Structure and Functioning of Ecosystems Flashcards
What are the biotic and abiotic elements that an ecosystem relies on?
Biotic - plants, animals and microorganisms
Abiotic - non-living chemical and physical features.
What is a trophic level?
A feeding level occupied by a particular type of organism within an ecosystem.
What are autotrophs?
Primary Producers
What are heterotrophs?
Consumers
What are saprotrophs?
Decomposers
What is the only significant energy source for ecosystems?
Radiant energy from the Sun.
What are the 5 trophic levels?
L1 - primary producers
L2 - primary consumers (herbivores)
L3 - secondary consumers (carnivores)
L4 - tertiary consumers (omnivores
L5 - apex predators
Why does biomass decrease with each successive trophic level?
Energy is lost at the transfer between stages through respiration and decay. The size of the organisms generally increases up the trophic levels, but the number of organisms sustained decreases.
What is a tropical rainforest Gersmehl diagram like?
It represents an active nutrient cycle with a large above-ground biomass store. The litter store is small because of rapid decomposition, and the small nutrient store is a result of rapid leaching due to heavy precipitation.
What is a northern coniferous forest Gersmehl diagram like?
Represents a poor nutrient cycle with slow replenishment and a small biomass store due to cold conditions inhibiting growth and biodiversity. Cold, acidic conditions inhibit the breakdown and decay of litter. Cold conditions also inhibit weathering so there is a small nutrient store in the soil.
What is Primary Productivity?
The rate at which energy in an ecosystem is converted into organic matter.
What is Gross Primary Productivity?
A measure of all photosynthesis in an ecosystem.
What is Net Primary Productivity?
The amount of energy fixed in photosynthesis minus the respiration cost.
