北京市生态涵养区生态资产时空格局及驱动因素

Spatio-temporal patterns and driving factors of ecological assets in Beijing's ecological conservation area

生态涵养区作为重要的生态屏障和水源保护地,是北京市实现绿色发展和生态保护的重要支撑。基于改进的生态资产估算模型,获得2000年、2005年、2010年和2015年4期北京市生态涵养区生态资产时空分布格局,基于栅格尺度数据进行面板固定效应回归和分位数回归,检验了生态资产时空格局的驱动因素。结果表明:(1)北京市生态涵养区4期生态资产呈先快速增长后缓慢降低的趋势,森林生态系统积累生态资产价值占比长期保持在70%以上,是生态涵养保护的重要支撑,但2015年其占比较2010年下降了3个百分点。(2)气候变化中年均降雨量对生态资产具有显著的促进作用,年均气温的升高对低分位水平下的生态资产具有显著的抑制作用,而对高分位水平的生态资产有正向推动作用;人为干扰度稳定在一定范围内时对生态资产具有显著的正向促进作用;像元单位空间人口的增加对生态资产有阻滞作用;像元单位空间GDP的增加对生态资产有显著的促进作用。(3)陡坡地和斜坡地的生态资产均在每年360亿元以上,远高于其他坡度的生态资产;南坡面积占比最大,其生态资产积累最高,东北坡次之;低山丘陵地带占比高达71.45%,生态资产的年均值远高于其他区域。

As an important ecological barrier and water conservation area for the capital,the ecological conservation area plays a key role for Beijing to achieve green development and ecological protection.In this paper,we used an ecological assets model modified by NPP,precipitation,soil and water conservation data to estimate the ecological assets and analyze the spatio-temporal variations of Beijing's ecological conservation area in 2000,2005,2010,and 2015.Panel fixed effect regression and quantile regression based on grid scale data were used to test the driving factors of the spatio-temporal pattern of ecological assets.The results showed that:(1)the four periods of ecological assets in Beijing's ecological conservation area showed a trend of rapid growth and then a slow decline.The growth rate of ecological assets reached 133.81%in 2005,dropped to 44.45%in 2010,and changed to-11.02%in 2015.The value of the forest ecosystem accounted for more than 70%of ecological assets in Beijing's ecological conservation area for a long time,which was important for ecological conservation and protection,but its share in 2015 dropped by 3 percentage points compared with that in 2010.From 2000 to 2015,the value of climate regulation,soil conservation and hydrological regulation functions was always higher than that of other ecosystem services.(2)the annual average precipitation had a vital role in promoting ecological assets.The increase of annual average temperature had a significant inhibitory effect on the ecological assets at 10%and 25%quantile levels,while a positive role in promoting the ecological assets at 75%and 90%quantile levels.When the degree of hemeroby was stable within a certain range,it had a significantly positive effect on ecological assets.The increase of population per unit of pixel space had a blocking effect on ecological assets,while the increase of GDP per unit of pixel space had the opposite effect on ecological assets.(3)In terms of the influence of topographic factors on ecological assets,the ecological assets of steep slopes and slopes were above 36 billion yuan per year,which were much higher than those of other slopes.The area of the southern slope was the largest,and its annual ecological assets accumulation was the highest,reaching 18.34 billion yuan,followed by the northeast slope,with an annual ecological value of 14.95 billion yuan.Moreover,the low mountain and hilly areas accounted for up to 71.45%,the annual average value of ecological assets was much higher than other regions.