module 4 Flashcards
Ecology
the interactions of one organism with another as well as their environment
levels
Individual
Population
Community
Ecosystem
Biome
Biosphere
abiotic factors
nonliving features of an environment
Light
Wind
Temperature
Water
Availability
pH levels → soil and water
Salinity
Humidity
Minerals
biotic factors
living features of an environment
Predation
Competition (for resources)
Pathogens
Plants
Animals
Microbes
nitrogen cycle
→nitrogen fixing bacteria that is present in soil that fixes atmospheric nitrogen → soluble nitrogen compounds → when in the soil → decomposers (eg. bacteria and fungi) converts it to useful compounds taken up by plants → plants use nitrogen to make protein and nucleic acids
Carbon oxygen cycle
transfer of oxygen and carbon between living and non-living components of an ecosystem
Driven by photosynthesis (CO2 + H2O → (in presence of sunlight) C6H12O6) and cellular respiration (C6H12O6 + O2 → ATP + CO2 + H2O)
Competitive exclusion principle
Two species can’t coexist if they are competing for the same resource → one species will outcompete the other species and the second species is eliminated
Resource partitioning
species adapt to slight different niches so that they can coexist (different ecological niches but the same environment)
eg.red and yellow birds
food chains
- represent simple feeding relationships between organisms in an ecosystem
- Shows predation arrow goes from the organism which is being eaten to the organism that eats it
- represents the flow of energy
producer –> primary consumer –> secondary consumer –> tertiary consumer
food webs
- culmination of food chains from the same ecosystem
- organisms can exist on more than one trophic level
- allows us to see the relationship between different organisms in an ecosystem
- can show detritivores and decomposers
keystone species
- If it is reduced in numbers → potentially cause the ecosystem to collapse
- eg. cassowary –> spreads seeds across an ecosystem
trophic levels
broad divisions of the different levels throughout an ecosystem
- arranged into ecological pyramids
- pyramids of biomass
- pyramid of energy
- pyramid of numbers
pyramid of biomass
- loses about 10% of biomass as each trophic level goes higher
- compare matter
biomass
total dry weight of organisms in trophic level
pyramid of numbers
producer, herbivore, carnivore
pyramid of energy
represent energy of the entire trophic level
- energy is lost due to metabolic reactions
- lost due to kinetic energy and heat
how does extinction occur and mass extinction
ecological consequence –> loos f biodiversity –> loss of keystone species –> loss of ecosystems
- rate of extinction increases dramatically –> mass extinction due to human impacts (climate change, pathogens, introduced species and diseases, pollution)
extinct animals
thylacine
- apex predator
- increase in prey numbers led to the reduction of producers
- competed with wild dogs
- loss of habitat
- new disease
carrying capacity
the maximum number, density, or biomass of a population that a specific area can support sustainably
allelopathy
- Process where allelochemicals are released by some sort of plant species to influence the germination of seeds, mortality of seedlings and the growth of neighbouring species
- Can be beneficial or harmful
- Prevents overcrowding → leaf litter increasing seedling mortality of eucalyptus
competition
Two organisms compete for limited resources
interspecific competition
two or more different species dependent on the same prey
- lion and cheetah
intraspecific competition
competition for resources within the same species
- both fighting for sunlight
predator
consumer organisms from another species
prey
organism that was consumed
disease
- Caused by the introduction of new species, stressors (pollution)
- Population with genetic diversity will help populations against the disease
Large genetic diversity → genetic variation → some with resistance to the pathogens → reproduce → population that is resistant - eg. Tasmanian devil facial tumour disease, amphibian chytrid fungus
symbiotic relationships
- mutualism
- commensalism
- parasitism
mutualism
relationship between different species which benefits both organisms
- flowering plants and insects
commensalism
relationship between two organisms in which one benefits and the other is unaffected
- shark and remora fish
parasitism
relationship in which one organism benefits and the other is harmed
- parasite tape worm
- host human
distribution
where the species inhabits
types of distribution
- random: resources are abundant
- uniform: resources are scarce
- clumped: protects for predation therefore gathers
sampling
- transect mapping (distribution and sessile)
- quadrat sampling (distribution and sessile)
- capture-mark-recapture (abundance and sessile)
abundance
number of organisms in a population at a certain time and place
average number per quadrat
total organisms in all quadrats/ total number of quadrats
total population
average number per quadrat X total area /area of quadrat
or
density (per m2) X total area
capture remark recapture
mobile population
abundance = number captured X number recaptured/number marked in recapture
rock formations
explains continental drift
aboriginal rock paintings
evidence of fauna and flora changing
- shows how species have evolved and adapted
ice core drilling
- cores taken from glaciers and polar caps are used to determine climate
- shows the atmosphere at the time through trapped debris
- frozen hydrogen and oxygen in the form of isotopes
banded iron formations
- sedimentary deposits formed at the bottom
- evidence of oxygenation (shows that the oxygen had no oxygen before)
australia’s species
reproductively isolated
Sclerophyll plants
- adapted to abiotic factors of dry climate and nutrient deficient soil
- thick waxy cuticle
- eucalyptus
Megafauna
an arbitrary compilation of relatively large mammalian, reptilian, and avian taxa, ranging in size from ~10 kg or less up to >2,000 kg
eg. Thylacine
Woolly rhinoceros
Procoptodon
- Evolved due to glacial conditions → extinct due to warmer temperatures from climate change → human induced (increased fire, reduction of grasslands, loss of freshwater)
