population sizedecreases
Predation
if population of prey increases population of predators alsoincreases as
morefood is available decreases preypopulation decreases predator
population as there is less food
carryingcapacity
max stable population size an ecosystem cansupport
populationsizes tend to fluctuatearoundthis level
varies in responseabioticand bioticfactors
succession
changes in community over time
due to either abiotic factors or the speciespresent
2types of succession primarysuccession ecologicalcommunity
develops in absence of soil on newly formed or exposed land e.g after a
déieloipsrontiannd on whichSecondary succession ecologicalcommunity
soil present land cleared of all plants leglatte
is
a forest fire
stages of succession
pioneers colonise land
speciallyadapted to live indry hostile condition
changeinenvironment
ispioneerspeciesdie andcomposeintobasic soil humus
enables other species to survive
change in biodiversity
isgfagnii.fm nbereetatgersadapted out competeandreplace less adapted
climax community formed
climax community
stablecommunity so no further succession
conservation
often involves managementof succession preventing formationofclimax
community andpreserving certain habitats
controlling succession
grazing livestock sheet and cattle grazingprevents climaxcommunity
forming as seedling can't grow properly
controlled fires after fire pioneer species are first to grow back by
the time other species grow back they will beremovedby next controlled
fire conserves pioneerspecies
conservation methods
fishingquotas limit no of fish legallycaught
protecting land areas made into national parksandnature reserves
protects habitats restrictsfarming and development on land
captivebreeding endangered species can be bred
seedbanks hold collection of seeds from differentplantspecies if plants
becomeextinct seeds can beused to reintroduce plants into habitats
conserving woodland
to protect habitats niches