关键词: 野核桃, 年龄结构, 数量动态, 生存分析, 坡向

Abstract: Juglans regia is a national class II endangered species in China. Some branches of J. regia can grow to mature trees after the trunk lies down or dies. To understand population structure and dynamics of J. regia individuals generating from branches, a census method was carried out on individuals generating from J. regia branches in the Wild Walnut Nature Reserve in Xinjiang, China. The age structure and static life table of J. regia population were established using the method of spatial sequence instead of time and smoothing technique, and the dynamic index of age structure was obtained. We drew population survival curve, mortality curve, disappearance curve, and survival function curve, and analyzed the age structure and dynamic trend of individuals generating from branches. The results showed that: (1) In four slope directions, the age structure dynamic indices (V_pi and V_pi′) were greater than 0, the age structure of J. regia was the growing type, and survival curve tended to Deevey-Ⅱ type; (2) In different slope directions, the abundance of individuals of 2nd age class was much higher than that of 1st age class, indicating higher difficulty for individuals of 1st age class to pass through environmental filter than individuals of 2nd age class; (3) Among the four populations, the shady slope population showed the highest growth, the semi-sunny slope population showed the highest stability and anti-interference ability, while the sunny slope population showed the lowest stability and anti-interference ability; (4) The results of survival function analysis showed that the J. regia population in sunny slope was stable in early life history and fragile in middle-aged stage, while the populations in semi-sunny, shady, and semi-shady slopes were fragile in early life history and stable in middle aged and late life stages.

Key words: Juglans regia, age structure, quantitative dynamics, survival analysis, slope direction.