{"thcode":2,"term":{"code":1196,"name":"tundra ecosystems","parent":1156,"scope":"Biological communities and habitats located in the treeless plains of Arctic regions where the subsoil is permanently frozen."},"uf":[],"bt":[{"code":1156,"name":"terrestrial ecosystems","parent":319,"scope":"Communities of living organisms in a specific geographical location which exist primarily on land and not in water."},{"code":319,"name":"ecosystems","parent":921,"scope":"The interacting populations of plants, animals, and  microorganisms occupying a certain area, and their relationship to the 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":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":[],"rt":[{"code":311,"name":"ecology","parent":650,"scope":"Study of the relations between living plants and animals and their environment."}]}