山西省植被NPP时空变化特征及其驱动力分析

Variation characteristics of vegetation net primary productivity and its driving factors in Shanxi Province

关键词:  山西省, 植被净初级生产力, 土地利用类型, MODIS, 驱动力

Key words:  Shanxi Province, vegetation net primary productivity(NPP), land use type, MODIS, driving factor

摘要:

为科学有效地管理和调控植被资源,解决水土流失、植被减少等生态问题,该研究依据山西省2005—2015年MOD17A3H数据,利用ARCGIS、ENVI等软件,运用统计学分析方法,揭示了山西省植被NPP时空分布变化规律及对气候、人为等影响因素的响应特征。结果表明:山西省植被NPP平均值为326.5 g(C)·m^-2·a^-1,其中草地、耕地、灌丛和林地的NPP多年平均值依次为300.3、353.6、366.5和390.1 g(C)·m^-2·a^-1; 植被NPP总体波动增大、变化为显著、极显著、显著增大区域面积比例达56.33%,集中在山西省西部; 植被NPP极显著、显著减小区域面积集中在山西省东南角,占比为2.22%; 草地NPP变化速率最大,耕地大于灌丛,林地最小; 植被NPP平均值和降水平均值之间表现为呈显著正相关。基于栅格单元值计算,全省17.01%的区域植被NPP与降水之间表现为显著或极显著正相关,集中在山西省北部; 全省3.66%的区域植被NPP与气温之间表现为显著或极显著负相关,集中在山西省中部。这表明2005—2015年,山西省植被NPP总体呈好转趋势; 不同植被对人类活动及环境变化的响应有所差异,草地、耕地生态结构稳定性较弱,NPP变化明显,灌丛和林地稳定性较强,NPP数值稳定; 植被NPP与降水之间呈显著正相关,与气温之间呈负相关,气候因子整体上促进植被NPP增大,人为因素整体上抑制植被NPP增大。

Abstract:

In order to solve the ecological problems like soil erosion, vegetation reduction by scientifically and effectively management of vegetation resources. In this paper, the data of MOD17A3H in Shanxi Province were used to analyze the temporal and spatial distribution of vegetation net primary productivity(NPP)in Shanxi Province from 2005—2015 by using the software such as ARCGIS and ENVI. The climate, land use types and elevation data were also used to analyze the response characteristics of vegetation NPP to climate and other influencing factors by using statistical method. The results were as follows: The average vegetation NPP of Shanxi Province during 2005—2015 was 326.5 g(C)·m^-2·a^-1, and the average NPP of grassland, farmland, shrubs and forestland during 2005—2015 were 300.3, 353.6, 366.5 and 390.1 g(C)·m^-2·a^-1; The overall fluctuation of NPP in vegetation in Shanxi Province increased significantly with a significant or extremely significant increase in the proportion of regional area reached 56.33%, mainly concentrated in the western part of Shanxi Province; The significant or extremely significant reduction of vegetation NPP area was mainly concentrated in the southeastern corner of Shanxi Province, accounting for 2.22% of the total area; The rate of change of NPP in grassland was the largest, the farmland was greater than the shrub, and the forest land was the smallest; There was a significant positive correlation between the average of vegetation NPP and the average of precipitation in Shanxi Province. Based on calculated pixel value, the area of vegetation NPP and precipitation had significant or extremely significant positive relation in the total study area, accounting for 17.01%, mainly concentrated in northern Shanxi Province; The area of vegetation NPP and temperature had significant and extremely significant negative correlation relation in the total study area, accounting for 3.66%, mainly concentrated in central Shanxi Province. The results indicated that the vegetation NPP of Shanxi Province during 2005—2015 was improving; The response of different vegetation to human activities and environmental factors was different, the stability of grassland and farmland was weak, and the NPP changes obviously, the stability of shrub and forestland was strong, and NPP was stable; There was a significant positive correlation between vegetation NPP and precipitation, and a negative correlation between vegetation NPP and temperature, as a whole, the climate factor promotes the rise of NPP, while the human factor is mainly manifested as the inhibitory effect on NPP changes.