Regional Estimation of Nitrous Oxide and Methane Flux from Subalpine Boreal Soils of the Northeastern United States

本研究的目的是评估美国东北部云杉林长期氮添加对氧化亚氮（N2O）和甲烷（CH4）净通量的区域影响。将要使用的方法包括对覆盖缅因州东部和纽约东部之间地区的一系列先前研究过的云杉森林的气体通量进行密集采样，以及从佛蒙特州南部的一个试验点对红云杉林进行长期氮添加。将使用遥感和地理信息系统方法来推断区域总量的测量结果，并将评价这两种方法的有效性。具体活动包括：1)密集测量云杉林类型内5个区域大气和土壤之间的净N2O和CH4烟道，记录氮经济差异；2)收集每个站点的叶面样品，测定冠层总木质素、氮和纤维素含量；3)利用宽带（TM）和高光谱分辨率（FLI， AVIRIS）传感器对冠层化学进行遥感；4)利用遥感数据和通过地理信息系统外推的广泛的硝化速率地面调查，估算云杉带N2O和CH4的净通量。该项目由美国国家科学基金会和美国国家航空航天局共同资助。研究人员完全有资格进行这类研究，项目的设施和制度支持也很好。

The purpose of the research is to assess the regional impact of chronic nitrogen additions to spruce-fir forests in the northeastern U.S. on net nitrous oxide (N2O) and methane (CH4) fluxes. The approaches to be used include intensive sampling of gas fluxes in a series of previously studied spruce-fir forests covering the region between eastern Maine and eastern New York, and from an experimental site in Southern Vermont where chronic N additions are being made to a red spruce stand. Both remote sensing and Geographic Information System (GIS) methods will be used to extrapolate measurements to regional totals, and an evaluation will be made of the effectiveness of these two approaches. Specific activities include: 1) intensive measurements of net N2O and CH4 flues between the atmosphere and soils in five areas within the spruce-fir forest type with documented differences in nitrogen economies, 2) collection of foliar samples from each site for determination of total canopy lignin, nitrogen and cellulose content, 3) remote sensing of canopy chemistry using broad-band (TM) and high spectral resolution (FLI, AVIRIS) sensors, and 4) the use of both remote sensing data, and extensive ground surveys of nitrification rates extrapolated through the use of a geographic information system, to estimate of net N2O and CH4 fluxes for the spruce-fir zone. The project is jointly funded by NSF and NASA. The investigators are well qualified for this type of research and the facilities and institutional support for the project are excellent.