不同森林类型林地土壤质量评价

Evaluation for Soil Quality of Forest Land in Different Forest Types

本文以湖南省宁远县不同森林类型林地土壤为研究对象,选取阔叶林(栎木纯林和常见阔叶树种混交林)、针叶林(杉木纯林和马尾松纯林)和针阔混交林(常见阔叶树种+杉木混交林和常见阔叶树种+马尾松混交林)共6种典型林分,测定31项土壤理化性质和生物指标,通过因子分析和判别分析筛选修订最小数据集,构建土壤质量评价指标体系,对土壤质量进行综合评价。结果表明:针叶林的pH值、养分元素、微生物生物量和酶活性均显著低于其他森林类型,且土壤容重最高,阔叶林具有较高的有机质与土壤有效元素,针阔混交林土壤养分介于两者中间;不同森林类型林地土壤质量评价指标体系包含容重、有机质、全钾、有效磷、微生物生物量磷和磷酸酶;6种森林类型的土壤质量指数(SQI)介于0.25-0.59之间,整体偏低,但中等质量及以上占62.5%;表现为常见阔叶树种混交林(0.52)>常见阔叶树种+马尾松混交林(0.48)>栎木纯林(0.45)>常见阔叶树种+杉木混交林(0.39)>马尾松纯林(0.34)>杉木纯林(0.32)。结论表明针叶林地的土壤质量显著低于阔叶林与针阔混交林,在针叶林中间种植当地常见阔叶树种能提高林地土壤质量,防止土壤退化。

Taking the forest soils of different forest types in Ningyuan as the object,choose broad-leaved forest(Quercus spp.forest and common broad-leaved mixed forest),coniferous forest(Chinese fir pure forest and Pinus massoniana pure forest)and coniferous and broad-leaved mixed forest(common broad-leaved tree species+Chinese fir mixed forest and common broad-leaved tree species+P.massoniana mixed forest).There are six typical forest stands in mixed forest and common broad-leaved tree species+mixed forest of P.massoniana.31 soil physical and chemical indicators were determined.The minimum data set was screened by factor analysis and discriminant analysis to construct soil quality evaluation index system.Overview,the results showed that the pH value,nutrient element,microbial biomass and enzyme activity of coniferous forest were significantly lower than other forest types,and had the highest soil bulk density;broad-leaved forest had higher organic matter and soil effective elements;Forest soil nutrients are in between.The soil quality evaluation index system of different forest types is bulk density,organic matter,total potassium,available phosphorus,microbial biomass phosphorus and phosphatase.The soil quality index(SQI)is between 0.25 and 0.59,which is low overall,but it is 62.5%above medium quality.The soil quality of the six forest types was common broad-leaved mixed forest(0.52)>common broad-leaved tree species+P.massoniana mixed forest(0.48)>Quercus spp.forest(0.45)>common broad-leaved tree species+Chinese fir mixed forest(0.39)>P.massoniana pure forest(0.34)>Chinese fir pure forest(0.32).This study indicated that the soil quality of coniferous forest land was significantly lower than that of broad-leaved forest and coniferous and broad-leaved mixed forest.Planting local common broad-leaved tree species in the middle of coniferous forest could improve soil quality and prevent soil degradation.