As the herds become larger, over-grazing becomes something that cannot be avoided at all times. When the land becomes over-grazed, erosion starts to happen. .
A good quality of soil is need to provide the plants that grow in it with enough nutrients to replenish itself after being eaten by animals. Humans and animals need nutrients to survive. So where do people think they get these nutrients? The plants they eat and the plants get them from the soil they grow in. Soil performs many functions inside the ecosystem. " Soil quality has been defined as: "the capacity of a soil to function, within ecosystem and land-use boundaries, to sustain biological productivity, maintain environmental quality, and promote plant and animal health"" (Wienhold, Hendrickson, Karn 2001). So in order for there to be a balanced ecosystem, the soil has to be of a great quality in order to support the life of plants and animals. Soil quality is only one measure of ecosystem health and is most useful when combined with other ecosystem attributes to be discussed in a later paper. Although droughts and over-grazing are some main problems, they are not the only ones. .
Droughts have had detrimental effects on animal populations. The lesser prairie chicken is one of these affected animals. "Since 1800, the lesser prairie chicken range has decreased *90% and the population size has decreased by more than 97% since 1800" (Applegate and Riley 1998). Most of this decrease has been caused by serious droughts. These droughts have caused a shortage in the lesser prairie chickens food source. This however is not the only reason for their decline. "Intensive agriculture and livestock grazing systems have reduced the mosaic of available habitats and in some cases prairie chicken populations have been completely eliminated over large areas of their historic range" (Applegate and Riley 1998). .
Water demands are increasing world-wide.