Biology 141 Lewis & Clark College

Habitat Degradation

K.E. Clifton

A variety of human activities induce changes to ecological landscapes:

Pollution

Invasive species

Habitat alteration or destruction

Over exploitation of species

Pollution: what is it and what isn't it?

Non-human "pollution": natural patterns of waste production and removal.

Anthropogenic (human caused) pollution:

The distinction between bio-degradable and non-biodegradable pollutants.

Biodegradables can be reabsorbed or converted within natural ecosytem function.

Many biodegradable compounds become toxic at high concentrations

Increasing nutrients and eutrophication.... too much of a good thing.

Non-biodegradable pollutants are hard to get rid of.

Bio-amplification.

Natural: red tides and resultant toxins (e.g, brevetoxins)

Human caused: DDT

 

Common pollutants and their consequences.

Emissions resulting from energy use:

global warming (next lecture)

acid rain

CFC's and ozone depletion

Pesticides and Herbicides: DDT, Atrazine, PCB's

Human waste:

Portland's combined sewer system has mostly been fixed, but raw sewage still gets dumped directly into the Willamette river during big rains.

Solid Waste/Garbage: where to put it?

Land fills

The ocean

Burn it

Recycle it

Managing waste

Sustainable agriculture

Bio-control.

Other management/remediation strategies