海南吊罗山濒危植物山铜材种群结构与动态特征

Population Structure and Dynamic Characteristics of the Endangered Plant Chunia bucklandioides in Diaoluo Mountain of Hainan

为探究海南吊罗山山铜材(Chunia bucklandioides)种群结构与动态特征,以当地山铜材野生种群为研究对象,将种群集中分布区域设为典型样地并开展样地调查,以空间代替时间构建种群年龄结构,采用动态量化分析、绘制存活曲线、计算生存函数等方法分析现有种群结构特点和动态特征,并通过时间序列预测模型推测种群未来发展趋势。结果表明:(1)吊罗山山铜材种群年龄结构接近不规则金字塔型,动态量化分析显示该种群为增长型种群,但第Ⅰ~Ⅲ龄级间存在衰退现象,种群增长性弱,稳定性差,受外界干扰敏感度高,有向稳定型种群转变的趋势。(2)随龄级增加,山铜材标准化存活个体数量减少,生命期望降低,死亡率和消失率总体呈上升趋势,存活曲线趋近于Deevey-Ⅱ型。(3)生存分析显示吊罗山山铜材种群具有前期增长、中期稳定、后期衰退的特点。(4)经过未来2、4、6龄级时间后,Ⅰ~Ⅲ龄级个体数量将逐渐减少,Ⅳ~Ⅶ龄级个体数量少量增加,幼龄苗木自我更新能力不足,种群存在规模收缩和衰退的风险。研究表明,生境碎片化、分布范围小、植株结实量少和幼龄个体不足是导致吊罗山山铜材濒危的主要因素,建议通过设立自然保护小区、辅助种子入土萌发、加快人工培育技术研究、人工扩大种群规模与数量和加强基础研究等方式,促进山铜材种群复壮与更新。

In order to explore the population structure and dynamic characteristics of Chunia bucklandioides in Diaoluo Mountain of Hainan,the local wild population of C.bucklandioides was taken as materials,and the concentrated distribution area of the population was set as a typical sample plot to survey,and construction of population age structure instead of space for time was designed.The current population structure and dynamic characteristics were analyzed by the dynamic quantitative analysis,survival curve drawing and survival function calculating,and the future development trend of C.bucklandioides was speculated by time sequence prediction model.The results showed that:(1)The age structure of C.bucklandioides population in Diaoluo Mountain was close to an irregular pyramid type.Dynamic quantitative analysis showed that the population was a growing population,but there was a decline trend from the age classⅠtoⅢ.The population had weak growth,poor stability,high sensitivity to external interference,and a trend towards a stable population.(2)With the increase of age class,the number of standardized survival individuals decreased,the life expectancy decreased,and the mortality and vanish rate showed an upward trend.The survival curve tended to be Deevey-Ⅱtype.(3)Survival analysis showed that the population of C.bucklandioides in Diaoluo Mountain increased in the early stage,stabilized in the middle stage,and declined in the late stage.(4)After two,four and six age classes in the future,there would be a gradually decreasing trend from I toⅢage class,and slightly increasing trend fromⅣtoⅦage class.The self-renewal ability of young seedlings was insufficient,and there was a risk of population shrinkage and decline.Consequently,habitat fragmentation,small distribution range,low seed yield and insufficient young individuals might be the main factors leading to the endangerment of C.bucklandioides in Diaoluo Mountain.The results suggested to promote the rejuvenation and renewal of C.bucklandioides population by setting up small nature reserve,assisting seed germination,accelerating artificial cultivation technology research,artificially expanding population size and quantity,and strengthening basic research.