弱。研究表明,高海拔寒冷生境的草地群落组成结构和地上净初级生产力易受到气候变暖的影响,趋于不稳定。本研究可为川西高山草地生态系统应对未来气候变暖的生态保护管理与政策制定提供科学依据。As an important ecological barrier in the upper reaches of the Yangtze River and the Yellow River,the alpine-subalpine region in western Sichuan is rich in biodiversity.The alpine-subalpine grassland ecosystem in the region is sensitive to local warming changes under the circumstance of global warming,but there were insufficient studies on the response of grassland ecosystem communities and their stability to warming.This was quite possibly due to poor research methodologies,such as the improper application of single indicator in a model or small research scales extending to a large scale,inevitably making parts of research conclusions are neither comprehensive nor convincing.To better predict the responses of alpine-subalpine grassland ecosystem to incoming climate changes at different elevations,in this study four sample plots of natural alpine-subalpine grassland were selected from 3000 m to 4130 m in the Yajiageng valley,northeast slope of the Gongga Mountain,western Sichuan,China;two common warming methods of simulating,Open Top Chambers(OTCs)warming and transplanting warming were used to simulate ambient temperature rise.The responses of five indicators,including aboveground vegetation species richness,communality height,total coverage,and Aboveground Net Primary Productivity(ANPP)at each plot in the period of 2012-2017 were recorded and the relationship between the indicators and the temporal stability of community biomass was analyzed.It has the following findings:(1)OTCs warming reduced species richness only in the coldest plots at the highest altitude,but did not affected those in middle-low altitude,whereas transplanting warming increased species richness in the coldest plots at the highest altitude site,but it decreased species richness at plots in the middle-low altitude.(2)OTCs warming only increased vegetation height in the coldest plots at the highest altitude,whereas transplanting warming increased vegetation height at all plots significantly.(3)Two warming methods both deceased the forb coverage

关 键 词：高山亚高山草地 增温 物种丰富度 地上净初级生产力 群落生物量时间稳定性 

分 类 号：Q14[生物学—生态学]