| Two existing disturbances in the Canadian boreal forest include fire and harvest, although climate change is expected to soon have a major effect. Hence, the overall objectives of this study were to quantify and compare soil carbon stocks and composition in (1) two jack pine chronosequences of either fire or harvest origin, and (2) along a latitudinal transect. The distribution of carbon was quantified among soil pools, and composition of the forest floors and light fractions was further characterized by CPMAS 13C nuclear magnetic resonance (NMR). While total soil carbon stocks (0-1 m) did not differ between the fire and harvest chronosequences, these were less at the warmer southern site compared to the northern site. Soil carbon within all profiles was dominated by labile pools. The relative importance of this labile carbon increased with time since disturbance in both chronosequences, and reached a maximum at the northern-most site. |
