模拟大气氮沉降对土壤碳排放的影响

发布时间：2018-07-07 14:12

  本文选题：氮氧化物污染 + 大气氮沉降　； 参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：洁净的大气环境对人类生存至关重要,但是人类社会的生活消费、交通、工农业生产排放的废气造成了严重的大气污染,给人类的健康造成了严重的威胁。NOx是一种严重的大气污染物,NOx的存在对环境物质、人类及其生物都会产生严重的危害,如NOx对人体有致毒作用,尤其是NO2；NOx是形成酸雨酸雾的主要污染物；NOx与碳氢化合物可形成光化学烟雾；NOx还参与臭氧层的破坏。除此以外,NOx化物还以干湿沉降的方式降落到地表或水体生态系统。沉降到水体的氮素可导致水体酸化、富营养化,沉降到土壤的氮素不仅可导致土壤酸化,还可以影响土壤中的生物化学过程从而激发其他的环境问题,如沉降到土壤中的氮素可以影响土壤的碳排放量即CO2通量,而CO2是主要的温室气体,其排放量的增加可导致全球变暖。工业革命以来全球碳氮循环格局的改变以及气候变化是人类所面临的最为严峻问题。相应地,大气氮沉降从0.34 g m-2·yr-1增加到了1 g m-2·yr-1左右,全球气温也上升了1.4-1.8℃。更为严重的是,这种趋势还将延续下去。基于过量的氮沉降和全球变化这两大备受关注的全球性问题,再加上土壤碳排放过程在全球碳循环中的地位,本文以内蒙古东乌珠穆沁典型温带草原为研究对象,开展了模拟氮沉降对草原生态系统土壤碳通量影响相关方面的研究。本文通过在固定区域模拟氮沉降试验的方式,模拟氮沉降试验设计氮添加水平分别为对照(CK,0kg N·ha-1·yr-1)、施氮(SN,100kg N·ha-1·yr-1),利用LI-8100土壤碳通量测量系统测定土壤碳通量,对比分析了氮添加和无氮添加处理条件下温带典型草原土壤碳通量特征及其对氮素添加的响应,以期在不断升高的大气氮沉降背景下,为预测该地区的固碳能力提供依据,并为草原生态系统的可持续发展和健康管理提供基础数据。
[Abstract]:The clean atmosphere environment is very important to the human survival, but the waste gas of human society, such as living consumption, transportation, industrial and agricultural production, has caused serious air pollution. The existence of no _ x is a serious atmospheric pollutant. It will cause serious harm to the environment, such as the toxic effect of no _ x to human body, especially no _ 2. No _ x is the main pollutant to form acid rain and acid mist, no _ x and hydrocarbon can form photochemical smog, no _ x is also involved in the destruction of ozone layer. In addition, nitrogen oxides also fall to the surface or water ecosystem by wet and dry deposition. Nitrogen deposition into the water can lead to acidification, eutrophication, and nitrogen deposition to the soil can not only lead to soil acidification, but also affect the biochemical process in the soil, thereby stimulating other environmental problems. For example, nitrogen deposition into the soil can affect the carbon emissions of soil, that is, CO2 fluxes, which are the main greenhouse gases, and the increase of their emissions can lead to global warming. Since the Industrial Revolution, the change of global carbon and nitrogen cycle pattern and climate change are the most serious problems facing mankind. Accordingly, the atmospheric nitrogen deposition increased from 0.34 g m ~ (-2) yr-1 to about 1 g m ~ (-2) yr-1, and the global temperature increased by 1.4-1.8 鈩，

本文编号：2105210