LAI & PAR DATA: LIGHT BAR - UNL (FIFE)

The Leaf Area Index and PAR Determined from the UNL Light Bar Data were collected in 1987, 1988, and 1989. Incoming, reflected, and transmitted photosynthetically active radiation (PAR) was measured with a LI-COR LI-191SA line quantum sensor. Absorbed and intercepted PAR calculated from these measurements. The objectives of this research were to characterize bi-directional reflectance factor distributions, estimate surface albedo, determine the variability of reflected and emitted fluxes in selected spectral wavebands as a function of topography, vegetative community and management practice, determine the influence of plant water status on surface reflectance factors, and determine sun angle affects on radiation fluxes.

基于UNL光棒数据测算的叶面积指数与光合有效辐射（Photosynthetically Active Radiation, PAR）采集于1987、1988及1989年。本研究采用LI-COR LI-191SA型线状量子传感器，测定了入射、反射与透射光合有效辐射，并基于上述实测数据计算得到吸收与截获的光合有效辐射量。本研究的目标如下：表征双向反射率因子分布特征；估算地表反照率；明确选定光谱波段内反射与发射通量随地形、植被群落及管理措施的变化规律；探究植物水分状况对地表反射率因子的影响；以及确定太阳角度对辐射通量的作用效应。