迹地炼山对杉木林植物多样性与土壤特性的影响u

依照立地条件相一致原则,采用空间代替时间方法,选取闽西北地区造林1 a及造林3a杉木(Cunningham ialanceolata)纯林,分别对炼山及未炼山林地的植物多样性及土壤特性进行研究.结果表明:炼山与未炼山造林后植被多样性差异显著.炼山在造林1a时增加灌木多样性,减少草本多样性,造林3a时灌草多样性均减少.随造林年限增加,仅炼山林地灌木多样性降低,其余均呈增加状态;炼山在造林1 a时增加土壤密度,造林3a时增加土壤含水率、密度及毛管孔隙度,其他土壤因子质量分数降低.随造林年限增加,炼山林地各土壤因子质量分数有所提升,未炼山林地反而下降;通径分析表明,炼山造林地内灌木多样性受土壤特性限制较未炼山林地小,但炼山林地草本多样性受土壤特性的限制远大于未炼山林地.影响较大的土壤因子为土壤孔隙度,磷、钾质量分数.总体看来,迹地炼山对杉木林植被及土壤影响较大,但随时间推移影响日益减小.

Effect of Burning Disposal Method on Undergrowth Vegetation Diversity and Soil Properties of Cunningham ialanceolata

In accordance with the same site conditions and employing the method of spatial sequence instead of temporal sequence,we studied the differences of species diversity and soil properties between burning and non-burning method in 1-a and 3-a Cunningham ialanceolata forests in the Fujian Northwestern.Burning logging lash had significant effect on species diversity.Burning increased shrub diversity but decreased herb diversity in 1-a forest.In 3-a forest,burning had different reduction degrees of diversity.With the prolonging of the planting year,shrub diversity increased but others all decreased;Burning increased soil bulk density,and other soil properties were decreased in 1 a forest.Soil moisture,soil bulk density and capillary porosity had increasing trend in 3-a forest,other soil properties were decreased.With the prolonging of the planting year,burning increased soil properties but soil properties in non-burning forest were decreased.By the path analysis,the effect between shrub diversity and soil characters was higher in non-burning forest than burning forest,but the herb diversity was different.The main factor was soil porosity,P and K.Therefore,burning disposal method has significant effect on undergrowth vegetation diversity and soil properties,but the effect is decreased with time.