海南吊罗山濒危植物美丽火桐种群结构与动态特征

Firmiana pulcherrima is not only an endemic species in China but also a national gradesecond-level key protected plant. It is naturally distributed in the tropical rainforest area of centralHainan. To explore the survival status, development trend and the main reasons for itsendangerment of the population, this paper conducted a field investigation on the naturalpopulation of F. pulcherrima in Diaoluo Mountain. The age-class structure of the population wasconstructed by replacing time with space. The population structure characteristics and dynamicchange rules were analyzed through methods such as static life table and dynamic quantitativeanalysis, and the future development potential of the population was predicted by time seriesmodel. The results were as follows: (1) The population of F. pulcherrima was a growing type. The number dynamic index of entire population structure when ignoring external interference Vpi isgreater than the number dynamic index of entire population structure when considering externalinterference Vpi, and both are greater than 0. The maximum risk probability of population tocompletely random disturbance Pmax was 1.82%. The population has a complete age structure,weak anti-interference ability, poor growth and stability. (2)The life expectancy of the populationreached the maximum at the second age class, and then decreased with the increase of age class.Mortality and vanish rates peaked at age I, VII and IX. The survival curve was Deevey-III type.(3)Survival analysis showed that the population decreased sharply in the early stage and tended tobe stable in the mid-late stages. (4)After 3,6 and 9 age classes in the future, the number ofindividuals in the remaining age classes increased except for the IV and VIII age classes. Thepopulation has strong natural regeneration ability. Consequently, strong light environmentscreening and interspecific competition are the main reasons for the endangerment of F.pulcherrima. It is suggested to take measures such as moderately thinning and pruning,strengthening population and habitat protection, actively carrying out artificial breeding andreturning population expansion to promote the growth and recovery of the population.