The effects of ice storm on seed rain and seed limitation in an evergreen broad-leaved forest in east China

摘要

Extreme climatic events almost universally play a major role in influencing the composition and structure of plant and animal communities, and thus could influence seed production, seed dispersal and seedling recruitment. We explored the effects of ice storm damage on seed rain and seed limitation in a 24-ha permanent forest plot in an evergreen broad-leaved forest in east China. We compared seed production before and after the storm in 2008. We evaluated the following hypotheses: 1) seed production after the ice storm was less than that before the storm; 2) seed limitation after the storm was more severe than before the storm. The results showed that seeds from one species, Eurya muricata, dominated the seed rain after the storm, accounting for more than half of the total seeds. Post-ice storm seed production of species other than E. muricata was only one fifth of that before the storm. Seed production in the second year after the ice storm recovered to pre-storm levels. The results indicate large inter-specific variation in response to the ice storm. Disturbance caused by the ice storm greatly increased seed diversity. The Jaccard similarity of species before and after the ice storm was 58%. There was no significant difference in seed limitation or dispersal limitation before and after the storm, but there was a significant difference in source limitation. Neither seed limitation nor dispersal limitation was correlated with dispersal modes. Only source limitation for rodent dispersed species increased after the ice storm.