图4. 青海不同林分灌木叶片(A)、枝干(B)和根(C) C、N、P含量及化学计量比与环境因子之间的冗余分析二维排序图。Altitude, 海拔; Canopy, 郁闭度; Slope, 坡度; MAP, 年降水量; MAT, 年平均气温; SC, 土壤碳含量; SN, 土壤氮含量; SP, 土壤磷含量; SCN, 土壤C:N; SCP, 土壤C:P; SNP, 土壤N:P; LC, 叶片碳含量; LN, 叶片氮含量; LP, 叶片磷含量; BC, 枝干碳含量; BN, 枝干氮含量; BP, 枝干磷含量; RC, 根碳含量; RN, 根氮含量; RP, 根磷含量。

Fig. 4. Two-dimensional sequence diagram of redundancy analysis between the C, N and P contents and their ratios in leaves (A), branches (B) and roots (C) of shrubs with environmental factors in different forest types in Qinghai. MAP, mean annual precipitation; MAT, mean annual air temperature; SC, soil carbon content; SN, soil nitrogen content; SP, soil phosphorus content; SCN, soil C:N; SCP, soil C:P; SNP, soil N:P; LC, leaf carbon content; LN, leaf nitrogen content; LP, leaf phosphorus content; BC, branch carbon content; BN, branch nitrogen content; BP, branch phosphorus content; RC, root carbon content; RN, root nitrogen content; RP, root phosphorus content.