Summer Decks; Ecology

• Population


  a localized group of individuals of the same species that can interbreed, producing fertile offspring

  
• Community

  all the organisms that inhabit a particular area; as assemblage of populations of different species living close enough together for potential interaction

  
• Ecosystem

  all the organisms in a given area as well as the abiotic factors with which they interact

  
• Biotic


  pertaining to the living organisms in the environment

  
• Abiotic

  nonliving; referring to physical and chemical properties of an environment

  
• Biosphere


  the entire portion of earth inhabited by life; the sum of all the planet's ecosystems

  
• Niche

  the sum of a species' use of the biotic and abiotic resources in its environment
• Clumped Distribution

  individual aggregated patches, some organisms group together where food is abundant

  
• Uniform Distribution

  evenly spaced, some organisms maintain evenly distributed spacing to avoid aggressive interactions between neighbors

  
• Random Distribution


  unpredictable spacing, some plants grow in random groups if their seeds were windblown across an area

  
• Population Ecology


  the study of populations in relation to their environment, including environmental influences on populations, on population density and distribution, age structure, and variations in population size
• Birth Rate


  rate of annual birth within a population
• Death Rate


  rate of annual death within a population
• Sex Ratio

  ratio of females to males within a population
• Age Structure


  the relative number of individuals of each age in a population
• Immigration Rate


  the rate of influx of new individuals INTO a population from other areas
• Emigration Rate

  the rate of movement of individuals OUT of a population
• Carrying Capacity


  the maximum population size that can be supported by the available resources, (symbolized by K)

  
• Density Dependent


  any characteristic that varies according to an increase in population density
• Exponential Growth


  growth of a population in an ideal, unlimited environment, (represented by a J-Shaped curve when population size is plotted over time)

  
• Logistical Growth


  population growth that levels off as population size approaches carrying capacity
• K-Selected

  stabilize around carrying capacity, have fewer offspring later in life, mature later, live longer and invest more parental care
• R-Selected

  reside in unstable environment, have many offspring early in life, mature earlier, shorter life span, no parental care
• Survivorship Curve

  the plot of the proportion or numbers in a cohort still alive at each age
• Type I Surivorship Curve

  low death rates during early/middle life then increase among older age groups (humans)
• Type II Surviorship Curve

  constant death rate over the organism's life span
• Type III Surviorship Curve

  very high death rates for the young and then declines for those few individuals that survive the early period (insects)
• Symbiosis

  an ecological relationship between organisms of two different species that live together in direct and intimate contact
• Commensalism


  a symbiotic relationship in which one organism benefits but the other is neither helped nor harmed
• Mutualism


  a symbiotic relationship in which both participants benefit
• Parasitism


  a symbiotic relationship in which one organism (the parasite) benefits at the expense of another (the host) by living either within or on its host
• Intraspecific Competition


  interactions between the same species competing for resources
• Interspecific Competition


  competition for resources between individuals of two or more species when resources are in short supply
• Predation


  an interaction between species in which one species (the predator) eats the other (the prey)
• Aposematic Coloration


  the bright coloration of animals with effective physical or chemical defenses that acts as a warning to predators
• Batesian Mimicry


  a type of mimicry in which a harmless species look like a species that is poisonous or harmful to predators
• Cryptic Coloration


  camouflage that makes a potential prey difficult to spot against its background
• Mullerian Mimicry


  a mutual mimicry by two unpalatable species
• Pioneer Species

  the first species to colonize previously disrupted or damaged ecosystems, beginning a chain of ecological succession that ultimately leads to a more biodiverse steady-state ecosystem
• Climax Community


  in a community of organisms in a specific area there is one state of equilibrium controlled solely by climate