| 摘要: |
| 【目的】探讨尾巨桉栽培区立地因子筛选及立地类型划分，为该地区尾巨桉人工林立地选择特别是大径材培育提供科学依据。【方法】以栽培区7.5年生尾巨桉为研究对象，采用典型抽样法设置40块样地，收集生长数据（树高、胸径、优势高）、气候因子（年日照时数）和地形因子（坡向、坡度、坡位和海拔）数据，分析土壤理化性质，通过主成分分析、数量化理论Ⅰ研究立地因子与林木生长量之间的关系；运用聚类分析，对样地进行生产力等级和立地类型划分。【结果】以坡向、坡度、坡位、海拔、土壤养分等级、土壤质地、土壤密度和年日照时数8个立地因子与尾巨桉优势高建立数量化模型，模型的复相关系数为0.956，达极显著水平（P＜0.01）；数量化模型中，海拔、土壤质地、坡向和年日照时数均与尾巨桉优势高极显著相关（P＜0.01），年日照时数、海拔和土壤质地对尾巨桉优势高的贡献率达62.75%。根据数量化回归模型和调查样地的立地因子数据，计算得到各样地尾巨桉优势高预测值，进而划分出高、中、低3组优势高生产力等级，尾巨桉优势高分别为27.16 m、24.19～25.45 m和21.77～23.40 m；再以年日照时数、海拔、土壤质地3个立地主导因子划分为10个立地类型。不同生产组间年日照时数和土壤粘粒含量差异显著（P＜0.05）,年日照时数表现为高产组最长，低产组最短，土壤粘粒含量表现为高产组高于中、低产组，海拔表现为高产组显著低于中、低产组，土壤有机质、全P、有效Mg和有效Cu含量均表现为高产组显著高于中、低产组，土壤有效Mn含量表现为高产组显著高于低产组。【结论】影响尾巨桉栽培区人工林生产力的主导立地因子为年日照时数、海拔和土壤质地，尾巨桉在年日照时数较长、海拔较低以及土壤粘粒、有机质、全P、有效Cu、有效Mg和有效Mn含量较高的立地环境中生长更好。 |
| 关键词: 尾巨桉人工林 立地因子筛选 立地评价 数量化理论Ⅰ |
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| 基金项目:“十三五”国家重点研发计划项目（2016YFD0600502）；广东省林业科技创新项目（2019KJCX005）；湛江桉树培育国家长期科研基地运行补助项目（2020132509） |
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| Site factor selection and evaluation of Eucalyptus urophylla×E.grandis plantation |
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ZHANG Cheng,OUYANG Linnan,CHEN Shaoxiong,et al
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| Abstract: |
| 【Objective】Site factors selection and classification of Eucalyptus urophylla×E.grandis plantation were investigated to provide basis for site selection and cultivation of large diameter timber.【Method】A total of 40 plots of Eucalyptus urophylla×E.grandis at the age of 7.5 years were set up by typical sampling method.Growth (height,diameter at breast height and dominant height),climatic factor (annual sunshine hours) and topographic factors (slope direction,slope,slope position and altitude) were collected,and chemical and physical properties of soil were analyzed.Principal component analysis and quantitative theory Ⅰ were used to analyze the relationship between site factors and tree growth.Cluster analysis was used to classify the productivity levels and site types.【Result】The quantitative model obtained with selected site factors of slope direction,slope,slope position,altitude,soil nutrient grades,soil texture,soil density and annual sunshine hours had complex correlation coefficient of 0.956,reaching extremely significant level (P<0.01).In the quantitative model,altitude,soil texture,slope direction and annual sunshine hours had extremely significant correlation with dominant height of Eucalyptus urophylla×E.grandis(P<0.01),and total contribution rate of annual sunshine hours,altitude and soil texture to dominant height was 62.75%.According to the quantitative regression model and site factors of survey sites,the predicted values of dominant height of Eucalyptus urophylla×E.grandis were obtained and site productivity levels were divided into 3 groups.The dominant heights were 27.16 m,24.19-25.45 m and 21.77-23.40 m,respectively.The site types were divided into 10 types based on annual sunshine hours,altitude and soil texture.Annual sunshine hours and soil clay were significantly different among different yield groups (P＜0.05).The longest annual sunshine hours was in high yield group and the shortest was in low yield group.The soil clay in high yield group was higher than that in middle and low yield groups.Altitude in high yield group was significantly lower than that in middle and low yield groups.Soil organic matter,total P,available Mg and available Cu in high yield group were significantly higher than those in middle and low yield groups,and soil available Mn in high yield group was significantly higher than that in low yield group.【Conclusion】The main site factors affecting productivity of Eucalyptus urophylla×E.grandis plantation were annual sunshine hours,altitude and soil texture.Eucalyptus urophylla×E.grandis grew better in site environment with longer annual sunshine hours,lower altitude and higher contents of soil clay,organic matter,total P,available Cu,available Mg and available Mn. |
| Key words: Eucalyptus urophylla×E.grandis plantation selection of site factor site evaluation quantitative theoryⅠ |
