Population Size & Ecosystem Flashcards
What is definition of population?
A group of organisms of the same species
What is the definition of community?
All of the organisms of all species in an ecosystem
What is an habitat?
Place an organism lives
What is an ecosystem?
A community and the non-living parts of its environment together form an ecosystem
What is primary succession?
The change in structure and species composition of a community over time in an area that has not been previously colonised
What are the seral stages?
Pioneer stage (lichens)-> mosses-> grasses-> herbaceous plants-> shrubs-> climax community (trees)
What is climax community?
-A stable self perpetuating community that has reached equilibrium with its environment and no further changes occur
-animal diversity is at its peak and includes verts and invertebrates
-plant diversity can decrease slightly if light is blocked by tree canopy
What is a disclimax?
Disruptive climax is when human activity maintains a stable community and can prevent the formation of a climatic climax community
What is the carbon cycle?
The carbon cycle is the way carbon moves through the Earth’s atmosphere, living things, and the environment:
1. Carbon in air: Carbon is in the air as carbon dioxide (CO₂). 2. Plants absorb it: Plants take in CO₂ during photosynthesis and make food. 3. Animals breathe it out: Animals eat plants and release CO₂ when they breathe. 4. Decomposition: When plants and animals die, decomposers break them down, releasing carbon. 5. Oceans and rocks: CO₂ is absorbed by oceans and can get trapped in rocks. 6. Fossil fuels: Dead plants and animals turn into fossil fuels, and burning them releases more CO₂.
This cycle helps keep carbon moving through the environment.
What are detritivores?
Animals with a tube gut that feed on dead organic materials e.g woodlice
What are saprophytes?
Fungi & bacteria that carry out extracellular digestion of the organic material
What is a niche?
An organisms role in the ecosystem is its niche, this applies particularly to its feeding role
What is photosynthetic efficiency?
The ability of a plant to absorb light energy
What is the equation for photosynthetic efficiency?
PE: quantity of light energy incorporated into product / quantity of light energy falling on plant X 100
PE is usually really low = 1% - 8%
What is primary production?
The production of new organic matter/biomass in producers (autotrophic)
What is gross primary production (GPP)?
The rate at which light is absorbed to fix CO2 into molecules is the gross primary production
What is net primary production?
-photo autotrophs use some of these organic molecules up in respiration
-what remains is the NPP
-this is the plant biomass that is available to be consumed by the next trophic level
GPP - respiration = NPP
What is secondary production?
The production of new organic matter/ biomass in consumers
What is the equation of energy transfer?
EET= energy available after transfer/ energy available before transfer X 100
What is equilibrium species?
Where the control of their population is by competition within a stable habitat
What is carrying capacity?
The maximum population size that can be sustained by a particular environment
What are the factors that affect population size?
-Artificial situation e.g bacteria in flask
-> available food, overcrowding
-natural situation e.g birds on an island
-> predation, parasites
What are biotic factors?
Biotic factors are living and use parts of the environment of an organism
What are abiotic factors?
Abiotic factors are non-living parts of the environment of an organism
