Topic 10 Ecosystems Flashcards
What is a biosphere?
Volume of the earth’s surface where organisms can be found
What is ecology?
Study of interactions between organisms and their environment
What is an ecosystem?
A community of living organisms interacting with each other and with abiotic components
What are examples of abiotic components?
Light intensity, water, minerals
What is a community?
Populations of all the different species of organisms living in a habitat at any time
What is the definition of a species?
A group of organisms that can interbreed and produce fertile offspring
What are autotrophs?
Producers
Make their own food
Plant and a,gas photosynthesise to produce ATP to make glucose from CO2 and H2O
What are heterotrophs?
Primary or secondary or tertiary consumers
Organisms that eat plant material exclusively
Herbivores or carnivores
What are decomposes?
Final tropic level
Break down animal and plant remains returning nutrients to soil
Why are energy loss along a food chain?
Significant amount of energy dissipated as heat from cellular respiration
Some die without being eaten
Not all dead animal/plant can be digested by consumers
What are issues with pyramids of biomass?
- dry mass has to be taken or estimated
- diff components of biomass have different energy contents per kilogram
- doesn’t take into account reproduction rates and the effect of time/season on relative biomass
What is an advantage of pyramid of biomass?
Amount of energy in trophies level more accurately represented
How to measure pyramids of energy and what’s its unit?
Calorimeter
Kj m-2 yr-1
What are limitations of all pyramids?
-only provide a snapshot view of the ecosystem
- population size fluctuate overtime
- many assumptions built in
How to assess abundance?
- individual counts
- percentage cover
- ACFOR scales (abundance, common, frequent, occasional, rare) (very subjective)
