摘要
The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has important ecological meaning and profound social and economic signiifcance. Here, spatio-temporal variation in vegetation cover under the TNSP was examined using the NDVI average method, major climatic factors such as temperature and precipitation, and linear regression trend analysis from 1982 to 2006. We found that in the past 25 years, NDVI vegetation in the study area has consistently risen at a rate of 0.007 per decade. Vegetation cover, temperature and precipitation are positively correlated. The area of vegetation associated with precipitation is larger than the area related to temperature;precipitation is the key factor affecting vegetation growth across the TNSP. From 1982 to 2006, regions with improved vegetation cover were found in the central and southern part of the Greater Khingan Mountains, central part of the Lesser Khingan Mountains, northeastern part of the Changbai Mountains, Yanshan Mountians, Western Liaoning Hilly Region, Altai Mountains, Tien Shan Mountains, eastern part of the Qilian Mountains, eastern part of the northwest desert as wel as southern part of the Gul y Region of the Loess Plateau. However, vegetation cover declined on both sides of the Greater Khingan Mountains, western part of the Hulun Buir Plateau, northern part of the Sanjiang Plain, southern part of Horqin Sandy Land, southern part of the northwest desert and northern part of the Gul y Region of the Loess Plateau.
本文基于1982-2006年连续25年的GIMMS AVHRR NDVI植被覆盖指数,采用了最大化NDVI均值法、与气温及降水变化的相关性和一元线性回归趋势分析法,对中国三北防护林工程区连续25年的植被覆盖时空变化特征进行了动态变化研究。结果表明:(1)近25年来,研究区植被NDVI平均值总体呈缓慢上升趋势,增速为每10年0.007;(2)研究区植被和气温、降水整体呈正相关关系,植被与降水正相关面积明显大于植被与气温正相关面积,说明降水是研究区植被生长的关键因子;(3)1982-2006年,研究区植被覆盖增加的区域主要分布在大兴安岭中、南部,小兴安岭中部,长白山东北段,燕山,辽西低山丘陵区,阿尔泰山,天山,祁连山东段,西北荒漠区东部和黄土高原丘陵沟壑区南部等;植被覆盖减少的区域主要是在大兴安岭两侧,呼伦贝尔高原西部,三江平原北部,科尔沁沙地南端,西北荒漠区南部和黄土高原丘陵沟壑区北部等。
基金
National Natural Science Foundation of China(41171116
40961038)
