Litter production, seasonal pattern and nutrient return in seven natural forests compared with a plantation in southern China

The amount and pattern of litterfall and its nutrient returnwere studied in seven natural forests of Schima superba Gardn.and Champ. (SCS), Castanopsis fabri Hance (CAF), Tsoongiodendronodorum Chun (TSO), Cinnamomum chekiangense Nakai (CIC), Altingiagracilipes Hemsl. (ALG), Castanopsis carlesii (Hemsl.) Hayata(CAC) and Pinus massoniana D. Don (PIM), and compared with thatof an adjacent 29-year-old plantation of Chinese fir (Cunninghamialanceolata Lamb.) (CUL) in Jianou, Fujian, China. Mean annualtotal litterfall over 3 years of observations varied from 4.63Mg ha^–1 in the CUL to 8.85 Mg ha^–1 in the PIM; ofthis litterfall, the leaf contribution ranged from 62 to 73per cent. Litterfall in the CAF, ALG and CAC showed an unimodaldistribution pattern, while for the five other forests, thelitterfall pattern was multi-peak. The rank order of the eightforests, according to nutrient return mass with the exceptionof P, was different from the order when rank was according tototal mass of litterfall. The highest annual N, K and Ca returnsfrom total litterfall were noticed in the TSO, the CAF and theCUL, respectively. The amounts of P and Mg potentially returnedto the soil were the highest in the PIM. The leaf fraction providedgreater potential returns of N, P, K, Ca and Mg to the soilthan other litter fractions. The results of this study demonstratethat natural forests have a greater capability for maintainingsite productivity than the monoculture coniferous plantation,due to higher amount of above-ground litter coupled with greaternutrient returns; therefore conservation of natural forestsis recommended as a practical measure in forest management torealize sustainable development of forestry in mountainous areasof southern China.