This study was carried out at Haibei Research Station of Alpine Meadow Ecoystem and the experiment plot was set on winter spring pasture.Using a compartment model.we divided the ecosystem into four compartments,they are atmosphere,soil,vegetation and grazing animal compartments.We measured the P storage in each of the compartments,and studied the direction and the amounts of P flowing among these compartments,and its' supply requirement state in the ecosystem.the P cycling process in the Alpine Meadow Eco...