Soil samples were taken from each of the 64 plots on 20 August
2005 and 21 August 2007 coinciding with maximal aboveground
biomass. Soil samples were collected from the 32 plots of clipping
control on 19 August 2006. In each plot, five soil cores (15 cm in
depth and 5 cm in diameter) were randomly taken and completely
mixed to obtain a composite sample. After removing roots or stones
by sieving with a 2 mm mesh size sieve, the soil samples were
stored in ice boxes and subsequently transferred to the lab for
dissolve organic C (DOC), inorganic N concentration,