Premium
Improved assessment of gross and net primary productivity of Canada's landmass
Author(s) -
Gonsamo Alemu,
Chen Jing M.,
Price David T.,
Kurz Werner A.,
Liu Jane,
Boisvenue Céline,
Hember Robbie A.,
Wu Chaoyang,
Chang KuoHsien
Publication year - 2013
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
eISSN - 2169-8961
pISSN - 2169-8953
DOI - 10.1002/2013jg002388
Subject(s) - primary production , moderate resolution imaging spectroradiometer , environmental science , ecosystem respiration , land cover , atmospheric sciences , boreal ecosystem , productivity , leaf area index , flux (metallurgy) , carbon cycle , ecosystem , taiga , meteorology , remote sensing , land use , forestry , satellite , geography , ecology , physics , economics , biology , macroeconomics , materials science , astronomy , metallurgy
We assess Canada's gross primary productivity (GPP) and net primary productivity (NPP) using boreal ecosystem productivity simulator (BEPS) at 250 m spatial resolution with improved input parameter and driver fields and phenology and nutrient release parameterization schemes. BEPS is a process‐based two‐leaf enzyme kinetic terrestrial ecosystem model designed to simulate energy, water, and carbon (C) fluxes using spatial data sets of meteorology, remotely sensed land surface variables, soil properties, and photosynthesis and respiration rate parameters. Two improved key land surface variables, leaf area index (LAI) and land cover type, are derived at 250 m from Moderate Resolution Imaging Spectroradiometer sensor. For diagnostic error assessment, we use nine forest flux tower sites where all measured C flux, meteorology, and ancillary data sets are available. The errors due to input drivers and parameters are then independently corrected for Canada‐wide GPP and NPP simulations. The optimized LAI use, for example, reduced the absolute bias in GPP from 20.7% to 1.1% for hourly BEPS simulations. Following the error diagnostics and corrections, daily GPP and NPP are simulated over Canada at 250 m spatial resolution, the highest resolution simulation yet for the country or any other comparable region. Total NPP (GPP) for Canada's land area was 1.27 (2.68) Pg C for 2008, with forests contributing 1.02 (2.2) Pg C. The annual comparisons between measured and simulated GPP show that the mean differences are not statistically significant ( p > 0.05, paired t test). The main BEPS simulation error sources are from the driver fields.