Patterns And Influencing Factors Of Seed Predation,Dispersal And Germination,and Early-stage Seedling Establishment In A Fragmented Landscape,Eastern China

Due to the area effect and edge effect,habitat fragmentation can alter foraging behavior and shelter condition of scatter-hoarders,and can consequently affect seed predation and dispersal patterns.Also,by altering light condition,predator and pathogen activity,habitat fragmentation can influence seed germination and seedling survival.However,previous studies largely overlooked the effects of habitat fragmentation on multi-species level seed predation and dispersal and lacked synthetical analyses on the effects of biotic and abiotic factors on seed germination and early-stage seedling establishment.To explore how species identity,abundance of scatter-hoarders,seed production and patch attributes work together to influence seed fate and dispersal distance,and how species identity and patch attributes associated with treatments(open/enclosure/enclosure+fungicide)affect seedling emergence and mortality,we conducted seed predation and dispersal experiments using seed-tagging methods for six Fagaceae species,and seed germination and early-stage seedling establishment experiments using enclosure and fungicide for nine woody plants in the forests on study islands and mainland of the Thousand Island Lake region in Zhejiang Province,eastern China.The main results are as follows:(1)There were significant differences in seed fate and dispersal distance among six Fagaceae species.(2)Seeds were removed faster on the islands than on the mainland,and even faster on small islands than on large islands.Seeds had the highest probability of removal on small islands.Further,seeds were removed faster at the island edges than in the interior.(3)There was a significant interactive effect between island size and species identity on the probability of seeds eaten in situ.More seeds of Quercus fabri were eaten in situ on larger islands.The relative abundance of scatter-hoarders had a negative effect on the probability of seeds cached.(4)On germination stage,seed predation resulted in seed consumption for most species,and the effects of seed predators increased with island area.Pathogen infection was more host-specific.(5)On the early stage of seedling establishment,predation and pathogen infection both enhanced seedling mortality,and the intensity of their effects and the interaction effects between habitat fragmentation and them varied widely among species.These findings implied that habitat fragmentation posed species-specific effects on seed predation and dispersal patterns,seed germination and early-stage seedling establishment,which would contribute to forest regeneration and biodiversity maintenance.