Carbon pool dynamics in the Lower Fraser Basin from 1827 to 1990

To understand the total impact of humans on the carbon cycle, the modeling and quantifying of the transfer of carbon from terrestrial pools to the atmosphere is becoming more critical. Using previously published data, this research sought to assess the change in carbon pools caused by humans in the Lower Fraser Basin (LFB) in British Columbia, Canada, since 1827 and define the long-term, regional contribution of carbon to the atmosphere. The results indicate that there has been a transfer of 270 Mt of carbon from biomass pools in the LFB to other pools, primarily the atmosphere. The major losses of biomass carbon have been from logged forests (42%), wetlands (14%), and soils (43%). Approximately 48% of the forest biomass, almost 20% of the carbon of the LFB, lies within old-growth forest, which covers only 19% of the study area. Landfills are now becoming a major sink of carbon, containing 5% of the biomass carbon in the LFB, while biomass carbon in buildings, urban vegetation, mammals, and agriculture is negligible. Approximately 26% of logged forest biomass would still be in a terrestrial biomass pool, leaving 238 Mt of carbon that has been released to the atmosphere. On an area basis, this is 29 times the average global emissions of carbon, providing an indication of the past contributions of developed countries such as Canada to global warming and possible contributions from further clearing of rainforest in both tropical and temperate regions.