16S and ITS full-length amplicon sequencing of forest soils after tree mortality across ridges and valleys in Dinghushan

This project contains amplicon sequencing reads in FASTQ format from mineral soil samples collected in July 2022 within a 20-ha forest dynamics plot in the Dinghushan Biosphere Reserve, Guangdong, China. A total of 72 tree-level composite soil samples were collected from a depth of 0–30 cm beneath 36 large dead canopy trees and 36 adjacent living conspecific trees of comparable diameter at breast height. The paired sampling design included six canopy tree species distributed across two contrasting topographic settings: ridge and valley. Five soil cores collected beneath each tree were combined and homogenized to form one composite sample. Full-length bacterial 16S rRNA genes were amplified using primers 27F and 1492R, whereas fungal internal transcribed spacer regions were amplified using primers ITS1F and ITS4R. Sequencing libraries were prepared using the Oxford Nanopore Technologies Ligation Sequencing Kit v14 and sequenced on a PromethION platform with R10.4.1 flow cells. These data support analyses of soil bacterial and fungal community composition, diversity, and mortality-associated changes in taxon abundance under contrasting topographic conditions.