Why can the removal of vegetation trigger mass movements? The soil loses nutrients and begins to crumble. The plant roots bind the soil and regolith together. The shaking triggers mass movements. The plant roots lubricate the loose sediment.

The removal of vegetation can trigger mass movements due to several reasons: 1. **Loss of Nutrients**: Vegetation plays a crucial role in maintaining soil fertility by adding organic matter and nutrients. When vegetation is removed, the soil loses these essential nutrients, leading to soil degradation and increased susceptibility to mass movements. 2. **Soil Crumbling**: Vegetation helps to stabilize the soil through the presence of plant roots. These roots bind the soil particles together, preventing erosion and soil crumbling. Without vegetation, the soil becomes loose and crumbly, making it more prone to mass movements. 3. **Shaking Triggers Mass Movements**: The removal of vegetation can lead to increased soil instability. When the soil is loose and crumbly, even slight shaking or vibrations can trigger mass movements, such as landslides or rockfalls. 4. **Lubrication of Loose Sediment**: Plant roots can also act as a natural lubricant, holding loose sediment particles together. Without vegetation, the loose sediment becomes more susceptible to mass movements as it can easily slide or flow. Therefore, the removal of vegetation can trigger mass movements due to the loss of nutrients, soil crumbling, shaking triggering mass movements, and the lubrication of loose sediment.