Ecosystem carbon dioxide (CO₂), water vapor, and heat exchanges in alpine wetlands on the Qinghai–Tibetan Plateau are not comprehensively understood. Thus, we studied variability of net ecosystem CO₂ exchange (NEE), ecosystem respiration (Re), gross primary production (GPP), evapotranspiration (ET), and heat fluxes over a headwater wetland ecosystem in the Qinghai Lake region. Results showed that the headwater wetland ecosystem was net CO₂ absorption on the annual scale, in which monthly NEE, GPP, and Re in two consecutive years varied from −165.16 to 93 g CO₂ m⁻² mo⁻¹, 6.66 to 384.45 g CO₂ m⁻² mo⁻¹, and 6.9 to 232.02 g CO₂ m⁻² mo⁻¹, respectively. The monthly ET from June to September was smaller than precipitation; these results reversed in the remaining months. Annual ET was 362.1 mm in 2015 and 324.96 mm in 2016. The net radiation (R_n), sensible heat (H), latent heat (LE), and ground heat (G) fluxes showed similar monthly patterns. Values of monthly average half-hour R_n, H, LE, and G at the daytime showed R_n > LE > H > G, and the time of the monthly half-hour G peak obviously lagged the R_n, H, and LE. Monthly average Bowen ratios were <1 from May to October, but it reversed in the rest of the months.

This study discusses the impact of two different ecological restoration approaches on the distribution of soil particle size and organic carbon, expecting to provide references for research on the effects of ecological restoration on the soil carbon pool in alpine regions. By replacing the method of time sampling with spatial sampling, grasslands enclosed only in the growing season and woodlands enclosed all year round were respectively selected as the research objects. Through centrifugation, the soil samples were classified by grain size into sand (50–2000 μm), silt (2–50 μm), and clay (<2 μm) to analyze the distribution of organic carbon in soil particles of different sizes. The major findings were as follows. First, sand accounted for the largest proportion of all the soil components in the grasslands and woodlands that had been restored for different years, followed by silt and clay. Second, most of the organic carbon in the grasslands and woodlands was from sand and silt. As the restoration years increased, the proportion of organic carbon in clay grew in fluctuation. In short, both ecological restoration approaches have improved the soil structure and raised the content of soil organic carbon (SOC). Specifically, the restoration scheme of the woodlands exerted a more significant influence on the soil components and the distribution of organic carbon than that of the grasslands.