51
spectroscopy to describe optical properties of dried plant materials in the 0.4–2.5
micron range that enable detection of plant biochemistry from spectroscopy.
Similarly, Curran (1989) summarized spectral features across this same spectral
range that could be used in RS of plants, identifying not just the specific absorption
features associated with pigments but also features related to harmonics and overtones related to molecular bonds of hydrogen (H) with carbon (C), nitrogen (N), and
oxygen (O) in organic compounds (e.g., Fig. 3.3). In addition, by the late 1980s,
researchers began to utilize novel, experimental airborne imaging spectrometer systems to map vegetation canopy chemistry in diverse landscapes. Using an earlygeneration NASA imaging spectrometer, the airborne imaging spectrometer (AIS,
Vane and Goetz 1988), these studies illustrated the capacity to map landscape variation in foliar biochemical properties, including nitrogen and lignin (Peterson et al.
1988; Wessman et al. 1988; Wessman et al. 1989). AIS was the precursor to the
Airborne Visible/Infrared Imaging Spectrometer (AVIRIS, Vane 1987). Following
on this work, several others explored the impacts of leaf functional traits on reflectance properties of plant canopies and the ability to retrieve canopy chemistry,
leveraging several important airborne campaigns including the Oregon Transect
Ecosystem Research (OTTER) project and the Accelerated Canopy Chemistry
Program (ACCP) (e.g., Card et al. 1988; Peterson et al. 1988; Matson et al. 1994;
Bolster et al. 1996; Martin and Aber 1997).
These early studies became the basis for studies using imaging spectrometry to
infer nutrient use and cycling in natural ecosystems (e.g., Martin and Aber 1997;
Ollinger et al. 2002; Ollinger and Smith 2005). By the 1990s, the promise of
spectroscopy for ecological characterization led to the increased use of handheld
portable spectrometers in the field (e.g., instruments from Analytical Spectral
Devices, GER, Spectra Vista Corporation, Spectral Evolution, Ocean Optics, LiCor,
and PP Systems), as well as research that led to the use of narrowband SVIs for
characterizing rapid changes in leaf function in response to the environment and
leaf physiology (e.g., photochemical reflectance index, PRI, Gamon et al. 1992;
Penuelas et al. 1995; Gamon et al. 1997). The review by Cotrozzi et al. (2018)
provides a more detailed summary of the history of spectroscopy for plant studies,
while Table 3.1 provides a summary of the key functional traits observable with
spectroscopic RS approaches. As a consequence of studies at the leaf level and
using early imaging spectrometers, a host of airborne sensor systems emerged, such
as AVIRIS (Green et al. 1998), HyMap (Cocks et al. 1998), Airborne Prism
Experiment (APEX, Schaepman et al. 2015), the Carnegie Airborne Observatory
(CAO, Asner et al. 2012), AVIRIS-Next Generation (Miller et al. 2018; Thompson
et al. 2018), and the US National Ecological Observatory Network (NEON) imaging spectrometer (Kampe et al. 2010) in the twenty-first century. The NASA prototype satellite EO-1 (Middleton et al. 2013) included the Hyperion sensor as an early
test of the capacity to make hyperspectral measurements from space, leading to the
development of a number of spaceborne missions planned for the early 2020s
(Schimel et al., Chap. 19).
3 Scaling Functional Traits from Leaves to Canopies
spectroscopy to describe optical properties of dried plant materials in the 0.4–2.5
micron range that enable detection of plant biochemistry from spectroscopy.
Similarly, Curran (1989) summarized spectral features across this same spectral
range that could be used in RS of plants, identifying not just the specific absorption
features associated with pigments but also features related to harmonics and overtones related to molecular bonds of hydrogen (H) with carbon (C), nitrogen (N), and
oxygen (O) in organic compounds (e.g., Fig. 3.3). In addition, by the late 1980s,
researchers began to utilize novel, experimental airborne imaging spectrometer systems to map vegetation canopy chemistry in diverse landscapes. Using an earlygeneration NASA imaging spectrometer, the airborne imaging spectrometer (AIS,
Vane and Goetz 1988), these studies illustrated the capacity to map landscape variation in foliar biochemical properties, including nitrogen and lignin (Peterson et al.
1988; Wessman et al. 1988; Wessman et al. 1989). AIS was the precursor to the
Airborne Visible/Infrared Imaging Spectrometer (AVIRIS, Vane 1987). Following
on this work, several others explored the impacts of leaf functional traits on reflectance properties of plant canopies and the ability to retrieve canopy chemistry,
leveraging several important airborne campaigns including the Oregon Transect
Ecosystem Research (OTTER) project and the Accelerated Canopy Chemistry
Program (ACCP) (e.g., Card et al. 1988; Peterson et al. 1988; Matson et al. 1994;
Bolster et al. 1996; Martin and Aber 1997).
These early studies became the basis for studies using imaging spectrometry to
infer nutrient use and cycling in natural ecosystems (e.g., Martin and Aber 1997;
Ollinger et al. 2002; Ollinger and Smith 2005). By the 1990s, the promise of
spectroscopy for ecological characterization led to the increased use of handheld
portable spectrometers in the field (e.g., instruments from Analytical Spectral
Devices, GER, Spectra Vista Corporation, Spectral Evolution, Ocean Optics, LiCor,
and PP Systems), as well as research that led to the use of narrowband SVIs for
characterizing rapid changes in leaf function in response to the environment and
leaf physiology (e.g., photochemical reflectance index, PRI, Gamon et al. 1992;
Penuelas et al. 1995; Gamon et al. 1997). The review by Cotrozzi et al. (2018)
provides a more detailed summary of the history of spectroscopy for plant studies,
while Table 3.1 provides a summary of the key functional traits observable with
spectroscopic RS approaches. As a consequence of studies at the leaf level and
using early imaging spectrometers, a host of airborne sensor systems emerged, such
as AVIRIS (Green et al. 1998), HyMap (Cocks et al. 1998), Airborne Prism
Experiment (APEX, Schaepman et al. 2015), the Carnegie Airborne Observatory
(CAO, Asner et al. 2012), AVIRIS-Next Generation (Miller et al. 2018; Thompson
et al. 2018), and the US National Ecological Observatory Network (NEON) imaging spectrometer (Kampe et al. 2010) in the twenty-first century. The NASA prototype satellite EO-1 (Middleton et al. 2013) included the Hyperion sensor as an early
test of the capacity to make hyperspectral measurements from space, leading to the
development of a number of spaceborne missions planned for the early 2020s
(Schimel et al., Chap. 19).
3 Scaling Functional Traits from Leaves to Canopies