基于碳足迹的黑龙江垦区农业生态系统碳源/汇时空变化

SPATIOTEMPORAL VARIATION OF CARBON SOURCE/SINK IN AGRICULTURAL ECOSYSTEM BASED ON CARBON FOOTPRINT IN HEILONGJIANG LAND RECLAMATION AREAS

关键词:  农田生态系统  碳排放  碳吸收  碳足迹  黑龙江垦区

Key words:  farmland ecosystem  carbon emissions  carbon absorption  carbon footprint  Heilongjiang Land Reclamation Areas

摘要:

目的 文章研究从时间和空间两方面分析垦区主要粮食作物、经济作物和蔬菜瓜果类作物的碳源/汇变化特征，明确影响碳足迹的主要因素，旨在为促进垦区农田生态系统固碳减排、发展低碳农业和保障农业可持续发展提供科学依据。方法 基于1992—2019年黑龙江垦区农作物播种面积、产量和农业投入等数据，利用农田生态系统碳足迹模型，分析黑龙江垦区农田生态系统碳排放、碳吸收和碳足迹时空变化特征。结果 （1）1992—2019年黑龙江垦区农田生态系统碳排放、碳吸收和碳足迹均表现为增加趋势，但碳吸收量明显高于碳排放量，两者比例为22.8∶1，且碳足迹占同时期种作物播种面积的比例较低（在4.0%~5.0%），垦区农田生态系统碳汇功能较强。（2）农田灌溉和氮肥施用是碳排放的主要贡献因子，占比分别为38.0%和34.4%。黑龙江垦区农田生态系统单位面积碳排放量在145.2~401.9 kg/hm²，高于全省但低于全国平均水平。水稻、玉米、豆类、小麦四大类作物贡献了垦区94.9%的碳吸收量。（3）在空间上，黑龙江垦区农田生态系统碳排放、碳吸收和碳足迹均主要分布于黑龙江省东部和东北部的宝泉岭分局、红兴隆分局、建三江分局和牡丹江分局。结论 黑龙江垦区农田生态系统处于较高的碳生态盈余状态，具有较好的生态屏障作用，对于促进区域低碳农业发展具有现实意义。

Abstract:

This study is intends to analyze the characteristics of carbon source/sink change of main food crops, cash crops and vegetable or fruit crops from the perspectives of time and space, and identify the main factors affecting carbon footprint, aiming to provide scientific basis for promoting farmland ecosystem carbon sequestration and emission reduction, developing low-carbon agriculture and ensuring sustainable agricultural development in Heilongjiang Land Reclamation Areas. Based on the data of crop sown area, yield and agricultural input from 1992 to 2019, this paper analyzed the spatiotemporal characteristics of carbon emission, carbon absorption and carbon footprint of farmland ecosystem in Heilongjiang Land Reclamation Areas by using the carbon footprint model of farmland ecosystem. The results were showed as follows. The carbon emission, carbon absorption and carbon footprint of the farmland ecosystem in Heilongjiang Land Reclamation Areas all showed an increasing trend from 1992 to 2019, but the carbon absorption was significantly higher than the carbon emission, with a ratio of 22.8∶1, and the carbon footprint accounted for a relatively low proportion (between 4.0% and 5.0%) in the same period, indicating that the farmland ecosystem in the reclamation area had a strong carbon sink function. Farmland irrigation and nitrogen fertilizer application were the main contributing factors of carbon emission, accounting for 38.0% and 34.4%, respectively. The carbon emissions per unit area of farmland ecosystem in Heilongjiang province ranged from 145.2 to 401.9 kg/hm², which was higher than the provincial average but lower than the national average. Rice, maize, legumes and wheat contributed 94.9% of the carbon sequestration in Heilongjiang Land Reclamation Areas. In terms of space, the carbon emission, carbon absorption and carbon footprint of farmland ecosystem in Heilongjiang Land Reclamation Areas were mainly distributed in Baoquanling, Hongxinglong, Jiansanjiang and Mudanjiang sub-bureaues in the east and northeast of Heilongjiang province. Based on the above analysis, the farmland ecosystem in Heilongjiang Land Reclamation Areas is in a high state of carbon ecological surplus, which played a good role of ecological barrier, and had practical significance for promoting the development of regional low-carbon agriculture.