Ecology & the Environment Flashcards
(21 cards)
Population
Group of organisms of the same species in same area at the same time
Community
Multiple populations living in the same area
Ecosystem
Interaction between a community and the non-living parts if the environment
Investigating Population (2 areas)
Use quadrats to estimate the abundance
Random generator to create a set of coordinates in the area you have chosen.
Total area/area sampled x total number of plants counted
Biodiversity
the range and variety of different species of organisms within an ecosystem
- Food
- Shelter
- Maintenance of the physical environment
High biodiversity ensures the stability of ecosystems
Investigating the distribution of organisms
X
Abiotic Factors
non-living factor within an environment
- Light intensity
- Temperature
- Moisture lvels
- CO2 levels for plants
- Ph and mineral content
Biotic factors
Living factor in the environment
- Availability of food
- New predators
- New pathogens
- Competition
Trophic Levels
1: Producers
2: Primary consumers
3: Secondary consumers
4: Tertiary consumers
Pyramids
Easy
Transfers of energy along a food chain
Sun enters first trophic level when producers convert light energy into chemical energy
- Primary consumers eat producers breaking down the carbon compounds within their biomass
- Secondary consumers eat primary consumers and so on
Some energy and substances are lost to the environment between trophic levels
Energy loss between trophic levels
Only around 10% of the energy available at each trophic level is converted into biomass
This is why food chains are short, energy becomes too small to support another trophic level
Explaining energy loss from food chains
Energy may be lost from food chains as consumers aren’t able to digest and absorb all the chemical energy stored in food organisms
Both cycles
X
Effects of Air Pollution
CO pollution (carbon monoxide) as it binds to haemoglobin reucing oxygen transport in blood
SO2 (sulfur dioxide) combines with water vapour to form acid rain, damaging plants, aquatic life, and soil. (respiratory problems in humans)
Greenhouse gases
- CO2
- Water vapour
- Methane
CO2 is produced during the combustion of fossil fuel
Methane is produced by cattle as they digest grass and release by rice paddy fields
Enhanced Greenhouse effect
- The sun emits rays that enter the Earth’s atmosphere
- The heat bounces back from the Earth’s surface and some heat is reflected back out of space
- Some heat is absorbed by the greenhouse gases and is trapped within the Earth’s atmosphere
Consequences of global warming
Ocean temperatures increasing, Increasing temperatures, changes in or loss of habitats, decreases biodiversity as food chains are disrupted, increases in migration
Effects of Eutrophication
- fertilisers are high in nitrogen, an essential mineral for plant growth, so this can result in the overgrowth of aquatic plants and algae at the water surface
- aquatic plants below the surface die due to reduced light levels, and are broken down by decomposers
- decomposers increase in number and the increased respiration of these organisms uses up oxygen in water, reducing dissolved oxygen levels
- the water no longer contains enough oxygen to support other organisms, so many aquatic organisms die.
Effect of Sewage Pollution
This occurs when sewage is washed into waterways
- Sewage can cause an increase in growth of aerobic bacteria
- These bacteria reduce the availability of dissolved oxygen in water
- Aquatic organisms that are sensitive to oxygen levels die, leaving only organisms that can survive at low concentrations of oxygen
- The aquatic ecosystem decreases in biodiversity
Deforestation
Clearing of trees on a large scale
Effects of deforestation:
Leaching - Soil minerals are not taken up by trees and are instead washed away by rain into nearby bodies of water
Soil erosion - Soil is not held together by tree roots and organic matter, so is more likely to be washed away
