Jun 7, 2012

Attributing carbon changes in conterminous U.S. forests to disturbance and non-disturbance factors from 1901 to 2010

Fangmin Zhang, Jing M. Chen, Yude Pan, Richard A. Birdsey, Shuanghe Shen, Weimin Ju, Liming. He
Journal of Geophysical Research
  • States that recent climate variability (increasing temperature, droughts) and atmospheric composition changes (nitrogen deposition, rising CO2 concentration) along with harvesting, wildfires, and insect infestations have had significant effects on U.S. forest carbon (C) uptake
  • Attributes C changes in the conterminous U.S. forests to disturbance (harvesting, fire, insect infestation) and non-disturbance factors (CO2 concentration, N deposition, and climate variability)
  • Finds that on average, the C sink in the conterminous U.S. forests from 1950 to 2010 was 206 Tg C yr1 with 87% (180 Tg C yr1 ) of the sink in living biomass
  • Finds that the estimated C sink would be reduced by 95 Tg C yr1 if disturbance factors were omitted
  • Finds that the estimated C sink would be reduced by 50 Tg C yr1 if non-disturbance factors were omitted
  • Finds that neglecting rising CO2 concentration and N deposition respectively would underestimate the C sink by 13 and 24 Tg C yr1 respectively during the period of 1950–2010
  • The study also showed diverse regional patterns of C sinks related to the importance of driving factors: during 1980–2010, disturbance effects dominated the C changes in the South and Rocky Mountain regions, were almost equal to non-disturbance effects in the North region, and had minor effects compared with non-disturbance effects in the West Coast region