3.1 Effects of grazing on the GRSP concentration
The concentration of T-GRSP and EE-GRSP were determined for each grazing
succession stage (Fig. 1). Analysis of variance showed that the mean
concentrations of T-GRSP and EE-GRSP in soils were significantly
different (P < 0.05) between the surface (0-10 cm) and
subsurface (10-20 cm) soils. T-GRSP (10.42% (FB)-81.25% (KC)) and
EE-GRSP (12.63% (FB)-70.31% (K)) were higher in the surface than in
the subsurface soil. T-GRSP and EE-GRSP were highest in GK community
sites (14.71±0.67 and 3.69±0.15 mg/g, respectively, in surface soils,
and 8.85±0.92 and 2.30 ±0.19 mg/g, respectively, in subsurface soils).
The concentration of T-GRSP and EE-GRSP in surface soils had a
significant decreasing trend from GK, K, KT, KC to FB. However, the
contents were not significantly different among K, KT, and KC. T-GRSP in
surface soils was lowest in KT and FB, while EE-GRSP was lowest in KC
community sites. Overall, GRSP
contents gradually decreased with increasing intensities of grazing.