图4. 土壤因子与植物种群生物量(A)以及群落多样性指数(B)的冗余分析(RDA)。Sc、Am、As和Lp分别代表猪毛菜、草木樨状黄耆、猪毛蒿和牛枝子。H和D分别代表Shannon-Wiener多样性指数和Simpson优势度指数。MBC、MBN、MBP、C:N_m、C:P_m和N:P_m分别代表微生物生物量C含量、N含量、P含量、C:N、C:P和N:P。TOC、TN、TP、C:N_s、C:P_s、N:P_s、NH₄⁺-N、NO₃^--N和AP分别代表土壤有机C含量、全N含量、全P含量、C:N、C:P、N:P、NH₄⁺-N浓度、NO₃^--N浓度和速效P浓度。

Fig. 4. RDA of plant biomass (A) and community diversity (B) explained by soil factors. Sc, Am, As, and Lp represent Salsola collina, Astragalus melilotoides, Artemisia scoparia, and Lespedeza potaninii, respectively. H and D represent Shannon-Wiener diversity index and Simpson dominance index, respectively. MBC, MBN, MBP, C:N_m, C:P_m, and N:P_m represent microbial biomass C content, N content, P content, C:N, C:P, and N:P, respectively. TOC, TN, TP, C:N_s, C:P_s, N:P_s, NH₄⁺-N, NO₃^--N, and AP represent soil organic C content, total N content, total P content, C:N, C:P, N:P, NH₄⁺-N concentration, NO₃^--N concentration, and available P concentration, respectively.