Population Ecology Flashcards
Organize biosphere, biome, ecosystem, community, population, and organism from broadest to smallest level of biological organization
Biosphere- Biome- Ecosystem- Community- Population- Organism/Individual
Ecology
Interactions between organisms and the environment
Three different types of dispersion
examples
Uniform - penguins, plants that undergo allelopathy
Random - dandelions and other plants that have wind-dispersed seeds, oyster larvae
Clumped - plants that drop their seeds straight to the ground, animals that live in groups, sea stars, bald eagles
Two methods of quantifying a population
determine what type of organisms would be suited for qualification
- Quadrat Analysis
-plants, sedentary animals - Mark-release-recapture
- birds, snails, butterflies, large mammals, amphibians, fish fins
Biotic factors
examples
Living components of an ecosystem
ex. plants, animals, bacteria, fungi, protists
Abiotic factors
examples
Non-living or physical components of an ecosystem
ex. temp, water, sunlight, atmosphere, wind, rocks, soil, pH
Producers
autotrophs
convert the energy from sunlight or inorganic chemical compounds to synthesize organic molecules
photoautotrophs, chemoautotrophs
Consumers (herbivores, omnivores, and carnivores)
heterotrophs- are animals that depend upon producers for food
herbivores - only eat plant material
omnivores - eat variety of food sources plants, animals, algae (bears, crows, humans)
carnivores - eat other animals (lions, tigers, eagles, wolves)
Decomposers (detritivore)
heterotrophs - play a critical role in keeping ecosystems healthy
when they break down dead materials and waste they release nutrients that can be recycled and used as building blocks by primary producers (fungi, cockroaches, wasps, bacteria)
detritivores - earthworms , dung flies, mites, sea stars - consume the dead decomposing material created by decomposers
Demography
Study of vital statistics of a population and how they change over time
Death rates, birth rates, and life expectancies are of particular interest to demographers
Describe what a life table is
Age-specific summary of survival pattern of a population
best made by following the fate of a cohort, a group of individuals of the same age
Types of survivorship curves
examples
Type 1- humans
Type 2 - bird species
Type 3 - trees, marine invertebrates and most fish
Differentiate between semelparity and iteroparity
semelparity - reproduce once
iteroparity - reproduce repeatedly
Semelparity
examples
Big-bang reproduction
-reproduce once and die
ex. pacific salmon, bamboo, grain crops like wheat
Iteroparity
examples
Repeated reproduction
produce offspring repeatedly
ex. humans, all birds
Differences between exponential and logistical growth models
exponential - per capita growth rate (r) doesn’t change even if population gets very large
logistic - per capita growth rate (r) gets smaller as pop. approaches its max size
Define r, r-max, and K(carrying capacity)
r - intrinsic rate of population growth or per capita population growth rate, measures whether the population tends to grow >0, shrink,<0 or stays the same =0
r-max - maximum pop. growth rate
K - mam pop. size a particular environment can support
List density-dependent factors that limit population size
changes in intensity as a function of pop. size (biotic)
- competition for resources
- disease and parasitism
- predation
- toxic wastes
- social behavior
logistic
Differences between r-selected and K-selected species
r-selected are consistent with semelparity
- opportunistic
- short lifespan, death rate high, small offspring’s, no parental care, reproduction early in life
k-selected are consistent with iteroparity
- equilibrial
Quadrat Analysis
Used to quantify immobile organisms (plants and sedentary animals) as well as small slow moving organisms
Mark-release-recapture
Used to quantify mobile organisms
Assumptions when using mark-recapture method
animals are:
randomly dispersed
not immigrating or emigrating
none born or died
marked and unmarked have the same chance or being recaptured
type of marking used does not influence the animals chance of being recaptured or being preyed upon
Mark recapture formula
N=m1xn2/m2
N=total # of individuals in the population
m1= # of animals marked and released
n2= total # of animals caught in recaptured sample
m2= # of marked animals caught in recaptured sample
Clumped Dispersion
most common type of dispersion
-distance between neighboring individuals is minimized (individuals are clustered in groups)
arise from social predisposition to form groups (for thermoregulation, better foraging, cooperative hunting, safety from predators)
Inability of offspring to independently move from their habitat
Random Dispersion
Least common type of dispersion
distance between neighboring individuals is unpredictable
exhibited by individuals that do not from social groups (neither attract nor repel one another)
Uniform Dispersion
known as even distribution (less common that clumped more than random)
distance between neighboring individuals is evenly spaced
helps to ensure adequate resources for each individual
Type 2 survivorship curve
bird species
death rate is constant over the organisms life span
have relatively few offspring and provide significant parental care
Type 1 survivorship curve
- humans and most primates
- low death rates during early and middle life then an increase in death rates among older age groups
- small number of offspring provide lots of parental care
Type 3 survivorship curve
trees, marine invertebrates and fish
- high death rates for the young and then a slower death rate for survivors
lots of offspring not much care
Density-Independent factors
Alter birth rates and death rates irrespective of # of individuals in pop.
involves change in abiotic environment
-exponential growth
Quadrat formula
N=(A/a)*n
N=estimated total population size
A= total study area
a = area of one quadra t
n= mean # of organisms/quadrat
