Wenchao Yan

Tibetan Plateau peatlands store substantial organic carbon and are highly vulnerable to climate warming, yet the response of CO₂ emissions to whole-soil-profile warming remains unclear. We conducted a two-year whole-soil-profile warming experiment (0–300 cm) in a Zoige peatland with four treatments: control (CK), moderate warming (+2.5 °C, W2.5), high warming (+5 °C, W5), and variable warming (0–8 °C, VT). CO₂ responses to warming were non-linear, season-dependent, and intensified over time. W5 significantly increased growing-season CO₂ fluxes to 345.52 and 394.57 mg m⁻² h⁻¹ in 2022 and 2023, respectively. During the non-growing season, warming had no significant effect in the first year, whereas all warming treatments significantly increased CO₂ fluxes in the second year. Principal component analysis further indicated a temporal shift in the factors associated with CO₂ emissions, from carbon availability (DOC and SOC) in the first year toward inorganic nitrogen (NH₄⁺-N and NO₃⁻-N), available phosphorus, and soil environmental conditions (e.g., Eh) under prolonged warming. These findings highlight the importance of warming intensity, duration, and belowground biogeochemical reorganization in regulating alpine peatland carbon–climate feedbacks.

Forests are pivotal to hydrologic regulation, yet province-wide dynamics across complex terrain remain insufficiently quantified. We quantified Sichuan’s forest water conservation dynamics (1990–2023), coupling the InVEST water yield model with a topographic–hydraulic correction (topographic index, saturated hydraulic conductivity, land-cover-specific flow velocity). The model used precipitation and potential evapotranspiration, land-use/cover, soil texture, and rooting depth, and was calibrated to provincial water resources statistics. Outputs were stratified by elevation and slope and monetized via a replacement cost (reservoir capacity) method. Sichuan exhibited a persistent high-capacity belt along basin–mountain transitions and the southeastern ranges, contrasting with low values on the western plateau; period maxima intensified in 2020–2023. Interannual variability closely tracked precipitation anomalies against largely stable atmospheric demand; per-unit capacity declined monotonically with slope, and total capacity generally increased with elevation, with >3500 m both highest and most variable. Economic value rose overall but fluctuated and showed marked inter-city heterogeneity. We conclude that climate pacing operating on a terrain-anchored template governs Sichuan’s forest water conservation service, supporting precision, slope-aware forest management, and differentiated ecological compensation to stabilize hydrologic regulation under climate variability.

Numerous studies have demonstrated that in residential areas of Western cities, both luxury and legacy effects significantly shape tree species diversity dynamics. However, the specific mechanisms driving these diversity patterns in China, where urbanization has progressed at an unprecedented pace, remain poorly understood. In this study we selected 20 residential settlements and 7 key socio-economic properties to investigate the change trend of tree diversity (2006–2021) and its socio-economic driving factors in Beijing. Our results demonstrate significant increases in total, native, and exotic tree species richness between 2006 and 2021 (p < 0.05), with average increases of 36%, 26%, and 55%, respectively. Total and exotic tree Shannon-Wiener indices, as well as exotic tree Simpson’s index, were also significantly higher in 2021 (p < 0.05). Housing prices was the dominant driver shaping total and exotic tree diversity, showing significant positive correlations with both metrics. In contrast, native tree diversity exhibited a strong positive association with neighborhood age. Our findings highlight two dominant mechanisms: legacy effect, where older neighborhoods preserve native diversity through historical planting practices, and luxury effect, where affluent communities drive exotic species proliferation through ornamental landscaping initiatives. These findings elucidate the dual dynamics of legacy conservation and luxury-driven cultivation in urban forest development, revealing how historical contingencies and contemporary socioeconomic forces jointly shape tree diversity patterns in urban ecosystems.