State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, Lanzhou University, Lanzhou 730020, PR China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China.
Engineering Research Center of Grassland Industry, Ministry of Education, Lanzhou University, Lanzhou 730020, PR China; College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China.
Sci Total Environ. 2024 Dec 10;955:176785. doi: 10.1016/j.scitotenv.2024.176785. Epub 2024 Oct 11.
Foraging tunnel disturbances by small subterranean herbivores can alter soil properties and nutrient dynamics in grasslands, potentially altering soil organic carbon (SOC). Examining the impact of foraging tunnel disturbances on mineral-associated organic carbon (MAOC) and particulate organic carbon (POC) is crucial for understanding SOC changes and its stability. However, the effects of these disturbances on POC and MAOC are not well documented. This study uses the plateau zokor (Eospalax baileyi) as a focal subterranean herbivore to investigate the effects of foraging tunnel disturbances on POC and MAOC in alpine steppes, alpine meadows, and alpine meadow steppes. Ninety paired quadrats were used for soil and plant sampling across three alpine grassland types. Results show that foraging tunnel disturbances consistently reduced POC concentrations across all grassland types, with reductions of 44.01 % in alpine steppes, 20.86 % in alpine meadows, and 29.58 % in alpine meadow steppes. MAOC concentrations decreased by 16.49 % in alpine steppes, while no significant changes in MAOC were observed in alpine meadows and alpine meadow steppes. The reduction in the POC to MAOC ratio indicates increased SOC stability. However, despite this increased stability, the change may lead to a decrease in overall carbon sequestration potential, as the total SOC in the soil declines. The main factors influencing POC and MAOC were soil moisture, belowground biomass, and microbial biomass carbon, with their influences varying by grassland type. The findings demonstrate that foraging tunnel disturbances by plateau zokors can lead to substantial modifications in SOC composition, influencing both its stability and sequestration potential. The disturbances necessitate tailored management strategies to mitigate their impacts, considering the unique characteristics of each grassland type to preserve carbon sequestration potential. This study contributes to a deeper understanding of the ecological role of small subterranean herbivores in the carbon cycle of alpine grassland ecosystems.
地下小型食草动物的觅食隧道干扰会改变草原土壤特性和养分动态，从而可能改变土壤有机碳 (SOC)。研究觅食隧道干扰对矿物结合有机碳 (MAOC) 和颗粒有机碳 (POC) 的影响对于理解 SOC 变化及其稳定性至关重要。然而，这些干扰对 POC 和 MAOC 的影响尚未得到充分记录。本研究以高原鼢鼠 (Eospalax baileyi) 为焦点地下食草动物，研究了觅食隧道干扰对高山草原、高山草甸和高山草甸草原三种高山草地类型中 POC 和 MAOC 的影响。在三种高山草地类型中，使用 90 个配对样方进行土壤和植物采样。结果表明，觅食隧道干扰一致降低了所有草地类型的 POC 浓度，其中高山草原减少了 44.01%，高山草甸减少了 20.86%，高山草甸草原减少了 29.58%。高山草原 MAOC 浓度降低了 16.49%，而高山草甸和高山草甸草原 MAOC 浓度没有显著变化。POC 与 MAOC 比值的降低表明 SOC 稳定性增加。然而，尽管这种稳定性增加，由于土壤中总 SOC 减少，总碳固存潜力可能会降低。影响 POC 和 MAOC 的主要因素是土壤水分、地下生物量和微生物生物量碳，其影响因草地类型而异。研究结果表明，高原鼢鼠的觅食隧道干扰会导致 SOC 组成发生重大变化，影响其稳定性和固存潜力。这些干扰需要制定有针对性的管理策略来减轻其影响，同时考虑到每种草地类型的独特特征，以保留碳固存潜力。本研究有助于更深入地了解小型地下食草动物在高山草原生态系统碳循环中的生态作用。
