摘要
为阐明黄河三角洲不同人工林类型对盐碱化土壤碳(C)氮(N)磷(P)含量及生态化学计量特征的影响,选取刺槐、臭椿、杨树、白蜡、榆树、国槐和柽柳等7种典型人工林为研究对象,运用模糊数学隶属函数法综合评价林型对土壤营养和化学计量特征的影响.结果表明:黄河三角洲地区7种林型土壤C、N含量处于全国土壤平均含量的最低水平,P含量居中等水平.各林型土壤表层C、N含量较高,P含量从上至下分布规律不同,分别呈逆向、“V”型和倒“V”型分布.臭椿林土壤C、N、P元素平均含量最高,柽柳林土壤最低,前者分别是后者的1.5、1.7和1.2倍.7种人工林土壤N:P平均值为0.76,远远低于全球平均水平(5.9)和我国平均水平(3.9),表明该区域人工林受到严重的土壤N限制.综合评价对林地土壤营养、土壤物理性质和化学计量改良作用最好的是国槐林,改良作用最差的为白蜡林.建议在该区域优先选择国槐改良盐碱化土壤,其次为杨树和榆树.
Abstract
To clarify the effect of plantation types on the stoichiometry characteristics of carbon (C),nitrogen (N) and phosphorus (P) in saline soil of Yellow River Delta,seven plantations were selected,including R.pseudoacacia,Ailanthus altissima,Populus euramericana,Fraxinus chinensis,Ulmus pumila,Sophora japonica,Tamarix chinensis.This research comprehensively evaluated the effects of plantation types on soil stoichiometry using membership function of fuzzy mathematics method.The results showed that soil N and C contents were at the lowest level of national average content;P content was at the middle level.The content of soil C and N was higher at the topsoil of forests,while the content of soil P showed different trend of reverse type,"V" type and inverted "V" type,respectively,from the topsoil to the lower soil layer.Compared with other six forests,the contents of soil C,N and P in Ailanthus altissima were the highest of,respectively,1.5,1.7 and 1.2 times in Tamarix chinensis.Average value of N:P was 0.76 in the soil of seven forests,which was lower than the average level of global (5.9) and China (3.9).This suggested the growth of plantations were seriously limited by soil N in the Yellow River Delta.The improving effect of Sophora japonica forest was the best on soil nutrient,soil physical characteristics and chemical stoichiometry,while that of Fraxinus chinensis forest was the worst in the Yellow River Delta by comprehensive evaluation.Therefore,Sophora japonica is first selected as plantation type in Saline-alkali land,and then Populus euramericana and Ulmus pumila.
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维普
万方数据