Energy flow (ecology)Energy flow is the flow of energy through living things within an ecosystem. All living organisms can be organized into producers and consumers, and those producers and consumers can further be organized into a food chain. Each of the levels within the food chain is a trophic level. In order to more efficiently show the quantity of organisms at each trophic level, these food chains are then organized into trophic pyramids.
Upland and lowlandUpland and lowland are conditional descriptions of a plain based on elevation above sea level. In studies of the ecology of freshwater rivers, habitats are classified as upland or lowland. Upland and lowland are portions of plain that are conditionally categorized by their elevation above the sea level. Lowlands are usually no higher than , while uplands are somewhere around to . On unusual occasions, certain lowlands such as the Caspian Depression lie below sea level.
Edge effectsIn ecology, edge effects are changes in population or community structures that occur at the boundary of two or more habitats. Areas with small habitat fragments exhibit especially pronounced edge effects that may extend throughout the range. As the edge effects increase, the boundary habitat allows for greater biodiversity. Urbanization is causing humans to continuously fragment landscapes and thus increase the edge effect. This change in landscape ecology is proving to have consequences.
Regime shiftRegime shifts are large, abrupt, persistent changes in the structure and function of ecosystems, the climate, financial systems or other complex systems. A regime is a characteristic behaviour of a system which is maintained by mutually reinforced processes or feedbacks. Regimes are considered persistent relative to the time period over which the shift occurs. The change of regimes, or the shift, usually occurs when a smooth change in an internal process (feedback) or a single disturbance (external shocks) triggers a completely different system behavior.
Rewilding (conservation biology)Rewilding is a form of ecological restoration aimed at increasing biodiversity and restoring natural processes. It differs from ecological restoration in that, while human intervention may be involved, rewilding aspires to reduce human influence on ecosystems. It is also distinct in that, while it places emphasis on recovering geographically specific sets of ecological interactions and functions that would have maintained ecosystems prior to human influence, rewilding is open to novel or emerging ecosystems which encompass new species and new interactions.
Arroyo (watercourse)An arroyo (əˈrɔɪoʊ; from Spanish arroyo aˈroʝo, "brook"), also called a wash, is a dry watercourse that temporarily or seasonally fills and flows after sufficient rain. Flash floods are common in arroyos following thunderstorms. Wadi (Arabic) is used in North Africa and Western Asia for similar landforms. The desert dry wash biome is restricted to the arroyos of the southwestern United States. Arroyos provide a water source to desert animals. Arroyos can be natural fluvial landforms or constructed flood control channels.
ShoalIn oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material and rises from the bed of a body of water to near the surface. It often refers to those submerged ridges, banks, or bars that rise near enough to the surface of a body of water as to constitute a danger to navigation. Shoals are also known as sandbanks, sandbars, or gravelbars.
DrumlinA drumlin, from the Irish word droimnín ("little ridge"), first recorded in 1833, in the classical sense is an elongated hill in the shape of an inverted spoon or half-buried egg formed by glacial ice acting on underlying unconsolidated till or ground moraine. Assemblages of drumlins are referred to as fields or swarms; they can create a landscape which is often described as having a 'basket of eggs topography'. The low ground between two drumlins is known as a dungeon; dungeons have colder microclimates in winter from settling cold air.
Mississippi RiverThe Mississippi River is the primary river, and second-longest river, of the largest drainage basin in the United States. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The main stem is entirely within the United States; the total drainage basin is , of which only about one percent is in Canada.
OvergrazingOvergrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature reserves. It can also be caused by immobile, travel restricted populations of native or non-native wild animals. Overgrazing reduces the usefulness, productivity and biodiversity of the land and is one cause of desertification and erosion.
