Answer:
Allan Savory noticed that grasslands co-evolved with large numbers of migrating ruminants, and therefore are co-dependent on each other's survival. These animals grouped together and constantly bunched due to the predator-prey connection, eat the grasses following the seasons throughout their migration in arid regions (Brittleness scale, of Non-Brittle to Brittle environments).
As they move, they drop nutrient-rich dung and urine, while trampling organic litter (live or dead grasses, leaves, etc) and seeds into the soil. These actions break down materials into the surface, providing more covered soil and keeping materials from chemically decomposing (oxidation, as opposed to the fast biological decomposition that occurs in areas with consistent rainfall(Non-Brittle)). The true testament to his insights of Holistic Management re: grasslands is known as the 4th Key Insight: That time, rather than numbers governs over-grazing or over-trampling.
The important component here is that the time exposed to these animals plays the significant role in whether you have healthy grasslands, not the number of animals exposed to the area of consideration. The amount of "rest" (time) for grasses between eating or trampling is just as crucial as the time in an exposure.
Explanation:
Explained in his book and courses under "Holistic Management", by Allan Savory and Jody Butterfield, and Sam Bingham
