Ecology: Abiotic and Biotic Factors

Abiotic and Biotic Factors

• Abiotic: Non-living components of an environment, not containing any living organisms.
• Biotic: Living organisms.
• Biotic Community: A self-sustaining community of living things; an ecosystem.
• Biotic Factor: Any environmental influence of living organisms, especially climatic and edaphic influences.

Abundance and Diversity

• Abundance: Relative number of individuals of a species in a defined area.
• Alpha Diversity (Local Diversity): Variety of organisms in a given habitat or location.
• Beta Diversity: Variety of organisms occupying a number of different habitats over a region; regional diversity.
• Biosphere (Ecosphere): Portion of Earth and its atmosphere in which living organisms exist or can support life.
• Biome: Largest ecological regions distinguishable by characteristic plants and animals.
• Biomass: Weight of living organisms per unit area at a given time.

Adaptations and Environmental Pressures

• Acclimation: Reversible physical change in an adapting organism in response to environmental pressures.
• Acclimatization: Adaptation to a different climate.
• Adaptation: Ability of species to respond to environmental constraints by developing adaptive structures through evolution to continue existence.
• Alien Species: Intentionally or unintentionally introduced organisms; some become invasive alien species (IAS).
• Allopatric Speciation: Isolation occurs through geographic separation of populations.
• Coevolution: Interactions between species impacting how both evolve.
• Cline: Gradient of variations in a species across a geographical location.

Ecosystem Components and Interactions

• Allelopathy: Chemical plant interaction where one plant inhibits another's growth.
• Amensalism: Interaction where one population is negatively affected while the other is unaffected.
• Association: Floristically homogenous vegetation types that exist as integrated units.
• Autogenic: Originating from within a system.
• Autotroph: Self-nourishing organism; capable of manufacturing its own food.
• Autecology: Approach in ecology studying organisms or a single species, a population-centered approach.
• Benthic: Organisms living on the sea floor.
• Biocoenosis: Term equivalent to the biotic component of an ecosystem.
• Biogeochemical Cycles: Movement of chemical elements between environment and organisms.
• Biological Magnification/Food Chain Concentration: Increase in levels of a certain substance as it moves through a food chain.
• Biotope: Environmentally uniform area; physical aspect of an ecosystem.
• Canopy: Overhead branches and leaves of vegetation.
• Carnivores: Consumer components of ecosystems that depend on flesh for food.
• Carrying Capacity: Amount of animal or plant life a given environment can sustainably support.
• Commensalism: Relationship where one population benefits and the other isn't affected.
• Competition: Process where organisms modify the environment to influence factors needed for growth.
• Closed System: Exchanged energy, but not matter, between its environment.
• Colluvium: Mixed deposits of soil and rock near slopes due to erosion.
• Chernozem: Common soil type in prairies, grasslands, and steppes.
• Climax: Culminating stage of plant succession in an ecosystem.
• Climate: State of atmospheric conditions on a year-to-year basis in a location.
• Climax Stage: Culminating stage of plant succession in an environment, vegetation reaching stability.
• Chablis: Formation of gaps in a forest by falling dominant or emergent trees.
• Chaparral: Evergreen shrub community adapted to dry seasons.
• Commensalism: One species benefits and the other is not affected.

Other Ecological Terms

• Albedo: Luminosity shining from a reflective surface.
• Algae Bloom: Explosion of phytoplankton, often due to pollution enriching waters.
• Alluvium: Sediment transported by water (rivers/streams).
• Amensalism: One species negatively affects another, but the latter is unaffected.
• Anemophilous: Seed plants pollinated by wind.
• Atmospheric Cycles: Nutrients like nitrogen and carbon (CO2) commonly in the atmosphere.
• Basal Area: Forest tree density expressed in square feet.
• Bog: Marshy land covered by shrubs and mosses.
• Closed system: Exchanged energy, but not matter.
• Colluvium: Soil/rock deposits accumulated at the base of slopes.
• Chernozem: Common soil type in prairies, grasslands and steppes
• Climax stage: Culminating stage of plant succession for a given environment .
• Coevolution: Interactions between species influencing both species' evolution.
• Carrying Capacity: Amount of animal or plant life an environment sustainably supports.
• Competition: Organisms in an environment impacting environmental factors necessary for growth.
• Food Chain Concentration: Increase in level of something as it moves through the food chain.
• Succession: Change in species composition (often vegetation) in an ecosystem over time.