潍坊市农田生态系统碳源和碳汇变化及其影响因素分析

发布时间：2018-04-25 05:25

本文选题：农田生态系统 + 碳源　；参考：《东北农业大学》2015年硕士论文

【摘要】：不断排放的CO2和CH4等温室气体加剧了全球温室效应,引起了以气候变暖为标志的气候变化,造成了气候恶化等生态问题。全球气候变暖带来的气候环境恶化成为目前面临的主要环境问题,如何减少空气中温室气体的排放以及深入研究有关陆地生态系统碳循环以及碳源和碳汇等问题,成为当今探索气候变化的重点问题。然而,土地作为人类活动的主要载体,农作物的大量耕种,让农田生态系统成为温室气体主要的碳源和碳汇,农作物在利用光合作用以及一些人为活动直接或间接的吸收CO2的同时,也通过农作物本身、土壤的呼吸作用以及农业生产投入所带来的化石燃料等原料的消耗间接的向大气释放CO2。并且随着人口的增加、人类生活质量的提高,不得不增加耕作强度,农田生态系统将产生越来越多的碳排放量。在如今倡导低碳减排的背景下,研究如何实现农田生态系统固碳增汇成为农业领域亟需解决的重要问题。以2003-2012年潍坊市数据资料为基础,收集潍坊市10年间主要农作物的产量值、种植面积以及农业生产投入过程中有关农药、化肥、农膜、农机、柴油以及灌溉的使用数据,对潍坊市农田生态系统的碳源和碳汇状况进行系统分析。研究结果表明:(1)对2003-2012年潍坊市农田生态系统碳排放和碳吸收总量进行分析,农田生态系统碳源大于碳汇,10年碳吸收总量达到21735.98万t,碳排放量达到160743.96万t,碳排放总量与碳吸收总量的比值为1:7.4,且农田生态系统碳吸收量和碳排放量的增长率分别为10.69%和7.02%。考虑碳排放强度以及碳吸收强度,碳排放强度增长率从2003年的0.055%减少到2012年的0.048%,而碳吸收强度的增长率从2003年的1.18%增加到2012年的1.98%。碳吸收强度相对于碳排放强度明显较高,表明潍坊市农田生态系统具备一定的碳汇功能。(2)对12种主要的农田作物进行研究后发现,蔬菜、玉米、小麦对农田生态系统的贡献较大,所占比例分别为73.31%、12.31%和11.68%。(3)蔬菜作为主要的碳汇作物,其比例为73.31%,从6种不同碳排放途径进行分析,农田灌溉是主要的碳源,所占比例为87.32%。10年间,蔬菜的碳吸收量呈现出先减少后增加的趋势,由于粮食作物带来的经济效益较低,一些农户选择利用高经济效益的蔬菜等经济作物取代低经济效益的粮食作物。其他作物的碳吸收量量相对较小,占碳总吸收量的2.66%。农业生产投入的六种碳排放途径中,碳排放比例中农业灌溉比例最重,2012年农业灌溉的碳排放量占碳排放总量的86.48%,随着不断增加耕地有效灌溉面积,农田灌溉碳排放得到增长;同时由于潍坊市提倡有机、绿色食品的生产,农药和化肥的使用量逐渐减少,二者造成的碳排放数量也逐渐减少。(4)10年间潍坊市农田生态系统净碳汇均小于0,农田生态系统为碳源系统,且碳汇量变化趋势呈现三阶段波动变化。同时,碳汇强度整体呈现波动减少的状态,由于近几年种植面积的逐渐加大引起了净碳汇的增加,碳吸收小幅度递增,且碳排放量也表现出一定程度的增加。由于碳排放总量远远超过了碳吸收总量,说明潍坊市能源消耗所占的比重较大,也同时反映出潍坊市农田生态系统碳排放和碳吸收的极度不平衡。虽然灌溉的使用,使得潍坊市保证了较高产量的蔬菜供应,但是削弱了农田生态系统的碳汇功能,这种形势不容乐观。(5)碳足迹减幅为0.221万hm2,碳足迹由38.990万hm2减少到38.769万hm2,整体呈现递减的趋势。碳足迹与生态生产性土地面积的比例较低,比值为1.456%。碳足迹强度10年的均值达到0.14 hm2/万元,且农田生态系统每增加1万元的产值可以制造0.14 hm2的碳足迹。潍坊市农田生态系统碳足迹强度数值较低,反映出潍坊市农田生态系统在能源利用方面效率较高,碳足迹效益也较高。2003-2012年间,碳足迹与该区域的生态承载力的差值均为负值,潍坊市农田生态系统依旧处于碳生态盈余状态。(6)土地利用方式、农作物产量和农业生产投入在影响潍坊市农田生态系统碳源和碳汇的因素中是最主要的三个因素;同时,气候条件和降水量以及不同的农作物种植种类和土壤条件都是影响碳源和碳汇的因素。
[Abstract]:Greenhouse gases, such as CO2 and CH4, have intensified the global greenhouse effect, resulting in climate change marked by climate warming, resulting in ecological problems, such as climate deterioration. The deterioration of the climate and environment caused by global warming has become the main environmental problem at present. How to reduce the emission of greenhouse gases in the air and further study The carbon cycle of terrestrial ecosystems, carbon sources and carbon sequestration issues have become a key issue in the exploration of climate change. However, as the main carrier of human activities, land is cultivated in large quantities, making the farmland ecosystem become the main carbon source and carbon sink of greenhouse gases, and crops are using photosynthesis and some human activities. With the direct or indirect absorption of CO2, the consumption of the raw materials such as the crop itself, the respiration of the soil and the consumption of fossil fuels brought by the agricultural production input will release CO2. indirectly to the atmosphere. As the population increases, the improvement of the quality of human life has to increase the intensity of farming, and the farmland ecosystem will produce more and more. The more carbon emissions, in the background of low carbon emission reduction, the study of how to achieve carbon sequestration in the farmland ecosystem has become an important problem to be solved in the agricultural field. Based on the data of the city of Weifang in 2003-2012 years, the output value of major crops, the area of planting and the input of agricultural production in the period of 10 years are collected. The carbon sources and carbon sequestration conditions of agricultural ecosystem in Weifang were analyzed systematically by the data of pesticide, chemical fertilizer, agricultural membrane, agricultural machinery, diesel and irrigation. The results showed that: (1) the carbon emission and carbon absorption of farmland ecosystem in Weifang city were analyzed in 2003-2012 years. The carbon source of farmland ecosystem was larger than carbon sink, and the carbon absorption was total for 10 years. The amount reached 217 million 359 thousand and 800 t, the carbon emissions reached 1 billion 607 million 439 thousand and 600 t, the ratio of carbon emission to carbon absorption was 