粤港澳大湾区陆地生态系统演变对固碳释氧服务的影响

基于CASA模型、碳税法和工业制氧法,测算了粤港澳大湾区2015年固碳释氧量及其价值,并结合ESA CCI-LC产品探讨了2000-2015年研究区陆地生态系统演变及其导致的固碳释氧量和价值的变化。结果表明：（1）2000-2015年,研究区城市扩张明显,主要表现为城镇用地侵占农田和草地。（2）研究区陆地生态系统91.03%固碳释氧量及其价值集中在森林和农田生态系统,2000-2015年陆地生态系统演变造成区域内固碳量和释氧量分别减少了53.49 G g和518.65 G g,对应固碳释氧价值损失量分别为1.79亿元和2.06亿元,合计3.85亿元,91.57%损失量是由城市扩张导致的。（3）城市覆盖面积与固碳释氧价值呈现强负相关,其扩张会促使生态系统固碳释氧价值逐渐减少,林地覆盖面积与固碳释氧价值呈现强正相关,其比重增加将有利于生态系统固碳释氧价值的培育。本文利用"邻域代理法"获得了研究区多类陆地生态系统演变情况及其对固碳释氧服务的影响,具有一定的推广价值。在未来发展过程中,粤港澳大湾区应该优化陆地生态系统类型,合理控制城市扩张,保护森林和农田资源,减少人类活动作用,增强生态系统自然演变过程。

Impacts of the terrestrial ecosystem changes on the carbon fixation and oxygen release services in the Guangdong-Hong Kong-Macao Greater Bay Area

In this study, we used the Carnegie-Ames-Stanford Approach (CASA) model, carbon and industrial oxygen production methods to calculate the carbon sequestration oxygen release amount and its value in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in 2015, and combined with European Space Agency (ESA) Climate Change Initiative Land Cover (CCI-LC) products, we discussed the evolution of the terrestrial ecosystem in the study area from 2000 to 2015 and the changes in carbon sequestration oxygen release and its value. The findings suggest the following: (1) During 2000-2015, the urban expansion of the study area was obvious, mainly manifested as the encroachment of urban land on farmland and grassland. (2) 91.03% of the total amount and value of carbon fixation and oxygen release were provided by the forest and farmland in the GBA. The terrestrial ecosystem changes in the GBA during 2000-2015 had brought about losses of 53.49 G g in carbon fixation and 518.65 G g in oxygen release, respectively, and the corresponding values decreased by 179 million yuan and 206 million yuan, respectively, of which 91.75% of these losses were caused by urban encroachment on other land use types. (3) The carbon fixation and oxygen release values have a strong negative correlation with urban coverage, which means that urban expansion can significantly reduce the carbon fixation and oxygen release values. On the contrary, there is a strong positive correlation between the value of carbon fixation and oxygen release and the forest coverage, and the increase in forest coverage is beneficial to the increases in the carbon fixation and oxygen release values. In this paper, the "neighborhood proxy method" was used to obtain the variations in the amount of carbon fixation and oxygen release and the values thereof caused by the terrestrial ecosystem changes, which was worth of widely use. Looking ahead, the government of the GBA is highly recommended to optimize the structure of terrestrial ecosystems by controlling urban expansion, protecting forest resources and reducing the artificial role but enhancing the natural role in the ecosystem changes, so as to achieve green sustainable development.