A Case Study of Carbon Sequestration Potential of Land Use Policies Favoring Re-growth and Long-term Protection of Temperate Forests

Abstract

There is a traditional view suggesting forests remove carbon dioxide from the atmosphere (Pregitzer & Euskirchen,2004), but they cease to serve as a carbon sink as they fully mature (Odum, 1969). Recent modeling of old-growthforest carbon sequestration indicate they continue to serve as a "net sink" of carbon even after maturity (Carey, Sala,Keane, & Callaway, 2001; Zhou et al., 2006) - sequestering an average of 2.4 +/- 0.8 tC ha-1 yr-1 (tC = metric tons ofcarbon; ha = hectare; yr =year), and yielding a ratio of heterotrophic respiration (Rh) to net primary production (NPP)of approximately 0.65 +/- 0.02 (Luyssaert et al., 2008). These figures show the strongest correlation amongst temperateforest regions.Two calculations are made using this carbon sequestration average. One is made identifying the amount of carbonsequestered through a small-scale land protection organization, yielding a net carbon sequestration of approximately224 metric tons of carbon per year. The other is based on the amount of land required to offset current anthropogenicemissions of carbon in the global carbon budget, showing approximately 235 million hectares of new forest growthwould be required to offset current global anthropogenic emissions. One implication of these calculations is thetraditional assumption of carbon neutrality increasing with age (Magnani et al., 2007) is incorrect, suggesting matureforest protection may be a favored policy choice for carbon sequestration strategies.