Using MODIS derived <i>f</i>PAR with ground based flux tower measurements to derive the light use efficiency for two Canadian peatlands
We used satellite remote sensing data; fraction of photosynthetically active radiation absorbed by vegetation (<i>f</i>PAR) from the Moderate Resolution Imaging Spectroradiometer (MODIS) in combination with tower eddy covariance and meteorological measurements to characterise the Light U...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2009-02-01
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| Series: | Biogeosciences |
| Online Access: | http://www.biogeosciences.net/6/225/2009/bg-6-225-2009.pdf |
| Summary: | We used satellite remote sensing data; fraction of photosynthetically active radiation absorbed by vegetation (<i>f</i>PAR) from the Moderate Resolution Imaging Spectroradiometer (MODIS) in combination with tower eddy covariance and meteorological measurements to characterise the Light Use Efficiency parameter (ε) variability and the maximum ε (ε<sub>max</sub>) for two contrasting Canadian peatlands. Eight-day MODIS <i>f</i>PAR data were acquired for the Mer Bleue (2000 to 2003) and Western Peatland (2004). Flux tower eddy covariance and meteorological measurements were integrated to the same eight-day time stamps as the MODIS <i>f</i>PAR data. A light use efficiency model: GPP = ε×APAR (where GPP is Gross Primary Productivity and APAR is absorbed photosynthetically active radiation) was used to calculate ε. The ε<sub>max</sub> value for each year (2000 to 2003) at the Mer Bleue bog ranged from 0.58 g C MJ<sup>−1</sup> to 0.78 g C MJ<sup>−1</sup> and was 0.91 g C MJ<sup>−1</sup> in 2004, for the Western Peatland. The average growing season ε for the Mer Bleue bog for the four year period was 0.35 g C MJ<sup>−1</sup> and for the Western Peatland in 2004 was 0.57 g C MJ<sup>−1</sup>. The average snow free period for the Mer Bleue bog over the four years was 0.27 g C MJ<sup>−1</sup> and for the Western Peatland in 2004 was 0.39 g C MJ<sup>−1</sup>. Using the light use efficiency method we calculated the ε<sub>max</sub> and the annual variability in ε for two Canadian peatlands. We determined that temperature was a growth-limiting factor at both sites Vapour Pressure Deficit (VPD) however was not. MODIS <i>f</i>PAR is a useful tool for the characterization of ε at flux tower sites. |
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| ISSN: | 1726-4170 1726-4189 |