江苏省农田植被净碳汇时空格局分析

Spatial-temporal pattern of net carbon sink of farmland vegetation in Jiangsu Province

科学地开展区域农田植被净碳汇及其时空格局研究,对采取合理的农业管理措施,达到农田生态系统减源增汇目的具有重要意义。以江苏省13个地级市为研究单元,采用2000—2015年农作物产量、农田投入等相关统计数据估算江苏省农田植被净碳汇,综合运用重心移动、空间自相关分析等方法分析其时空格局。结果表明:(1)2000—2015年,苏北及苏中地区农田植被净碳汇总量呈波动上升趋势,苏南地区总体呈下降趋势;江苏省各市农田植被净碳汇强度总体呈上升趋势;(2)江苏省农田植被净碳汇重心基本分布在江苏省宝应县境内,呈多次振荡式向西北方向迁移;(3)江苏省农田植被净碳汇表现为"北热南冷"相对稳定的空间格局,沿海和内陆地区的农田植被净碳汇水平明显高于沿江地区。总体而言,江苏省农田植被表现为较强的碳汇功能,苏北和苏中地区是未来江苏省农田植被净碳汇的主要潜力区,应根据地区差异,通过制定差别化的农业管理措施发挥农田生态系统整体的生态屏障作用。

Scientific research on net carbon sink and its spatial-temporal pattern of regional farmland vegetation is of great significance to take reasonable agricultural management measures and to achieve the goal of reducing carbon source and increasing carbon sink of farmland ecosystem.Taking 13 prefecture-level cities in Jiangsu Province as the research areas,we estimated the net carbon sink of farmland vegetation by using relevant statistical data such as crop yields and farmland investments from 2000 to 2015.By the aid of migration of gravity center and spatial autocorrelation methods,we also analyzed the spatial-temporal pattern of net carbon sink.The results showed that:1)The total net carbon sink of the farmland vegetation within all cities in Jiangsu was positive,and the total net carbon sink in northern and central Jiangsu Province showed an upward trend while that in southern Jiangsu was in a downward trend.The amount of net carbon sink of farmland vegetation was shown as northern Jiangsu>central Jiangsu>southern Jiangsu.The net carbon sink intensity of farmland vegetation had a rising trend,and in terms of spatial distribution the highest area was central Jiangsu,the moderate was northern Jiangsu,and the lowest was southern Jiangsu.In the past 16 years,the gravity center of net carbon sink of farmland vegetation was basically located in Baoying County,Jiangsu Province,and moved northwestward in general with a distance of 27.68 km.The overall pattern of net carbon sink of farmland vegetation remained relatively stable,with the spatial characteristics of“north hot and south cold”,indicating an obvious geographical agglomeration phenomenon.The total net carbon sink of farmland vegetation in coastal areas and inland areas of Jiangsu Province was significantly higher than those areas along the Yangtze River.The proportion of hot spots increased from 30.77%in 2000 to 38.46%in 2015,while the cold area decreased from 30.77%in 2000 to 23.08%in 2015.In conclusion,the farmland vegetation in Jiangsu Province showed a strong capacity of carbon sink in the past 16 years.Northern Jiangsu and central Jiangsu will be the main potential areas of net carbon sinks in farmland vegetation of Jiangsu Province in the future.Different cities in Jiangsu Province can formulate different measures of agricultural management in order to function as the ecological barrier of the farmland ecosystem