Relationships between spectral reflectance and pigment concentrations in stacks of deciduous broadleaves
Relationships between spectral reflectance and pigment concentrations in stacks of deciduous broadleaves
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DOI：
10.1016/s0034-4257(99)00048-6
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发表时间：
1999-11-01
影响因子：
13.5
通讯作者：
Blackburn, GA
中科院分区：
文献类型：
--
作者：
Blackburn, GA
本文介绍了用四种落叶树不同衰老阶段的树叶堆叠进行的实验室实验结果。这一方法在色素浓度(单位叶面积和单位地面面积)和叶面积指数方面产生了广泛的差异，这在植物冠层尺度上是可以预期的，并提供了叶绿素和类胡萝卜素与叶面积指数之间的独立差异。使用光谱辐射计测量了每个堆叠的每个叶片增量的光谱反射率，并使用这些数据来评估一些现有的和新的光谱转换与叶片堆叠内的色素浓度(单位地面面积)之间关系的性质和强度。可见光区域内窄波段的反射率与叶绿素浓度有适度的关系，而比值指数，利用近红外和可见光，特别是绿色波段的反射率更成功。红边的波长位置与叶绿素浓度有关，而反射率和伪吸光度的一阶和二阶导数的幅度特征与叶绿素的相关性更强。光谱反射率的变化与类胡萝卜素浓度无显著相关，但有两个比值指数与类胡萝卜素与叶绿素a的比值高度相关。有趣的是，叶面积指数(LAI)与包括宽带归一化差和简单比值植被指数在内的所有光谱比值指数无关。这表明，当组成植被冠层的叶片具有不同的叶绿素浓度(单位叶面积)时，光谱指数估计这些冠层的叶面积指数的适用性可能有限。(C)爱思唯尔科学公司，1999年。
This article presents the findings of a laboratory experiment using stacks of leaves obtained from four species of deciduous tree at various stages of senescence. This methodology generated a wide variation in pigment concentrations (per unit leaf area and per unit ground area) and leaf area index, as may be expected at the plant canopy scale, and provided independent variation between the chlorophylls and carotenoids and leaf area index. Spectral reflectance was measured for each leaf increment of each stack using a spectroradiometer and these data were used to evaluate the nature and strength of relationships between a number of existing and novel spectral transformations and the concentrations of pigments (per unit ground area) within the leaf stacks. Reflectance in narrow wavebands within the visible region was moderately related to chlorophyll concentrations, while ratio indices, employing wavebands in the near-infrared and visible, particularly the green, were more successful. While the wavelength position of the red edge was related to chlorophyll concentration, characteristics of the amplitude of the first and second derivatives of reflectance and pseudo absorbance were more strongly correlated with chlorophyll. No transformation of spectral reflectance that was tested was strongly related to the concentration of carotenoids but two ratio indices were highly correlated with the ratio of carotenoids to chlorophyll a. Interestingly, leaf area index (LAI) was unrelated to all spectral ratio indices including the broad-band normalized-difference and the simple ratio vegetation indices. This indicates that spectral indices may have limited applicability for estimating the LAI of vegetation canopies when the leaves that comprise these canopies have differing chlorophyll concentrations (per unit leaf area). (C)Elsevier Science Inc., 1999.