学术论文

      云南西双版纳柚木人工林立地类型划分及评价

      Site Classification and Evaluation of Teak Plantation in Xishuangbanna,Yunnan Province,China

      摘要:
      【目的】探讨西双版纳柚木人工林立地类型,为西双版纳及其他类似地区的柚木人工林立地选择提供科学依据。【方法】对12~26年生的柚木人工林,采用典型抽样方法,设置51块样地,测定样地内柚木生长指标,记录地形因子,分析土壤理化性质;采用逐步回归方法筛选土壤主要化学因子,以主成分分析划分土壤养分等级。运用数量化理论Ⅰ,分析立地因子与样地林木生长量的关系。【结果】土壤养分等级、土壤质地、坡向、坡位、坡度、土壤密度和海拔等立地因子与优势木高生长拟合的数量化模型复相关系数为0.865,达极显著相关(P<0.01);土壤密度、土壤质地、坡度以及8个土壤养分因子( pH值、交换酸含量、全K含量、全P含量、有效P含量、交换性Ca2+含量、交换性 Al3+含量和有效 Fe含量)组成的土壤养分等级与生长均极显著相关( P <0.01);在数量化模型中,土壤因子(土壤养分、土壤密度和土壤质地)对柚木优势木高生长贡献率达58.3%,且影响均极显著(P<0.01);根据数量化回归模型中各样地立地因子得分,划分4组生产力等级,并以土壤密度、土壤质地及土壤养分3个立地因子划分11个立地类型,且对各生产力等级生长情况及立地因子特点进行评述,4组生产力等级由高产到劣产,柚木优势木年均高生长量分别为1.70~1.81,1.22~1.31,1.08~1.12和0.51 m。【结论】柚木生长在通气透水性较好的粉砂质壤土上好于在砂壤土、重壤土上;对土壤密度敏感,喜欢较高土壤密度;在盐基饱和度、全 K 含量、有效 P 含量和交换 Mg2+含量均高的立地上最佳;在强酸性、土壤交换性 Al3+和有效 Fe 含量高时生长极差。在本区选择合适的立地发展柚木时,应着重考虑土壤密度、质地以及酸度等,选取较高肥力的立地;对因立地差而生长不良的现有林分应及时改造,以尽量降低损失。
      Abstract:
      Objective]Site classifications and evaluation of teak ( Tectona grandis ) plantation by sample plot survey and analysis is to build a scientific basis for site selection of teak plantations of Xishuangbanna or other similar regions.[Method]51 sample plots distributed in 12 - 26 years old plantations were set up and growth traits of teak were measured,and site topography factors were recorded. Soil samples were collected for analyzing soil chemical and physical properties. 8 factors of soil chemical properties selected by stepwise regression method were used to divide soil nutrient grades by principal component analysis,and the relations between soil factors and the growth of teak together were analyzed by quantity theory I.[Result]The multiple correlation coefficient of quantity model fitted by the selected site factors ( soil nutrient grades,soil texture,slope orientation,slope position,slope degree,soil bulk density and Elevation) was 0.865,indicating a highly significant correlation (P <0. 01). Soil density,soil texture,slope degree and the soil nutrient grades consisting of 8 soil nutrient factors ( pH,the contents of exchangeable acid,total K,total P,available P, exchangeable Ca2 +,exchangeable Al3 + and available Fe) were highly significantly correlated with the growth (P<0. 01). The contribution rate of site soil factors to height growth of dominant trees reached 58 . 3%,indicating a highly significant correlation in the quantity model ( P<0. 01 ) . According to the scores of site factors of each sample plot obtained from the&nbsp;quantity regression model,site productivity levels were divided into 4 groups,and 11 site types were identified according to soil density,soil texture and soil nutrient grade. Growth and site factors for each productivity group were estimated. The average annual height growth of dominant trees of the four groups of site productivities ranked from high to low were 1. 70-1. 81,1. 22 -1. 31,1. 08 -1. 12,and 0. 51 m respectively. [Conclusion]Teak grew better in silty loam with good drainage system than in sandy loam or heavy loam. Teak was sensitive to soil density and preferred higher soil density;Teak grew best at sites with high levels of base saturation,total potassium,available phosphorus,and exchangeable magnesium; in strong acid soil,teak grew very poor due to low nutrient and poor fertility with high concentration of soil exchangeable aluminum and available iron. Soil density,texture and soil acid should be particularly considered when selecting higher fertility sites and suitable for growth of teak in Xishuangbanna region. Teak plantations planted at unsuitable sites with poor site quality should be improved so as to reduce the loss.
      Author: Du Jian Liang Kunnan Zhou Zaizhi Huang Guihua Li Bijun Ma Huaming
      作者单位: 中国林业科学研究院热带林业研究所 广州 510520
      刊 名: 林业科学 ISTICPKU
      年,卷(期): 2016, 52(9)
      分类号: S758.8
      机标分类号: S72 S71
      在线出版日期: 2016年11月14日
      基金项目: “十二五”国家科技支撑课题“柚木和西南桦珍贵用材林定向培育技术研究与示范”(2102BAD21B01)。