Chapter 7 - Ecology Flashcards
What is the water cycle?
The movement of water in a large continuous loop from the sea through the air to land and back to the sea. It is a closed system.
What are the inputs/ways water get into the system?
Precipitation e.g. rain, hail, sleet, snow
What are the outputs/ways water can leave the system?
- Evaporation
- Transpiration
- Evapotranspiration = general term for evaporation and transpiration together
What processes are involved with the water that isn’t in the system?
- Condensation
- Vapour transport
What are transfer/flows of water?
Mechanisms that allow water to move from one place to another
What are the 3 transfer/flows?
- Percolation = water flows horizontally through soil and rocks under influence of gravity
- Run-off = water moving across land
- Groundwater = water held underground or in crevices of rocks
What affects the rate of decay?
- Temperature (optimum for enzymes)
- Oxygen (respiration by decomposers)
- Water (lack=slow decay)
What are detritivores?
Organisms that feed on dead animal/plant amtter. As they feed, they break down matter and increase SA for decomposers Examples: -Maggots -Earthworms -Woodlice
What do dead organisms break down into when they decay?
Minerals and carbon dioxide
How is biogas produced?
The anaerobic decay of waste material - involves anaerobic bacteria
What is biogas made up of?
- Methane
- Carbon dioxide
- Water vapour
- Small amounts of other gases
Where is biogas produced?
- naturally in marshes, septic tanks and sewers
- generators (large tanks) are used for biogas production
What processes are involved in the carbon cycle?
- Respiration
- Photosynthesis
- Decomposition
- Combustion
- Fossilisation
- Food chains
What is a sink of carbon?
Things that store carbon
e.g. fossils, plant matter
What is a source of carbon?
Things that release carbon
e.g. decomposed organic matter, respiration, fossils when used as fossil fuels
What are trigger agents?
Things that trigger the sources
What is biodiversity?
The variety of different organisms on earth or within an ecosystem
Factors that affect biodiversity are:
- Temperature
- Altitude
- Precipitation
- Soil
- Presence of other species
Why is biodiversity important?
Ensures stability of ecosystems by reducing the dependence of one species on another for for food, shelter and the maintenance of physical environment
What human activities reduce biodiversity?
- Deforestation
- Hunting
- Pollution
- Eutrophication (excess nutrients in lakes/rivers due to use of pesticides/fertilisers)
- Collection of species for zoos and research
What are the four air pollutants?
- Smoke
- Carbon monoxide
- Carbon dioxide
- Sulfur dioxide
How is acid rain formed?
Many hydrocarbons contain sulfur impurities and when combusted the sulfur oxidises to form sulfur dioxide. Sulfur dioxide dissolves in water in the clouds to form acid rain.
What are the effects of acid rain?
- Weakens and damages buildings and statues
- Makes rivers too acidic for some aquatic life
- Damages waxy layer on leaves
How is smog formed?
Nitrogen oxides are atmospheric pollutants that can react with other substances to form harmful smog
