摘要
【目的】监测沙区区域植被物候,并确定植被物候与气候要素的关系,对理解沙区生态系统对气候变化的动态响应至关重要。【方法】本研究利用1982年1月至2015年12月的归一化差值植被指数(NDVI)时间序列数据,通过高阶曲线拟合的方法提取毛乌素沙地植被物候,包括生长季开始日期、结束日期和长度,分析其时间变化和空间特征,并利用偏相关性分析法确定其与气象因子(气温和降水量)的关系。【结果】毛乌素沙地植被生长季开始日期集中在第96~144天,生长季结束日期集中于第280~300天,生长季长度介于135~195 d。从东到西生长季开始日期逐渐推迟,生长季长度逐渐缩短,生长季结束日期没有明显变化。在过去34年中,毛乌素沙地植被生长季开始日期和长度分别呈现显著提前和延长的趋势,分别为0.54和0.94 d/a,生长季结束日期呈现推迟趋势,但该趋势并不显著。毛乌素沙地植被的生长季开始日期主要受2—4月的平均气温影响,结束日期主要受8—10月的累计降水量的影响。【结论】毛乌素沙地植被物候特征发生了明显变化,主要体现在生长季的提前和延长,这对该区域植被恢复与荒漠化的逆转具有一定的促进作用。
[ Objective ] Monitoring regional vegetation phenology in sand area and determining the relations between vegetation phenology and meteorological factors are crucial to understand the dynamic response of sand area ecosystem to climate change. [ Method ] In this study, through normalized difference vegetation index (NDVI) time series data, we extracted vegetation phenology by Polyfit- Maximum method, and analyzed the trends and relationships between vegetation phenology and climatic factors (air temperature and precipitation) in the Mu Us Desert of northern China over the past three decades (1982-2015). [ Result] In the Mu Us Desert, The beginning date of growing season concentrated in the 96th - 144th day, the ending date of growing season concentrated in the 280th -300th day, and the length of growing season ranged in 135 - 195 days. From east to west, the beginning date of growing season postponed gradually and growing season length shortened gradually, while there was no obvious change in the ending date of growing season. In the past 34 years, the beginning date and length of growing season for vegetation in the Mu Us Desert showed significantly advanced and prolonged trend, and the changing rates were 0. 54 day/year and 0.94 day/year, respectively. While the ending date of growing season showed postponed trend but not delayed obviously. The beginning date of growing season for vegetation in the Mu Us Desert was mainly affected by the mean air temperature from February to April, and its ending date was mainly affected by the accumulated precipitation from August to October. [ Conclusion] The vegetation phenology characteristics have changed significantly in Mu Us Desert, which was mainly reflected in the advancement and extension of growing season. This will promote the vegetation restoration and desertification reversion in the study area.
作者
朱娅坤
秦树高
张宇清
张举涛
邵艳莹
高岩
Zhu Yakun;Qin Shugao;Zhang Yuqing;Zhang Jutao;Shao Yanying;Gao Yan(Yanchi Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Key Laboratory of State Forestry Administration on Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2018年第9期98-106,共9页
Journal of Beijing Forestry University
基金
国家重点研发计划课题(2016YFC0500905)
中央高校基本科研业务费专项(2015ZCQ-SB-02)
关键词
NDVI
植被物候
毛乌素沙地
气象因子
时空动态
NDVI
vegetation phenology
Mu Us Desert
meteorological factor
spatiotemporal dynamics