Aboveground biomass and net primary production at an early stage of secondary succession after clear cutting of a deciduous broad-leaved forest

Aboveground net primary production (ANPP) was estimated using a harvest technique and an allometric technique using the diameter at breast height (DBH) at an early stage after clear-cutting a deciduous broad-leaved forest. The number of stems per hectare increased from 40,700 in May 2005 to 53,300 in November 2009. During the same period, basal area increased from 3.4 to 12.0 m^2ha^. The study stand consisted of shrubs, sub-canopy trees and canopy trees. Although these tree types had similar relative basal areas in May 2005, canopy trees increased during the study period. The mortality and recruitment of shrubs was more than twice that for the other types. We were not able to use the harvest technique to accurately estimate the interannual variation in ANPP due to the high variation in stand biomass. The allometric technique underestimated the stand biomass and growth because it omitted trees smaller than breast height. However, the allometric technique was able to evaluate the mortality and growth of recruits. When estimating ANPP, it is important to evaluate the mortality and growth of recruits in shrub-rich stands due to the production of shrubs. Therefore, the allometric technique is effective for evaluating the interannual variation in the ANPP in shrub-rich stands.