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• Observed neighbourhood species richness (SR), phylogenetic diversity (PD) and beta diversity (BD) all decreased from early-, mid- to late-successional species. • Early-successional trees had higher NSR but a lower PD than homogeneous Poisson null model (HomoPNM). • Mid-successional trees showed no significant departure in SR and PD from HomoPNM. • Late-successional trees had lower SR and lower PD than HomoPNM. • Both SR and PD of all three species groups were well fitted by the heterogeneous Poisson model. A long-standing paradigm in ecology is that species diversity in a community accrues over succession. Central to this process are the mechanisms that regulate neighbourhood diversity around species of different functional groups such as early vs late-successional species. However, there is poor understanding of the accumulation of this neighbourhood diversity and its contribution to community diversity. We calculated neighbourhood species and phylogenetic diversities for adult trees of 10 species belonging to three groups: early-, mid-, and late-successional species in a 25-ha forest stem-mapping plot in subtropical China. We compared these diversities with homogeneous and heterogeneous Poisson null models to assess the roles of individual species and habitat heterogeneity in community assembly. We also calculated the neighbourhood species composition to quantify beta diversity turnover across different species groups. We observed that species richness, phylogenetic diversity and beta diversity all decreased from early- to mid- and late-successional species. Compared with homogeneous Poisson null model, early-successional trees had higher neighbourhood species but a lower phylogenetic diversity. Mid-successional trees showed no significant departure in richness and phylogenetic diversity from the null model. In contrast, late-successional trees had lower neighbourhood species richness and also a lower phylogenetic diversity than the null model. Both neighbourhood richness and phylogenetic diversity of all three species groups were well fitted by the heterogeneous Poisson model, indicating that environmental filtering predominated neighbourhood diversity. Our results underscore the importance of the early successional species in the accumulation of neighbourhood diversity and their contributions to diversity of plant communities. We suggest that secondary forests, which are mostly composed of early successional species, warrant a due attention in biodiversity conservation. [ABSTRACT FROM AUTHOR]

The large-scale distribution patterns of alien invasive plants (AIP) can provide key information and a theoretical basis for management strategies, including the prevention of invasions, the control and eradication of established AIPs, and the identification of areas at high risk of invasion. This study aims to quantify distribution patterns of AIP in China, to develop approaches that measure the social, economic, and ecological impacts, and to identify areas that are at higher risk of plant invasion. Based on published literature, there were 384 AIPs in China, representing 233 genera from 66 families. Climatic factors were among the primary factors determining AIPs' overall distribution patterns. The majority of AIPs were tropically distributed in China, meaning that they were mainly restricted to southern China. Temperate-distributed AIPs, those distributed only or predominantly in northern China, were fewer but had higher average rates of spread than tropically distributed AIPs. Average ecological and economic impact per AIP was negatively correlated with AIP richness, meaning that areas with relatively few AIPs nevertheless have some of the most detrimental ones. Our comparative evaluation showed that the risk of invasion differed among regions of China, with high-risk areas in southern China (Yunnan, Guangxi, and Guangdong) and central coastal areas of eastern China (Shandong, Hebei, and Jiangsu). In the context of climate change, areas around latitudes of 33° N, including Hebei, Shandong, Henan, and Jiangsu, should be given more attention for the control and prevention of plant invasions. Predictions of high-risk areas for future invasions differed depending on the scale of aggregation and the evaluation index, indicating that invasive risk assessments should be based on multiple factors. [ABSTRACT FROM AUTHOR]