Modeling canopy CO₂ and H₂O exchange of a temperate mixed forest

Abstract

[1] We tested a multilayered model that simulated half-hour canopy CO 2 and H 2 O exchange of a temperate forest mixed with broadleaved trees and Korean pine. The variables input to the model for scaling the fluxes from leaf to canopy included the vertical profiles of height, canopy thickness, and leaf biomass of the five dominant tree species. The diurnal and seasonal patterns of modeled CO 2 and H 2 O fluxes agreed with measured values well during the nonstressed periods, while the model showed overestimation during the water-stressed and high-temperature periods, which appeared infrequently in our study site. We showed a strong correlation between 20-layer daily modeled fluxes and eddy covariance measurements for CO 2 (r 2 = 0.734) and H 2 O (r 2 = 0.785), during May to September 2003-2007. Different layered methods exerted influence on the radiation absorption within the canopy sublayers and hence on the CO 2 and H 2 O flux outputs. CO 2 and H 2 O fluxes based on the Gaussian 5-layered method were 8% and 1% lower than those based on the 20-layered method.

Improving SWAT for simulating water and carbon fluxes of forest ecosystems

“…Howland Forest Main US-Ho1 ME 45.2041 -68.7402 60 Evergreen Needle-leaf Forest Richardson et al (2009) Missouri Ozark US-MOz MO 38.7441 -92.2000 219 Deciduous Broad-leaf Forest Gu et al (2006Gu et al ( , 2012Gu et al ( , 2015 Morgan Cook et al (2004) Park Falls US-PFa WI 45.9459 -90.2723 470 Mixed Forest Davis et al (2003) Niwot Ridge US-NR1 CO 40.0329 -105.5464 3050 Evergreen Needle-leaf Forest Monson and Turnipseed, (2002)…”

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