• Modeling stand-level canopy maintenance respiration of black spruce ecosystems in Alaska: implications for spatial and temporal scaling

      Zhang, Xinxian (2001-05)
      Canopy respiration represents an important part of the carbon budget of black spruce forests. In this study I scaled hourly models of foliar maintenance respiration (Rm) to estimate canopy Rm for individual stands, and investigated issues in scaling the models to estimate canopy Rm using mean monthly temperature data. I used data from several stands to develop hourly stand-specific and stand-independent models of canopy Rm. Analysis of stimulated canopy Rm indicated that stand-level controls over foliar N concentration should be considered in models that estimate canopy Rm of black spruce stands across the landscape. Uncertainty analyses indicated that the parameter that describes maintenance respiration rate at 0C̊ per g N has the greatest influence on annual estimates of canopy maintenance respiration. Finally, comparisons of monthly Rm between the hourly and monthly versions of the models indicated that mean monthly temperature can be used to drive models of canopy Rm with little loss of precision.