ecosystems Flashcards
ecosystem
a community of animals, plants and bacteria, interrelated with the physical and chemical environment
examples of ecosystem
rock pool
playing field
large tree
entire biosphere of earth
tiny colony of bacteria
components of an ecosystem
habitat
population
community
habitat
the place where an organism lives
population
all of the organisms of one species who live in the same place at the same time
community
all the populations of different species who live in the same place at the same time, and who can interact with each other
niche
the role of each species in an ecosystem
impossible for two species to occupy exactly the same niche in the same ecosystem bc one would outcompete the other
examples of niches
what it feeds on, what it excretes, how it reproduces
competition
when two or more individual share a limited resource
the ‘struggle’ for resources
intraspecific competition
competition between individuals in the same species
interspecific competition
competition between different species
examples of intraspecific competition
food
water
breeding sites
mates
*availability determines size of population
examples of interspecific competition
food
water
breeding sites
factors affecting ecosystems
abiotic
biotic
abiotic factors
any physical/chemical factor that influences the populations
(extreme values –>, species may perform better/worse or even die)
examples of abiotic factors
temperature
ph
light
availability of water
humidity
atmospheric composition
edaphic composition
radiation
salinity
graph showing general effect of abiotic factor on organism activity
abiotic factor can be ph or any variable that has an optimum level and lethal levels are both extremes
graph showing abiotic factors without lethal level at both extremes
abiotic factor - light
greater light intensity = greater rate of photosynthesis, more seeds, higher population , more animal supported
why is soil important for plants
provide minerals needed for growth
provides water
allows anchorage for roots
biotic factors
anything that influences populations that is a result of another organism’s activity (whether it is currently living or has once lived)
examples of biotic factors
predation
disease
competition for food. territory, breeding partners
pollination by insects
seed dispersal by insects
adaptations to biotic factors
dancing before mating to ensure they are same species
dynamic ecosystem
ecosystem that can change
non-living elements change and living grow and die, populations of species rising and falling
types of changes in ecosystems that affect population size
cyclic change
directional change
unpredictable/erratic change
cyclic change
repeat in a rhythm, e.g. tides. predator/prey fluctuations
directional changes
go in one direction, long-lasting. e.g. erosion of a coastline
unpredictable change
effects of lightning/hurricanes
