Population dynamics and protection strategies of Litsea coreana Levl. var. sinensis with Guizhou Province in China as an example

Studying the dynamics of plant populations is crucial to the conservation and management of endangered plants. The diameter at breast height (DBH), tree height, crown width, and environmental factors of a total of 15 plots in five populations in Guizhou Province, China were measured in this study. The method of substituting diameter at breast height for age was used to divide the population into 7 age classes. The age structure, static life table, and relationship between the population characteristics and environmental factors of the Litsea coreana Levl. var. sinensis population were studied. Moreover, the time series model was used to predict the population dynamics. Results showed that the age structure of population in Zhengan County (Population ZA) had an inverted J-shape with abundant seedlings and insufficient middle-aged and elderly individuals. The age structures of populations in Daozhen County (Population DZ), Kaiyang County (KY), Meitan County (Population MT), and Xishui County (Population XS) were spindle-shaped with few young individuals and many middle-aged and elderly individuals. The mortality rate of each population fluctuated with the increase in age class, and the populations were extremely unstable. The survival curve was close to the Deevey III type, and the degree of deviation was related to the lack of young individuals. After the age stages II, IV, and VI, the number of aged plants in the different populations initially increased then decreased, and population stability was difficult to maintain. Redundancy analysis showed that the DBH, tree height and crown width of the population decreased with the increase of annual mean temperature, and the population density was restricted by soil nutrient conditions to a certain extent. The results of this work provide scientific basis for the conservation and sustainable utilization of natural populations of L. coreana var. sinensis in Guizhou Province, China.