soil fauna

This study was carried out in Hongyuan county (31°50'–33°22' N, 101°51'–103°23' E, 3500 m a.s.l. elevation).Surface-dwelling and soil-dwelling arthropods, as well as soil nematodes, were investigated in the CK and OTC chambers during September 2019 and 2020. The following soil properties were measured according to the Soil Agricultural Chemical Analysis Methods: total carbon (TC), total nitrogen (TN), total phosphorus (TP), nitrate nitrogen (NO3--N), ammonium nitrogen (NH4+-N), available phosphorous (AP), carbon nitrogen ratio (C/N), carbon phosphorus ratio (C/P), nitrogen phosphorus ratio (N/P), power-hydrogen (pH) and soil moisture (SM).
The species richness (SR) and plant community coverage (PC) were measured within a 50 × 50 cm plot, with three replicates in each chamber. Coverage was measured using visual estimations. Both above-ground (AB) and below-ground biomass (BB) from each plot were harvested and oven-dried in the laboratory at 65 ℃ until a constant weight was achieved.