{"thcode":2,"term":{"code":310,"name":"ecological processes","parent":101,"scope":"Dynamic biogeochemical interactions that occur among and between biotic and abiotic components of the biosphere."},"uf":[{"name":"ecological models","usewith":false},{"name":"environmental processes","usewith":false}],"bt":[{"code":101,"name":"biological and physical processes","parent":1174,"scope":"All continuing activities, functions, and phenomena associated with organisms and non-living matter."},{"code":1174,"name":"topics","parent":1,"scope":"Themes, subjects, and concerns for which USGS information resources are relevant."},{"code":1,"name":"Categories","parent":null,"scope":"Thematic terms for categorizing information resources.  This thesaurus is intended to support finding and understanding scientific information."}],"nt":[{"code":30,"name":"algal blooms","parent":310,"scope":"Exceptional growth of algae and cyanobacteria in lakes, rivers or oceans due to excessive nutrients or climatic conditions."},{"code":88,"name":"bioaccumulation","parent":310,"scope":"The biological sequestering of a substance at a higher concentration than that at which it occurs in the surrounding environment or medium.  Also, the process whereby a substance enters an organism through the gills, epithelial tissues, dietary, or other sources."},{"code":93,"name":"biogeochemical cycling","parent":310,"scope":"The cycling of chemical constituents through a biological system."},{"code":108,"name":"biological productivity","parent":310,"scope":"The rate at which primary producers in the ecosystem utilize solar energy to produce food for consumption by other organisms. Do not use this term for productivity of organisms related to studies of the reproduction rates of a species."},{"code":2277,"name":"carbon flux","parent":310,"scope":"The rate and amount of carbon exchanged between the oceans, atmosphere, land, and living things."},{"code":196,"name":"contaminant transport","parent":310,"scope":"Processes involved in the movement of impurities through air, water, and soil."},{"code":268,"name":"dispersal (organisms)","parent":310,"scope":"The dissemination or geographic spread of individuals of a plant or animal population."},{"code":308,"name":"ecological competition","parent":310,"scope":"The struggle between members of two or more species for scarce environmental resources."},{"code":315,"name":"ecosystem functions","parent":310,"scope":"The total life activities of organisms in habitats and the effects of those activities on the nonliving components of the environment."},{"code":2281,"name":"ecosystem resilience","parent":310,"scope":"Measure of the persistence of systems and of their ability to absorb change and disturbance and still maintain the same relationships between populations or state variables. (Holling, 1973)"},{"code":359,"name":"eutrophication","parent":310,"scope":"The process by which water becomes enriched with plant nutrients, most commonly phosphorus and nitrogen."},{"code":365,"name":"extinction and extirpation","parent":310,"scope":"Extinction is the complete disappearance of a species from the earth.  Extirpation is the complete disappearance (elimination) of a species from a given region, island, or area."},{"code":522,"name":"habitat alteration and disturbance","parent":310,"scope":"Changes in the environments where plants and animals live.  Includes natural changes as well as results of human actions, deliberate or accidental."},{"code":743,"name":"migration (organisms)","parent":310,"scope":"The movement of animals, often periodical, from one area to another due to seasonal changes, availability of food, or climatic conditions."},{"code":915,"name":"pollination","parent":310,"scope":"Wind, bees, or other agents transfer plant pollen from flower anthers or cones to stigmas, thereby fertilizing plants for reproduction."},{"code":1123,"name":"succession (biological)","parent":310,"scope":"Gradual replacement of one species in an area by another."},{"code":1356,"name":"transpiration","parent":310,"scope":"Evaporation of water from plants."}],"rt":[{"code":311,"name":"ecology","parent":650,"scope":"Study of the relations between living plants and animals and their environment."},{"code":921,"name":"population and community ecology","parent":1174,"scope":"Interactions of a single species (population) or an association of different species (community) occupying a particular region, including their biotic and abiotic environments."},{"code":1710,"name":"soil formation","parent":451,"scope":"Geological, geochemical, and ecological processes that work together to produce soils."},{"code":2289,"name":"state and transition modeling","parent":2286,"scope":"Modeling of systems such as ecosystems to predict the consequences of natural events and management actions by describing how specified events and actions may change the components and relationships in the system."}]}