All study areas of BEF China are located in south-eastern China, about 400 km west of Shanghai in the border area of Jiangxi and Zhejiang Province, including the two counties Dexing and Kaihua.
The project region belongs to the subtropics. According to international classification standards (Köppen & Geiger 1928), the climate is warmtemperate with a dry season in winter and warm summers, by concentration of precipitation in the summer months (May to June). The annual average temperature is 15.1°C and the mean annual precipitation is 1964 mm. The elevation of all sites ranges from 105 to 275 m a.s.l..
The natural vegetation is characterized by subtropical forests that are extremely species-rich. In the Gutianshan National Nature Reserve, (GNNR) where the Comparative Study Plots (CSPs) have been established, a total of 1426 seed plant species of 648 genera and 149 families has been recorded as occurring naturally. About 258 of the species are woody (Lou & Jin 2000).
The species composition is characterized by families with temperate distribution range (e.g. Fagaceae) as well as with subtropical (e.g. Anacardiaceae, Lauraceae) or tropical ones (e.g. Symplocaceae,Theaceae, Rutaceae, Myrsinaceae). Dominant species are Cyclobalanopsis glauca, Castanopsis eyrei, Daphniphyllum oldhamii and Lithocarpus glaber.
The topography in the region is characterized by agricultural land use in the valleys (rice, corn, legumes and other vegetables) and forested hills and mountains. The relief includes moderate to steep inclinations from 10° to 40°. Lower parts of the slopes are often used as tea plantations, while the predominant land use from the middle slopes upwards are plantations of Cunninghamia lanceolata and Pinus massoniana. These plantations are manually clear-cut every 20 to 25 years.
Tectonically, both experimental sites (ESPs) are a part of the Neo-Proterozoic Jiangnan belt located between the Yangtze craton in the northwest and the Cathaysia block in the south-east. This oceanic subduction convergent zone can be interpreted as a Neo-Proterozoic orogenic belt (Shu & Charvet 1996) uplifted at about 1,000 Ma ago. The Jiangnan orogenic belt consists of Middle-Upper Proterozoic basement and unconformably overlying Sinian (Ediacaran) to Mesozoic cover rocks (Gu et al. 2002).
In the study area (CSPs), the Middle and Upper Proterozoic sedimentary rocks are composed of a series of slightly metamorphosed (greenschist facies) gray-green sandstone, siltstone, and slate and gray-green and purplish red graywacke. At the Gutianshan National Nature Reserve, an about 850 Ma old granite intrusion forms the bedrock of all CSPs. Only the south-eastern margin is composed of silty to clayey slates. The bedrock of the experimental sites (ESPs) consists mainly of non-calcareous slates with varying sand and silt contents. Joints are filled with siliceous-rich material, mainly quartz. Rock outcrops appear at shoulder positions and along road cuttings.
The soils at experimental sites A and B are Cambisols and Cambisol derivatives, interfered by Regosols on ridges and crests. The substrates of the soils on slopes and crests are of comparable grain sizes and differ in thickness related to the topographic position. Owing to the mountainous topography, erosion is a typical feature that leads to a mixing of parent material and soil components from crest to valley positions.
The study areas are divided into two categories:
