Paper 3 Flashcards
Define community
group of populations, living together and interacting with each other in an area
What is the law of tolerance?
The distribution of the species in an ecosystem is determined by the limits of physical and chemical factors that can be tolerated
Define keystone species
Species that has a disproportionate effect on the structure of an ecological community
Eat exerts a top down influence on lower trophic levels
Prevent lower traffic levels from monopolising critical resources
Define niche
The unique role a species plays in a community
What is a fundamental niche?
The potential mode of existence of a species, given its adaptations
What is a realised niche?
The actual mode of existence, which results from its adaptations and competition with other species
Describe the symbiotic relationship between zooxanthellae and Coral
Coral provides algae with a protected environment, and compounds they need for photosynthesis
The algae provide coral with oxygen , help with a waste removal, and supplies, coral with glucose glycerol, and amino acids
What does the competitive exclusion principle state?
No two species can occupy the same niche for extended periods of time
One species will have an advantage over the other
The less well adapted species will struggle to survive and reproduce
The less well adapted species will be eliminated
Define food chain
A linear sequence, showing feeding relationships and energy flow between species each of which feeds on the previous one
What are pyramids of energy?
Show the flow of energy between trophic levels
Measured in units of energy per unit area per unit time
Define biomass
The total dry mass of organic matter in organisms or ecosystems
What is the food conversion ratio?
A measure of an animals efficiency in converting feed mass into the desired output
Mass of food eaten divided by desired output
Define ecological succession
The predictable and orderly changes in composition of an ecosystem over time
Define primary succession
The emergence of an entirely new ecosystem
Define secondary succession
The replacement of one ecosystem by another following environmental change
Define biome
A geographical area that has particular climate and sustains a specific community of plants and animals
Define biosphere
The total of all areas were living things are found
Define climograph
A diagram which shows the relative combination of temperature and precipitation in an area
What are Gershmel diagrams?
They show the differences in nutrient flow and storage between different ecosystems
What are the sinks for nutrient storage in Gershmel diagrams?
Biomass
Litter
Soil
What are the nutrient inputs of Gershmel diagram?
Nutrients dissolved in raindrops
Nutrients from weathered rocks
What are the nutrient outputs from Gershmel diagrams?
Nutrients lost through surface run-off
Nutrients lost through leeching