Characteristics of herbaceous plant community composition, niche and stability under different main-tenance measures at Sanxingdui City Wall, Sichuan, China.

To understand the distribution characteristics and restoration status of vegetation at Sanxingdui City Wall, we sampled five typical communities of the city wall at the Sanxingdui site and explored the stability and niche characteristics of herbaceous plant communities under different maintenance measures (natural regeneration, planting, abandoned field, shrub removal, and pruning) following the niche theory and the improved contribution law method. A total of 87 herbaceous species belonging to 73 genera and 31 families were recorded. Compositae and Gramineae were dominant, and perennial herbs were the majority. There were differences in the niche breadth of major herbaceous species under different maintenance measures. The niche breadth of annual plants was higher under natural regeneration and shrub removal, and that of perennial plants was higher under planting, abandoned field, and pruning measures. The niche overlap and similarity of herbaceous plants were higher under natural regene-ration, shrub removal and pruning measures, and were the lowest under planting measure. The importance values were positively correlated with the niche breadth, but the ranking was not completely consistent. Species with higher niche breadth usually had higher probability of niche overlap and higher niche similarity. Combined with the M-Godron's stability analysis, community stability was comparable among shrub removal, pruning, and natural regeneration measures whereas the abandoned field and planting showed lower community stability. We recommended the implementation of in situ conservation measures based on natural regeneration, supplemented by scientific artificial maintenance (shrub removal, pruning, etc.) when necessary, so as to achieve a stable species composition and promote the sustainable development and vegetation landscape restoration at Sanxingdui City Wall.