o level notes on effect of human activity on ecosystem

 
  Home  |  Add to Favourites  |  Feedback  |  Help


 



 

   

Human Impact on an Ecosystem

Conservation

Conservation is positive care management of the environment to maintain biodiversity.

Involved Activities:
preservation of ecosystems
restoration of spoilt habitats
balanced use of resources
the safeguarding endangered species
Example of Conservation Practice  (only one example required)

Set-aside in Agriculture
Farmland - a commercially managed habitat
Reduced species diversity, low population of native species
Set-aside - agricultural activity suspended in part of the farm
‘Return to nature’ and/or reintroduction of ‘lost’ species
Natural community re-established

Pollution

Pollution is any human activity that contaminates any part of the biosphere with substances that degrade or harm the natural community.

Pollution also threatens

human health
food production
supply of natural raw materials
restricts recreational activities
future generations are denied their right to a wholesome planet
Pollutant: a substance made during human activity in a quantity that harms the natural environment.

Sulphur Dioxide - an example of a pollutant (only one required)

Main Source: fossil fuel burning.
Converted to sulphuric acid in the atmosphere.
Pollution of land and water habitats by ‘acid rain’.
Increased acidity of soil and water - plant and animal life directly inhibited.
Soil Problems - less fertile.
Toxic metal levels increased.
Reduced mineral recycling due to decline in the populations of bacteria and fungi.
Aquatic Habitat Problems
Acidification kills algae and bacteria.
Insect and fish life decline.
Ultimately - lifeless lakes.
Terrestrial Plant Problems
Damages cell membranes and destroys chlorophyll.
Weakens plant’s immune system - greater disease damage.
Human Health Problems
Lung and breathing trouble.
Metal contaminated drinking water can cause nervous system difficulties.
Building Damage

Stonework, mortar and metalwork attacked.
Sulphur Dioxide Control
Burn natural gas instead of coal, oil or peat.
Remove sulphur dioxide before the waste gases are released.
Greater use of renewable energy sources and nuclear power.
Less use of the car - greater use of public transport.
Spread lime - reduces soil and water acidity.
Fossil Fuel Burning - an example of one human polluting activity. <SSH> (only one required)

Acid Rain
sulphur dioxide causes two thirds of the problem
nitrogen oxides causes the remainder of the problem
Carbon Dioxide - suspect in ‘Global Warming’ (enhanced Greenhouse Effect)
Carbon dioxide levels have risen by almost 30% since Industrial Revolution.
Carbon dioxide is a ‘greenhouse gas’.
Atmospheric temperature has been increasing.
Is carbon dioxide a major factor in ‘global warming’.
Suspected effects of ‘global warming’: sea level rise, climate change, increased
desertification, less agricultural land, plant and animal distribution changes.
Smoke: huge mass of tiny carbon particles.
Reduce photosynthesis - less light and blocked stomata.
Human health - lung damage.

Role of Micro-organisms in Pollution Control

Organic Waste (i.e. human sewage and farm slurry.)

Organic waste is food and nutrient source for bacteria and fungi.
Increased use of special ‘fermenters’ for household, district and city waste.
The natural gas produced can be used as an energy source.
Waste reduced to by 98% i.e. 2% of original mass.
Oil Spillage: bacterial decomposition of oil, speed up by inoculating the oil.

Bioremediation: bacteria and fungi can be used to decontaminate soil and groundwater of pesticides, metals and even radioactive materials.


Waste Management

Major Problems
Large volume: domestic (2 mt), agricultural (22 mt), industrial (6 mt) in Ireland. {mt = million tonnes}
Disposal: landfill, recycle, destroy or convert to other uses.
Landfill Difficulties
Local groundwater polluted.
Current sites almost full – strong local protest against new sites.
Incineration Difficulties

Atmospheric pollution - local and regional.
Strong local protest against placing an incinerator in their area.
Possible pollution of ground water.
Waste Minimisation
Much better than waste disposal.
Packaging makes up 50% of domestic waste and is easy to reduce.
New uses for materials previously dealt with as waste e.g. much slurry now use as organic fertiliser; fish waste used as poultry or pig feed; forestry waste now converted to sawdust for processed wood.
Recycle: multiple uses - glass bottles, metal cans, and paper.
Role of Micro-organisms in Waste Management

Breakdown of domestic and agricultural organic waste by bacteria and fungi.
Purposely designed treatment tanks are used for aerobic and anaerobic decay.
Kitchen organic waste can be broken down in a ‘compost bin’ for garden fertiliser.
   
  Copyright © 2008 Intel Corporation Contact us | About skoool | skoool Awards | About Supporters | Terms of Use | Privacy & Security