soil metagenome

Soil and fallen debris samples were collected from Mount Segrila. Five alpine rhododendron forests with similar canopy coverage and stand age were selected at different altitudes (3500 m, 3700 m, 3900 m, 4100 m, and 4300 m) as sampling sites. At each altitude, three sample plots (25 m x 25 m) were established within representative forest canopies. The intersection point of the diagonals in each plot was designated as the burial site for litter decomposition bags. Each bag measured 20 cm x 20 cm, with a mesh hole diameter of 0.25 mm. From each plot, three litter bags, each containing 10.00 g of plant litter, were randomly selected, buried at a depth of 5 cm in the soil, and securely fixed in place for subsequent retrieval. In total, 45 litter bags were buried (5 altitude levels x 3 plots x 3 replicates). Decomposition bags and surface soil samples (0-10 cm depth) were collected at each altitude at three time points: 4 months, 8 months, and 12 months after burial. All samples were transported to the laboratory in insulated containers with ice packs. Decomposed litter samples were cleaned to remove impurities and then dried at a constant temperature of 65 degrees Celsius until a constant weight was reached, in order to determine mass loss and changes in lignocellulose components. Soil samples were passed through a 2.0 mm sieve to remove visible stones, invertebrates, large root fragments, and plant debris. A portion of each soil sample was frozen at -80 degrees Celsius for subsequent DNA sequencing, while the remaining soil was air-dried for analysis of physical and chemical properties.