Spatial pattern of Adiantum reniforme var.sinense,Endemic to the Three-Gorge Reservoir Region

The spatial distribution pattern of Adiantum reniforme var.sinense was analyzed by Ripley’s K-function.Population patterns and spatial association of A.reniforme var.sinense depend on spatial scales and individual plant sizes,and so do their intraspecific relationships.On the scales less than 4.5 m,the population is usually characterized by clumped distribution,and their spatial association is considerably obviously positive.By contrast,if the scales enlarge beyond some points(5 m),the plants will disperse randomly,and their spatial association will loosen greatly.Mature individuals are more likely to follow clumped distribution than those small ones.The spatial association between plants will turn weak if their size differences are large.The abundant seedlings in the plot implied regeneration of A.reniforme var.sinense was moderate,but the seedlings distributed unevenly.Finally,according to the habitat of A.reniforme var.sinense in nature,we proposed a few strategies for its preservation which included reducing clear-cutting,increasing properly shrub coverage and decreasing herb coverage.