Plants growing in forests at different succession stages in diverse habitats may adopt various life strategies from the perspective of plant functional traits. However, species composition differs with forest succession, and the effects of forest succession on traits have often been explored without considering the effects of species identity. We comprehensively investigated intraspecific variations in 12 traits of six overlapping species (two tree species and four understory shrub species) in three typical subtropical evergreen broad-leaved forests at different succession stages in eastern China. We found that intraspecific variations differed among traits. Fine root specific length presented large intraspecific variation, leaf area, specific leaf area and fine root tissue density showed medium intraspecific variations, and other traits displayed small intraspecific variations. Trees and understory shrubs in the early-stage forest exhibited higher leaf thickness, dry matter contents and tissue densities of leaves, roots, twigs, and stems and lower leaf area and specific leaf area. Those in the medium- and late-stage forests displayed contrasting trait characteristics. From the perspective of plant functional traits, plants in the early-stage forest formed a series of trait combinations for a resource conservative strategy with a low growth rate to adapt to fragile habitats with poor soil nutrients and changeable soil temperature and humidity, and those in the medium- and late-stage forests (especially the former) formed converse trait combinations for a resource acquisitive strategy with a high growth rate to adapt to low light availability and strongly competitive habitats. Our study reveals that plants in forests at different succession stages adopt various life strategies and provides data to the TRY and China plant trait databases.

Abstract. Functional trait databases are emerging as a crucial tool for a wide range of ecological studies, including next-generation vegetation modelling across the world. However, few large-scale studies have been reported on plant traits in the Tibetan Plateau (TP), the cradle of East Asian flora and fauna with specific alpine ecosystems, and no report on plant trait databases could be found. In this work, an extensive dataset of 11 leaf functional traits (TiP-Leaf), mainly for herbs and shrubs and a few trees on the TP, was compiled through field surveys. The TiP-Leaf dataset, which was compiled from 336 sites distributed mainly on the plateau surface and the northern margin of the TP across alpine and temperate vegetation regions and sampled from 2018 to 2021, contained 1692 morphological trait measurements of leaf thickness, leaf fresh weight, leaf dry weight, leaf dry-matter content, leaf water content, leaf area, specific leaf area and leaf mass per area and 1645 chemical element trait measurements of leaf carbon, nitrogen and phosphorus contents. Thus, 468 species that belong to 184 genera and 51 families were obtained and measured. In addition to leaf trait measurements, the geographic coordinates, bioclimate variables, disturbance intensities and vegetation types of each site were also recorded. The dataset could provide solid data support to effectively quantify the modern ecological features of alpine ecosystems, thereby further evaluating the response of alpine ecosystems to climate change and human disturbances and improving the next-generation vegetation model. The dataset, which is available from the National Tibetan Plateau Data Center (TPDC; Jin et al., 2022a; https://doi.org/10.11888/Terre.tpdc.272516), can make a great contribution to the regional and global plant trait databases.

Plot-based data are an important foundation for studying plant community characteristics and compiling vegetation monographs, vegetation map, and vegegraphy. It is the key data source of studies in vegetation ecology. To understand the species composition, community characteristics, and distribution pattern of special plateau vegetation on the Qingzang Plateau (QZP), this study uses the data of 338 sites including 758 plots in different regions of the QZP from 2018 to 2021 to analyze the species composition, floristic characteristics, and vegetation classification of plateau plant communities. A plot-based dataset of plant community on the QZP is then established. The 758 plots have 837 plant species belonging to 279 genera from 65 families in the alpine and temperate vegetation communities. The largest number of species are found in five families: Asteraceae (134 species), Poaceae (88 species), Fabaceae (75 species), Rosaceae (43 species), and Cyperaceae (40 species), as well as five genera: Artemisia (29 species), Pedicularis (27 species), Saussurea (25 species), Astragalus (23 species), and Poa (23 species). The floristic composition is mainly temperate (145 genera) and cosmopolitan (36 genera). The growth forms of the species are mainly herbs (83.51%) and shrubs (10.87%), and the life forms of herbs and woody plants are mainly perennial herbs (88.23%) and deciduous shrubs (83.67%), respectively. A total of 338 sites can be divided into four vegetation formation groups, 10 vegetation formations, 20 vegetation subformations, 78 alliance groups, and 117 alliances, in which 34 are steppe alliances, 33 are meadow alliances, 33 are desert