Vertical distribution character of soil inorganic phosphorus in mountain meadow system of WuGong Mountain

The spatial distribution of soil inorganic phosphorus and the correlation between soil inorganic phosphorus and soil available phosphorus along the different altitudes (the altitude range from 1 600~1 900 m) and different soil depths were analyzed in mountain meadow system of Wugong Mountain. The soil inorganic phosphorus (P) content ranged in 175.48~524.06 mg·kg-1, significantly increased (P0.05) with the increase of altitude and decreased gradually with the increase of soil depth. There was a vertical distribution law and surface gathering character. The range of variation in water-soluble P, Al-P, Fe-P, O-P, Ca-P was 0.423~4.781, 16.27~90.72, 54.13~344.34, 19.66~90.32, 15.12~76.21 mg·kg-1, respectively. There were also vertical distribution and surface gathering character in each proportions of inorganic phosphorus. The percentage of Fe-P was the highest which followed by Al-P, O-P, Ca-P and water soluble P. There was a significantly positive correlations between soil available P and Al-P which suggest that Al-P was the potential resource for available P in this area. This research revealed the spatial distribution of soil inorganic P and the correlation between available P and soil inorganic P, determinate the resource of soil P which provided a guidance for vegetation restoration in mountain meadow ecosystem.