24 Remote Sensing of Terrestrial Photosynthesis 1
C.B. Field, J.A. Gamon, and J. Peftuelas
24.1 Remote Sensing, from the Leaf to the Globe
Most photosynthesis measurements involve remote determinations. In gasexchange systems, including those based on chambers, atmospheric gradients, and eddy correlation, photosynthesis determinations are remote in
the sense that the measurements are based on effects of leaves, plants, or
canopies on the gaseous environment. In radiation-based remote sensing,
the subject of this chapter, photosynthesis determinations are based on
interactions between leaves, plants, or canopies and the radiation environment. The wavelength bands potentially useful for measurements related to
photosynthesis range from the visible through the thermal and microwave
regions. While remote sensing generally connotes large-scale satellite measurements, radiation-based remote sensing can be effectively utilized to
address questions in photosynthesis research ranging in spatial scale from
the chloroplast to the globe.
For this brief chapter, we review some major approaches to assessing
photosynthesis using radiation-based remote sensing. We discuss measurements at a range of spatial scales and develop the theme that understanding
the concepts, constraints, and challenges of making accurate photosynthesis
measurements at leaf and plant scales is an important foundation for regional
and global estimates.
The motivation for developing remote sensing approaches to photosynthesis measurements comes from at least four areas. First, remote sensingbased assessments of photosynthesis may supplement alternative approaches
with additional information or offer less invasive and/or expensive methodologies. Second, remote sensing of photosynthesis provides opportunities to
develop and test our understanding of the upward scaling of physiological
phenomena. Just as the controls on photosynthesis may be different at the
leaf than at the chloroplast level (Woodrow et al. 1990), they may also differ
between the leaf and higher levels of organization. Third, a clearer picture
of broad-scale patterns of photosynthesis can suggest new hypotheses that
IThis is CIWDPB Publication number 1151
C.B. Field, J.A. Gamon, and J. Peftuelas
24.1 Remote Sensing, from the Leaf to the Globe
Most photosynthesis measurements involve remote determinations. In gasexchange systems, including those based on chambers, atmospheric gradients, and eddy correlation, photosynthesis determinations are remote in
the sense that the measurements are based on effects of leaves, plants, or
canopies on the gaseous environment. In radiation-based remote sensing,
the subject of this chapter, photosynthesis determinations are based on
interactions between leaves, plants, or canopies and the radiation environment. The wavelength bands potentially useful for measurements related to
photosynthesis range from the visible through the thermal and microwave
regions. While remote sensing generally connotes large-scale satellite measurements, radiation-based remote sensing can be effectively utilized to
address questions in photosynthesis research ranging in spatial scale from
the chloroplast to the globe.
For this brief chapter, we review some major approaches to assessing
photosynthesis using radiation-based remote sensing. We discuss measurements at a range of spatial scales and develop the theme that understanding
the concepts, constraints, and challenges of making accurate photosynthesis
measurements at leaf and plant scales is an important foundation for regional
and global estimates.
The motivation for developing remote sensing approaches to photosynthesis measurements comes from at least four areas. First, remote sensingbased assessments of photosynthesis may supplement alternative approaches
with additional information or offer less invasive and/or expensive methodologies. Second, remote sensing of photosynthesis provides opportunities to
develop and test our understanding of the upward scaling of physiological
phenomena. Just as the controls on photosynthesis may be different at the
leaf than at the chloroplast level (Woodrow et al. 1990), they may also differ
between the leaf and higher levels of organization. Third, a clearer picture
of broad-scale patterns of photosynthesis can suggest new hypotheses that
IThis is CIWDPB Publication number 1151