Detection of red edge position and chlorophyll content by reflectance measurements near 700 nm
Detection of red edge position and chlorophyll content by reflectance measurements near 700 nm
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DOI：
10.1016/s0176-1617(96)80285-9
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发表时间：
1996-05-01
影响因子：
4.3
通讯作者：
Lichtenthaler, HK
中科院分区：
文献类型：
--
作者：
Gitelson, AA;Merzlyak, MN;Lichtenthaler, HK
色素含量的测定和高光谱分辨率的反射率测量获得了春季，夏季和秋季枫树和七叶树叶覆盖范围广泛的叶绿素含量。一致的和诊断的差异，在红边范围内（680-750 nm）的反射光谱，获得了两个物种的研究的各种叶样品。这包括红色边缘的波长位置和690至710 nm范围内的反射率值的差异。这两个特性被认为是依赖于叶片叶绿素浓度。反射光谱的一阶导数在685-706、710、725和740 nm处有4个反射峰，这4个反射峰在不同程度上与叶龄和叶片色素浓度有关。第一个峰值的位置和大小与叶片叶绿素浓度有很高的相关性。在700 nm处的反射率与第一峰的波长呈线性关系。在黄绿色至深绿色叶（叶绿素总量在10 nmol/cm（2）以上）中，拐点位置随叶绿素含量变化的变化较小。700 nm附近的反射率被认为是一个非常敏感的指标的红边的位置，以及叶绿素浓度。750 nm和700 nm附近的反射率比值（R（750）/R（700））与叶绿素浓度成正比（相关系数r（2）>0.95）。在枫树和板栗叶片叶绿素含量为0.6 ~ 60 nmol/cm（2）的范围内，用独立数据集对新建立的R（750）/R（700）指标进行了检验，其估算误差小于3.7 nmol/cm（2）。
Pigment contents was determined in and high spectral resolution reflectance measurements were acquired for spring, summer and autumn maple and horse chestnut leaves covering a wide range of chlorophyll content. Consistent and diagnostic differences in the red edge range (680-750 nm) of the reflectance spectrum were obtained for the various leaf samples of both species studied. This included the differences in the wavelength position of the red edge and in the reflectance values in the range of 690 to 710 nm. Both characteristics were found to be dependent on leaf chlorophyll concentration. The first derivative of reflectance spectra showed four peaks at 685-706, 710, 725 and 740 nm that were dependent in different degree on leaf age and pigment concentration in the leaves. The position and the magnitude of the first peak showed a high correlation with the leaf chlorophyll concentration. Reflectance at 700 nm was linearly dependent on the wavelength of the first peak. Variation of inflection point position with change in chlorophyll content was found small for yellow-green to dark green leaves (total chlorophyll in the range above 10 nmol/cm(2)). Reflectance near 700 nm was found to be a very sensitive indicator of the red edge position as well as of chlorophyll concentration. The ratio of reflectances at 750 nm to that near 700 nm (R(750)/R(700)) was directly proportional (correlation r(2)>0.95) to chlorophyll concentration. The ratio R(750)/R(700) as a newly established index for non-invasive in-vivo chlorophyll determination was tested by independent data sets in the range of Chl contents from 0.6 to more than 60 nmol/cm(2) of maple and chestnut leaves with an estimation error of Chl of less than 3.7 nmol/cm(2).