气候与土地利用变化对粤港澳大湾区NPP的影响

Effects of Climate and Land Use Change on NPP in Guangdong-Hong Kong-Macao Greater Bay Area

关键词:  植被净初级生产力  气候变化  温度  降水  粤港澳大湾区

Key words:  NPP  climate change  temperature  precipitation  Guangdong-Hong Kong-Macao Greater Bay Area

摘要:

植被净初级生产力（Net Primary Productivity，NPP）是陆地生态过程中的重要参数，是全球碳循环的关键环节。本研究采用Carnegie-Ames-Stanford Approach （CASA）模型反演粤港澳大湾区NPP，探讨其时空格局变化规律及其与气候和土地利用变化的关系。结果表明，2001-2018年粤港澳大湾区年NPP均值为0.89 kg·C·m^-2，空间分布上呈现由中心区和东南区向东北、西北方向递增的趋势。随时间变化，NPP总体呈现增加趋势，其速率约为0.001 kg·C·m^-2·a^-1；从NPP未来变化趋势看，大部分区域NPP未来呈下降趋势。NPP与平均气温、累积降雨总体呈正相关关系，但NPP与累积降雨的相关性大于NPP与平均气温的相关性；总体而言，NPP对平均气温和累积降雨的变化呈正响应，其响应均值分别为0.007 kg·C·m^-2·a^-1·℃^-1和0.000 1 kg·C·m^-2·a^-1·（100 mm）^-1。土地利用变化对NPP产生显著影响，其中城市扩张对NPP产生极显著负效应（P<0.000 1），而生态恢复对NPP产生极显著正效应（P<0.000 1），且城市扩张对NPP的影响远高于生态恢复对NPP的影响。研究结果可为理解NPP对气候变化的响应提供参考，同时为粤港澳大湾区生态系统修复、空间规划和生态文明建设提供理论依据。

Abstract:

Net Primary Productivity (NPP) is an important parameter in the terrestrial ecological process and a key link in the global carbon cycle. In this study, the Carnegie-Ames-Stanford Approach (CASA) model was used to invert the NPP in the Guangdong-Hong Kong-Macao Greater Bay Area, and its spatiotemporal pattern change and its relationship with climate and land use changes were explored. The results show that the average annual NPP of the Guangdong-Hong Kong-Macao Greater Bay Area from 2001 to 2018 was 0.89 kg·C·m^-2, and the spatial distribution showed an increasing trend from the central area and the southeast area to the northeast and northwest. With the change of time, NPP generally showed an increasing trend, and the rate was approximately 0.001 kg·C·m^-2·a^-1. From the perspective of future changes in NPP, NPP in most regions will show a downward trend in the future. NPP is generally positively correlated with average temperature and accumulated rainfall, but the correlation between NPP and accumulated rainfall is greater than the correlation between NPP and average temperature. In general, NPP showed a positive response to changes in average temperature and accumulated rainfall, and the response value were 0.007 kg·C·m^-2·a^-1·℃^-1 and 0.000 1 kg·C·m^-2·a^-1·℃· (100 mm)^-1, respectively. Land use change has a significant impact on NPP, in which urban expansion has a very significant negative effect on NPP (P<0.000 1), while ecological restoration has a very significant positive effect on NPP (P<0.000 1), and the impact of urban expansion on NPP is much higher than that of ecological restoration on NPP. The results can provide a reference for understanding the response of NPP to climate change, and provide a theoretical basis for ecosystem restoration, spatial planning and ecological civilization construction in the Guangdong-Hong Kong-Macao Greater Bay Area.