冀北山地3种生态景观林优势种群结构动态研究

Study on dynamics of dominant population structure for three ecological landscape forests in the mountainous regions of northern Hebei

为阐明冀北山地油松林、白桦林、白桦华北落叶松林3种典型生态景观林优势种群的发展趋势,为其经营改造提供依据,本研究运用种群径级结构、高度结构和时间序列预测分析等方法,研究了3种生态景观林优势种群结构的动态变化规律。结果表明:冀北山地白桦林、白桦华北落叶松林的各优势种群幼苗幼树个体缺乏,中径级、大径级个体较多,基本呈衰退趋势;油松林的油松种群的小径级个体数量多,属于进展型种群。时间序列分析表明,在未来的Ⅱ径级、Ⅳ径级和Ⅵ径级后,油松林的油松种群随着时间推移,小径级个体数相对仍保持较多的状态,表明油松种群保持相对稳定的状态;而白桦林、白桦华北落叶松林各优势种群呈现衰退趋势,实施适当的抚育间伐措施已成必然。

In order to clarify the development trend of the three ecological landscape forests in the northern mountainous region of Hebei province, and provide some scientific basis for rea- sonable exploitation and utilization, dynamic changes of population structure for three forests were studied in this paper, using diameter class, height class and time sequence analysis meth- od. The results showed that Betula platyphylla and Betula platyphylla-Larix principis-rup- prechtii dominant population belonged to the declining type, with lack seedlings and more in- termediate diameter class trees, large diameter trees. The small diameter class numbers in Pi- nus tabulaeformis were high, which belonged to the progressive population. Time sequence prediction model for the three typical forests populations after 11 , IVand VI diameter class indi- cated that the number of individuals of the small diameter class were high, which showed Pinus tabulaeformis population was stable and the other populations showed declining trends. The implementation of appropriate thinning measures is concluded inevitable.