Abstract: Plant species composition and community characteristics are the basis for the structure, function and dynamics of forest ecosystems, which determines forest ecosystem services such as productivity, carbon sequestration and biodiversity conservation. Plant species composition and community characteristics are important indicators for long-term positional observation of biological elements in terrestrial ecosystems by the China Ecosystem Research Network (CERN) and the National Ecosystem Observation and Research Network (CNERN). Mixed evergreen and deciduous broadleaf forest is a zonal vegetation type in northern subtropical China, and is one of the vegetation types that responds sensitively to environmental change. Subalpine coniferous forest is a typical vegetation type in the upper part of the vertical belt spectrum of the Shennongjia mountainous area, preserving a large area of natural primary forests that are the only remaining ones in Central China, and it is an important ecological barrier in the Qinba mountainous area. Two 100 m × 100 m long-term monitoring sample plots of subalpine coniferous forest and mixed evergreen and deciduous broadleaf forest have been set up in 2001 and in 2008, respectively, by the Shennongjia Forest Ecosystem Research Station (National Field Station for Forest Ecosystems in Shennongjia, also known as Shennongjia Biodiversity Research Station of CAS). Plant community inventories were conducted in 2010 in accordance with CERN and CNERN monitoring specifications. Tree layer surveys were conducted in 100 10 m × 10 m sub-samples, and shrub and herb layer surveys were conducted in 13 10 m × 10 m sub-samples. In the tree layer, all woody plants with diameter at breast height (DBH) ≥ 1 cm were surveyed, and the indicators included plant species name, diameter at breast height (DBH), height, etc. In the shrub layer, woody plants with DBH < 1 cm were monitored, and the indicators included species name, multiplicity, average basal diameter, average height, and cover, etc. In the herb layer, herbaceous plants were monitored, and the indicators included species name, multiplicity, average height, and cover. Six data tables for this dataset were formed through statistical organization: (1) species name, abundance, average diameter at breast height (DBH), average height, coverage, and life form of the tree layer, (2) dominant species, number of species, density, average height of dominant species, and canopy density of the sub-sample plots of trees, (3) species name, abundance, average base diameter, average height, coverage, and life form of the shrub layer, (4) dominant species, number of species, density, average height of dominant species, and total coverage of the shrub sample plot, (5) species name, abundance, average height, coverage, and life form of the herbaceous layer, and (6) dominant species, number of species, density, average height of dominant species, and total coverage of the herbaceous sample plot. The establishment and sharing of this dataset can provide background data for in-depth investigation of the impact of environmental changes on the community structure and productivity of subtropical forest ecosystems, and provide basic data support for the evaluation of ecosystem service functions, biodiversity conservation and ecological quality monitoring in the region.

Key words: Shennongjia, Mixed evergreen and deciduous broadleaf forest, Subalpine coniferous forest, Plant species composition, Community characteristics, Long-term monitoring