仙湖苏铁种群年龄判断及年龄结构特征

Age estimation and age structure of Cycas fairylakea population in Shenzhen City

根据苏铁类植株体残存的营养叶叶基数、开花痕数以及生长单元发生率等茎干特征,建立了仙湖苏铁种群年龄判断方法,计算出该种群年龄.进一步采用年龄结构图、年龄分布曲线和曲线估计等方法,从基株和无性系水平探讨了仙湖苏铁种群的年龄结构特征.年龄结构图显示,仙湖苏铁无性系种群为稳定种群,基株种群为衰退种群;年龄分布曲线和曲线估计结果则表明仙湖苏铁无性系和基株种群均为衰退种群.综合3种方法的分析结果,仙湖苏铁种群为衰退种群,必须采取一定措施予以保护.

Based on the structural characteristics of Cycas trunk, including vegetative leaf base scars, sporophyll concave rings, and average occurrence probabilities of vegetative leaf and sporophyll, a method for the age estimation of Cycasfairylakea population was developed, and the age of each individual was calculated. Three approaches, i. e., age structure diagram, age distribution curve and curve estimation were used to study the age structure of C. fairylakea population at genet and clone population levels. The age structure diagram showed that the clone population of C. fairylakea was stable, but the genet population was in declining. However, both of the clone and genet populations were in declining when using the other two approaches. It was considered that the C. population was in declining, and needed an urgent protection.