摘要
基于2000-2014年间植被生长季(4-10月)的MODIS NDVI数据反演浑善达克沙地地区植被覆盖变化,结合2000-2013年该地区周边11个气象站点的气温和降水数据,分别从年际变化和月变化角度分析该地区植被覆盖变化对气候变化的响应。研究表明,浑善达克沙地植被NDVI,不论是植被生长季平均值,还是其各月份值都呈上升趋势。研究区植被覆盖度的显著增加是气候和人为因素综合作用的结果,一定程度上反映了生态恢复重建措施的有效性,但其植被NDVI年际变化趋势与降水量的关系更密切,其相关系数达到0.75,是驱动植被覆盖年际波动的最直接因素。在空间分布上,研究区的南部、中部和北部边缘区域的植被覆盖增加趋势较明显,而中部和西部部分区域未发生明显的趋势性变化。从月变化来看,4月草地植被变化受气温变化影响较明显;5-8月与前一月降水变化关系密切,说明植被生长对降水变化具有一定的滞后性。从沙地类型植被覆盖年际变化趋势看,所有类型都呈增加态势,增加态势最大的类型是移动沙地,最小的是固定沙地。
MODIS NDVI collected during the growing season(from April to October)from 2000 to 2014were adopted and integrated in this study to extract the time series characteristics of vegetation dynamics in Otindag sand country.The response of vegetation changes to climate data including temperature and precipitation recorded at fifteen meteorological stations were analyzed during 2000 to 2013using annual and monthly time scales.The results revealed that regardless of the time scale(monthly or annual),the NDVI tended to increase over the 15-year observation period a result of climate and human activity Ecological restoration,indicating that ecological restoration work has produced benefits.The annual NDVI was correlated with precipitation(r=0.75),indicating that precipitation was the dominant factor in vegetation dynamics.With respect to spatial pattern,the NDVI in southern,central and northern fringe regions of the study area tended to increase but no obvious trends were observed in the central and some western areas of the region.Correlation between monthly average NDVI and climatic factors during the growing season showed that the response of vegetation change to temperature in April and May was strong,indicating that temperature was important in the early stages of the growing season.Correlation between NDVI and precipitation of the previous month were strongest from May to August revealing a hysteresis response of plant growth to rainfall.Shifting sand dunes showed the largest increase in NDVI while the smallest increase occurred in fixed sand dunes.
出处
《草业学报》
CSCD
北大核心
2016年第1期33-46,共14页
Acta Prataculturae Sinica
基金
内蒙古自治区自然基金(2013ZD084)
国家自然科学基金(41301456)
内蒙古师范大学重大项目培育专项项目(2013ZDPY0)资助