A local ecosystem Flashcards
what is abiotic and biotic, give examples:
- biotic: living organisms
plants, animals, fungi, algae - abiotic: non-living
soil, rock, temperature, wind
methods to test:temperature
thermometer, soil and air temp
methods to test: aspect
clinometer, nesting, roots
methods to test: humidity
hygrometer, transpiration
methods to test:wind speed
anemometer, plant growth
methods to test: light availability
light (lux) meter: photosynthesis
methods to test: soil salinity
silver nitrate (drop onto soil sample, see if any white colour forms: meaning salt is present), water/mineral uptake
methods to test: soil pH
universal indicator (sprinkle barium sulphate then few drops of indicator, read the graph), growth restrictions
Compare/contrast- terrestrial and aquatic environment: buoyancy
terrestrial:
- little, from air
aquatic:
- higher
- no gravity/less dense
Compare/contrast- terrestrial and aquatic environment: temperature variation
terrestrial:
- large variation,
- based on sunlight (abiotic)
aquatic:
- stable, doesn’t absorb heat as fast
- poor heat conductor
Compare/contrast- terrestrial and aquatic environment: light penetration
terrestrial:
- easy through the atmosphere
- better, absorbs it better on some surfaces
aquatic:
- 100m+ is black
- poor, only surface is good
Compare/contrast- terrestrial and aquatic environment: strength of natural forces
terrestrial:
- have potential to be more damaging
aquatic:
- more stable
- tornado, volcano, tidal wave
distribution meaning
where a species can be found, a range
abundance meaning
how many individuals are there are at a specific time and area
sedentary meaning
doesn’t move, corals
community meaning
lots of different species
environment meaning
organisms surroundings, both abiotic and biotic
ecosystem meaning
an environment which has living organisms interacting as well as with abiotic features
how to measure quadrats and purpose
lay down random sampling squares, record findings
- a sample of a community
- overall view
- series population density: counting individuals
- percentage cover: where species occupy space
- frequency occurrence of species
how to measure transect and purpose
line of string/tape, record on the line
- useful for the transition of species as environmental conditions change
- investigate gradients eg. zonations
what does quadrats and transects measure:
quadrats:
ABUNDANCE
transect:
DISTRIBUTION
general equation for aerobic cellular respiration
glucose + oxygen –> carbon dioxide + water + ATP
role of respiration in ecosystem
changes glucose to create ATP, useable/chemical energy:
- growth and repair
- movement
- keep organs working
- chemical reactions
- movement of substances in organisms
- synthesis of compounds
role of photosynthesis in ecosystem
- energy needed for all life processes
- changes light energy from the sun into glucose
detail of respiration cycle:
Stage 1: Glycosis
- produces ATP in cell cytoplasm
Stage 2: Krebs cycle
- found in mitochondria, ATP
- expels carbon dioxide
Stage 3: Electron transport chain
- produces most ATP
- expels water
-
population trends: stable/in balance
- where numbers remain constant in an area over a period of time
- assume resources are sufficient to sustain a steady population
population trends: explosion
- number increase dramatically due to more plentiful resources available
(eg. Crown of thorns)
- natural environmental conditions
- human impact: high nutrient run off, phytoplankton
population trends: decreasing
- disease, predation, competition, loss of habitat, human impact all contribute to decline/extinction
eg. northern hairy wombat
- endangered from loss of habitat from farming
- competition with rabbits, sheep, cattle for food
- loss of native grasses
- inbreeding: susceptible to disease
predator-prey relationship:
where one species eats another, is dependent on density, control each others population: equilibrium
factors affecting predator/prey relationship
- size of the ecosystem
- availability of food for prey
- reproductive cycles
- diseases
- seasonal migrations
- summary: all populations depend on births, deaths, emigration, immigrations
relationships:
- predator-prey
- allelopathy: where organism secretes substance with an inhibitory effect on another organism, prevents growth of other plant (eg. casuarina glauca)
- parasitism: external and internal parasite, benefits one, harms the host
- symbiosis:
- commensalism: where one species benefits, no harm to the other
- mutualism: where both species benefit
decomposers:
recyclers: organisms which absorb nutrients from dead tissue or waste products of organisms- returning organic matter to the soil (eg. bacteria and fungi)
detritus/detritivores
detritus: dead plant and animal matter
detritivores: worms, snails which break down detritus to form what is finally consumed by decomposers
trophic interactions:
transfer of energy between levels
food chains:
linear relationship of ONE transfer of energy
- starting from producer,
- arrow showing flow of energy to
- NOT equal energy transfer each time
food web:
network of branching diagram show feeding relationships of all things in an ecosystem or particular area
biomass:
mass of organisms in an area, by units of energy, dry mass
- can be in pyramid form
- energy is lost in each step
adaption
special features adapted to a particular environment:
- general (wings on bird, human fingers)
- specific (humps on camel, burrowing frog skin)
structural adaptations:
- SHAPE and size of features
- (Tazi have large proboscis eyes, see better in dark)
physiological adaptations:
- FUNCTION of structural feature
- (network of blood vessels in paws of red kangaroo, risen and licked to cool down)
behavioural adaptations
- ACTION done by organism, reactions to stimuli
- (lizard lie in sun to warm up, find shelter to cool)
intraspecific, interspecific and competition
- intra: between one species
- inter: between different species
- comp: struggle between organisms for same resource
short term consequence on ecosystem for species competition
- usually one species is outcompeted, decrease in abundance of species
long term consequence on ecosystem for species competition
- less successful may become extinct
- each organism adapts to habit its own niche in the ecosystem
human impacts:
land clearing, habitat destruction erosion salination, desertification species loss and loss of biodiversity depletion of the world's ozone layer global climate change, greenhouse gas emissions
evaluate how human impacts can affect an environment
pros: maintenance, science, species protection, restoration
cons: pollution, habitat destruction, invasive species
discuss how decomposers are vital to ecosystem health
- decomposers: recycle nutrients (making nutrients/minerals available) –> constant supply to other organisms
- reduces the likelihood of diseases –> removal of faeces
- remove dead organisms –> increase diversity
- could cause disease if populations too high
explain how competition can affect a community
intra:
- lead to increase/decrease to population
- changing time spent mating
- tercundity declines longtime
inter:
- greater effect on communities –> flow onto the food web
