基于粗糙集理论的城市生态林地土壤肥力评价研究

Soil fertility quality evaluation based on rough set theory for urban ecological forest

以北京大兴区白皮松林、白蜡林、油松林、国槐林4种城市生态林地为研究对象,将以主观经验评价为特征的特尔斐法和以客观赋权为基本内容的粗糙集理论相结合进行林地土壤肥力的综合评价。结果表明:城市生态林对土壤肥力具有明显的改善作用,其中不同城市生态林地的全氮、有效磷、速效钾和有机质平均比对照提高了75.00%、191.16%、43.48%、67.69%;林地pH值也有明显变化,其中白皮松林地、白蜡林地、油松林地、国槐林地分别比对照荒地下降了3.44%、2.55%、3.10%、22.59%。由土壤肥力综合评价可知,不同林地土壤肥力由优到劣为国槐林地(7.1)>白蜡林地(5.6)>白皮松林地(4.6)>油松林地(3.6)> CK(2.4)。

To evaluate the soil fertility of Pinus bungeana forests,Fraxinus chinensis forests,Pinus tabulaeformis forests and Sophora japonica forests,with the control of the abandoned land,the study combined the subjective method with the objective method.The results of the comprehensive evaluation based on Delphi method and rough set theory showed that the four kinds of urban ecological forests had a significant improvement on soil fertility.Compared with the abandoned land,the total N,available P,available K and organic matter in different urban ecological forest lands were increased by75.00%,191.16%,43.48%and67.69%on average.Soil integrated fertility index(IFI)followed the order of Sophora japonica forests(7.1)>Fraxinus chinensis forests(5.6)>Pinus bungeana forests(4.6)>Pinus tabulaeformis forests(3.6)>the abandoned land(2.4).