Ecosystem services offered by urban forests must be proactively managed to remain diverse and sustainable. Recent research findings deserve a systematic synthesis to elucidate inherent knowledge structures and dynamics. This study focused on the urban tree diversity theme from 2000 to 2022. Web of Science Core Collection database provided bibliometric details on academic publications. The data‐driven quantitative analysis explored research quantities, emphasis, trends, patterns, linkages, and impacts by countries, institutions, authors, journals, and citations. Publications and research topics have expanded continually, with accelerated growth in recent years. Research activities, outputs and interactions demonstrated conspicuous spatial clustering. A few countries, institutions and researchers generated a notable proportion of publications. Their scholarly contributions were visualized in knowledge graphs as complex networks of nodes and inter‐node links. Keyword analysis generated a network to indicate research hotspots and frontiers to steer and prioritize future studies. Recent findings affirmed that cities can harbor substantial tree diversity due to enhanced habitat heterogeneity and successful species adaptation. Aligning tree traits with environmental conditions and management objectives can improve benefits. Urbanization can filter tree traits to shape community assemblages through stressors: habitat degradation, fragmentation and loss, in conjunction with pollution, climate change, and introduced species. Diversity preservation strategies include protecting remnant natural vegetation, connecting green spaces, and restoring complex canopy geometry and biomass structure. The emerging frontiers are marked by modeling future species distributions, leveraging technologies like remote sensing, linking ecology with human values, and committing to community‐based stewardship. Management can be upgraded by interdisciplinary perspectives integrating ecological science and social engagement. The findings highlight the need for biodiversity enrichment anchored by native species, trait‐matched assemblages, adaptive policies, and community participation to create livable‐green cities. This review synthesizes key advances in urban tree ecology and biodiversity research to inform the planning and stewardship of resilient urban forests.

Stellaria multipartita sp. nov. (Caryophyllaceae) from Chongqing, China, is described and illustrated based on morphological and molecular data. The new species is similar to S. radians by the palmately fimbriate petals with more linear divisions. Different characters are: shape of the leaves (oblong-triangular to ovate-triangular vs. oblong-lanceolate to ovate-lanceolate in S. radians), petals (10–12-cleft vs. 5–7-cleft in S. radians), and seeds (with mamillate ornamentation vs. scrobiculate ornamentation in S. radians). A molecular phylogenetic analysis supports the recognition of Chongqing population as a new species for science.

Nitrogen (N) and phosphorus (P) are key elements essential for plant growth and development. Due to fertilizer application, rapid urbanization, and fossil fuel combustion, nitrogen deposition has reached relatively high levels in China. However, there is still uncertainty regarding the response of N:P stoichiometry in plants and soil to N deposition across different ecosystems. Therefore, a meta-analysis was conducted using 845 observations from 75 studies to evaluate the response of plant and soil N and P concentrations and N to P ratios across various ecosystems to N addition. The analysis revealed that N concentration and N:P stoichiometry in plants and soil increased under N addition, while P concentration in plants and soil decreased on average. Furthermore, the magnitude of these responses was related to the N input rate and experimental duration. Finally, the effects of N addition on N concentration, P concentration, and N:P in terrestrial ecosystems would alter their allocation patterns, depending on relevant climate factors such as mean annual temperature and mean annual precipitation. This study highlights the ecological impact of N addition on the biogeochemical cycling of major elements (N and P) in terrestrial ecosystems in China. These findings are necessary for improving our understanding of the characteristics of plant ecological stoichiometry and helping to plan measures for increasing N deposition.

Studying community assembly has always been a central issue in ecological research and is necessary for understanding mechanisms of species coexistence and biodiversity. Environmental heterogeneity is a driver of biodiversity, but much remains to be learned about how evolutionary processes are affected by environmental factors. We aimed to clarify the evolutionary processes in different vegetation communities in the Huangshan Scenic Area, Anhui Province, China. We constructed a phylogenetic tree of these communities based on a constraint tree and three DNA barcode regions. Community I was characterized by a weakly overdispersed phylogenetic structure for all three plant groups. The structure of Community II showed clustered for total plants and shrubs, overdispersed for trees. However, the phylogenetic structure was clustered for total plants, overdispersed for trees and shrubs in Community III. The main drivers of these patterns were spatial and climatic factors. Phylogenetic α-diversity had a significant positive relationship with species richness. The values of phylogenetic β-diversity reached their maximum at intermediate elevations among three vegetation communities for total plants. The main factors that affected diversity patterns were spatial variables, not climatic factors, indicating that environmental heterogeneity determined the mechanisms of biodiversity and species coexistence in the community. Our results showed that deterministic processes may control community assembly in three different vegetation regions.

The Wuyi Mountains in China are one of the largest and most complete subtropical forest ecosystems at the same latitude in the world. However, our limited understanding of the function of this distinctive ecosystem means that the interrelationship between species diversity and ecosystem functioning needs to be investigated if evergreen broadleaf forests (EBLFs) are to be protected. Here, we calculated species richness, the Shannon–Wiener index, and the Pielou index in large-, medium-, and small-scale (20 m × 20 m, 10 m × 10 m, and 5 m × 5 m) forest dynamics plots (FDPs). We also investigated the interrelationships between species diversity and aboveground biomass (AGB)/productivity in FDPs at the different scales using the generalized linear regression model. The results showed that species diversity and AGB positively interrelated with each other, whereas there was no species diversity-productivity interrelationship in the subtropical BLF on the Wuyi Mountains. The structural equation model (SEM) showed that elevation was a key factor directly affecting AGB. These findings lead to the conclusion that productivity is not solely correlated with species diversity and that abiotic factors probably mediate the positive interrelationship between species diversity and ecosystem functioning. This study provides theoretical basis that can be used to protect EBLFs in subtropical areas and the results can be used to improve the construction of artificial forest communities and vegetation restoration at the same latitude.