Human footprint – A measure of the human influence globally

How and How Much?

• Estimated 83% impacted• How?– Conversion to ag and urban– Filling of wetlands and estuaries

• But, this is largely direct and easily measured indirect impacts– Atmospheric transfers– Ozone hole– No place is completely untouched

Extinction Rate

• Difficult to calculate but can be done• Natural extinction rate 0.0001%– Based on 1 sp./1 million sp./yr

• Based on changes of trackable species in the fossil record

• Can estimate future extinction rates (see Science Focus p. 188)

• Current estimate on rate 0.01 – 0.1%

Types of Extinction

• Local – lost from one part of its range

• Ecological – still present but no longer plays a role

• Biological – gone

• (see Core Case Study @ start of chapter)

passenger pigeon

Extrinsic or Intrinsic Value

Species Introductions

• Same risk whether intentional or not

• New ecosystem and may fail to establish

• When successful, have a selective advantage– Competition– Predation (ability,

avoidancePurple loosestrife

Species Introductions

• New regs make it difficult to intentionally introduce

• Primary reason to introduce – biocontrol

• http://www.invasivespeciesinfo.gov/laws/publiclaws.shtml

Purple loosestrife beetle

Endangered Species Act of 1973

• Amended 1982, 1985, 1988 (Reagan Administration)

• Primary Goal: identify and protect endangered species in the US and abroad

• Determination by: National Marine Fisheries Service (marine), Fish & Wildlife Service (freshwater and terrestrial)

• Determination based on biological factors only

Endangered Species Act of 1973

• Many species in hotspots – unique ecosystems with high biodiversity/imperiled

• Once named, their habitat is protected• A recovery plan must be developed• Amendments allow for some habitat

destruction (habitat conservation plan)• About 1400 species named in US, but TNC

estimates 1/3 of US sp. at risk of extinction

Newest addition to the List

Snuffbox mussel – Epioblasma triquetra