chapter 10C – interdependency

biodiversity

variety of all organisms on Earth

species diversity

• variety of different organisms living in a particular habitat / region

genetic diversity

• variety of genes / alleles present in a species

  • increase genetic diversity = increase individuals survive and reproduce when environmental conditions change

ecosystem diversity

• variety of physical environments in which organisms live in and interact

• changes over time

ecology

study of how organisms interact with one another and their environment

• study of ecosystems

ecological organisation

cells, organisms, populations, communities, ecosystem

ecosystems

• multiple communities interacting with one another and their environment

ecosystems are made up of:

• abiotic + biotic factors

• contain many individual and population interactions

• flow of energy / nutrients between organisms

biotic factors

• property of the environment relating to organisms

examples of biotic factors

• predator-prey relationship

• symbiosis

• competition

abiotic factor

• property of the environment relating to non-living things

examples of abiotic factors

• temperature of air

• temperature of water

• nutrient / water availability

components of an ecosystem

• population

• community

• ecosystem

species

• a group of similar organisms capable of interbreeding under natural conditions to produce viable and fertile offspring

population

• group of individuals of the same species living in the same geographic location

• number of individuals in a population and is dependent on immigration, emigration, births, deaths

community

• group of interacting populations of different species in the same geographical region

ecosystem

• multiple communities interacting with one another and their physical environment

classification of organisms

• domain

• kingdom

• phylum

• class

• order

• family

• genus

• species

King Philip Came Over For Good Spaghetti

naming organisms

• Genus species

  • e.g. Macropus rufus

• same genus = more closely related

• same species = produce fertile offspring

carrying capacity

• maximum population size an environment can sustain indefinitely

influences of population growth rate

• influenced by amount of offspring produced by an individual / pairs of individuals each generation

what happens in an unstable environment

organisms produce large numbers of short-living offspring

• let them take chances at survival until reproductive age

stable environments

fewer offspring but invest more resources in each individual

• increase lifespan, chances of survival

r reproduction

• quick and many strategy

• large number of offspring

• little to no parental care

• high mortality rate of offspring

• reach sexual maturity quickly

  • become self-sufficient adults earlier than other organisms

• boom and bust

  • rapid, exponential growth followed by a massive die-off

• many aquatic animals, insects, rodents

k reproduction

• small and few method of reproduction

• smaller number of offspring

  • larger in size

• dependent on parental care

• reach sexual maturity slower

• population growth in K-strategists will remain constant at the carrying capacity

• e.g. most mammals, including humans, chimpanzees, whales, elephants

growth curve

population distribution

• range of geographical areas that members can be found in

population density

• number of individuals in a population per unit area

density-independent factors

• environmental factors that affect population growth but are not affected by population density

  • limit size of a population regardless of population density

density-dependent factors

• affect population growth and becomes stronger as population density increases

examples of density-independent

• climate

• natural disturbance events

  • cyclone

  • volcanic eruptions

• functionally unlimited resources

  • O2

  • CO2

examples of density-dependent factors

• disease

• predation

• competition

• resources

• availability

• accumulation of waste

more carrying capacity fyi!

symbiosis

• interaction of two different species living in close proximity to each other

mutualism

overall benefit

commensalism

one benefits, one has no significant benefit

• barnacles attach to whales

parasitism

one obtains nutrients at the expense of a host organism

amensalism

one harmed / killed, other no effect

• e.g. predator trampling over grass

predation

one organism kills / hunts organism for food

competition

between two or more organisms competing for the same pool of resources

interspecific competition

• different species competing for the same pool of resources

intraspecific competition

• same species competing for the same pool of resources

keystone species

• effects on ecosystem is greater than expected relative to its population size

  • critical – is often the focus of conservation efforts

• e.g. apex predators, ecosystem engineers

apex predator

• no natural predators

• top of food chain

ecosystem engineer

• creates / significantly alters, or maintains structure of environment

• e.g. beavers construct dams where many species of fish (such as trout / salmon) live in