Linking bacterial life strategies with multifunctionality of karst soils by vegetation restoration

1. Study areaThe study area was located in the karst regions of Guangxi and Guizhou provinces of Southwest China (22°42–27°53 N, 104°82–108°37 E). 2. Experimental design and sample collectionsThe sampling was carried out between August and October 2018. Four land use type, i.e., cropland, plantation forest, natural regeneration, and secondary forest, were selected from seven counties along the climatic gradient.Both the natural regeneration and plantation sites were previously cropland and restored during 2002–2003, with a restoration period of ~15 years at the time of sampling. The selected nearby croplands have been under maize cultivation for a long period, and the secondary forests have been preserved for 60 ± 5 years.A standardized 30 × 30 m plot were established in each sampling site. At each plot, 20 mineral soil cores (depth: 0–15 cm; diameter: 38 mm) was collected and pooled.