文献类型：期刊文献

英文题名：Precipitation and Minimum Temperature are Primary Climatic Controls of Alpine Grassland Autumn Phenology on the Qinghai-Tibet Plateau

作者：An, Shuai[1];Chen, Xiaoqiu[2];Zhang, Xiaoyang[3,4];Lang, Weiguang[2];Ren, Shilong[5];Xu, Lin[6]

第一作者：安帅

通讯作者：Chen, XQ[1]

机构：[1]Beijing Union Univ, Coll Appl Arts & Sci, Beijing 100191, Peoples R China;[2]Peking Univ, Coll Urban & Environm Sci, Minist Educ, Lab Earth Surface Proc, Beijing 100871, Peoples R China;[3]South Dakota State Univ, GSCE, Brookings, SD 57007 USA;[4]South Dakota State Univ, Dept Geog & Geospatial Sci, Brookings, SD 57007 USA;[5]Shandong Univ, Environm Res Inst, Qingdao 266237, Peoples R China;[6]China Agr Univ, Coll Resources & Environm Sci, Beijing 100193, Peoples R China

第一机构：北京联合大学应用文理学院

通讯机构：[1]corresponding author), Peking Univ, Coll Urban & Environm Sci, Minist Educ, Lab Earth Surface Proc, Beijing 100871, Peoples R China.

年份：2020

卷号：12

期号：3

外文期刊名：REMOTE SENSING

收录：;EI(收录号：20201008275037);Scopus(收录号：2-s2.0-85080891150);WOS:【SCI-EXPANDED(收录号:WOS:000515393800090)】；

基金：This work was funded by the Premium Funding Project for Academic Human Resources Development in Beijing Union University no. BPHR2019DZ01 and the National Natural Science Foundation of China under grant nos. 41771049 and 41471033.

语种：英文

外文关键词：land surface phenology; MODIS data; middle senescence date; impacts of climatic factors; precipitation sensitivity; alpine grassland ecosystem

摘要：Autumn phenology is a crucial indicator for identifying the alpine grassland growing season's end date on the Qinghai-Tibet Plateau (QTP), which intensely controls biogeochemical cycles in this ecosystem. Although autumn phenology is thought to be mainly influenced by the preseason temperature, precipitation, and insolation in alpine grasslands, the relative contributions of these climatic factors on the QTP remain uncertain. To quantify the impacts of climatic factors on autumn phenology, we built stepwise linear regression models for 91 meteorological stations on the QTP using in situ herb brown-off dates, remotely sensed autumn phenological metrics, and a multi-factor climate dataset during an optimum length period. The results show that autumn precipitation has the most extensive influence on interannual variation in alpine grassland autumn phenology. On average, a 10 mm increase in autumn precipitation during the optimum length period may lead to a delay of 0.2 to 4 days in the middle senescence date (P < 0.05) across the alpine grasslands. The daily minimum air temperature is the second most important controlling factor, namely, a 1 degrees C increase in the mean autumn minimum temperature during the optimum length period may induce a delay of 1.6 to 9.3 days in the middle senescence date (P < 0.05) across the alpine grasslands. Sunshine duration is the third extensive controlling factor. However, its influence is spatially limited. Moreover, the relative humidity and wind speed also have strong influences at a few stations. Further analysis indicates that the autumn phenology at stations with less autumn precipitation is more sensitive to precipitation variation than at stations with more autumn precipitation. This implies that autumn drought in arid regions would intensely accelerate the leaf senescence of alpine grasslands. This study suggests that precipitation should be considered for improving process-based autumn phenology models in QTP alpine grasslands.