What is the effect of overgrazing on nutrient cycling?

Overgrazing has a profound effect on nutrient cycling, particularly by leading to soil compaction, increased erosion, and disrupted nutrient dynamics. When livestock graze excessively, they can remove grasses and forbs that are crucial for maintaining soil health and preventing erosion. This removal of vegetation exposes the soil to the elements, making it more susceptible to erosion by wind and water.

The compacted soil that results from overgrazing can severely affect water infiltration and root penetration, thereby limiting plant growth. Compacted soils retain less moisture and air, which can hinder the microbial activity necessary for nutrient cycling. Essential nutrients that would typically be cycled through plant uptake, decomposition, and organic matter buildup can be lost from the system, leading to a decline in soil fertility.

Furthermore, the disruption of nutrient cycling means that not only are nutrients not being replenished as they should be, but the natural processes that help in soil formation and health are also diminished. Therefore, option B accurately captures the negative consequences of overgrazing on nutrient cycling and soil health.