Remote estimation of gross primary production and light use efficiency at a boreal bog and an abandoned peatland pasture in western Newfoundland, Canada

• Main Author: Gillani, Syed Shah Mohioudin
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 2018
• Subjects: Canada; Newfoundland
• Online Access: https://research.library.mun.ca/13719/; https://research.library.mun.ca/13719/1/thesis.pdf

The pristine peatlands store approximately 1/3 of the global soil carbon (C) pool and function as a climate cooling mechanism. A peatland’s production is persistently larger than its decomposition due to its high soil water content. However, peatlands disturbed via drainage have been identified as a potential C source. Gross primary production (GPP) and light use efficiency (LUE) are two critical indicators for studying the C budget in terrestrial ecosystems. However, the knowledge of GPP and LUE values in boreal peatlands is still limited because so few measurements have been carried out in peatlands. Field measurements in boreal peatlands cover less than 0.01% of global peatlands; this significantly limits our capacity to understand the C budget of global peatlands. Normally, estimation of the C budget for global peatlands requires field-based measurements to be up-scaled from the field level to the global level. Another commonly-adopted approach for estimating the C budget for global peatlands is to estimate the C budget based on the remotely sensed measurement with global coverage. This approach needs to use the algorithm derived from field measurements. However, there are significant uncertainties over the field-based algorithm used to estimate the GPP and LUE in boreal peatlands due to the very limited availability of field measurements. Moreover, none of the field-based estimations of GPP and LUE were done for drained peatlands. Therefore, more studies are needed to estimate the GPP and LUE for both pristine peatlands and disturbed peatlands based on field measurements. To fill this gap, I conducted a study to estimate GPP and LUE using eddy covariance tower (EC) measurements and MODIS satellite data in a boreal bog and an adjacent abandoned peatland pasture. I have assessed the relationships of GPP with photosynthetic active radiation (PAR) alone, vegetation indices (normalized difference vegetation index [NDVI] and enhanced vegetation index [EVI]), and their products (PAR×EVI, PAR×NDVI) at both research ...