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Human footprint – A measure of the human influence globally

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

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Human footprint – A measure of the human influence globally

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  1. Human footprint – A measure of the human influence globally

  2. 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

  3. 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%

  4. 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

  5. Extrinsic or Intrinsic Value

  6. Species Introductions • Same risk whether intentional or not • New ecosystem and may fail to establish • When successful, have a selective advantage • Competition • Predation (ability, avoidance Purple loosestrife

  7. 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

  8. 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

  9. 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

  10. Newest addition to the List Snuffbox mussel – Epioblasmatriquetra

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