Threats to Biodiversity

Photo of a forest fragment, surrounded by newly created cattle pasture in Amazonas, Brazil;Photo of a sign on St. Lucia (provided by John Battista, LSU – taken by one of his former students)

Image from Wikipedia

K/T (Cretaceous-Tertiary)Mass Extinction

~ 65 m.y.a.;Ended the reign of

the dinosaurs

P/Tr (Permain-Triassic) Mass Extinction

~ 251 m.y.a.; ~ 96% of all marine species &~ 70% of all terrestrial species

Current mass extinctioncould result in ~ 50% of species

going extinct in 100 years(Wilson 2002)

?

Extinction

Image of Passenger Pigeon (extinct North American bird, once found in Louisiana) from Wikipedia

Extinction

“Martha” – the last living passenger pigeon – died on Sept. 1, 1914 in

captivity in Cincinnati, OH

Image of Dodo (extinct Indian Ocean island bird) from Wikipedia

Extinction

“Not only are species at risk of extinction, but some processes that undergird ecosystem functions, or that are glorious in and of themselves, are put at risk

from human activities...” Groom et al. (2006, pg. 78)

Photo from Wikipedia; For more information on HIPPO, see: E. O. Wilson (2002) The Future of Life

Habitat destruction E. O. Wilson(b. 1929)Invasive species

Pollution

Human Population

Overexploitation

HIPPO

Photos of forest destruction in Brazil & Malaysia

HIPPO

Habitat Destruction & Degradation

Image from Discover Magazine, Jan-Feb 2010 Special Issue, “Top 100 Stories of 2009” –“#92: Nowhere to Hide from the Buzz of Civilization

HIPPO

Habitat Destruction & Degradation

“An ever-expanding network of roads, railways, rivers, and shipping lanes means that only 10 percent of the earth’s surface is now remote, defined as being at least 48 hours away from a major city. More than half of the world‘s

population lives within an hour of a major city…”

Kudzu

SnakeheadWalking catfish

HIPPO

Invasive Species

“Photoshopped” image of airplanes from www.surfersvillage.com

HIPPO

Pollution

NASA image from May 24, 2010 posted on Wikipedia

HIPPO

Pollution

A.D.2000

A.D.1000

A.D.1

1000B.C.

2000B.C.

3000B.C.

4000B.C.

5000B.C.

6000B.C.

7000B.C.

1+ million years

8

7

6

5

2

1

4

3

OldStoneAge New Stone Age

BronzeAge

IronAge

MiddleAges

ModernAge

Black Death —The Plague

9

10

11

12

A.D.3000

A.D.4000

A.D.5000

18001900

1950

1975

2000

2100

?Future

Billions ofPeople

Image from the Population Reference Bureau © 2006

HIPPO

Human Population“More people means more of all the other HIPPO effects” (Wilson, 2002)

Atlantic Cod

HIPPOOverexploitation

Photo from Wikipedia

Habitat destruction & fragmentation

Jared Diamond(b. 1937)

Introduced species

Overkill

Secondary or cascade effects

Jared Diamond’s “Evil Quartet”

Image of shrinking forest cover on Borneo from www.planttreesaveplanet.com

Curran et al. (1999) Science Impacts of logging are exacerbated through

increased frequency of El Niño events

Compounded Effects & Synergies

Erosion of biodiversity in a site often results from multiple causes