1:7.4, and the growth rate of carbon absorption and carbon emission of farmland ecosystem was 10.69% and 7.02%. respectively, and carbon emission intensity and carbon absorption intensity were considered. The growth rate of carbon emission intensity decreased from 0.055% in 2003 to 0.048 in 2012. %, and the growth rate of carbon absorption intensity increased from 1.18% in 2003 to 2012, the 1.98%. carbon absorption intensity was significantly higher than the carbon emission intensity, indicating that Weifang farmland ecosystem has a certain carbon sequestration function. (2) after the study of 12 major cropland crops, it was found that vegetable, vegetable, corn, and wheat contributed greatly to the farmland ecosystem. The proportion of the 73.31%, 12.31% and 11.68%. (3) vegetables as the main carbon sink crops, the proportion of 73.31%, from the 6 different ways of carbon emission analysis, farmland irrigation is the main carbon source, the proportion of the proportion of 87.32%.10 years, the carbon absorption of vegetables first decreased and then increased, due to the economic efficiency of grain crops. The benefit is low, some farmers choose to use economic crops such as high economic benefits to replace low economic crops. The carbon absorption of other crops is relatively small and the total carbon absorption of the six kinds of 2.66%. agricultural production inputs, the proportion of agricultural irrigation in the proportion of carbon emissions is the heaviest, the agricultural irrigation carbon row in 2012. 86.48% of the total amount of carbon emissions, with the continuous increase of the effective irrigation area of cultivated land, the carbon emissions from farmland irrigation have been increased. At the same time, because of the promotion of organic food in Weifang, the use of pesticides and fertilizers is gradually reduced, and the amount of carbon emissions from the two is gradually reduced. (4) the net carbon of farmland ecosystem in Weifang during the 10 years. The remittance is less than 0, and the cropland ecosystem is carbon source system, and the trend of carbon sequestration varies in the three stage. At the same time, the intensity of carbon sequestration decreases as a whole. As the growing area increases in recent years, the net carbon sink increases, the carbon absorption amplitude increases, and the carbon emissions also increase to a certain extent. As the total amount of carbon emissions is far beyond the total amount of carbon absorption, the proportion of energy consumption in Weifang is larger, and it also reflects the extreme imbalance of carbon emission and carbon absorption in the farmland ecosystem in Weifang. Although the use of irrigation makes Weifang a high yield of vegetable supply, but weakens the carbon of the farmland ecosystem. This situation is not optimistic. (5) the carbon footprint is reduced to 2 thousand and 210 Hm2, the carbon footprint is reduced from 389 thousand and 900 hm2 to 387 thousand and 690 Hm2, and the overall trend is decreasing. The ratio of carbon footprint to eco productive land area is low, the ratio of 1.456%. carbon footprint to 10 years is 0.14 hm2/ million, and the farmland ecosystem increases by 10 thousand. The output value of yuan can produce a carbon footprint of 0.14 hm2. The carbon footprint intensity of Weifang farmland ecosystem is low, which reflects the high efficiency of the agricultural ecosystem in Weifang, and the efficiency of the carbon footprint is higher in the period of.2003-2012, the difference between the carbon footprint and the ecological carrying capacity of the region is negative, and the farmland ecosystem in Weifang It is still in the carbon ecological surplus state. (6) the land use mode, crop yield and agricultural production input are the most important three factors in the factors affecting the carbon source and carbon sink of the farmland ecosystem in Weifang. At the same time, the climatic conditions and precipitation as well as the different crop species and soil conditions are the causes of carbon and carbon sequestration. Prime.

【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S181

【参考文献】