[1] Generally speaking, these regions are devoid of trees, except for riparian or gallery forests associated with streams and rivers.
The tallgrass prairie, with moderate rainfall and rich soils, were ideally suited to agriculture so it became a productive grain-growing region.
While arid, shrub-steppes have sufficient moisture to support a cover of perennial grasses or shrubs, a feature which distinguishes them from deserts.
The expanses of grass once sustained migrations of an estimated 30 to 60 million American bison which maintained grazing pressure as a keystone species.
[7] Intensive farming, urbanization, and the spread of trees - that were formerly limited by periodic fires - continue to contribute to habitat loss.