冀北山地杨桦次生林五角枫更新幼苗种群结构与动态研究

Study on the structure and dynamic population of renewed Acer mono seedlings in secondary poplar-birth forest in the mountainous regions of Northern Hebei

对冀北山地杨桦次生林五角枫更新幼苗种群结构进行了研究,分析了五角枫幼苗种群的径级结构、高度结构、时间序列预测以及点格局。结果表明,五角枫更新苗总株数为1 094株/hm2,五角枫更新苗径级主要集中在0.5～2cm之间,占总株数的73.31%。其高度主要集中在0.5～2.5m,占总株数的81.81%。Ⅱ径级、Ⅳ径级和Ⅵ径级后,五角枫更新苗株数分别下降了5%,40%和83%,表明五角枫更新幼苗小径阶种群仍然保持较多的个体,五角枫种群保持相对的稳定性。五角枫更新幼苗在0～13m范围内呈聚集分布,在14～16m范围内呈随机分布,在17～25m范围内呈均匀分布。适当间伐五角枫更新幼苗对杨桦次生林结构优化和功能发挥具有重要意义。

The structure population of renewed Acer mono seedlings in secondary poplar-birth forest in Northern Hebei mountain was researched systematically with its diameter class, height class, time sequence, and point pattern analyzed. The results showed that the total plant number of renewed Acer mono seedling was 1 094/hm2 , and its diameter class between 0.5 cm and 2 cm, accounted for 73.31% of the total number of trees, with its height class between 0.5 cm and 2.5 cm accounting for 81.81% of the total number of trees. Time se- quence prediction model for renewed Acer mono seedling populations after 11 , IV and VI di- ameter calss indicated 5 %, 40% and 83 % decline in regeneration seedling number respective- ly. Small population remains larger number, which showed Acer mono seedlings were re- newed stably. Renewed Acer mono seedlings in the range of 0- 13 m was in an aggregated distribution, with its random distribution in 14%16 m, and its uniform distribution in 17- 25 m. Therefore, it is of great significance to proper intermediate cutting the renewed Acer mono seedlings for the optimization of its structure and function.