Abstract: To make clear whether Mongolian pine (Pinus sylvestris var.mongolica) plantation is limited by soil phosphorus (P) supply in southeast Horqin sand land and to find out the best leaf indicator of soil P supply, the concentrations of total P, inorganic P and organic P in the needles of different age ofP. sylvestris var. mongolica and the soil available P were analyzed. The results showed that in the study area, soil available P was rather low (0.12-0.63 mg·kg^-1), and had significant correlations with the inorganic P (cPi) and total P (cPt) concentrations in the current-year needles of P. sylvestris var. mongolica. The significant correlation between soil available P and needle cPt derived from the significant correlation between cPi and cPt. Compared with cPt, cPi could reflect the level of soil P supply more accurately and directly.

Key words: spatial distribution, marine bay, macroinvertebrate, Fujian Province, subtidal zone, environmental factor