Causes of Biodiversity Loss

Environmental Resource Management

Development• As population grows,

landscape changes• Settlements are growing into

megacities• Land uses are changed• Rivers are dammed or diverted• Modern agriculture & forestry

techniques displace plants

Biotechnology• Humans are now breeding new

species in a lab• Some new breeds of plants

and animals have been helpful• Scientists now creating new

life forms with unknown effects• New species modify habitats

and destroy other species• Research is expensive

Genetic Modification

• The total area of land around the world sown with genetically engineered crops increased 25 times between 1996 and 2000. A dramatic slowdown of this rate from 40% to 11% in between 1999 and 2000 may reflect public concern about the risks of these crops.

Use of Fossil Fuels• Combustion of oil, natural gas,

coal, and by-products like propane and gasoline pollute the air and increase the greenhouse effect

• CO2 content has increased more than 30% and methane content has increase 145% since pre-industrial times

Use of Fossil Fuels

Pollution• Wastes, gases, and toxic

chemicals from industry, energy production, sewage, fertilizers, transportation, and pesticides contaminate the air, soil, and water resources

• Contaminants are absorbed into the plants and animals

• We then eat those species!

Exploitation• Commercial and recreation

(fishing and hunting) overkill of a species

• Public demand for tropical hardwoods remains high

• Some animals seen as vermin or a threat, some used for “alternative medicine”

Poverty• Globalization puts pressure on

countries to build their economies – at the expense of their environments

• National debts in developing countries are often paid by clear cutting or cash crops

• Local dependence on the land is therefore even harder

“UN Environment Chief Targets Poverty”

• UNEP says the rich world is not doing enough to make sustainable development a realistic goal for every country.

• "The fundamental constraint to achieving sustainable development is social inequality and its associated evils: poverty and ignorance."

Bio-invasion• Invasive species are ones that

are not native to a particular ecosystem

• Pose threats to native species through competition for food

• Some “hitchhike”, others are intentionally introduced

• “Introductions, like extinctions, are forever.” Ellen Marsden

Life Out of Bounds• “Bioinvasion – the spread of

alien, "exotic" organisms – is gnawing away at ecosystems all over the world, largely unnoticed and unopposed.

• “The continuing increase in travel and trade around the globe is fostering the spread of more and more invaders of almost every conceivable description.”

Policies• Governments want to

encourage development, but are not ecologically based

• Lack of property rights and corrupt governments mean less interest in taking care of the resources

• Effective environmental protection laws are scarce

Policies

So, for final exam review the following with regard to Causes of Biodiversity Loss of Natural

Resources

• Development• Biotechnology• Use of Fossil Fuels• Pollution• Exploitation• Poverty• Bio-invasion• Policies