Ecosystems Flashcards
(15 cards)
What is an ecosystem?
A community of plants and animals interacting with each other and the environment in which they live.
What is a biomass?
A term for all living plants and animals in an ecosystem.
First tropic level
Consists of plants (producers) who produce their own food.
Second tropic level
Herbivores consume the plants from the first level.
Third trophic level
The smaller carnivores (meat eaters)
How is energy lost?
Through respiration, heat, excretion and non consumed elements eg bones.
What are detritivores
Are consumers that act to decompose dead organic matter eg bacteria and fungi.
What happens during a Nutrient cycle
Nutrients leave the biomass stop and fallout into the litter store.
DOM broken down by decomposers , decay into soil store.
Transferred by uptakes into the biomass store.
What factors affect the rate of nutrient transfer?
Climate
Soils
Vegetation type
What is plant succession?
The processes of the change over time in the plants in an ecosystem.
Where does a succession begin?
With colonisation, until plants invade and begin to grow on bare rock or soil (pioneer species)
Plants replace one another called serial stages.
Then finally it reaches its climatic climax - vegetation has reached a balance with environment.
Processes of environmental change
Plants most adapted to environmental dominate.
However they tend to modify it, improving soil- adding DOM,increasing depth,adding moisture & changing the PH.
Improve the micro climate , reducing ground wind speed & sheltering the soil. Reducing evaporation and temperatures.
As the soil and microclimate is less harsh , more plants can grow ( serial stage).
Changes during a succession
Soil
Depth increases Humus increase Moisture increase Stability increases PH decreases Colour darkens
What are the changes to Plants
Biomass and plant longevity increases.
Species diversity increases.
Stratification.
What is a plagioclimax?
The vegetation community that is found when human activities interfere with the natural sequence of succession and prevent it from reaching its climatic climax.
