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ucts. LAI field measurements were made using hemispherical photography and TRAC sunfleck
profiling in the landscape context of vegetation associations and physiography and in the temporal
context of the annual phenological cycle. Results of these field validation efforts will contribute to
a greater understanding of phenological dynamics evident in NDVI time series and will provide
valuable data for the validation of the MODIS LAI product.
ACKNOWLEDGMENTS
The authors express their sincere appreciation to Mark Murphy, Chris Murray and Maria
Maschauer for their assistance in the field. We thank Conghe Song for sharing of field instruments,
Malcolm Wilkins for research support, Paul Ringold for providing hemispherical photographic
images for use in the quality assurance and quality control aspects of the study, and Ross Lunetta,
David Holland, and Joe Knight for assistance in study design. International Paper Corporation,
Westvaco Corporation, the states of Virginia and North Carolina, Duke University, and North
Carolina State University provided access to sampling sites. We also thank three anonymous
reviewers for helpful comments on this manuscript. The U.S. Environmental Protection Agency
funded and partially conducted the research described in this chapter. It has been subject to the
Agency's programmatic review and has been approved for publication. Mention of any trade names
or commercial products does not constitute endorsement or recommendation for use.
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Ecology
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