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Glossary of Terms in Ecology and Restoration

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Adsorption: adherence of dissolved elements to particulate matter.

Alkalinity: concentration of alkali metals that form salts (e.g. Li, Na, K). High alkalinity raises pH and precipitates metals out of solution and is often associated with limestone substrates.

Allelopathy: growth suppression by one plant on another plant due to the release of inhibitory or toxic chemicals.

Allocation: the process of designating certain resources for certain purposes.

Alluvial Fan: lowland loose sediment deposited by water run-off -usually forms at the base of mountains in arid and semi-arid environments.

Alpine: refers to high mountain areas above the timberline (where trees cease to inhabit extremely cold environments).

Ameliorate: to make a situation better or more tolerable

Animal: any member of the animal kingdom including multicellular marine organisms, worms, insects, spiders, crustaceans, fish, amphibians, reptiles, birds, and mammals.

Anthropogenic: refers to the resulting influence of humans on nature.

Annual Growth: the amount of new plant biomass produced per year, usually measured as above-ground production.

Annuals: plants which display germination and rapid growth in wet seasons, quickly flower and produce seeds, and then wither. The success of this life form lies in the seeds, which often lie dormant until the next wet season.

Aspect: the direction (N,S,E,W) of reference or the direction of exposure to elements such as wind.

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Bajadas: lower slopes of mountains characterized by loose sediment and poor soil development.

Bathymetric: of or having to do with the depth of large bodies of water.

Benthic: refers to the bottom substrate of a body of water.

Biodiversity: the number (richness) and distribution (evenness) of species in an area.

Biogeochemical: refers to the recycling chemistry between plants, animals and the earth’s sediments.

Biomass: the total amount of living matter within a given unit or area. Syn: live matter

Biome: a complex of ecological communities characterized by distinctive vegetation and climate.

Bioremediation: the use of microorganisms and/or plants (phytoremediation) to decontaminate polluted water and soil.

Biosphere: the part of the world in which life can exist.

Bog: a wetland with acidic substrate mainly composed of moss and peat and having a characteristic flora.

Broadcast Seeding: spreading a seed mixture evenly over harrowed ground and raking.

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Calcareous: refers to soils or an area with soils containing large amounts of calcium carbonate, usually derived from limestone sediment.

Catchment: refers to an area (usually smaller than a watershed) which "catches" rainfall and is drained by a common stream.

Chaparral: refers to areas with broad-leaved evergreen shrubs found in climates with hot dry summers and mild wet winters.

Climate: the average or prevailing weather conditions of a place over a period of years (BLM Technical Reference 4400-7).

Clay: 1.) sedimentary grains < 1/256 mm. 2.) fine particles of aluminum silicates and other minerals typically both definitions apply.

Community: an assemblage of interacting plants and animals forming a distinctive group within a given area.

Competition: the active demand of two or more organisms for the same limited resource (i.e. space, nutrients, water, food, female).

Composition: refers to the relative proportion of space or biomass occupied by each species in a given area.

Conservation: 1.) the planned management of natural resources. 2.) the retention of natural balance, diversity, and evolutionary change in the environment (Mojave-Southern Standards & Guidelines, BLM).

Corridor: a natural or restored pathway for a population of organisms to use in order to breed and/or remain contiguous.

Cover: usually refers to the percentage of ground covered by living or organic material.

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Deciduous: refers to plants which do not retain their leaves from year to year. Opp: Evergreen

Denuded: stripped of all vegetative cover as after a severe disturbance such as a landslide.

Desertification: a process of landscape change usually due to land mismanagement or climate change whereby the land becomes increasingly arid and vegetation is replaced by more dry-adapted species.

Distribution: 1.) the spatial arrangement of organisms in a defined area- which fall into one of three categories: clumped, uniform, or random. 2.) the geographic area in which a species naturally occurs Syn: range. 3.) in a statistical sense, it is the total observed (or estimated) frequency of occurrence for the studied subject (or statistic).

Disturbance: any event which alters or stresses an environment’s structure and function.

Dredging: use of motorized equipment to clean, deepen, or widen areas inundated with water.

