Understory vegetation and soil microorganisms respond to afforestation on the Loess Plateau

This dataset contains field survey data from a large-scale, long-term afforestation study carried out across three vegetation zones on China's Loess Plateau: forest, forest-grassland transition, and grassland. Sampling locations were in Yongshou County (forest zone), Ansai District (forest-grassland transition zone), and Shenmu City (grassland zone). Within each vegetation zone, artificial black locust (Robinia pseudoacacia) stands of varying ages (20, 30, and 40 years) were chosen, while native vegetation communities served as control. A total of 29 main plots and 115 subplots (2m x 2m) were surveyed.

The dataset contains:

Understory plant species diversity, cover, and biomass (aboveground, belowground, and litter layer biomass)

Soil physicochemical properties include soil moisture content, bulk density, organic carbon, total nitrogen, alkali-hydrolyzable nitrogen, total phosphorus, available phosphorus, total potassium, and available potassium.

Soil bacterial and fungal diversity (α- and β-diversity indices)

The data were collected in August 2025. Soil samples (0-20 cm depth) were analyzed using standardized techniques. Microbial community characteristics were determined using high-throughput sequencing on the Illumina MiSeq platform. This dataset is useful for studying vegetation-belt-dependent afforestation effects, understory communities, plant-soil interactions, and aboveground-belowground coupling mechanisms.