Ecology Flashcards
change in species composition (3)
pioneer = change in abiotic conditions/environment
other species colonise
these are better competitors
climax community = stable
more species present
more complex food webs
SO change in one condition has little effect on others
since alternative food sources
xerophytes ??????
low water retention
sunken stomate reduce transpiration
reduced wp gradient
transects > quadrats
series of changes over a distance so there is sampling of each community
SUCCESSION PROCESS
pioneer colonise change in environment e.g. incr in organic matter new species arrive and survive they are better competitors incr in diversity incr in biomass + niches less hostility = stability climax
controlling pests w/ biological agents
ADV specific to one pest no chemicals in environment one application due to reproduction pests dont develop resistance DISADV takes time to reduce pest population pest not completely eliminated may become pest itself
NEW SPECIES
geographical isolation
separate gene pools = no interbreeding
different selection pressures
variation due to mutation so selection for adv allele
reproduction SO change in allele frequency
forest
succession and conditions change to favour trees
trees in waterlogged soil
roots unable to respire
active transport of minerals stopped
community defintion
populations of diff communities in ecosystem
niche defintion
specific role played by one specie in ecosystem
drainage leads to elimination of species
change in set of conditions
if ecosystem supports few species
low diversity in species adapted to extreme environments since they are not suitable conditions
migration
more availability food
more complex food webs benefits farmers
variety of predators that feed on crop pests
competition types
inter = diff species intra = within species
what limits size of pops in climax community
nutrient availability no. producers providing energy light affects photosynthesis diseases kill weaker organisms spaces for habitats competition for light
soil nitrate conc increases over time
increase in decomposition of species
increase nitrification
conservation of greenland
made up of species X
species Y outcompetes species X
species Y in removed
increase in index of diversity
why?
incr in no. species and no. organisms in species
initial environment = hostile
organisms change environment
incr niches
incr species
fishing at different depths
less interspecific competition for food
weird graph with eh correlation
ranges overlap? not a sig factor SO other factors involved
correlation not causal
chemical agent incr the population
pests were resistant
they reproduce and this pop increases
respiration experiment - same temp
enzymes
respiration
‘U’ TUBE EXPERIMENT
seeds in flask and NaOH which absorbs CO2…
… coloured liquid went down
no change with anaerobic respiration
O2 taken up by seeds
CO2 absorbed
decrease in pressure
no oxygen taken up no pressure change
GPP highest in hot temp
Why is NPP lower in high temp?
high temp = increase respiration rate
increase in respiratory loss
NPP = GPP - R
extra nutrients
growth or fat stores
mean expenditure energy higher in cold month
more energy lost in march to maintain body temp
no oil on birds SO energy used to maintain body temp
How this affects breeding?
more energy used for other process
less energy available for breeding
less successful breeding
sample randomly
avoid
representative data
allow stat tests
correlation coefficient
null hypothesis
negative value
looking for correlation between two variables
no correlation between X and Y
negative correlation
cutting and burning forests and CO2 conc
conc increases
cutting - less photosynthesis so no removal of CO2
burning - combustion produces CO2