Drill Seeding: sowing seeds in rows of drilled holes.

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Ecological Restoration: altering an area in such a way as to reestablish an ecosystem’s structure and function, usually bringing it back to its original (pre-disturbance) state or to a healthy state close to the original. Syn: rehabilitation

Ecosystem: a collection of interacting organisms and their physical environment (matter and energy) that functions together as a single large-scale unit.

Ecotone: a distinct area where one plant community changes into another plant community, usually caused by changes in the environment such as changes in elevation or soil characteristics.

Ecotope: an area with uniform environmental conditions and characteristic plants and animals. Syn: biotope

Edaphic: of or having to do with soil.

Edge Effect: the resulting influence two starkly different plant communities (e.g. forest-meadow) have on the animals that inhabit the area.

Endemic: refers to a species that is not only native to a geographic area but is also restricted to that area or specific habitat.

Ephemeral: characterized as episodic and lasting a short duration.

Erosion: depletion of surface soil or rock due to geologic forces such as water, wind, ice, and gravity.

Estuarine: of or having to do with the area where the sea meets a freshwater stream/river.

Eutrophic: refers to a body of water which is excessively rich in dissolved nutrients and usually poor in dissolved oxygen. Opp: oligotrophic

Evolve: proceeding through the natural process of change caused by genetic mutations and selection upon those mutations for environmentally favorable traits. Two different environments can lead to the evolution of two different organisms from one ancestor.

Exotic: refers to a species that is foreign to a geographic area and usually alienated from its natural competitors and predators.

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Facultative: refers to the ability to change metabolic pathways (i.e. aerobic and anaerobic) given the environmental conditions.

Filtration: removal of particulate matter from water due to obstruction and reduced water velocity.

Forb: herbaceous plants.

Fragmentation: 1.) refers to the break up of an organism’s population and breeding grounds. 2.) refers to the reduction in connectivity among ecosystems within a landscape.

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GIS: refers to the Geographic Information System consisting of satellite images of the earth’s topography, land developments, and vegetative/non-vegetative coverage.

Gene flow: refers to the exchange of heritable traits in a population of organisms. Lack or low gene flow is considered detrimental because it does not yield a great amount of variability (gene pool) from which the population can use to overcome changing environmental conditions.

Genetic: of or having to do with the precise heritable traits (genes) retained by an individual. Individuals that have been geographically separated for a long time usually have slightly different genetic make-ups.

Grading: altering a land surface by cutting, filling and/or smoothing to meet a designated form and function.

Graminoids: include grasses, sedges (grass-like plants), and rushes (marsh plants).

Granivory: refers to the loss of seeds due to consumption by another organism. Syn: predation

Gravel: rounded sedimentary particles >2 mm in diameter.

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Habitat: the physical environment in which organisms live.

Herbivory: refers to the loss of vegetation due to consumption by another organism. Syn: predation

Heterogeneous: refers to anything which displays a varied composition or a mixture of elements. Opp: homogeneous

Homogeneous: refers to anything which displays a uniform or consistent composition. Opp: heterogeneous

Hue: relation to the spectral colors (red, yellow, green, blue, purple, or a mixture of these colors).

Hydric (Hydrophilic): characterized as requiring ample water or moisture.

Hydrology: scientific study of water distribution, properties, and effects.

Hydrosphere: the aqueous part of the earth, including all bodies of water and water vapor in the atmosphere.

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Indigenous: refers to a species that is native to a geographic area. Syn: native

Infiltration: the flow of water into a porous material.

Invasive: refers to a species, not previously present in a plant community, that aggressively increases in abundance due to ecosystem disturbance or because it is an exotic species alienated from its competitors and herbivores.

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Karst: a limestone-rich landscape characterized by chemical erosion producing various sinkholes, fissures, underground streams, and caverns.

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Lacustrine: of or having to do with lakes.

Landscape: a complex of interacting ecosystems and humans.

Legume: plants belonging to the pea family (e.g. alfalfa and red clover) which typically host symbiotic nitrogen-fixing bacteria.

Limnetic: of or having to do with deep open waters of lakes or ponds.

Lithosphere: the solid outer part of the earth that is composed of rock.

