{"title":"[Climate change affects plant aboveground biomass by regulating the growth periods in alpine grasslands of the Tibetan Plateau, China].","authors":"Cong-Ying Yang, Ying Ding, Fu-Lin Ma, Hua-Kun Zhou, Xiao-Li Wang, Qiang Zhang, Xiao-Wei Liu, Wubuli Mutalifu, Liang Guo","doi":"10.13287/j.1001-9332.202405.020","DOIUrl":null,"url":null,"abstract":"<p><p>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 <i>Stipa sareptana</i> var. <i>krylovii</i> (the dominant species) decreased significantly. However, absolute and relative biomass of subdominant species (<i>Kobresia humilis</i>) increased significantly, indicating that the dominance of <i>K. humilis</i> increased. The warm-wet climates enhanced aboveground biomass accumulation of <i>K. humilis</i> by extending the period of reproductive growth. Mean annual temperature and annual precipitation decreased aboveground biomass of <i>S. sareptana</i> 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.</p>","PeriodicalId":35942,"journal":{"name":"应用生态学报","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"应用生态学报","FirstCategoryId":"1087","ListUrlMain":"https://doi.org/10.13287/j.1001-9332.202405.020","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Environmental Science","Score":null,"Total":0}
引用次数: 0
Abstract
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.
气候变化对青藏高原高寒草地的植物生物量和物候期有明显影响。物候期的变化与植物生长期和生殖生长期的长短密切相关,可能进一步影响地上生物量的积累。本研究基于青藏高原高寒草地1997-2020年植物生物量和物候期的定点观测数据以及相应的气候数据,采用普通线性回归和片断结构方程模型等统计方法,探讨了研究区年际气候变化特征、植物生物量和物候期的变化趋势以及生物量与物候、气候因子之间的相关性。结果表明,1997-2020年研究区年平均气温和年降水量显著增加,呈现明显的 "暖湿 "趋势。Stipa sareptana var. krylovii(优势种)的地上生物量和相对生物量显著下降。然而,次优势物种(Kobresia humilis)的绝对生物量和相对生物量却大幅增加,表明 K. humilis 的优势地位增强。温暖湿润的气候延长了蒿属植物的生殖生长期,从而增加了其地上生物量的积累。年平均气温和年降水量缩短了 S. sareptana 的无性生长期,从而减少了其地上生物量。总之,较暖较湿的气候通过调节物候期的变化显著影响了地上生物量的积累,其种间反应的差异导致群落组成发生了较大的变化。该研究区域可能呈现出从高山草地向高山草甸发展的趋势,因此急需开展进一步的工作。