Measuring foliar chemistry alongside airborne observations in the National Ecological Observatory Network
Abstract
The chemical composition of canopy foliage mediates key ecosystem processes including productivity, herbivory and nutrient export. However, long-term datasets that can reveal directional change in canopy foliar traits in response to environmental drivers are scarce. Advances in imaging spectroscopy have enhanced our ability to remotely sense canopy reflectance, and a better understanding of links between observed reflectance and measured foliar constituents will enhance our ability to map unsampled regions and predict foliar chemical change over time. In this talk, I will present the current canopy foliage sampling plan for the National Ecological Observatory Network (NEON). NEON will analyze sun-lit canopy leaves and needles across all 47 terrestrial observation sites every 3-5 years throughout the 30-year lifetime of the observatory. Sampling will occur in plots adjacent to flux towers as well as those distributed across the landscape, with individuals targeted to represent locally dominant canopy species. Measured variables include leaf mass per area, chlorophyll content, carbon and nitrogen concentrations and stable isotopes, major and minor elements, and lignin. Sampling will coincide with overflights of the NEON Airborne Observation Platform in order to maximize the utility of ground-based observations for developing regressions with hyperspectral data, with algorithm development lead by the community. To demonstrate the kind of data that will be collected and made publicly available once the observatory becomes operational, results from three linked ground-aerial prototype campaigns from summer 2016 will be shown. Prototype data highlights strong taxonomic controls on foliar physical and chemical properties but also notable variation within species and genera across sites and environmental gradients. NEON's canopy sampling program will hopefully provide exciting, continental-scale opportunities to advance our understanding of the controls on foliar chemistry across space and time in diverse ecosystems.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.B51I..06W
- Keywords:
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- 0439 Ecosystems;
- structure and dynamics;
- BIOGEOSCIENCESDE: 0476 Plant ecology;
- BIOGEOSCIENCESDE: 0480 Remote sensing;
- BIOGEOSCIENCES