河南省植被NPP时空分异及其驱动因子

Spatio-temporal differentiation of vegetation net primary productivity in Henan Province as well as its driving factors

植被净初级生产力(net primary productivity,NPP)是判定生态系统碳源/碳汇的主要参数之一,具有区域差异性。综合MOD17A3HGF、地形和人类活动等数据,运用重心、趋势分析和地理探测器等方法,探究2010—2020年河南省植被NPP时空分异及其对驱动因子的响应,揭示各因子解释力及交互作用。结果表明,时间上,2010—2020年植被NPP呈波动微上升趋势,多年均值为424.89 gC·m^(-2)·a^(-1);重心演变时间分异明显,平均重心距离几何中心较近。空间上,植被NPP自东北向西南递增,以中值区(300~600 gC·m^(-2)·a^(-1))为主。影响因素上,降水与植被NPP的相关性高于气温;植被NPP随海拔、坡度的增加而先增加后减少,海拔小于200 m、坡度小于2°的区域对研究区NPP贡献最大;阳坡植被NPP相较于阴坡更高;土地利用变化下,向耕地的转化对NPP总量增长起主要作用。地理探测显示,对植被NPP变化解释力最强的单因子为降水;双因子交互均表现为增强关系,其中降水∩经度q值最高。研究结果可为河南省生态保护和高质量发展提供数据支持。

The net primary productivity(NPP)of vegetation,exhibiting regional differentiation,serves as a crucial parameter for determining the carbon source/sink of ecosystems.Based on the MOD17A3HGF,topography,and human activity data,this study delved into the spatio-temporal differentiation of vegetation NPP in Henan Province m 2010 to 2020 and its response to driving factors using methods like the gravity center model,trend analysis,and the geographical detector model.Moreover,it revealed the explanatory power and interactions of the driving factors.The results are as follows:①Temporally,the vegetation NPP m 2010 to 2020 displayed a slightly fluctuating upward trend,averaging 424.89 gC·m^(-2)·a^(-1).Its gravity center exhibited significant temporal differentiation,with the average center of gravity closer to the geometric center.②Spatially,the vegetation NPP values increased from the northeast to the southwest and were dominated by median values(300~600 gC·m^(-2)·a^(-1)).③In terms of influencing factors,the vegetation NPP showed a higher correlation with precipitation compared to temperature.Moreover,it first increased and then decreased with an increase in altitude and slope.The areas with altitudes below 200 m and slopes less than 2°contributed the most to NPP in the study area.The vegetation NPP on sunny slopes was higher than that on shady slopes.In the case of land use changes,the shift to arable land plays a significant role in the increase of total NPP.④The geographical detection results indicate that precipitation exhibited the highest explanatory power for changes in vegetation NPP.The two-factor interactions all showed an enhanced relationship,with the q value of precipitation∩longitude being the highest.These findings provide data support for ecological protection and high-quality development of Henan Province.