关键词: 核桃, 低温逆境, 抗氧化酶, 超氧阴离子, 超微结构

Abstract: To explore community succession dynamics and stability change of Pinus massoniana plantation, the community structure, reproduction potential, species diversity, Godron index were determined among different successional stages (10, 18, 22, 28 and 50 a) in Laohuling in Southern Guangxi, by using a spacefortime substitution approach. The result showed that with the succession, the dominance of deciduous trees declined, but the dominance of evergreen trees increased. The reproduction potential of community increased first and decreased afterwards. The distribution of diameter size followed the unimodal type for P. massoniana, presenting a decline trend due to lack of seedlings. An ‘L’ or inverseJ type distribution was found for Lithocarpus glaber diameter size, with adequate supplement of seedlings. With the forest succession, the species richness decreased, the Simpson index and Shannon index increased first and decreased afterwards, and the Godron index increased. The relationship between Godron index and diversity index was not linear, and the species diversity could not fully represent the community stability.

Key words: walnut, chilling stress, antioxidant enzyme, superoxide anion, ultrastructure.