Briefly describe the general process of Tianshan herdsmen transitioning from grazing to pasture, and briefly evaluate the benefits of transitioning from pasture to pasture.

Process: Migrate from the foot of the mountain to the mountainside in spring and summer, and move from the mountainside to the foot of the mountain in autumn and winter. Reason: As the temperature rises in summer, part of the ice and snow in the Tianshan Mountains melts, forming meadows or grasslands. Herdsmen drive their livestock to the mountainside. In winter, when the temperature is low, ice and snow form again on the mountainside, so herdsmen move to the foot of the mountain. Benefits: 1. Ensuring sufficient food for livestock 2. Seasonal replacement of pastures can reduce the harm of grazing to pastures