Chapter 9: Sustaining Biodiversity

Fossil record shows evidence of extinction as a natural process:

• background or natural rate of extinction: loss of species at a low rate

• mass extinction : widespread extinction of large numbers of species

• 5 mass extinctions in the past (last one was 65 million years ago

• Causes of mass extinctions: abrupt climate changes, such as a meteorite impact event

Extinction

The real reason dinosaurs went extinct

• Species are becoming extinct ___________________ times faster than they were before modern times. • By the end of this century, the extinction rate is expected to be 10,000 times the background rate. • Conservative estimates of extinction = ______________ Growth of human population will increase this loss E.O. Wilson estimates that if 1% extinction rate, 1/2 of all species will be gone by 2100

Are Humans Causing a Mass Extinction?

Endangered Species:

Species that has so _____ individuals that the species could soon become extinct over some or most of its natural range.

Threatened Species:

Species that is still relatively abundant, but because of __________________ is likely to become endangered in the near future.

Threatened & Endangered Species

Percentage of Various Species Threatened

with Premature Extinction

Worldwide about 25% of mammals are at risk of extinction.

The highest percentages at risk are:

apes & monkeys (______)

moles & shrews (______)

antelopes & cattle (______)

Threatened & Endangered Species

Tasmanian Tiger (extinct)

Estimates from the IUCN (International Union for Conservation of Nature)

• economic & _______________ importance

• scientific & ______________ importance: ecological services include nutrient recycling, watershed value, production of oxygen, moderating climate, & detoxifying toxic substances

Bioremediation: To solve (remedy) an environmental problem using a living thing.

• ______________ & recreational importance

Why Preserve Wild Species?

http://www.youtube.com/watch?v=8shr4ZTI5pY

http://permaculturenews.org/2014/04/10/bioremediation-industrial-pollution-utilizing-fungi-bacteria-plants-reduce-oil-pollution-ecuadorian-amazon-basin-world/

HIPPCO •____________, fragmentation & degradation

•I_________ (nonnative) species •P____________ and resource use growth

•P____________ •C_________________ O___________________

(poaching, overfishing etc.)

Causes of Extinction & Depletion

•Indian Tiger

•Black Rhino

•African Elephant

•Asian or Indian Elephant

1. Habitat Loss/Fragmentation

Former Range

Current Range

Most Serious Threat to Biodiversity

Habitat Fragmentation Reduces Genetic Diversity in a Population

Area preserved for wildlife refuge must have adequate population size for genetic diversity

Why is Genetic Diversity Important? Improves odds that members of population will be

able to survive _______________________ http://evolution.berkeley.edu/evolibrary/article/_0_0/agriculture_02

Managing populations of waterfowl is difficult:

• Birds need ___________ for habitat (places along whole route

• Wetlands are critical, yet are quickly disappearing

• Requires _____________ efforts to protect habitats along the flyways.

Habitat Loss and Migratory Birds

2. Introduction of Invasive Species Introduction can be either deliberate or accidental Nonnative species may have no natural

•_____________ •_____________ • ____________

Examples: Kudzu in Southeastern US (deliberate)

Zebra Mussels in the Great Lakes (accidental-Ballast water)

Zebra Mussels Kudzu

2. Invasive Species • Once a species is introduced to

an area, it is difficult to “turn back the clock” and eradicate it.

• The more time before control measures are taken, the less likely the efforts will succeed.

2. Invasive Species Ballast Water: Accidental

Shipping Routes

Biological Control Gone Bad In the 1930’s cane toads were introduced into

Australia to control beetle populations that was devastating the cane sugar crop.

Cane toad did not control the beetle population, yet its population grew exponentially in Australia.

Cane Toads are poisonous, and are able to outcompete many native species.

3. Population Growth and Resource Use

4. Pollution Pacific Ocean Garbage Patch

4. Pollution Bee colony collapse syndrome •Honeybees responsible for 80% of insect-pollinated plants, including many important crops like apples, almonds

•Dying due to… • Pesticides? • Parasites?

