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Leaf area index (LAI) is a dimensionless quantity that characterizes plant canopies. It is defined as the one-sided green leaf area per unit ground surface area (''LAI = leaf area / ground area, m2 / m2'') in broadleaf canopies.〔Watson, D.J., 1947. Comparative physiological studies on the growth of field crops: I. Variation in net assimilation rate and leaf area between species and varieties and within and between years. Annals of Botany, 11: 41-76.〕 In conifers, three definitions for LAI have been used: *Half of the total needle surface area per unit ground surface area 〔Chen, J.M., and Black, T.A. (1992): Defining leaf area index for non-flat leaves. Agricultural and Forest Meteorology 57: 1–12〕 *Projected (or one-sided, in accordance the definition for broadleaf canopies) needle area per unit ground area *Total needle surface area per unit ground area LAI ranges from 0 (bare ground) to over 10 (dense conifer forests). == Interpretation and application of LAI == LAI is used to predict photosynthetic primary production, evapotranspiration and as a reference tool for crop growth. As such, LAI plays an essential role in theoretical production ecology. An inverse exponential relation between LAI and light interception, which is linearly proportional to the primary production rate, has been established: : where ''P''max designates the maximum primary production and designates a crop-specific growth coefficient. This inverse exponential function is called the primary production function. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「leaf area index」の詳細全文を読む スポンサード リンク
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