Litterfall, accumulation and turnover of nutrients in the forest floor of warm-temperate forests of central Japan

Abstract

Examined the forest floor of six subtropical/warm-temperate forests, three natural and semi-natural forests developed on contrasting topography, and Cryptomeria plantations of different ages, on Mt Kiyosumi, Chiba Prefecture. Annual input of nutrient elements to the soil through litterfall was estimated to be 63-121 kg/ha for N, 2.8-7.0 kg/ha for K, 1.1-1.7 kg/ha for Na, 45.6-131.0 kg/ha for Ca, and 10.2-28.4 kg/ha for Mg. The Abies-Tsuga forest occurred on shallow soil on a ridge, and had the greatest accumulation of nutrients on the forest floor and surface soils (0-15 cm). The amounts of nutrients accumulated in the forest floor and surface soils (0-15 cm) of the evergreen Quercus (Cyclobalanopsis)-Castanopsis forest on a crest slope and the deciduous Quercus-Cornus forest on a valley bottom were about half those of the Abies-Tsuga forest, but the latter deciduous forest developed on deep soils, and nutrients were stored in the lower soil layer (15-50 cm). Turnover times of nutrient elements in the forest floor and soil system were 1.6-10.8 yr for Ca. 3.2-15.8 yr for Na, 8.6-25.1 yr for Mg, 9.5-31.7 yr for K, and 20.3-100.9 yr for N. -from Authors