Species abundance patterns of supratidal sandy grassland along China’s Shandong Peninsula and their responses to human disturbances

Abstract

Aims Supratidal zones of sandy coastlines are occasionally influenced by storm surges, and they contain distinctive plant communities and some unique species. Our objective was to solve the questions: 1) how sandy coast plants are grouped into plant communities and 2) how such anthropogenic disturbances as tourist trampling and pond fishery affect such communities. Methods Three long sandy coasts were investigated for species composition and abundances, representing three typical states of human disturbances: nearly original state, tourist trampling and pond fishery. Each coast was investigated with 20 sampling lines of 50 m. Their species abundance patterns were compared and analyzed via four classic models of species abundance patterns: the neutral theoretical model, geometric series model, overlapping niche model and broken stick model. Important findings The neutral theoretical and geometric series models fit the species abundance patterns of the coastal plant communities well, and the broken stick and overlapping niche models were not reliable. The disturbances could decrease vegetation cover and cause local extinction of some rare species. Some evidence suggests that plant species on sandy coasts are variable, thus that stochastic establishment of plant individuals may well play a major role in community assembling, as the neutral theory describes. However, these species have very small differences in their traits and resource capturing, and their integrative effects are supposed to take many years to accumulate for ultimately causing evident differences, which can be fitted via the geometric series model at times. Local governments ought to control anthropogenic disturbances, so as to conserve the rare plants.