title: Drivers of seedling survival in a temperate forest and their relative importance at three stages of succession.
abstract: Negative density dependence (NDD) and niche partitioning have been perceived as important mechanisms for the maintenance of species diversity. However, little is known about their relative contributions to seedling survival. We examined the effects of biotic and abiotic neighborhoods and the variations of biotic neighborhoods among species using survival data for 7503 seedlings belonging to 22 woody species over a period of 2 years in three different forest types, a half-mature forest (HF), a mature forest (MF), and an old-growth forest (OGF), each of these representing a specific successional stage in a temperate forest ecosystem in northeastern China. We found a convincing evidence for the existence of NDD in temperate forest ecosystems. The biotic and abiotic variables affecting seedlings survival change with successional stage, seedling size, and age. The strength of NDD for the smaller (<20 cm in height) and younger seedlings (1-2 years) as well as all seedlings combined varies significantly among species. We found no evidence that a community compensatory trend (CCT) existed in our study area. The results of this study demonstrate that the relative importance of NDD and habitat niche partitioning in driving seedling survival varies with seedling size and age and that the biotic and abiotic factors affecting seedlings survival change with successional stage.
authors.affiliation: Key Laboratory for Forest Resources & Ecosystem Processes of Beijing Beijing Forestry University Beijing 100083 China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yan
authors.affiliation: Key Laboratory for Forest Resources & Ecosystem Processes of Beijing Beijing Forestry University Beijing 100083 China.
authors.forename: Chunyu
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Division of Forestry and Natural Resource West Virginia University Morgantown West Virginia.
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory for Forest Resources & Ecosystem Processes of Beijing Beijing Forestry University Beijing 100083 China.
authors.forename: Xiuhai
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Georg-August University Göttingen Germany ; Department of Forest and Wood Science University of Stellenbosch Stellenbosch South Africa.
authors.forename: Klaus
authors.initials: K
authors.lastname: von Gadow
keywords: Community compensatory trend; negative density dependence; niche partitioning; seedling survival