ecosystems Flashcards
(113 cards)
community
All the populations of diff species who live in some place at a given time, who can interact w/ each other
ecosystem
all interactions between the living and non-living components in a defined area
simple + complex ecosystem
Simple ecosystem = desert
Complex ecosystem = tropic rainforest
biotic
Living = influences the populations within a community
examples of biotic factors
Predation
Competition (inter-specific) for space, food, water, light etc.
Cooperation between organisms (can be between the same species or different species)
Parasitism
Disease
Camouflage
Mimicry
o A hoverfly is harmless, yet it has evolved body colouring like that of a wasp. This deters potential predators into thinking that it is a wasp and could deliver a harmful sting
abiotic factors
any physical or chemical factor (non-living) that influences the populations within a community
examples of abiotic
- Availability of water
- Light
- Temperature
- Humidity
- Atmospheric composition
- pH
- Salinity
- Soil composition
biomass
mass of living material of the organism or tissue
chemical energy that is stored within the organism or tissue
niche
Role of a particular species
How does low light intensity affect the ecosystem
Plants develop photosynthetic pigments that require less light
Grow larger leaves
Reproductive systems that only work in optimum light intensities
How does temp affect the ecosystem
Temp has the biggest effect on enzymes in the organisms that live in the ecosystem
May trigger migration/ hibernation
Dormancy/ leaf fall/ flowering in plants
Biomass can be measured in terms of:
The dry mass of an organism or tissue (in a given area)
The mass of carbon that an organism or tissue contains
The chemical energy content of the organism when burned in pure oxygen
dry mass
mass of the organism or tissue after all the water has been removed
how can biomass change
biomass of deciduous trees decreases over autumn = lose leaves
biomass sometimes given with units of time as well
shows the average biomass of an organism within a given area over that time period
How are ecosystems organised
trophic levels
Producers in an ecosystem
organism that converts light energy into chemical energy by photosynthesis
autotrophs, chemotrophs and photoautotrophs
Autotrophs
Convert energy from environment into complex organic matter, then are used as respiratory substrates or for growth
Chemo/photoautotrophs
Use light/ chemicals to convert small inorganic molecules into complex organic ones
consumers
Higher/est trophic levels
Feed on complex organic matter made by autotrophs and other organisms and use the products of digestion as respiratory substrates or for growth
why is there max trophic levels
rarely have more trophic levels than quaternary as there isn’t sufficient biomass and stored energy left to support further organisms.
Decomposers
Feed on waste or dead organsims to gain energy by digesting and respiring organic matter
Recycling - returns inorganic ions to the air/soil
Why are ecosystems dynamic
Always changing due to many interlaced intearctions that any small change causes several others–> alters flow of biomass
pyramid of numbers
pyramid of numbers good
- Easy method