Abstract
The objective of this study was to investigate the effect of the initialstand age distribution on the carbon dynamics of sugi (Cryptomeria japonica) planted forests on a national scale. We ran simulations of carbon dynamics of sugi planted forests for all of Japan from 2005 to 2050 using the simulation system developed in previous a study. The initial stand age distributions were set as follows: Case 1) actual distribution, Case 2) 30-year younger distribution, Case 3) 30-year older distribution, and Case 4) uniform distribution. The carbon removal rate was higher for Cases 2 and 4 than Case 1 for the earlier simulation period, but as the young stands decreased, the carbon removal rate also decreased in the later simulation period. These results indicated that the effect of the initial stand age distribution on national-scale carbon dynamics was limited in a 45-year simulation. Through this simulation study, we reconfirmed that young stands are essential for maintaining the national-scale carbon removal rate, and also that clearcutting and subsequent replanting are critical for future carbon absorption.
