Response of fine root carbon, nitrogen, and phosphorus stoichiometry to soil nutrients in Pinus taiwanensis along an elevation gradient in the Wuyi mountains
The ecological stoichiometric characteristics of fine roots reflect environmental changes. Thus, they provide a theoretical basis to explore the mechanisms of global changes affecting plants. The objective of the present study was to analyze the stoichiometry of Pinus taiwanensis is fine roots inhabiting five different elevation gradients (i.e., 1,200,1,400, 1,600,1,800,and 2,000 m) in Wuyishan National Nature Reserve. The fine roots were collected and the carbon (C), nitrogen (N),and phosphorus (P) concentrations and stoichiometric characteristics were analyzed. The results showed that: (1) The annual average C concentration of fine roots was (486.2764.32) mg/g, and was not significantly affected by elevation. There was no significant correlation between the C concentration of fine roots and soil nutrients; (2) The annual average N concentration of fine roots was (9.262.09) mg/g, and was not significantly affected by elevation. But, there was a close correlation between the N concentration of fine roots and C concentration of soils; (3) The annual average P concentration of fine roots was (0.390.13) mg/g, which was closely correlated with altitude gradients and soil P contents, but negatively correlated with the soil C:N ratio; (4) The annual average N: P ratio of fine roots was 26.94 12.51, which was negatively correlated with altitude, soil P concentration, and the soil C:N ratio. Therefore, fine roots absorb N at the expense of C,fine root P is primarily limited by soil P supply,which would be further exacerbated by N deposition in the Wuyi Mountains.