Using 137Cs technique to quantify soil conservation capacities of different ecosystems in Wolong Natural Reserve,...

Reliable information about soil conservation capacities of different natural ecosystems is an important reference for the design of targeted erosion and sediment control strategies. The objective of this paper is to quantify the soil conservation capacities of different natural ecosystems that can represent different climatic zones. The (137)Cs technique has been used to estimate soil redistribution rates in different natural ecosystems over the past 40 years in Wolong Nature Reserve. The reserve, transiting from the Chengdu plain to the Qinghai-Tibet plateau, maintains rich ecosystems from subtropical to frigid. The net soil erosion rates of 5 selected ecosystems that represent a warm coniferous-broadleaf-mixed forest, a cold-resistant deciduous taiga forest, a cold-resistant shrub, an evergreen cold-resistant taiga forest, and an alpine meadow are 0.17, 0.16, 0.13, 0.11 and 0.06 kg x m(-2) x a(-1), respectively. Their soil conservation capacities are reversed in order. The reference inventories for (137)Cs in different ecosystems range from 1658 to 3707 Bq x m(-2) with the altitude. Results of this study indicate that any attempt to develop effective erosion and sediment strategies in areas with similar climates should consider natural ecosystem types.