Aquifers: Wet underground layers of water-bearing permeable rock or unconsolidated materials (gravel, sand, or silt) from which groundwater can be usefully extracted using a water well.
Biomass: The mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals.
Clovis hunters: Members of a prehistoric Paleo-Indian culture that first appeared 11,500 RCYBP (radiocarbon years before present), at the end of the last glacial period and was characterized by the manufacture of "Clovis points" and distinctive bone and ivory tools. Archaeologists' most precise determinations at present suggest that this radiocarbon age is equal to roughly 13,500 to 13,000 calendar years ago.
Dust Bowl: A period of severe dust storms causing major ecological and agricultural damage to American and Canadian prairie lands from 1930 to 1936 (in some areas until 1940). The phenomenon was caused by severe drought coupled with decades of extensive farming without crop rotation, fallow fields, cover crops or other techniques to prevent wind erosion. Deep plowing of the virgin topsoil of the Great Plains had displaced the natural deep-rooted grasses that normally kept the soil in place and trapped moisture even during periods of drought and high winds.
Ecosystem: A biological environment consisting of all the organisms living in a particular area, as well as all the nonliving (abiotic), physical components of the environment with which the organisms interact, such as air, soil, water and sunlight.
Forb: A broad-leaved herb other than a grass, especially one growing in a field, prairie, or meadow.
Homesteaders: American settlers on the Great Plains who acquired their land via the US Homestead Act, a law that privatized immense parcels of uncultivated land. Homesteaders were given a title to the land by the government after they had applied for it and “improved” it (i.e. cultivated it for farming).
Invasive species: Non-indigenous species, or "non-native", plants or animals that adversely affect the habitats and bioregions they invade economically, environmentally, and/or ecologically.
Mesic: Having or characterized by moderate or a well-balanced supply of moisture; "mesic habitats."
Middle latitudes: The areas on earth between the tropics and the polar regions, approximately 30° to 60° north or south of the equator. The middle latitudes are an important region in meteorology, having weather patterns which are generally distinct from weather in the tropics and the polar regions.
Pampas: The fertile South American lowlands, covering more than 289,577 square miles. The climate is mild, with precipitation of 23.6 inches to 47.2 inches, more or less evenly distributed through the year, making the soils appropriate for agriculture.
Prairie: An extensive area of flat or rolling, predominantly treeless grassland, especially the large tract or plain of central North America. Prairies are considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and grasses, herbs, and shrubs, rather than trees, as the dominant vegetation type..
Sandhill crane: A large crane of North America and extreme northeastern Siberia. The common name of this bird references habitat like that at the Platte River, on the edge of Nebraska's Sandhills in the American Midwest. This is the most important stopover area for the Lesser Sandhill Crane (Grus canadensis canadensis), with up to 450,000 of these birds migrating through annually.
Sandhills: A region of mixed-grass prairie on grass-stabilized sand dunes in north-central Nebraska, covering just over one quarter of the state.
Share (or plowshare): A component of a plow which is the cutting or leading edge of a moldboard which closely follows the coulter (one or more ground-breaking spikes) when plowing.
Steel moldboard plow: A plow equipped with a curved iron plate (moldboard) that lifts and turns the soil. Also known as turnplow.
Steppes: An ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes.
Tundra vegetation: Characteristically, herbaceous perennials with scattered trees, mosses, lichens, and sedges. Tundra vegetation is restricted by the intense winter cold, insufficient summer heat, and waterlogged soil.
Veld: A grassland especially of southern Africa usually with scattered shrubs or trees.