[目的]植被恢复是改善黄土高原水土流失和生态环境的重要手段。评估植被恢复对生态系统养分循环和生态服务功能的影响需进一步明晰林地植被与土壤的化学元素计量和分布特征，这对合理开展植被恢复类型筛选具有重要意义。[方法]选取晋西黄土区4种典型植被恢复类型(油松Pinus tabuliformis人工林、刺槐Robinia pseudoacacia人工林、侧柏Platycladus orientalis人工林、辽东栎Quercus mongolica天然林)，分别测定乔木层的树枝、树叶、树干、树皮、树根和灌木层、草本层的地上、地下部分以及0～100 cm 土壤各层的碳、氮、磷质量分数，结合单因素方差分析法、最小显著差法、冗余分析法等分析植被恢复类型对生态系统养分循环和生态化学计量的影响。[结果]①相比其他植被恢复类型，辽东栎天然林样地的灌木层和草本层生物量最高，其地上部分生物量分别为(8。62±0。78)、(5。91±0。18)t·hm-2，地下部分生物量分别为(3。65±0。36)、(3。54±0。25)t·hm-2。②辽东栎天然林草本层碳质量分数最高，为(552。90±19。33)g·kg-1，氮质量分数最低，为(10。36±0。30)g·kg-1。③植物与土壤的碳、氮、磷质量分数具有显著相关关系(P＜0。05);辽东栎天然林的土壤碳磷比最高，为15。22±0。28，而刺槐人工林土壤碳磷比最低，为8。28±0。26。④Mantel Test和冗余分析结果表明:人工林中，土壤和植被中的养分相关关系显著(P＜0。05)，然而在辽东栎天然林中两者相关性相对较小，而且辽东栎天然林的乔木层对土壤和植被化学计量特征的影响相对较弱。[结论]近自然造林可以提高植被多样性，并提供更好的生态系统服务。图5表2参41
Relationship between stoichiometry and ecological factors at various levels of typical vegetation restoration ecosystem in the loess area of western Shanxi Province
[Objective]Vegetation restoration is an important method of improving soil erosion and ecological environment in the Loess Plateau.This study aims to assess the impact of vegetation restoration on nutrient cycling and ecological service functions in ecosystem,and further clarify the stoichiometry and distribution characteristics of chemical elements in forest vegetation and soil,which is of great importance for selecting rational models of vegetation restoration.[Method]4 typical vegetation restoration types were selected in the loess area of western Shanxi Province,namely Pinus tabuliformis plantation,Robinia pseudoacacia plantation,Platycladus orientalis plantation,and Quercus mongolica natural forest.The contents of carbon(C),nitrogen(N),phosphorus(P)in branches,leaves,trunks,barks,roots of the tree layer,as well as those in the aboveground and underground parts of the shrub layer,herbaceous layer,and 0-100 cm soil layers were determined respectively.The effects of vegetation restoration types on nutrient cycling and eco-stoichiometry were analyzed by single factor analysis of variance(ANOVA),minimum significant difference(MSD)and redundancy analysis(RDA).[Result](1)Compared with other vegetation restoration types,the shrub layer and herbaceous layer in Q.mongolica forest had the highest biomass,with aboveground biomass of(8.62±0.78)and(5.91±0.18)t·hm-2 and underground biomass of(3.65±0.36)and(3.54±0.25)t·hm-2,respectively.(2)Q.mongolica natural forest had the highest C content,which was(552.90±19.33)g·kg-1,and the lowest N content,which was(10.36±0.30)g·kg-1.(3)There was a significant correlation(P＜0.05)between C,N and P contents in plants and soil.Soil C and P ratio in Q.mongolica was the highest(15.22±0.28),while that in R.pseudoacacia was the lowest(8.28±0.26).(4)Mantel Test and RDA showed that there was a significant correlation between nutrients in soil and vegetation in plantation forests(P＜0.05),but in Q.mongolica natural forest,the correlation was relatively small and the influence of tree layer on soil and vegetation stoichiometric characteristics was relatively weak.[Conclusion]Near natural afforestation can promote vegetation diversity and provide better ecosystem services.[Ch,5 fig.2 tab.41 ref.]
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