Litter: the uppermost layer of organic debris, usually under deciduous plants, which may be slightly decomposed.

Littorial: of or having to do with shores of lakes or seas.

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Mesa: a flat-topped natural elevation or broad terrace.

Mesic: characterized as requiring a moderate amount of water. Opp: hydric and xeric

Metapopulation: multiple populations of an organism within an area in which interbreeding could occur, but does not due to geographic barriers.

Microhabitat (Microsite, Microenvironment): a small area with physical and ecological characteristics that distinguish it from its immediate surrounding area.

Mitigation: 1.) restoring, replacing, or creating ecological habitats (usu. wetlands) in one area to compensate for loss of natural habitats in another area due to development. Syn: compensatory restoration 2.) avoiding, minimizing, or reducing ecosystem losses.

Mitigation Banking: creates “mitigation credits” that can be purchased by developers in lieu of compensatory restoration.

Mitigation Banks: 1.) sites selected for habitat restoration or creation 2.) market-based banks that exchange “mitigation credits” on the developing site for wetland restoration/creation requirements on another site.

Mottling: marble-like pattern that occurs in soils where the water table fluctuates periodically.

Multiple Use: refers to land management which does not permanently impair the land, but instead, manages the land so that present resources are valued for meeting the needs of the American people and future changes in the lands resources can be made (Federal Land Policy and Management Act).

Mutualism: a symbiotic relationship between two organisms in which both organisms benefit from the relationship. e.g. Pollination of flowers by honey bees

Mycorrhizae: modified roots consisting of a mutually beneficial relationship between plant roots and fungi. Plants support fungi by providing sugar and a hospitable environment. Fungi support plants by providing increased surface area for water uptake and by selectively absorbing essential minerals. Syn: fungus roots

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Naturalized: refers to a previously exotic or foreign species which has established in and conformed to an ecosystem.

Nitrogen fixation: an important biochemical pathway in which atmospheric nitrogen (N2) is converted to inorganic nitrogen (NO3-, NH3, or NH4+) which can then be used by plants. The few organisms which are able to carry out this process are: cyanobacteria (blue-green algae), some symbiotic bacteria such as Rhizobium and Frankia, and humans.

Nutrients: chemical compounds in a usable form for plants and/or animals.

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Obligate: refers to the inability to change metabolic pathways, mode of feeding, or ecological relationships; restricted to specific environmental conditions.

Oligotrophic: refers to a body of water which is poor in dissolved nutrients and usually rich in dissolved oxygen. Opp: eutrophic

Oxidize: a chemical reaction in which the reference element or compound losses electrons to another "reduced" element or compound- usually to oxygen (a powerful electron attractor). Oxidation typically results in the breaking up of complex compounds.

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Palustrine: of or having to do with a marsh or grassy wetland environment.

Patch (dynamics): an area of uniform composition (homogeneous). Patch dynamics is the relationship between homogenous areas in a heterogeneous landscape.

Pathogen: any disease causing agent- usually a bacterium or virus.

Percolation: the trickle or seepage of water through a porous material.

Perennial: lasting throughout the year or through many years.

Perennials: plants that grow relatively slowly throughout the year and generally persist beyond the life-span of their seeds.

Pest: any animalthat is not valued by human society and usually overgrows or competes with valued animals.

Phytoremediation: the use of plants to decontaminate water and soils rich in dissolved nutrients (as phosphates).

Playa: a dry lake bed or lowland areas that are periodically flooded, commonly occurs in Southwestern United States.

Population: a group of interbreeding organisms not separated by geographic barriers which would inhibit breeding between all individuals.

Precipitation: separation of dissolved elements from water by forming a solid substance with other elements.

Predation: 1.) refers to consumption of an organism by another organism. 2.) refers to the consumption and/or killing of animals.

Productivity: 1.) the amount of atmospheric carbon dioxide fixed into plant sugar (starch). 2.) the amount of plant matter accumulated in a given time.

Propagule: any part of a plant that can give rise to a new individual and aids in dispersal of the species.

Pupae: the stage between larval and adult where insects undergo extensive body transformations during dormancy or inactivity (diapause).

