How Do Soil Temperature and Moisture Respond to the Impact of Grazing: A Modeling Analysis for the Qinghai Alpine Grassland Ecosystems
摘要
Soil hydrological properties and vegetation properties regulate soil climate, but grazing-induced changes to these properties and their effects on soil temperature and moisture remain poorly understood. We conducted a modeling study to evaluate how each property of vegetation and soil impacted by grazing regulates water and thermal dynamics in cold, alpine environments of the northeastern Qinghai-Tibetan Plateau. The validated Canadian land surface model (CLASSIC) was used to simulate the responses of soil temperature and moisture to changes in vegetation and soil properties documented by (Journal of Hydrology, 590, 125397, 2020) for the following scenarios of grassland degradation: ND (no degradation), LD (low), MD (medium), and HD (high degradation). Results are based on different model factor experiments. Results showed minimal differences in experiment 1 (soil texture only). However, in experiment 2, which also incorporated vegetation parameters, the temperature differences were pronounced, with the HD scenario showing the highest increase in summer soil temperature and decrease in winter temperature compared to the ND scenario. Experiment 3 (full experiment with all factors included) that introduced empirically derived water retention parameters showed the moisture content to decrease in the HD scenario compared to ND in addition to further amplification of temperature annual amplitude, while MD showed increased moisture after precipitation. This suggests that management practices aimed at reducing soil degradation can help stabilize soil temperature and moisture levels. Moreover, the findings underscore the importance of vegetation in moderating temperature fluctuations in medium degradation scenarios, highlighting the need for integrated soil and vegetation management strategies.
Graphical Abstract