雷琼地区尾细桉人工林立地类型划分及其质量评价

Site Classification and Quality Evaluation of Eucalyptus urophylla×E.tereticornis Plantation in Hainan Island and Leizhou Peninsula Region

[目的]对雷琼地区尾细桉人工林进行立地类型划分和立地质量评价,为雷琼地区尾细桉造林立地选择及生产潜力的提升提供科学依据。[方法]在雷州半岛和海南岛1~18年生的尾细桉人工林内采用典型抽样方法设置112块样地,调查样地内尾细桉的生长指标,记录立地因子,采集土样测定土壤理化性质,利用数量化理论Ⅰ的方法建立尾细桉优势木高年均生长量与立地因子的关系模型,采用K-均值聚类分析和相关性分析法对尾细桉人工林进行立地类型划分及质量评价。[结果]海拔、坡度、土壤厚度、成土母岩、pH值、土壤质地、土壤密度7个立地因子与优势木高生长量拟合的复相关系数为0.712,达极显著相关(P<0.01);土壤质地、成土母岩和土壤密度是主要影响尾细桉优势木高生长的立地因子,依此将雷琼地区尾细桉人工林划分归类为12个立地类型;根据适宜性和生产力情况对立地质量进行评价,分为高产组、中产组、低产组和劣产组4个等级,最适宜、较适宜和适宜等级总占比为91.89%,表明雷琼地区尾细桉种植基本合理;土壤pH值、有机质、全磷、全钾和速效钾对尾细桉人工林生长影响显著。[结论]雷琼地区适宜尾细桉生长,营造尾细桉人工林时应选择酸性壤土、中低密度的立地,在造林及抚育管理中应及时补充磷肥和钾肥,可充分发挥林地生产潜力;对不适宜立地及时进行改种,提高造林的科学性和合理性。

[Objective]To study the site type and quality evaluation of Eucalyptus urophylla×E.tereticornis plantation in Hainan Island and Leizhou peninsula coastal area,so as to provide reference for site selection and production potential promotion of E.urophylla×E.tereticornis plantation in Hainan Island and Leizhou peninsula region.[Method]112 plots were set up in 1-to 18-years-old E.urophylla×E.tereticornis plantations in Leizhou and Hainan.The growth indexes of E.urophylla×E.tereticornis were investigated,the site factors were recorded,and soil samples were collected to determine the soil physical and chemical properties.The quantitative theory I was used to establish the relationship model between site factors and the dominant high annual mean growth of E.urophylla×E.tereticornis,the site classification and quality evaluation of E.urophylla×E.tereticornis plantation were carried out by k-means cluster analysis and correlation analysis.[Result]The multiple correlation coefficient between site factors(altitude,slope,soil depth,parent rock,pH value,soil texture,and soil density)and the height growth of the dominant tree was 0.712,which was highly significant(P<0.01).Soil texture,parent rock and soil density were the main site factors affecting height growth of dominant trees of E.urophylla×E.tereticornis.According to these factors,E.urophylla×E.tereticornis plantation in Hainan island and Leizhou peninsula region could be divided into12 site types.According to the suitability and productivity,the site quality was evaluated and divided into four grades:high yield group,middle yield group,low yield group and poor yield group.The total proportion of the most suitable,more suitable and suitable grades was 91.89%,which indicated that the distribution of E.urophylla×E.tereticornis plantation area in Hainan island and Leizhou peninsula region was basically reasonable.The soil factors such as pH,organic matter,total phosphorus,total potassium and available potassium had significant effects on the growth of E.urophylla×E.tereticornis plantation.[Conclusion]Most of the site conditions in Hainan island and Leizhou peninsula region are suitable for the growth of E.urophylla×E.tereticornis.When planting E.urophylla×E.tereticornis plantation,it is suggested to choose the high yield group sites with acid loam soil and medium and low density.In afforestation and tending management,it is necessary to supplement phosphorus and potassium fertilizer in time to give full play to the production potential of forest land,timely replant the unsuitable site to improve the scientificity and rationality of afforestation.