弄岗喀斯特季节性雨林蚬木种群时空格局动态研究OA

Excentrodendron tonkinense,a national second-class key protected wild plant and one of the dominant species in the karst seasonal rainforest,still faces the threat of environmental disturbances.To explore the spatial distribution dynamics of its population,this study analyzed the relationship between population distribution dynamics and environmental factors based on the population and environmental survey data of a 15 hm2 plot in the karst seasonal rainforest of Nonggang,Guangxi from 2011 to 2021,using spatial point pattern methods and zero-inflated models.The results showed that the number of individuals in the population decreased from 1851 to 1786 over 10 years.The proportion of small diameter classes(1-5 cm)was over 50%in all years,and the diameter class structure was inverted"J"shaped.The population was significantly aggregated at the 0-50 m scale in three years,and the overall aggregation intensity of the population was mainly driven by the aggregation degree of the spatial distribution pattern of small trees.The distribution range of the population was significantly affected by soil moisture content,total phosphorus and total potassium in the habitat,and its abundance changes were influenced by both biotic and abiotic factors.The spatial distribution of the population had strong habitat specificity.Adult trees preferred habitats with low concavity and low diversity,while small trees preferred habitats with high plant diversity.Under well-protected conditions,the population size of E.tonkinense still needs to be dynamically monitored.In specific conservation practices,it is necessary to focus on protecting slope habitats and reducing human disturbances.