Above-ground biomass and nutrient distribution in a 15-year-old ginkgo (Ginkgo biloba) plantation in Central Korea

Above-ground tree biomass and distribution of nutrients between tree components and within the major components of the ecosystem were determined for a 15-year-old ginkgo (Ginkgo biloba L.) plantation in central Korea. Total ecosystem biomass (excluding roots) was 160.6 Mg ha^-1, of which 79% was soil organic matter, 6% was forest floor and 15% was living, above-ground biomass. Total above-ground tree biomass was 23.8 Mg ha^-1, of which 10% was foliage. Concentrations of N, P, and Mg were greatest in foliage, while concentrations of Ca and K were greater in branch or stembark than foliage. Total ecosystem nutrient contents were (kg ha^-1) 5544 for N, 1384 for Ca, 554 for K, 480 for P, and 145 for Mg, respectively. The forest floor had the largest accumulation of N, P, K, Ca, and Mg in live and dead above-ground components. The greatest proportion of total ecosystem nutrient capital was contained in the mineral soil. Of the total contents of N and P, more than 90% were contained in the upper 20 cm mineral soil. Foliage-only harvesting of ginkgo trees commonly practiced in Korea might degrade site-quality, proper plans for nutrition-management should be considered if foliages were to be harvested regularly.