Seasonal Dynamics And Neighborhood Effects Of The Woody Seedlings In Mid-montane Humid Evergreen Broad-leaved Forest In Gaoligong Mountains

The coexistence mechanism of tree species has always been one of the core issues in community ecology research.The species diversity is rich in the mid mountain moist evergreen broad-leaved forest in Gaoligong Mountain.Ecologists put forward various hypotheses and theories to try to explain the coexistence mechanisms of species in forest communities.The interaction between individuals of different tree species in a certain temporal and spatial environment is called the neighborhood effect.The study of neighborhood effect helps to validate the relevant hypotheses and theories of tree species coexistence.Seedlings are the most important stage in the life histories of plants and also the most vulnerable period in natural forest regeneration.The seedlings play an important role in the formation and development of community structure.The survival and growth of species during this period are influenced by various biotic and abiotic factors.The survival status of seedlings is closely related to environmental factors such as precipitation,light,and soil.Therefore,woody seedlings from 100 2 m × 2 m seedling quadrats in a 4 ha middle-mountain wet evergreen broad-leaved forest dynamic plot in Gaoligong Mountain were selected as research objects in this study.The effects of neighborhood densities and habitat factors on the survival of seedlings were analyzed.The following results were obtained in this study: 1.During the survey periods,a total of 56 species of seedlings were recorded.The dominant species with the highest number of seedlings was Psychotria morindoides.The number of seedlings showed fluctuation in different seasons,and the mortality rate of seedlings was higher in the dry season and lower in the rainy season.2.During the dry season,both habitat factors and neighbor density did not have a significant effect on individual survival.During the rainy season,the light environment was a significant factor affecting the survival of seedlings,while neighbor density did not have a significant impact on individual survival in Gaoligong Mountain.In this study,the short research time and low seedling densities may be the reason for no density dependence on seedling survival.