利用宽带植被指数估算温带山地草原的二氧化碳通量。
Estimating carbon dioxide fluxes from temperate mountain grasslands using broad-band vegetation indices.
作者信息
Wohlfahrt G, Pilloni S, Hörtnagl L, Hammerle A
机构信息
Institute of Ecology, University of Innsbruck, Innsbruck, Austria.
出版信息
Biogeosciences. 2010 Feb 17;7(2):683-694. doi: 10.5194/bg-7-683-2010.
The broad-band normalised difference vegetation index (NDVI) and the simple ratio (SR) were calculated from measurements of reflectance of photosynthetically active and short-wave radiation at two temperate mountain grasslands in Austria and related to the net ecosystem CO exchange (NEE) measured concurrently by means of the eddy covariance method. There was no significant statistical difference between the relationships of midday mean NEE with narrow- and broad-band NDVI and SR, measured during and calculated for that same time window, respectively. The skill of broad-band NDVI and SR in predicting CO fluxes was higher for metrics dominated by gross photosynthesis and lowest for ecosystem respiration, with NEE in between. A method based on a simple light response model whose parameters were parameterised based on broad-band NDVI allowed to improve predictions of daily NEE and is suggested to hold promise for filling gaps in the NEE time series. Relationships of CO flux metrics with broad-band NDVI and SR however generally differed between the two studied grassland sites indicting an influence of additional factors not yet accounted for.
利用奥地利两个温带山地草原光合有效辐射和短波辐射的反射率测量值，计算了宽带归一化植被指数（NDVI）和简单比值（SR），并将其与同时采用涡度协方差法测量的净生态系统CO交换量（NEE）相关联。在同一时间窗口内测量和计算的中午平均NEE与窄带和宽带NDVI及SR之间的关系，不存在显著的统计学差异。对于以总光合作用为主的指标，宽带NDVI和SR预测CO通量的技能较高，而对于生态系统呼吸作用则最低，NEE介于两者之间。一种基于简单光响应模型的方法，其参数根据宽带NDVI进行参数化，能够改进对每日NEE的预测，并且有望填补NEE时间序列中的空白。然而，两个研究的草地站点之间，CO通量指标与宽带NDVI和SR的关系通常存在差异，这表明还有尚未考虑的其他因素的影响。
Zotero 插件