Distribution and bio-ecological characteristics of Abies chensiensis, an endangered plant
濒危植物秦岭冷杉地理分布和生物生态学特性研究

Qinling fir, Abies chensiensis, is endemic to China and was listed in the China Plant Red Data Book as one of the third class protected plants. It is only found scattered in small forest fragments in Mts. Qinling, Bashan and Shennongjia from 1300 m to 2300 m a. s. l. in Shaanxi, Gansu,Henan, Sichuan and Hubei provinces. To assist in efforts to effectively conserve and restore this species, the geographic distribution, community structure and demographic characteristics of populations were studied through field investigations and statistical analysis. In the A. chensiensis communities in the Qinling Mountains, we recorded 102 plant species, belonging to 63 genera and 40 families. Among them, the temperate geographical elements comprise 84.21%, and the tropical geographical elements 15.79%. The communities in Qinling could be divided into five associations by cluster analysis on the importance values of the dominant species. The habitat of the communities was wet and shaded, and the coverage was relatively high. The structure of the communities was complex, and the age difference among individuals was significant. The natural regeneration of this species occurred mainly in canopy gaps on shaded slopes. The growth of young seedlings was relatively slow, but DBH increased relatively quickly during the 40-100 years stage, as did height during the 30-70 years stage. The sexual reproduction for this A. chensiensis population began at 30-40 years old, and the seed-bearing interval was about 3-5 years. Mature trees of A. chensiensis produced on average eight cones, and the mean number of seeds per cone was 56. The lack of seedlings was the main barrier for regeneration of this species. Insufficient seeds and low survival rate from seed to seedling were the weak link. In the future, in situ conservation should be considered as the most important management activity for this species, and natural regeneration should be promoted. At the same time, the artificial populations should be expanded from seeds collected in years of high seed set.