The plateau pika ( Ochotona curzoniae ) is a burrowing mammal of the alpine meadows on the Tibetan Plateau. Its digging activity reshapes the vertical soil structure, forming heterogeneous soil mounds that significantly alter the local microenvironment, regulating vegetation distribution patterns, soil physicochemical properties, and nutrient cycling processes. This biologically driven disturbance of plant-soil interactions affects the greenhouse gas (GHG) emissions in the alpine meadow ecosystem. However, limited knowledge exists regarding how pika mounds alter GHG fluxes in the Kobresia ecosystem. In this study, we measured CO 2 , net ecosystem exchange (NEE), ecosystem respiration (ER), and fluxes of nitrous oxide (N 2 O) and methane (CH 4 ) across newly formed mounds, 1-year-old mounds, 2-year-or-older mounds, and adjacent intact Kobresia pasture as reference during the peak growing season (late July to early August 2023). We also assessed above- and belowground plant biomass, soil properties, and microbial communities in both mounds and intact Kobresia pasture. Results showed clear successional differences in NEE: newly formed mounds acted as net carbon sources (NEE = 199.78 mg m⁻ 2 h⁻ 1 ), whereas the intact control (CK) was a net carbon sink (NEE = −419.97 mg m⁻ 2 h⁻ 1 ; P < 0.001). In contrast, 1-year-old and ≥2-year-old mounds reverted to net carbon sinks, but with weaker sink strength than CK. Meanwhile, ER increased with mound age but remained lower than CK. Relative to CK, CH 4 uptake was enhanced on mounds, whereas N 2 O emissions were elevated, with the strongest responses occurring during early successional stages. The partial least squares structural equation model (PLS-SEM) suggested that variation in NEE and ER was associated with changes in plant biomass and soil properties, including water content, available phosphorus, total nitrogen, and nitrate nitrogen. Furthermore, CH 4 and N 2 O emissions were associated with bacterial diversity and related soil characteristics. This study highlights that net carbon absorption and ecosystem respiration within pika mounds are strongly associated with plant and soil variables, while CH 4 and N 2 O fluxes were strongly associated microbial community shifts and soil properties. Growing-season measurements provide useful insights into the mechanisms by which plateau pika mounds regulate GHG fluxes during the peak growing season.
Li et al. (2026) studied this question.