摘要
基于2001—2020年归一化植被指数(NDVI)、增强型植被指数(EVI)2种遥感植被指数以及蒙古高原94个气象站点的月最高、最低温和降水量数据,利用累积NDVI的Logistic曲线曲率极值法和动态阈值法2种物候识别方法提取蒙古高原植被返青期,分析蒙古高原昼夜非对称变暖的时空变化及其对植被返青期的影响。结果表明:(1)2001—2020年蒙古高原生长季开始前6个月(上一年11月—当年4月)平均最高温[0.7℃·(10a)-1]和最低温[0.3℃·(10a)-1]均呈上升趋势,最高温的变暖速率是最低温的2.3倍。(2)季前昼夜非对称变暖对植被返青期均产生提前作用,但与最高温相比,最低温对返青期的影响程度更大,且影响范围更为广泛。(3)季前昼夜非对称变暖对不同植被类型返青期产生不同影响,白天变暖对灌丛、农田和稀疏植被返青期的影响更明显,夜间变暖对森林和草地返青期的影响更强,特别是森林地区(25.5%)。研究白天和夜间非对称变暖对蒙古高原植被物候的影响,对揭示温度对春季植被物候的影响机制有重要意义。
Two phenological identification methods,namely,the logistic curve curvature extreme value method and the dynamic threshold method of cumulative NDVI,were used to extract the data based on the normalized difference vegetation index(NDVI)and enhanced vegetation index remote sensing vegetation indices from 2001 to 2020,as well as the highest temperature,the lowest temperature,and precipitation data of 94 meteorological stations in the Mongolian Plateau.The temporal and spatial changes of the Mongolian Plateau’s asymmetric circadian warming and its impact on the start of growing season were analyzed.The research shows the following:(1)The average maximum temperature[0.7℃·(10a)−1]and the minimum temperature[0.3℃·(10a)−1]in the preseason 6 months(November of the previous year to April of the current year)in the Mongolian Plateau from 2001 to 2020 both showed an upward trend,and the warming rate of the highest temperature was 2.3 times that of the lowest temperature.(2)The asymmetric warming of the preseason day and night has an early effect on the start of growing season;however,compared with the highest temperature,the lowest temperature has a greater impact on the start of growing season,and the impact range is wider.(3)The preseason asymmetrical warming of day and night has different effects on the start of growing season of different vegetation types.The effect of daytime warming on the start of the growing season of shrubs,farmland,and sparse vegetation is more obvious,and the effect of nighttime warming on the start of the growing season of forest and grassland is more obvious,especially in forest areas(25.5%).Studying the effects of daytime and nighttime asymmetric warming on vegetation phenology on the Mongolian Plateau is of great significance to reveal the mechanism of temperature effects on vegetation phenology in spring.
作者
张港栋
包刚
元志辉
温都日娜
ZHANG Gangdong;BAO Gang;YUAN Zhihui;WEN Durina(College of Geographical Science,Inner Mongolia Normal University,Hohhot 010022,Inner Mongolia,China;Inner Mongolia Key Laboratory of Remote Sensing&Geography Information System,Hohhot 010022,Inner Mongolia,China)
出处
《干旱区地理》
CSCD
北大核心
2023年第5期700-710,共11页
Arid Land Geography
基金
国家自然科学基金项目(41861021)
内蒙古自治区自然科学基金项目(2021MS04014)资助。
关键词
最高温
最低温
非对称变暖
返青期
蒙古高原
the highest temperature
the lowest temperature
asymmetric warming
start of growing season
Mongolian Plateau
