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Ecosystem Dynamics Test - Coggle Diagram

- - - - density
        
        the number of individuals per unit area or volume
      - composition
        
        includes characteristics of populatio
        
        e.g. age, sex ratios, age structure, fertility rate and average number of offspring per female.
      - distribution
        
        pattern of how a population is physically spaced (based on availability of resources)
        
        Random distribution
        
        Uniform distribution
        
        Clumped distribution
        
        e.g. school of fish
        
        e.g. penguin colony
        
        e.g. specific tree species in a forest
      - abundance
        
        relative representation of a species in a particular ecosystem. (estimate)
        
        can be measured as population size/density and knowing sample of areas of ecosystem help determine population distribution.
        
        Total abundance
        
        refers to the total number of organisms of each species present, or the number of organisms per unit area which live in a particular part of their distribution
        
        e.g. bird monitoring surveys - only deliver abundance data like nest rate instead of total population size estimates.
      - size
        
        number of individuals in a population
        
        Example of population size and distribution of woylie populations has been severely reduced by habitat loss and predation.
  - - - relatively predictable ecosystems, larger, longer-lived species out compete smaller, faster-growing species
        
        such species have steadier population growth pattern + exist in numbers close to carrying capacity of environment
        
        K-selected species e.g. kangaroos, elephants, whales, gorillas, oak trees.
        
        longer life cycle, relatively large size, parental care
    - - unpredictable ecosystems, such as those that occur after a fire or land clearing, opportunistic species move in and colonise quickly.
        
        colonising populations show a pattern of rapid increase where the maximum reproductive potential of the species is reached then decline in numbers.
        
        r-selected species e.g. frogs, rats, weeds, swarming insects like locusts.
        
        short life cycle, relatively small size, lack of parental care.
  - - - Quadrats can be placed at regular intervals along transect line in order to generate population data.
        
        will show hanging distribution pattern of a species in response to a change in an abiotic variable
        
        data used to identify optimal conditions, zones of stress and zones of intolerance.
      - can measure distribution of species in response to an incremental abiotic factor.
        
        Quadrats = rectangular frames of known dimensions - used to establish population densities
        
        Transects = straight line along abiotic gradient = population data can be recorded to determine a pattern
      - Similarities
        
        useful method with species = immobile
        
        data used to calculate density in specific locations
        
        used together to gain data
        
        using a significantly large sample size and a random number generator = increase reliability
      - differences
        
        Quadrat: frame positioned in random locations
        
        Transect: line drawn across community
        
        Quadrat: average number of individuals are counted + average per quadrat then multiplied to gain total population estimation
        
        Transect: information gather from along line and used to estimate distribution of species within that community.
    - - N = Mn/m
        
        N = population size to be estimated
        
        M = number of individuals initial caught and marked
        
        n = number of individuals caught in the second capture
        
        m = number of individuals marked in the second capture
      - assumptions
        
        no death, immigration or emigration
        
        sampling methods = identical for capture and recapture
        
        marking doesn't affect survival rate of animals
        
        all members of population mix randomly, enough time was given between captures for organisms to mix - each member has = chance of capture each time.