新疆地区草地植被物候时空变化

植被物候是反映环境条件和气候变化最客观、最敏感的指示器,研究新疆草地物候变化对于深入理解和预测陆地生态系统的动态变化具有重要的意义。利用土地覆盖动态产品(MCD12Q2)物候数据对新疆地区2001-2014年间草地物候的时空变化进行了研究,主要结论如下:1)草地植被物候多年均值由低海拔到高海拔呈明显的区域性差异。海拔每升高1000 m,返青期推迟13 d,枯黄期提前7 d,生长季长度缩短20 d;2)新疆不同草地类型的返青期在第100~136天,枯黄期在第256~291天,生长季长度为122~190 d;3)新疆草地返青期整体呈提前趋势,提前速率为0.11 d·yr^-1,草地枯黄期呈推迟趋势,推迟速率为0.14 d·yr^-1,生长季长度呈延长趋势,延长速率为0.25 d·yr^-1。

Spatio-temporal variations in grassland vegetation phenology in Xinjiang

Vegetation phenology is the most objective and sensitive indicator of environmental conditions and climate change. Therefore, grassland phenology research in Xinjiang has significance for understanding and predicting the dynamics of terrestrial ecosystems in this area. In this study, the spatio-temporal changes in grassland phenology in Xinjiang were evaluated using phenology data from the land cover dynamic product (MCD12Q2) for Xinjiang during 2001-2014. The main conclusions were as follows: 1) The perennial mean vegetation phenology in Xinjiang grassland showed obvious regional differences from low to high altitude. With every 1000 m increase in elevation, the SOG (start of the growing season) was delayed by 13 d, the EOG (end of the growing season) was advanced by 7 d, and the LOG (length of the growing season) was shortened by 20 d. 2) SOG occurred within 100th-136th days, EOG occurred within 256th-291th days, and the LOG occurred within 122-190 days. 3) Grassland SOG was advanced by 0.11 d·yr^-1, while the EOG was delayed by 0.14 d·yr^-1, and the LOG was prolonged by 0.25 d·yr^-1.