Subjects: Biology >> Botany >> Applied botany submitted time 2022-03-18 Cooperative journals: 《广西植物》
Abstract： Camellia kweichowensis is a rare 5-locular capsule-bearing representative species of the section Camellia with biological importance and economic value. This study explored the reasons for its endangered status and effective ways to conserve and utilize resources. In this study, by combining the sample investigation and actual measurement methods, the analysis of population age structure and survivability, we studied the quantitative characteristics of population structure dynamics and future development trend. The results were as follows: (1) The primary vegetation of C. kweichowensis had typical characteristics of subtropical humid evergreen broad-leaved forests. While the mixed evergreen and deciduous broad-leaved forest accounted for the main stand, the coniferous broad-leaved mixed forest of Pinus armandii + Betula luminifera + Liquidambar formosana + Nyssa sinensis + Camellia sp. + Eurya sp. + Schima sp. was common. (2) The growth population of C. kweichowensis dominated the growth structure. The points were mainly concentrated in the small and medium tree stages, and the sum of the proportion constituted 73.02% of the overall population. Deevey-Ⅱ type characteristic of the population survival curve was obvious, the life expectancy of C. kweichowensis was the maximum at the seedling stage. The change trend of mortality and the vanishing curves of the same plot were approximately the same. The quantitative dynamic analysis indicated that the three plots had abundant seedling pools, but were sensitive to the disturbance outside the habitat. The probability of surviving to Ⅶ age-class dropped significantly to 36.17%. On the whole, the population structure showed the characteristics of “growth in the early stage and decline in the late stage of Ⅳ age-class”. (3) The time-series forecast analysis indicated that after the growth period of 2-, 4-, 6-, 8-, and 10-diameter scales, the C. kweichowensis population dynamics tilted toward the succession of middle trees (Ⅴ-Ⅶ age-class), big trees (Ⅷ-Ⅹ age-class), and aged trees (Ⅺ-ⅩⅢ age-class). In conclusion, due to the limited habitat resources and space, intraspecific and interspecific competition intensifies, which reduces the survival rate of population seedlings and the number of young, and increased the mortality of adult plants caused by human predatory logging. As a result, the population renewal and diffusion are hindered, the distribution area is narrow, and the species tend to be endangered.
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