Characteirstics Of Phosphorus Acquisition And Utilization In Phyllostachys Edulis Forests Based On Hedley Fractionation

Phyllostachys edulisis one of the important forest species in South China. It iswidely distributed and has a long planting history. Partly estimated, the area of Ph.edulis plantation is accounted for about20%of total bamboo fotests area all over theworld. Phosphorus （P） is one of the essential nutrients for plant growth, which is notonly the important element in compounds of the plant, but also associated with thevarious important metabolic activities, therefore, it plays a vital role in plant growth.In order to study the relationship between Ph.edulis expansionand phosphorus distributions.Soil samples from0-10cm and10-30cm soil layer werecollected from the Ph. edulis forest and broad-leaved forest thatwere analyzed forfractionation of organic and inorganic soil phosphorus by Hedley method. The resultsshowed that:1)The contents of different phosphorus fractionations in soil of the Ph. edulisforest were as following order:Residual-P>NaOH-Po>Sonic-Po>NaOH-Pi>NaHCO₃-Po>NaHCO₃-Pi>Resin-P>HCl-PandResidual-P>NaOH-Po>Sonic-Po>NaOH-Pi>NaHCO₃-Po>NaHCO₃-Pi>Resin-P>HCl-Pin the broad-leaved forest.So Ph. edulis forest and the broad-leaved forest showedthe general law.2)The percent （NaHCO₃-Po/（Resin-P+NaHCO₃-Pi+NaHCO₃-Po））represents aminimum index of the portion of phosphorus that may be easily mineralized throughbiological processes.The percent in Ph. edulis forest was81.56%and85.99%inbroad-leaved forest.The percent in Ph. edulis forest was lower than that inbroad-leaved forest.3)The average phosphorus concentration in organs of Ph. edulisranged from0.194to1.663mg·kg^-1, and in the order of leaf>base>base root> culm> branch.Phosphorus concentration in the organs of young bamboo wasthe highest in all ages.Phosphorus concentration in the organs of Ph. edulis were higher than broad-leavedspecies.For example, the average phosphorus concentration in leaf of broad-leavedspecies was0.883g·kg^-1while1.270g·kg^-1in the leaf of Ph. edulis. It suggested thatPh. edulisis one of species that need high phosphorus concentration.4)The average phosphorus concentration inrhizome was0.902g·kg^-1and0.447g·kg^-1in therhizome root.Phosphorus concentration in rhizome and rhizome rootweredecline as they growing.This implied that phosphorus transfers from old rhizometo rhizome tips. It might be one of the reason of Ph.edulis expansion.These findings suggestedthat both NaHCO₃-Po/ （Resin-P+NaHCO₃-Pi+NaHCO₃-Po） in Ph. edulis forest was lower than that inbroad-leaved forest and the abundantphosphorus that Ph. edulisneed, which maybethe reasons of bambooexpansion. Furthermore, Ph. edulis transfers phosphorus fromold rhizome to new rhizome and new bamboo by phosphorus integration, whichensures bambooexpansion.