Ecology and Environment Flashcards
Define a Habitat
The place where an organism lives (field)
Define a Population
All the organisms of one species in a habitat
Define a Community
All the different species in a habitat
Define a Ecosystem
All the organisms living in a particular area and all the non-living (abiotic) conditions (temp,climate)
Investigate the population size of an organism
- Place 1m^2 quadrat randomly in area
- Count organism cover in quadrat
- Repeat the experiment 10 times
- Work out average of all calculations
Define Biodiversity
Variety of different species of organisms on Earth or within an ecosystem
How do Abiotic factors affect communities
- Environmental conditions - light intensity (plants) , moisture level and soil pH
- Toxic chemicals - Excess fertilisers in lakes cause eutrophication = death of organisms
How do Biotic factors affect communities
- Availability of food
- Number of predators
- Competition
Define a Producer
Make their own food using energy from sun (food chain start with a producer)
Arrangement of a Food Chain:
- Producer are eaten by primary consumers
- Primary consumers eaten by secondary consumers
- Secondary consumers eaten by tertiary consumers
Define Decomposers
- All of food chain eventually die and eaten by decomposers
- Decomposers break down dead material and waste
Why is only 10% of energy transferred from one trophies level to another?
- Some parts of food not energy or excreted
- Used for staying alive (respiration)
- Transferred to surroundings by heat
What is the Carbon Cycle
- Plants and animals decompose, they broken down by microorganisms (bacteria)
- Microorganisms = Decomposers
- Decomposers release CO^2 back into air by respiration
What is the Nitrogen Cycle
- Decomposers -turn nitrogen to ammonia
- Nitrifying bacteria-Turn ammonium ions in decaying matter into nitrates
- Denitrifying bacteria-Turn nitrate back into N^2 gas
How is Acid Rain caused?
- Burning of fossil fuels releases CO2 and sulfur dioxide (coming from sulfur impurities) into the atmosphere
- When gas mixes with rain clouds it forms dilute sulfuric acid
- This then falls as acid rain
- Internal combustion engines in cars and power stations are main cause of acid rain