5. Climate Change

Case Study: Overfishing

Major commercial fishing methods. Modern methods enable increasing harvest of decreasing populations.

6. Overexploitation

Overfishing: Whales 6. Overexploitation

Prior to 1986, overharvest drove _____ major whale populations to commercial extinction. Populations are in process of recovering since the 1986 International Whaling Ban.

• low ____________________(e.g., blue whale, California condor)

• specialized ___________(e.g., giant panda)

• feed at high ___________(e.g., Bengal tiger)

• large _______ (e.g., Asian elephant)

• limited ____________(e.g., green sea turtle)

• limited __________ (e.g., woodland caribou)

Characteristics of Extinction–Prone Species:

• fixed _____________ patterns (e.g., whooping crane)

• preys on ________________ (e.g., timber wolf)

• small _______________(e.g. endemic island species)

• commercially valuable (e.g. rhinos for horns)

• behaviors that contribute to extinction (e.g., Carolina parakeet- flocks hover over injured bird.)

Characteristics of Extinction–Prone Species Cont.

Why are top consumers more vulnerable to extinction?

•Must be ________________ by a large amount of producers/lower consumers.

Much of energy consumed is given off as heat.

Therefore, there is less energy available for higher trophic levels (animals higher in the food chain).

• Harmful concentrations of toxins get stored in body tissue such as fat.

• Due to the energy pyramid, toxins get _______________ up the food chain.

________________

Top Consumers also suffer from:

Worldwide Extinctions

Biodiversity Hotspots

Protecting Biodiversity Two approaches to species protection:

• ________________ approach: aims to preserve balanced populations of species in their native habitats; advantage: it focuses on protecting sufficient land to protect ecological integrity & provide habitat for the majority of wild species;

• ___________ approach: based on identifying & protecting endangered species on a case– by–case basis; advantage: it identifies which species are at greatest risk & focuses attention on those species.

• consensus among conservation biologists is that protecting biodiversity requires both approaches

International Treaties on Biodiversity • 1975: Convention on International Trade in

Endangered Species (CITES) – Signed by _______ countries – International trade regulation for endangered

species. For example- ban on ivory trade.

• 1992: Convention on Biological Diversity (BCD) – Focuses on ecosystems – Ratified by _______ countries (not the U.S.)

Example of an issue for consideration by CITES: International trade of rhino horn is banned by CITES, but due to the high price of rhino horn poaching is a persistent problem. The next CITES delegation will consider whether to allow farming of rhino for their horns. Discuss pros and cons of this strategy:

• Pros- creates source of horn without killing of wild rhinos.

• Cons- hard to determine source of horn and could facilitate the sale of horn from wild sources.

Farming of crocodiles for their skins helped to preserve wild crocodile populations.

World Protected Areas

The Good News: More land is being protected over time

Unlike traditional parks & reserves, biosphere or nature reserves recognize local people's needs for access to sustainable use of resources in parts of the reserve.

Protecting Biodiversity

• ____________________________________(NMFS) charged with protection of marine species;

• _________________________charged with listing & protection of all other species;

Protecting Wild Species in the United States Endangered Species Act (ESA) of 1973 requires listing & protection of endangered & threatened species in US.

Government Agencies Involved:

California Condor

Florida panther

Success Story: Bald Eagle

U.S. Wilderness Areas • US Wilderness Society estimates that a

wilderness area should be at least _________ in order to be protected from human activity.

• About _______of US land area is protected as wilderness: ¾ is in Alaska

• About _______of land area in lower 48 states is protected

• _______ wilderness areas in lower 48 states: only ____ are larger than 4,000 km2

• About 400,000 km2 (150,000 mi2) of public lands could still qualify as wilderness areas, but strong opposition to setting these lands aside exists from timber, mining, ranching, energy, and other interests