毛竹扩展对杉木林和阔叶林群落结构与多样性的影响.

To understand the effect of moso bamboo (Phyllostachys edulis) expansion on the community structure and species diversity of different artificial forests, continuous ecological interfaces from a moso bamboo stand to a Chinese fir (Cunninghamia lanceolata) stand, and broad-leaved forest (dominated by Camptotheca acuminata+Sassafras tzumu) were selected to set transects. The results showed that the density of moso bamboo increased with the expansion to Chinese fir stand or broad-leaved forest, accompanied by an increase in bamboo density but a decreasein the original species. Bamboo expansion changed the community height and diameter at breast height (DBH) structures, such that the range of height in the community narrowed from 2-14 m in the Chinese fir stand and 6-20 m in the broad-leaved forest to 10-16 m in the bamboo stand, accounting for 91.79% and 80.45% of the total, respectively. In addition, the main range of DBH narrowed from 3-20 cm in the Chinese fir stand and 5-35 cm in the broad-leaved forest to 5-15 cm in the bamboo stand, accounting for 94.78% and 96.99% of the total, respectively. Margalef index and Shannon-Wiener index of shrub and herb layers increased during the expansion of moso bamboo to C. lanceolata and broad-leavedforest.Species evenness and dominance of the shrub layer did not change significantly; however, species evenness of the herb layer increased. At the same time, the S?rensen index and Jaccard index of the herb layer were significantly higher than those of the shrub layer. The Cody index was lower in the herb layer than in the shrub layer in the Chinese fir forest expansion but was close to that in the broad-leaved forest expansion. Overall, our results indicate that bamboo expansion would further simplify the community structure of second forests, but increase species diversity in shrub and grass layers. The understory vegetation in the Chinese fir stand exhibited an obvious increasing species turnover rate during bamboo expansion, but this was different in the expansion to broad-leaved forest. [ABSTRACT FROM AUTHOR]