油松优树选择方法的研究

论述了优树选择应遵循优良种源区选择优良林分，优良林分中的选择优良单株的系统选择原则。提出了标准差法选择方法和标准，要求优树胸径大于林分平均胸径加２倍标准差，且优树年平均出长量：胸径大于０．９ｃｍ、树高大于０．５ｍ。根据１９株人工林优树周转的标准地每木实测数据，对小标准地法和大树选优法作了比较；根据３２株优树的选优结果，比较了１－５株大树法选优法之间的相关关系，大树法间相关都显著，但以３株法为最好；

Study on selection methods and criteria of Pinus tabulaeformis in Shaanxi

The selection principle is selecting stand from fine seed source and from them selecting fine individuality.Methods for the selection of with sample plots and check trees were compared on the basis of 19 sample plots.Comparisons of 1~5 check trees with 32 plus trees were made.The correlation between the 1~5 check trees methods was significant.The parameters of sample plots could be estimated by using data of check trees while the 3 check trees were the most efficient.Criteria of plus tree selection for each seed cone were suggested according to the data of 773 plus trees.