Population Structure and Dynamic Analysis of Wild Cathaya argyrophylla in Dashahe National Nature Reserve, Guizhou, China

Abstract:

Cathaya argyrophylla is one of the endemic rare and endangered wild plant with extremely small population in China, and is also the key protected object and flagship species in Guizhou Dashahe National Nature Reserve. Based on survey data of wild C. argyrophylla in the reserve in 2022, the quantitative dynamic index was calculated, static life table was compiled, survival curve was drawn, and survival function and spectral analysis were introduced to describe its structural dynamics. The results showed that the age structure of wild C. argyrophylla population was inverted J-type, and the dynamic change index of population (V_pi) was 39.43%, which was greater than V_pi' and both of them were greater than 0, indicating that the C. argyrophylla population was a growth type, but the growth was slow, and it was sensitive to external disturbance. The survival curve of the population belonged to Deevey-II type, and the survival rate, cumulative mortality rate, mortality density and risk rate changed greatly in age class from I to III stage, and then tended to be stable. The life spectral analysis showed that the III age class was the main stage affecting C. argyrophylla population. Therefore, the large number of young individuals and high mortality rates of C. argyrophylla in the reserve was the main reason leading to the difficulties of regeneration. It was suggested that the reserve should strengthen the care of C. argyrophylla seedlings and improve the living environment, so as to promote the natural regeneration and recovery of C. argyrophylla population.