北京市农田生态系统碳汇及释氧功能年际变化研究

Study on the Internatianal Variability of Carbon Sink and Oxygen Release Function of Farmland Ecosystem in Beijing

以北京农田生态系统作为研究对象,对2004～2012年农田生态系统的碳汇及释氧功能的年际变化进行了研究,结果表明：北京市农田生态系统氧气释放量总体呈现逐年增加趋势,以2008年最高,年平均氧气释放量为270.9万吨,农田生态系统中粮食作物的年均氧气释放量所占比例最高为80.1％,在粮食作物中玉米的氧气释放量所占比例最高为69.3％,单位耕地面积的氧气释放量平均为12.89 t·hm-2·a-1,总体呈逐年增加趋势;北京农田生态系统碳蓄积量总体也呈增加趋势,年递增幅度为2.8％,年平均碳蓄积量为105.82万吨,其中粮食作物的碳蓄积比例增加较为显著,且粮食作物年均碳蓄积量所占比例最大为80.4％,在粮食作物中玉米的碳蓄积比例最大为68.5％,单位耕地面积年均碳蓄积量为5.03 t·hm-2,且呈逐年增加的趋势,年递增8.3％.北京市农田生态系统的固碳、释氧的气体调节作用的生态功能不容忽视.

Carbon sinks and oxygen releasing function was studied on Beijing farmland ecological system in 2004- 2012 years. The results show that： the oxygen release amount was increasing, and it is the highest in 2008, the average annual capacity was 2.709 million tons, the grain crops have in the highest proportion of 80.1%. The corn has the highest proportion of 69.3% in the grain crops. The releasing oxygen trend of the unit cultivated land area was increasing year by year, the average was12.89 t.hm-2.al; The carbon storage increased generally in Beijing farmland ecosystem, the annual growth rate was 2.8% and the average annual carbon storage was 1.0582 million. The proportion of carbon accumulation of the grain crops increased obviously, the carbon storage of grain crop accounted for the largest proportion of 80.4%, and the corn had the highest proportion of 68.5% in the grain crops. The carbon storage trend of the unit cultivated land area was increasing 8.3% year by year, the average carbon storage was 5.03 t hm-2.a-1 Ecological function of Beijing farmland ecosystem carbon fixation, and oxygen release gas regulating role could not be ignored.