Rangeland ecosystems are controlled by many factors, of which most important is climate. Other important factors include fire; selective removal of plants and animals; the placement of roads, fences, and watering points; grazing intensity; and agronomic-type practices, such as seeding, fertilizing, and irrigating. Managing soils for C sequestration as organic carbon is very much tied to controlling the type and density of vegetation. The importance of this relationship has been observed where desert grasslands have converted to shrublands, causing wind erosion that removed and redistributed soil organic matter, which in turn reduced nutrient supply, seed bank supply, aggregation, and water holding capacities. Management of inorganic C is less apparent.  Important questions in this regard include whether soils become a C source rather than a C sink when erosion exhumes petrocalcic horizons, when rangeland soils are irrigated, and when biosolids are added to rangeland soils.