内蒙古兴和县低山丘陵立地类型划分与林草适宜性评价

Site classification type and vegetation suitability evaluation for hilly land in Xinghe, Inner Mongolia

为了解半干旱区宜林荒山合理利用方式,于2016年7月和8月对兴和县低山丘陵造林地进行立地类型划分与林草适宜性评价。通过对38个样地的油松Pinus tabulaeformis树高和草本植物地上部分生物量进行多元线性回归分析,结果表明:影响油松生长的主导因子包括土壤厚度和平均土壤含水率,影响草本生物量的主导因子包括表土含水率、表土全氮质量分数、表土全磷质量分数和土壤砾石含量。通过单因素方差分析,选取和验证了地貌、地形、坡向、土壤质地、土层厚度、砾石含量作为立地划分因子,最终将研究区荒山荒坡造林地划分出8种立地类型。林草适宜性评价结果表明:第1级的立地同时适宜油松和草本植物的生长;第2级的立地较适宜油松生长,但不适宜草本植物生长;第3级的立地较为适宜草本植物生长,油松生长状况略差;第4级的立地不适宜油松生长,但草本植物生长稍好。根据各立地类型情况提出相应的林草措施建议。

For rational forestry use of barren hills in a semi-arid area,site classification and a vegetation suitability evaluation were conducted for afforestation on hilly land in July and August 2016 in Xinghe,Inner Mongolia.Three soil profiles were set to investigate soil moisture,physical and chemical properties in each plot,also the average height of young Pinus tabulaeformis and average aboveground biomass of three herbaceous quadrat were investigated in 38 plots with the size 10 m×20 m.Results concerning relationship between vegetation growth and site conditions showed that the main factors significantly affecting P.tabulaeformis included soil thickness and average soil moisture content(P<0.05);whereas,those significantly affecting herbaceous biomass included surface soil moisture content,surface total nitrogen content,surface total phosphorus content,and gravel content(P<0.05).Based on the single factor analysis,topography,landform,slope aspect,soil texture,soil thickness,and gravel content could make effect on soil moisture or total phosphorus content(P<0.05),and therefore these were selected as factors for site classification type with eight site types defined for afforestation in hilly land.In vegetation suitability evaluation,eight site types were divided into four ranks based on their vegetation growth.Sites in the 1st class were both suitable for P.tabulaeformis saplings and herbaceous plants.Sites in the 2nd class were suitable for P.tabulaeformis but not for herbaceous plants.Sites in the 3rd class were suitable for herbaceous plants,while P.tabulaeformis had a normal growth.Sites in the 4th class were not suitable for P.tabulaeformis,although the herbaceous plants grew well.In order to take full advantage of barren hills,sites in 1st and 2nd class were suggested to be forest land.Sites in the 3rd class could be planned as mixed forest of arbor and shrub,and sites in 4th class could be planned as grassland.