秦岭火地塘林区不同海拔森林土壤NO通量

发布时间：2019-01-19 19:04

【摘要】：选取秦岭火地塘林区不同海拔(1 560~2 160 m)的有代表性的5个森林样地,从2014年10月到2015年10月对其土壤NO通量采用静态箱—氮氧化物分析仪法进行1 a的监测。结果表明,土壤NO排放主要集中在植物生长季(2015年5月—2015年9月),但整个观测期NO排放保持在较低水平。在非生长季(2014年10月—2015年4月),大部分样地的NO排放先减少后增加,而且监测有NO吸收。不同海拔NO年排放总量分别为2 160m红桦林0.06 kg·ha~(-2)·a~(-1),2 040 m青gD林0.08 kg·ha~(-2)·a~(-1),1 963 m华山松林0.02 kg·ha~(-2)·a~(-1),1 585 m油松林0.11 kg·ha~(-2)·a~(-1),1 560 m锐齿栎林0.19 kg·ha~(-2)·a~(-1)。除华山松外,NO年排放总量随海拔的升高而减少。不同海拔5个样地土壤NO通量均与地温显著相关(P0.05)。华山松林土壤NO排放与土壤孔隙充水率呈负相关(P0.05)。油松林土壤NO排放与土壤铵态氮质量分数负相关(P0.05)。除油松林外,各样地的土壤孔隙充水率都低于60%,可以推断,硝化反应是本地区NO的重要生成源,但受到降雨和土壤有机质等理化性质的影响又伴随有反硝化过程。
[Abstract]:From October 2014 to October 2015, five representative forest plots with different elevations (1560m 2160m) in Huoditang forest area of Qinling Mountains were selected and their soil NO fluxes were monitored by static box-nitrogen oxide analyzer method for 1 year from October 2014 to October 2015. The results showed that the NO emission from soil was mainly concentrated in the plant growth season (May 2015 to September 2015), but the NO emission remained at a relatively low level throughout the observation period. In the non-growth season (October 2014 to April 2015), NO emissions in most plots decreased first and then increased, and NO uptake was monitored. The total annual emission of NO was 0.06 kg ha~ (-2) a ~ (-1) in the red birch forest at different elevations, 0.08 kg ha~ (-2) a ~ (-1) in the 2040 m green gD forest, and 0.08 kg ha~ (-2) a ~ (-1) in the 2,040 m green gD forest, respectively. Kg ha~ (-2) a ~ (-1), 0.11 kg ha~ (-2) a ~ (-1) and 0.19 kg ha~ (-2) a ~ (-1) in 1 963 m Pinus huashanensis forest and 1 585m Pinus tabulaeformis forest respectively. With the exception of Pinus huashanensis, the total annual NO emission decreased with the increase of altitude. Soil NO fluxes were significantly correlated with soil temperature in 5 plots at different elevations (P0.05). There was a negative correlation between soil NO emission and soil pore filling rate (P0.05). Soil NO emissions in Pinus tabulaeformis forest were negatively correlated with soil ammonium content (P0.05). With the exception of Pinus tabulaeformis forest, the porosity of soil was less than 60%. It can be inferred that nitrification is an important source of NO in this area, but it is accompanied by denitrification due to the physical and chemical properties of rainfall and soil organic matter.
【作者单位】：西北农林科技大学;陕西秦岭生态系统国家野外科学观测研究站;中国科学院生态环境研究中心;
【基金】：国家自然科学基金项目(41101182) 国家级创新项目西北农林科技大学基本科研业务费(Z109021106);西北农林科技大学博士科研启动基金项目(Z109021102)
【分类号】：S714

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