Habitat Loss Orange County, California. Desertification Desertification is the conversion of...

Habitat Loss

Orange County, California

Desertification

• Desertification is the conversion of grassland and savanna habitat into relatively sparse, unproductive vegetation

• The main cause of desertification is overgrazing by livestock

RioPuercoBasinNM

Rio Puerco Basin

1885 1977

Rio Puerco Today

Overgrazing – Texas and England

Left good, right overgrazed Left good, right overgrazed

Wetlands

• Wetlands are lands that are transitional between aquatic and terrestrial ecosystems

Freshwater Wetland Types

General Locations of U.S. Wetlands

Crane Species

• 1. Eurasian Crane, 2. Black-necked crane, 3. Munktrana,

• 4. Sandhill Crane,

• 5. Whooping Crane, 6. Japanese crane, 7. White-naped Crane, 8. Sarus Crane, 9. Australian Crane, 10. Siberian Crane, 11. Wattled Crane, 12. Demoiselle Crane, 13. Blue Crane, 14. Black Crowned Crane,

15. Grey Crowned Crane

Grey Crowned Crane

Grey Crowned Crane

Habitat Fragmentation

• Fragmentation is the breakdown of a habitat or ecosystem into smaller patches of that habitat or ecosystem that now are isolated from each other

HabitatFragmentation

Island Biogeography

Charles Darwin and Alfred Russel Wallace

The Galapagos

Galapagos Tortoise

Galapagos Mockingbirds

Galapagos Mockingbirds collected by Darwin

Malay Archipelago

Beetles and Moths Collected by A.R. Wallace

Butterflies from Malay Archipelago

Sphingid Butterfly Diversity Malay Archipelago

IslandHabitats inBaltic Sea

Reptile and Amphibian Species Area Curve for Caribbean Islands

Habitat IslandsIn the Great Basin

Bird Species

Mammal Species

Species Area Curve

S = cAz

where:

S = number of species

A = area of island

c = constant for habitat type - forest, desert, grassland, etc.

z = slope of curve

Ant speciesOn NewGuinea andNearbyIslands

Real Slopes for Species-Area Curves

Oceanic islands birds - New Guinea islands z=0.22

beetles - West Indies z=0.34

land plants - Channel Islands z=0.37

Habitat islands birds - Andes paramo z=0.29

birds - mtns of Great Basin z=0.165

mammals - mtns of Great Basin z=0.326

inverts -caves in West Virginia z=0.72

Robert MacArthur and E.O. Wilson - originators of the Equilibrium Theory of

Island Biogeography

Ruffed Grouse by Audubon

Ruffed Grouse – male mating display

Apostle Islands – Lake Superior

Krakatau – before and after 1883 eruption

Aerial photo of Anak Krakatau and Krakatau

Krakatau today

Mangrove islands off the Florida coast

Mangrove Island Close-Up

Dan Simberloff on MandolinNick Gotelli on Guitar

Simberloff’s defaunation experiment on Mangroves

Simberloff’s defaunation experiment on Mangroves

Bracken Fern

Bracken Fern - Australia

Number of species found on Bracken Fern

Picture Winged Drosophila

Picture Winged Drosophila – more than 500 species from 1 ancestor

Picture Winged Drosophila – more than 500 species from 1 ancestor

• http://www.pbrc.hawaii.edu/research_news/

Cichlid Diversity

African Rift Lakes

Cichlids from Lake Tanganyika (left) and Lake Malawi (right)