Simulation of Soil Temperature under Plateau Zokor's (Eospalax baileyi) Disturbance in the Qinghai Lake Watershed, Northeast Qinghai-Tibet Plateau

Simple Summary: The plateau zokor (Eospalax baileyi) is one of the main native soil mammals on the Qinghai-Tibet Plateau, and plays a key role in the terrestrial ecosystem there. Its disturbance will alter the soil properties and vegetation characteristics, and further, distinctly affect soil temperature. This study analyzed the soil temperature variation in three land surface types (grassland, mound, and bald patch) under the plateau zokor's disturbance from October 2018 to July 2020, and investigated the effect of environmental parameters on soil temperature change in the Qinghai Lake watershed. The results showed that: (1) The daily range of soil temperature was mound > bald patch > grassland, which became smaller as the depth increased. The appearance time of the maximum and minimum soil temperature at most depths showed the following order: mound, bald patch, then grassland. (2) The SHAW (simultaneous heat and water) model was applicable for the simulation of soil temperature under the plateau zokor's disturbance, especially during the growing season. (3) The influence of vegetation characteristics on soil temperature change was relatively smaller compared with soil properties after the disturbance of plateau zokor. The soil temperature is a key factor affecting the fragile terrestrial ecosystems on the Qinghai-Tibet Plateau, and has been remarkably altered by the soil mammal's disturbance. This study first analyzed the soil temperature variation in grassland, mound, and bald patch under the disturbance of plateau zokor (Eospalax baileyi) from October 2018 to July 2020 in the Qinghai Lake watershed. Then, the SHAW (simultaneous heat and water) model was used to simulate the soil temperature change of three land surface types, and the sensitivity of soil temperature to environmental parameters before and after the disturbance was explored. The results showed the following: (1) The daily range of soil temperature was mound > bald patch > grassland, which became smaller as the depth increased, due to the co-influence of vegetation coverage and soil bulk density. There was an obvious hysteresis of soil heat transfer for grassland, as compared with mound and bald patch, especially at 5 and 15 cm depths. (2) The SHAW model was applicable for the simulation of soil temperature under the plateau zokor's disturbance, especially during the growing season, and had better simulation accuracy for deep soil. (3) Air-entry potential and pore-size distribution index obviously affected soil temperature change, because of the change in root system and soil pores under the plateau zokor's disturbance. With the evolution of disturbance process, the response of soil temperature to the leaf area index weakened gradually, owing to the different duration of disturbance and restoration. In general, the plateau zokor's disturbance alters the soil properties and vegetation characteristics, and further, distinctly affects heat transfer and soil temperature.