In the 4th paragraph, it says disturbances like "accelerated erosion, or change in vegetation cover" tend to persist and grow over time, rather than a return to the pre-disturbance condition. Why do you think this is the case?

Erosion is the washing away of the uppermost part of the earth crust. Once erosion starts it only gets worse because, erosion wash away further soil, causing the eroding channel to futher expand, increasing the erosion.

Lack of vegetative cover allows erosion which washes away soil nutrients, further worsening the soil against soil vegetative cover.