2000-2019年滇黔桂岩溶区植被NPP时空变化及与气候变化的关系研究

Spatial-Temporal Changes of NPP and Its Relationship with Climate Change in Karst Areas of Yunnan,Guizhou and Guangxi from 2000 to 2019

滇黔桂岩溶区属于生态环境脆弱区,对其植被NPP(Net Primary Production)动态变化进行监测并探索其与气候变化的关系,对于研究区生态环境治理与保护具有重要意义。基于2000—2019年的MOD17A3 NPP数据,结合同期基于站点的气象数据,采用趋势分析、Mann-Kendall显著性检验、R/S分析及相关分析等方法,研究了滇黔桂岩溶区植被NPP的时空变化特征和未来趋势,并探讨了滇黔桂岩溶区植被NPP与气候变化之间的关系。研究结果表明:(1)2000—2019年滇黔桂岩溶区植被NPP均值为845.49 g·m^(−2)·a^(−1)(以C计),空间上呈现南高北低的分布格局,20 a间植被NPP总体呈现波动上升趋势,上升速度为4.02 g·m^(−2)·a^(−1),呈上升趋势的面积占总面积的80.19%,其中呈显著上升的区域占46.60%;(2)研究区未来植被NPP以上升趋势为主,且未来同向变化趋势远大于反向变化趋势;(3)研究区气温对研究区植被NPP呈现显著促进作用,而降水、相对湿度和日照时数对研究区植被NPP无明显作用。气候变化对植被NPP的影响有明显的空间异质性,不同地带岩溶区植被NPP对气候变化的响应程度相差较大;(4)植被NPP对前0—1月气温和日照时数变化响应程度较高,而对前2—3月降水及相对湿度变化响应程度较高。

The Yunnan,Guizhou,and Guangxi karst areas belong to the fragile ecological environment.Monitoring the dynamic changes of NPP(Net Primary Production)and exploring the driving mechanism of climate change on NPP is useful for understanding the response characteristics of NPP in karst areas to climate change.Based on the MOD17A3 NPP data from 2000 to 2019,combined with site—based meteorological data during the same period,this paper uses trend analysis,Mann-Kendall significance test,R/S analysis and correlation analysis to study the NPP of vegetation in the karst areas of Yunnan,Guizhou and Guangxi.The characteristics of temporal and spatial changes and future trends of NPP,and the relationship between NPP and climate change in karst areas of Yunnan,Guizhou and Guangxi is discussed.The results of the study show:(1)The average NPP in the Yunnan,Guizhou,and Guizhou karst areas from 2000 to 2019 was 845.49 g·m^(−2)·a^(−1),which showed a spatial distribution pattern of high in the south and low in the north region.During the past 20 years,the NPP showed a fluctuating upward trend,with an upward rate of 4.02 g·m^(−2)·a^(−1).The area with an upward trend accounted for 80.19%of the total area,and the area with a significant increase accounted for 46.60%;(2)The future NPP in the study area will increase,and the same direction change trend in the future is far greater than the reverse change trend;(3)The temperature in the study area significantly promoted the NPP in the study area,while precipitation,relative humidity and sunshine hours had no significant effect on the vegetation NPP in the study area.The impact of climate change on NPP has obvious spatial heterogeneity.The response of NPP in karst areas to climate change varies greatly;(4)NPP has a higher response to the changes of temperature and sunshine hours in the first 0–1 months,and a higher response to the changes of precipitation and relative humidity in the first 2–3 months.