【作者】 唐波；

【导师】 刘军； 慕长龙；

【作者基本信息】 四川农业大学 ， 森林培育， 2010， 硕士

【摘要】 本次试验采集了长江上游防护林不同群落类型的林地土壤,通过分析其理化性质和酶活性,采用土壤肥力综合评价法,对不同群落类型的土壤肥力进行了评价,并对不同林龄的柏木林地土壤肥力特征进行了讨论。1.柏木明显地改善了土壤物理性质,本研究发现随着柏木的生长、毛管持水量,最大持水量、总孔隙度,毛管孔隙度、非毛管孔隙度均逐渐提高,容重的变化虽规律性不明显,仍然呈现总体下降趋势；柏木林的生长对土壤化学性质产生一定负面影响,随着柏木的生长,土壤N、P、K、有机质表现出如余弦函数图形的震荡下降趋势,余弦周期与柏木林的生长更新周期有一定程度上的一致性,表明柏木林生长的一定阶段土壤化学性质指标会随着群落结构的变化得到一定上升,但是始终不能达到柏木林营造之前的水平,随着柏木林龄的增长,土壤化学指标阶段性的最大值也在降低；柏木林的生长对土壤酶活性具有一定抑制作用,大部分指标显示出震荡下降或连续下降的趋势；通过土壤肥力综合评价发现,土壤肥力综合指数依次为：迹地(对照)>40a生柏木林>70a生柏木林>50a生柏木林>30a生柏木林>20a生柏木林,土壤肥力随着柏木林的生长也表现出如余弦函数图形的震荡下降趋势,因此,柏木生长在一定程度上降低了土壤综合质量。2.通过5个群落类型之间土壤肥力综合评价得分的比较,柏木纯林的土壤肥力(0.4241)相对最高,接下来依次是针阔混交林>栎类林>松柏混交林,土壤肥力相对最低的马尾松纯林(0.1666)；针阔混交林的土壤相对肥力随生长季节的变化是秋季>春季>夏季,柏木纯林、马尾松纯林、栎类林、松柏混交林的土壤相对肥力随生长季节的变化则是春季>秋季>夏季,群落类型总的土壤相对肥力随生长季节的变化是春季>秋季>夏季；5个群落类型在0-20cm土层的土壤肥力相对20-40cm土层均为高。3.通过7个群落类型之间土壤肥力综合评价得分的比较,杉木的土壤肥力(0.4676)相对最高,接下来依次是斑竹>慈竹>枫香>针阔混交林>灌木,土壤肥力相对最低的群落类型是楠竹(0.2560)；灌木、杉木、枫香、楠竹、楠竹和针阔混交林的土壤相对肥力随生长季节的变化是夏季>秋季>春季,灌木、杉木、枫香、慈竹、斑竹的土壤相对肥力随生长季节的变化则是春季>秋季>夏季,群落类型总的土壤相对肥力随生长季节的变化是春季>秋季>夏季；7个群落类型的0-20cm土层的土壤肥力相对20-40cm土层均为高。更多还原

【Abstract】 It was analyzed comprehensively that indies of soil physical properties, soil chemistry properties and soil enzyme activities in the Different Vegetation Community Types in Shelter Forest in the upper reaches of the Yangtze River in northern Sichuan,were measured by standard plot sampling and normal lab analysis. The influences of planting C.funebris on the soil fertility are also discussio.The results obtained are as follows:The plantation of C.funebris would improve soil physical properties, the experiment results incidented that along with the C.funehri grow, capillary water-holding capacity, supreme water-holding capacity, total porosity,capillary porosity and non-capillary porosity is gradually improving, although the change in the field capacity still not obvious, it shows a general trend of decline. The growth of the C. funebris produce a certain negative effect on the soil chemistry properties. As the growth of cypress fores, the content of soil n, p, k, organic matter showed the trend of shock downward as a cosine function. The cosine cycle and the regenerate cycle of the C. funebris forest has a certain degree of consistency,it indicated that soil chemistry properties would rise at a stage,as the change of the community structure and still can’t attain the level before the plantation of C. funebris,as the growth of the C. funebris forest, the maximum of the soil chemistry properties at a stage would be decreased. Cluster analysis showed soil chemical properties ofindividually depth(0-20cm、20-40c)vary at forty-years-old C. funebris plantation.The plantation of C. funebris restrained soil enzyme activities which gradually declined with the growth of C. funebris. The results of integrated evaluation of soil nutrient fertility showed that soil fertility expressed a trend of shock downward as a cosine function with the growth of C. funebris,so the plantation of C.funehri reduced the soil comprehensive quality.The results of integrated evaluation of soil nutrient fertility among 5 community-types showed that Cupressus funebris pure forest(0.4241)is highest,and then,Pinus x Cupressus>Quercus> theropencedrymion,the lowest soil fertility is Pinus massoniana pure forest(0.1666).And the orders with the growing season of theropencedrymion is.autumn> spring>summer,and the others is spring> autumn> summer, summer, the total trend showed spring> autumn> summer.The soil nutrient fertility in the 0-20cm layer is more than what in the 20-40cm layer.1 The results of integrated evaluation of soil nutrient fertility among 7 community-types showed that the most soil fertility mark is Cunninghamia Lanceolata(0.4676),,and then Phyllostachys bambusoides>Neosinocalamus affinis>Liquidambar formosana> theropencedrymion>shrub,the lowest is Phyllostachys heterocycla (0.2560).And the orders with the growing season of Phyllostachys heterocycla and theropencedrymion is summer>autumn> spring,and the others is spring> autumn> summer.,the total trend showed spring> autumn> summer.The soil nutrient fertility in the 0-20cm layer is more than what in the 20-40cm layer.更多还原