Living Flashcards
Define an ecosystem
An ecosystem is a community of plants and animals that interact with the one another and their physical environment.
What sizes are ecosystem
Local - a pond or under a dead log
Regional
Global - tropical rainforest. Also called biomes
What happens at each level of the food chain the number of individuals ____________.
Why?
Declines
This is because not all individuals in any trophic level are consumed (eaten). This means not all energy is passed up to the next trophic level.
Name a small scale ecosystem
A freshwater pond
Pond producers:
Turn sunlight into energy
Plants- marsh marigold, water lily
Pond consumers:
Water boatmen, Great diving beetle, small fish (stickleback), Frogs, Heron, Dragonfly, Kingfishers
What is soil?
Soil is the top layer of the earth that is composed of disintegrated rock particles, humus, water and air.
What is litter?
Litter is organic matter in and on the soil, it includes humus and leaf litter.
What is biomass?
Biomass is the total mass of living organisms, mainly plant tissue, per unit area. It is a store of energy and is also known as standing crop.
What is the nutrient cycle?
A nutrient cycle is the movement and exchange of inorganic and organic matter back into the production of matter.
Where does nutrient cycling happen rapidly?
Why?
Tropical rainforests
Hot and wet
Impacts of components of an ecosystem
Example
If any component within an ecosystem is changed it will have a knock on effect on the rest of the ecosystem.
Yellowstone National Park in the USA, reintroduced wolves in 1995.
16 packs of grey wolves introduced. Each pack kills one elk a day. More kills by wolves = more food for scavengers Reduction in predation from coyotes leads to increase in mice and voles
Elk population falls from 20,000 to 10,000 in 8 years.
Reduction in grazing pressure.
Aspen and cottonwood regenerate. There is more tree cover. Increase in bank side trees stabilises river banks so there is less erosion. More woody debris in rivers creates pools and trout habitats
Competition from wolves results in decrease in coyote population.
Reduction in grazing pressure. Aspen and cottonwood regenerate. There is more tree cover.
Tropical rainforests occur..
..Along the equator
Constant 25-30°C
250mm rain per month
Deserts occur..
..15-30°
Over 30°C
Less than 300mm per year
Deciduous forests occur..
..30-60°N
500-1500 rain per year