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Random: 1.) having an undefined distribution (not clumped and not uniform). 2.) having a likelihood of being selected that is not biased from any other item in the selectable area.

Reclamation: alters an area to bring it to a healthy state unlike the original ecosystem. Syn: replacement

Reduce: a chemical reaction in which the reference element or compound gains electrons or hydrogen atoms (which have one electron) from another "oxidized" element or compound. Reduction typically results in building complex compounds.

Rehabilitation: altering a degraded habitat in order to improve ecological function.

Remediation: the process of correcting environmental degradation. Syn: amelioration

Resource: any component of the environment that can be utilized by an organism (Mojave-Southern Standards & Guidelines, BLM).

Restoration: altering an area in such a way as to reestablish an ecosystem’s structure and function, usually bringing it back to its original (pre-disturbance) state or to a healthy state close to the original.

Rhizosphere: the soil that surrounds and is influenced by plant roots.

Riparian: refers to the banks of a stream or river, usually characterized by hydrophilic (water-loving) vegetation.

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Safe-site: the environment immediately surrounding a seed which is favourable to germination and establishment. Syn: microsite, microhabitat

Salinity: the amount of chemical salts (compounds that include Na, K, Mg, Ca) contained in a solution.

Sand: sedimentary grains 2 -1/16 mm in diameter.

Savanna: tropical grasslands with scattered trees or shrubs.

Sedimentation: settling of particulate matter in water related to particle size, water velocity, and water flow.

Silt: sedimentary grains 1/16 - 1/256 mm in diameter.

Soil Horizon: layer of soil developed in response to localized chemical and physical processes resulting from the activities of soil organisms, addition of organic matter, precipitation, and water percolation through the layer.

Spodosol: type of soil layer with precipitated (solid) organic matter, aluminum, and iron.

Stand: an aggregation of plants growing in a continuous area and separated from other aggregations.

Stewardship: the individual’s responsibility to manage life and property with a reasonable regard to the rights of others.

Succession: a naturally occurring, progressive replacement of plant species and vegetation types due to competitive differences and environmental development.

Sustained yield: perpetual achievement and maintenance of a high level of annual (or regular periodic) output of the various renewable resources of the public lands. Sustained yield is a concept consistent with “Mulitple Use” (Mojave-Southern Standards & Guidelines, BLM).

Symbiotic: refers to the intimate relationship between two organisms often resulting in mutualism (win-win), parasitism (win-lose), or commensalism (win-no harm).

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Talus: an adjacent slope at the base of a steep incline characterized by unsorted rocky rubble.

Temperate: refers to geographic regions with moderate temperatures and climate e.g. Midwestern and Eastern United States.

Topographic: refers to the surface landscape of a geographic area, especially changes in elevation.

Topsoil: the surface layer of soil containing partly decomposed organic debris, which is usually high in nutrients, contains many seeds, and is rich in mycorrhizae.

Tundra: arctic and alpine regions characterized by bare ground, absence of trees, and growth of mosses, lichens, and low shrubs.

Turbidity: amount of sediment or particles suspended in water.

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Upland: 1.) terrestrial ecosystems located away from riparian zones, wetlands, springs, seeps, and dry washes 2.) ecosystems made up of vegetation not in contact with groundwater or other permanent water sources (Mojave-Southern Standards & Guidelines, BLM).

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Value: degree of lightness in a color.

Viability: the quality of possessing the ability to live, function and grow-a crucial characteristic of seeds.

Volatilization: evaporation of liquid substances into the atmosphere.

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Watershed: 1.) the entire geographic landscape that is drained by a waterway leading to a lake or reservoir 2.) a geographic area delineated by its peaks, which divide surface water flow into two directions.

Weed: any plant that is not valued by the human society and usually tends to overgrow or compete with valued flora.

Wetland: a general term for lowlands covered with shallow and sometimes temporary or intermittent waters. Syn: marsh, swamp, bog, wet meadow, sloughs, fen, river-overflow land

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Xeric: characterized as requiring very little water. Opp: hydric and mesic

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Other Glossaries

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Last Updated: 4 February 2004