Assessment of Biomass and Carbon Assessment of Biomass and Carbon Litterfall in Three Chestnut High Forest in Three Chestnut High Forest Stands in Northern Portugal Stands in Northern Portugal

-1 year -1 representing 69.8-79.4 % of the total litterfall. They also sequester the largest amount of carbon. 9 Branches fall contribution was smaller than leaves and only represented 4-6 % of the total litterfall. 9 Fruits and burs represented 6.4-12.4 % and 7.8-13.9 %, respectively of the annual total litterfall. 9 These results are consistent with Regina (2000) for the leaves component but not for the others because, in our case, the contribution of burs and fruits is greater than branches. However, the densities and ages of the stands are very different. The values of total litterfall are approximate to the values of 3.9 Mg ha -1 year -1 reported by Pires et al. (1994) for chestnut groves and 4.9 Mg ha -1 year -1