2001—2022年黄河流域生态区植被净初级生产力时空变化及影响因素分析

Analysis on the spatio-temporal variation and influencing factors of net primary productivity of vegetation in the ecological region of the Yellow River basin from 2001 to 2022

净初级生产力(NPP)代表了生态系统与大气的碳交换水平,是生态系统物质和能量循环的“转化器”,也是评价和预测生态系统可持续发展的重要指标。本研究以黄河流域为研究区,结合回归分析、Hurst指数和残差分析等方法,以生态区的视角对2001—2022年间黄河流域植被NPP的时空变化及其影响因素进行了分析,探讨气候和人类活动等因素对黄河流域植被NPP的影响,并对NPP未来演变趋势进行预测。结果表明:1)2001—2022年间黄河流域植被NPP年平均值为291.03 gC/m^(2),表现为北部低南部高的空间格局,秦巴山地落叶与常绿阔叶林生态区的植被NPP均值最高,为486.6 gC/m^(2)。2)黄河流域整体植被NPP以4.93 gC/(m^(2)·a)(p<0.01)的速率显著增加,黄土高原农业与草原生态区植被NPP年增长率最高,约为8.21 gC/(m^(2)·a)(p<0.01)。3)黄河流域82.26%面积的NPP未来变化趋势呈现增加与反持续性,但反持续性的强度有差异。4)月或季节的气温是影响黄河流域年植被NPP最重要的气候因素。5)黄河流域绝大部分区域受到气候和人类活动的共同促进作用,但在省会城市周边,气候、人类活动或气候和人类活动的耦合作用会起反作用。

Net primary productivity(NPP)represents the level of carbon exchange between ecosystem and atmosphere,is the‘converter’of ecosystem material and energy cycle,and is also an important index to evaluate and predict the sustainable development of ecosystem.Taking the Yellow River basin as the study area,combined with the methods of regression analysis,Hurst index and residual analysis,this study analyzes the temporal and spatial variation of vegetation NPP and its influencing factors in the Yellow River basin from the perspective of ecological region,discusses the influence of climate and human activities on vegetation NPP in the Yellow River basin,and predicts the future evolution trend of NPP.The results show that:1)The annual average NPP of vegetation in the Yellow River basin from^(2)001 to 2022 is 291.03 gC/m^(2),which is high in the north and low in the south.The mean NPP of vegetation in the deciduous and evergreen broad-leaved forest ecological region of Qinba Mountain is the highest,which is 486.6 gC/m^(2).2)The overall vegetation NPP in the Yellow River basin increased significantly at the rate of 4.93 gC/(m^(2)·a)(p<0.01).The annual growth rate of vegetation NPP in the agricultural and steppe ecological region of the Loess Plateau was the highest,about 8.21 gC/(m^(2)·a)(p<0.01).3)The future change trend of NPP in 82.26%of the Yellow River basin shows increase and anti-persistence,but the intensity of anti-persistence is different.4)The monthly or seasonal temperature is the most important climatic factor affecting the annual vegetation NPP in the Yellow River basin.5)Most areas of the Yellow River basin are jointly promoted by climate and human activities,but counterproductive in the surrounding areas of provincial capitals,climate,human activities or the coupling of climate and human activities.