This research aimed to: estimate the inputs of litterfall; model the decomposition process and assess the rates of
litter decay and turnover; study the litter decomposition process and dynamics of nutrients in old chestnut high
forests. This study aimed to fill a gap in the knowledge of chestnut decomposition process as this type of ecosystems
have never been modeled and studied from this point of view in Portugal. The study sites are located in the mountains
of Marão, Padrela and Bornes in a west-to-east transect, across northern Portugal, from a more-Atlantic-to-lessmaritime
influence. This research was developed on old chestnut high forests for quality timber production submitted
to a silviculture management close-to-nature. We collected litterfall using littertraps and studied decomposition
of leaf and bur litter by the nylon net bag technique. Simple and double exponential models were used to describe
the decomposition of chestnut litterfall incubated in situ during 559 days. The results of the decomposition are
discussed in relation to the initial litter quality (C, N, P, K, Ca, Mg) and the decomposition rates. Annually, the
mature chestnut high-forest stands (density 360-1,260 tree ha–1, age 55-73 years old) restore 4.9 Mg DM ha–1 of
litter and 2.6 Mg ha–1 yr–1 of carbon to the soil. The two-component litter decay model proved to be more biologically
realistic, providing a decay rate for the fast initial stage (46-58 yr–1for the leaves and 38-42 yr–1for the burs)
and a decay rate related to the recalcitrant pool (0.45-0.60 yr–1for the leaves and 0.22-0.36 yr–1for the burs). This
study pointed to some decay patterns and release of bioelements by the litterfall which can be useful for calibrating
existing models and indicators of sustainability to improve both silvicultural and environmental approaches for the
management of chestnut forests.
