The previous picture showed two grazed paddocks, one of them eaten down to nothing. Now compare with an ungrazed area: notice the carpet of plant matter on the roadside. This conserves moisture and, more importantly, contains millions of tiny microorganisims that, in this arid country, are the primary source of soil nutrient. Hooved animals like sheep, cattle, and goats don’t just eat the vegetation, they damage the soil structure simply by walking on it.
Nature is forgiving, but only within reasonable limits. Because of damage caused by overgrazing, vast areas of Australian rangeland will never be productive again. The environmental cost is obvious but it doesn’t even make economic sense.