Characteristics of soil phosphorus fractions of two typical stands in Zijinshan Mountain and their driving factors
This study investigated the influence of stand type on soil phosphorus(P)fractions and content with the aim of establishing a scientific basis for enhancing soil P availability and sustaining fertility in forest ecosystems.We examined the P fractions,microbial biomass P,litter and fine root chemical properties,and phosphatase activity in the 0-20 cm and 20-40 cm soil layers of a 77-year-old deciduous broad-leaved mixed forest and a 77-year-old coniferous and broad-leaf mixed forest in Zijinshan Mountain.Redundancy analysis of soil P fractions and environmental factors was conducted.The results indicated that the mixed deciduous broad-leaved forest had higher levels of active and stable P than the mixed coniferous and broad-leaved forest,suggesting greater availability and supply capacity in the former.In both forests,the proportions of soil P fractions to total P(TP)were consistently stable P>medium active P>active P.Significant differences were observed in NaHCO3-Po,NaOH-Pi,NaOH-Po,HCl-Pi,and Residual-P between stand types and soil layers(P<0.05),and NaHCO3-Pi differed significantly between soil layers(P<0.05).Redundancy analysis revealed that the soil P fractions in the deciduous forest was influenced by the litter C/P ratio(C/PL),fine root C/N ratio(C/NF),except for NaHCO3-Po,NaOH-Po,and HCl-Pi,the other P fractions were significantly(P<0.05)or highly significantly positively correlated(P<0.01)with DOC.The seven P fractions were positively correlated with C/PL and negatively correlated with C/NF,but not significantly.In contrast,soil P fractions in the coniferous and broadleaf mixed forest was affected by soil ammonium nitrogen(NH+4-N),litter N/P ratio(N/PL),and fine root P content(PF),with the exception of NaHCO3-Pi,the remaining P fractions showed significant(P<0.05)or highly significant positive correlations(P<0.01)with NH+4-N,were positively associated with PF,and had negative correlations with N/PL,although these were not significant.In conclusion,the deciduous broad-leaved mixed forest significantly enhanced soil available P.Variations in soil P fractions under different stand types were influenced by multiple factors,with changes in soil nitrogen content and microbial biomass P content being common regulatory elements across different stand types.
万方数据
维普
