气候变化通过调控青藏高原高寒草原植物生育期影响地上生物量积累  

Climate change affects plant aboveground biomass by regulating the growth periods in alpine grasslands of the Tibetan Plateau,China

作　　者：杨聪颖 丁颖 马扶林 周华坤[3,4] 王晓丽 张强 刘小伟 木塔力甫·吾布力 郭梁[7,8] YANG Congying;DING Ying;MA Fulin;ZHOU Huakun;WANG Xiaoli;ZHANG Qiang;LIU Xiaowei;MUTALIFU Wubuli;GUO Liang(College of Grassland Agriculture,Northwest A&F University,Yangling 712100,Shaanxi,China;Haibei Livestock Experiment Weather Station,Haibei 810200,Qinghai,China;Key Laboratory of Restoration Ecology of Cold Areas in Qinghai Province,Northwest Institute of Plateau Biology,Chinese Academy of Sciences,Xining 810008,China;Key Laboratory of Adaptation and Evolution of Plateau Biota,Chinese Academy of Sciences,Xining 810008,China;State Key Laboratory of Plateau Ecology and Agriculture/Ministry of Education Key Laboratory of the Alpine Grassland Ecology in the Three Rivers Region,Qinghai University,Xining 810016,China;Qinghai Academy of Animal and Veterinary Science,Qinghai University,Xining 810016,China;College of Soil and Water Conservation Science and Engineering,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute Soil and Water Conservation,Ministry of Water Resources and Chinese Academy of Sciences,Yangling 712100,Shaanxi,China)

机构地区：[1]西北农林科技大学草业与草原学院,陕西杨凌712100 [2]青海省海北牧业气象试验站,青海海北810200 [3]中国科学院西北高原生物研究所青海省寒区恢复生态学重点实验室,西宁810008 [4]中国科学院高原生物适应与进化重点实验室,西宁810008 [5]青海大学省部共建三江源生态与高原农牧业国家重点实验室/三江源区高寒草地生态教育部重点实验室,西宁810016 [6]青海大学畜牧兽医科学院,西宁810016 [7]西北农林科技大学水土保持科学与工程学院,陕西杨凌712100 [8]中国科学院-水利部水土保持研究所,陕西杨凌712100

出　　处：《应用生态学报》2024年第5期1260-1268,共9页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(42377471,UZIA2021);西北农林科技大学“青年英才培育计划”项目(2452020009)资助。

摘　　要：气候变化显著影响青藏高原高寒草原植物生物量及物候发生时间,且物候期的变化与植物营养生长期和生殖生长期长度紧密关联,可进一步影响植物生物量的积累。本研究基于1997—2020年青藏高原高寒草原植物生物量和物候定点观测及相应气候资料,应用简单线性回归及分段结构方程模型等统计方法,探究了研究区气候年际变化特征,不同植物生物量、物候期变化趋势,以及生物量与物候及气候因子的关联性。结果表明:1997—2020年间,研究区年均温和年降水量均呈显著上升趋势,呈现出明显“暖湿化”趋势;研究区优势种西北针茅的地上生物量及其在群落总生物量中的占比显著下降,而次优势种矮嵩草的生物量及其在群落总生物量中的占比则显著增加,表明矮嵩草在该高寒草原群落中的优势度日益升高;研究区暖湿化气候通过显著延长矮嵩草的生殖生长期提高了其地上生物量;年均温和年降水量通过显著缩短西北针茅的营养生长期进而降低其地上生物量的积累。总之,气候暖湿化通过调控物候期变化显著影响了植物地上生物量积累,物种间响应的差异性导致高寒草原植物组成发生了较大变化,研究区呈现出高寒草原向高寒草甸转变的趋势,亟待深入研究。Climate change significantly affects plant biomass and phenological occurrence time in alpine grasslands of Tibetan Plateau.The changes in phenological periods are closely related to the length of vegetative and reproductive growth periods,which may further affect aboveground biomass accumulation.In this study,based on fixed-point observations of plant biomass and phenology as well as the corresponding climatic data from 1997 to 2020 in the alpine grasslands of Tibetan Plateau,we used statistical methods such as ordinary linear regression and piecewise structural equation model to explore the characteristics of interannual climate change in the study area,the variation trends of plant biomass and phenological periods,and the correlations between biomass and phenological and climatic factors.The results showed that mean annual temperature and annual precipitation in the study area increased significantly from 1997 to 2020,suggesting a clear“warm-wet”trend.Aboveground biomass and relative biomass of Stipa sareptana var.krylovii(the dominant species)decreased significantly.However,absolute and relative biomass of subdominant species(Kobresia humilis)increased significantly,indicating that the dominance of K.humilis increased.The warm-wet climates enhanced aboveground biomass accumulation of K.humilis by extending the period of reproductive growth.Mean annual temperature and annual precipitation decreased aboveground biomass of S.sareptana by shortening the length of vegetative growth period.In a word,the warmer and wetter climate significantly affected aboveground biomass accumulation by regulating the changes in the phenological period,and the interspecific difference in their response resulted in a larger change in community composition.This study area may show a trend from alpine grassland to alpine meadow,and thus further works are urgently needed.

关 键 词：高寒草原 暖湿化 地上生物量 物候 矮嵩草 西北针茅 

分 类 号：S812[农业科学—草业科学]