Dynamics of carbon stocks of different pools in Huzhong National Nature Reserve, Northeast China under the disturbance of various severity fires.

Abstract

In this study, the FireBGCv2 model was used to simulate the dynamics of forest carbon pools of Huzhong Nature Reserve within the next 100 years under various forest fire severity scena-rios. The aim of this study was to explore the responses of different forest carbon pools to fire disturbance, and to provide scientific basis for forest fuel management. The results showed that forest fire significantly reduced forest carbon storage, with the greatest reduction under the scenario of high-severity forest fire. Fire disturbance affected carbon storage in different pools, and relocated carbon among those pools. Forest fire disturbance reduced carbon storage of living trees and duff, increased that of coarse woody debris in the early and middle stages of simulation, and decreased that in late stage. The carbon storage of shrub and herb strata increased significantly in the late simulation period. The higher the fire severity, the lower the carbon storage of living tree and shrub-herb carbon pools, with snag and coarse woody debris showing the opposite trend. The impact of forest fire disturbance on the total carbon pool distribution was as follows: forest fire increased the proportion of shrub and herb strata, snag, coarse woody debris and soil carbon pool, and reduced the proportion of living tree and duff. The higher severity forest fire was, the lower the proportion of carbon pool of shrub-herb, and the higher the proportion of carbon pool of coarse wood debris. The severity of forest fire had less impact on the proportion of other carbon pools. In addition, our results demonstrated periodic change of litter carbon that reached a high value within 20 years and then dropped to a low value within 10 years. Our results could provide sound basis for determining the forest fuel treatment interval. We suggested performing prescribed burning every 20 years in the Great Xing'an Mountains area to protect forest resources.