Fire is a major disturbance in terrestrial ecosystems. It is known to increase soil temperature, remove the litter layer and produce charcoal (Raison 1979; Neary et al. 1999; Certini 2005; Makoto et al. 2011). Thus, indirectly, fire changes nutrient flows and pools in the soil, including GHG fluxes (Kim et al. 2011), limiting nutrients such as P availability, NO3- availability and the C/N ratio is also changed within short term (Makoto et al. 2011). Therefore, fire is expected to impact tree growth significantly. But little have been done to quantify the effects of fire on tree growth when the trees remain relatively intact (relatively low intensity fire).
In Teshio experimental forest, 4 plots of were set up in 2007 and treated as control, burnt and burnt then the produced charcoal was removed. Total C and N, NO3-, available P dynamics were followed up through the year. This study will measure again these parameters 5 years after the burning and observe the responses of the trees.
Total C and N, NO3-, available P will be measured in soil sample will collected at same intervals as in 2007 (July, August, October and November) to establish comparable temporal dynamics. Tree rings will be sampled in the end of growing season to be analyzed according to the nutrient content variations. It is expected that the ring width will be larger soon after the burning due to increase in nutrients availability. The plots with charcoal removed are expected to show smaller variations, which will show the effects of charcoal in increasing or maintaining the nutrients in the soil.