Ecological succession of a natural community of Castanopsis sclerophylla on Laoshan Island, China

Abstract

Castanopsis sclerophylla was surveyed for its root turion capacity on Laoshan Island in Zhejiang Province and dispersion patterns of seedlings, genetic diversity and genetic variation coefficient was studied using a SSR (simple sequence repeat) molecular marker technique to explore the genetic diversity of C. sclerophylla (Lindl.) Schott as a community and evaluate the community’s development. The results showed that C. sclerophylla had strong root turion capacity, of which type Re2 was the most frequent, accounting for 32.4 and 82.4 % of the seedlings under the stock plant were from within-community mating; the 6 pairs of SSR primers chosen yielded high resolution with 97.6 % polymorphic sites; the within-community genetic diversity was over 88.9 % with stock plants (0.49) > seedling plants (0.45). Apparently, C. scerophyllan on Laoshan Island, propagating mainly by root turions, has developed high genetic diversity within a short period, keeping the community in a stage of stable growth and moving toward a climax community. The tillers, however, aggravate closing of the community so that it receives less pollen from outside. Within-community mating is thus reaching seriously high levels, which can lead to lower within-community genetic variation, a decline in DNA genetic diversity, and is bad for its development. Therefore, human interference should be taken to expand genetic exchange among communities.