Chapter 11

Sustaining Biodiversity: The Species Approach

Species Extinction

Local extinction: Ecological extinction: Biological extinction:

Endangered Species: Threatened Species:

30,000 plants and animals are endangered or threatened.

Species Extinction Estimating extinction rate is hard to do.

Extinction can take a long time We only know of 1.4 million species when there

could be 4-100 million. We have little knowledge on most species.

Compare current extinction to fossil records of past extinctions.

Observe how the # of species present increases with size of an area Species-area ratio suggest that on average a

90% habitat loss causes the extinction of about 50% of species.

Fig. 11-4, p. 225

Low reproductive rate(K-strategist)

Specialized niche

Narrow distribution

Feeds at high trophic level

Fixed migratory patterns

Rare

Commercially valuable

Large territories

Characteristic

Blue whale, giant panda,rhinoceros

Blue whale, giant panda,Everglades kite

Many island species,elephant seal, desert pupfish

Bengal tiger, bald eagle,grizzly bear

Blue whale, whooping crane,sea turtles

Many island species,African violet, some orchids

Snow leopard, tiger, elephant, rhinoceros, rare plants and birds

California condor, grizzly bear, Florida panther

Examples

Species Extinction

Effects of human activities on extinction rates. Extinction rate was 0.0001% before

humans 0.01% to 1% now

1% extinction rate would mean at least 1/5 of plants and animals will be extinct by 2030 or ½ by 2050.

Importance of Wild Species Instrumental value

Food crops, fuel wood, lumber, paper, medicines 62% of all cancer drugs were created by

bioprospecting discoveries. Genetic information

Allows species to change with changing environments

Humans use this info for new crops and foods Wild species provide us with ways to learn how

nature works and sustains itself Recreational pleasure

Ecotourism- $500 billion/yr (1 male lion living to 7 will generate 515,000 in tourists dollars in Kenya but only $1,000 if killed for skin)

H.I.P.P.O Habitat loss, degradation and fragmentation

HIPPO: Greatest threat is habitat loss, degradation and

fragmentation Deforestation of the TRF is leading cause Hotspots are very vulnerable

Most national parks and nature reserves are surrounded by damaging logging, mining and industrial activities.

Habitat fragmentation: Block migration routes and cause species population to

decrease in smaller areas More vulnerable to predators, competition, disease and

catastrophic events Increase road kill

H.I.P.P.OInvasive species

2nd biggest cause of extinctions Most species introduced to new areas are

beneficial Crops, cattle, poultry

1 in 7 nonnative species are harmful No natural predators, competitors, parasites,

or pathogens to control population Cost U.S. $137 billion/year ($16 million/hr)

H.I.P.P.OInvasive species

Accidently introduced invasive species Stowaways in aircrafts, ballast water from

tankers, hitchhikers on imported products Comb jellies in black sea have wiped out some

native fish populations b/c the feed on the planktonic larvae

Zebra mussels in Great Lakes have blocked water pipe systems

Fire ants were introduced in Mobile, Al and have caused $600 million/yr damage to crops and power poles.

H.I.P.P.OInvasive species Solutions

Prevent them from being introduced Research to identify major characteristics that

allow species to become successful invaders Increase ground surveys and satellite observations

to detect and monitor species invasions to better predict spreading and future invasions.

Improve inspections of imported goods Identify major harmful invasive species and pass

law banning their transfer from country to country Require cargo ships to discharge their ballast water

or other methods to ride possible invasive species Increase research to find and introduce natural

predators, parasites, and disease causing bacteria and viruses to control populations.

Fig. 11-14, p. 236

• Do not allow wild animals to escape.

• Do not spread wild plants to other areas.

• Do not dump the contents of an aquarium into waterways, wetlands, or storm drains.

• When camping use wood near your campsite instead of bringing firewood from somewhere else.

• Do not dump unused bait into the water.

• After dogs visit woods or the water brush them before taking them home.

• After each use clean your vehicle, mountain bike, surfboard, kayaks, canoes, boats, tent, hiking boots, and other gear before heading for home.

• Empty all water from canoes, kayaks, dive gear, and other outdoor equipment before heading home.

• Plant a variety of trees, shrubs, and other plants in your yard to reduce losses from invasive species.

• Do not buy plants from overseas or swap them with others using the Internet.

What Can You Do?

Invasive Species

Fig. 11-13, p. 236

• Climate similar to habitat of invader

• Absence of predators on invading species

• Early successional systems

• Low diversity of native species

• Absence of fire

• Disturbed by human activities

Characteristics ofSuccessful

Invader Species

• High reproductive rate, short generation time (r-selected species)

• Pioneer species

• Long lived

• High dispersal rate

• Release growth-inhibiting chemicals into soil

• Generalists

• High genetic variability

Characteristics ofEcosystems Vulnerable

to Invader Species

H.I.P.P.OPopulation growth, Pollution and Climate change

Population growth and excessive waste have caused many premature extinctions Pesticides- kill 1/5 of U.S. beneficial

honeybee colonies, 67 million birds and 6-14 million fish each year.

Climate change Could drive more than ¼ of all land

animals and plants to extinction by the end of the century.

H.I.P.P.OOverexploitation

Legitimate trade of wildlife is worth $10 billion/yr.

Illegal trade is worth $6-10 billion/yr Some species (dead or alive) are worth 100s of

1000s of dollars Killing species we don’t like

Some species are killed because they are considered pests (wolfs eating cattle or elephants trampling crops)

Exotic pets and plants

Protecting Wild Species: Legal and Economic Approaches

1975 Convention on International Trade in Endangered Species (CITES) 169 countries signed 900 species that can not be traded 5000 animals and 28,000 plants trade is

restricted Convention on Biological Diversity (CBD)

188 countries signed Reverse the global decline of biological diversity

Protecting Wild Species: Legal and Economic Approaches

U.S. Endangered Species Act 1973 Identify and legally protect endangered species

in the U.S. National Marine Fisheries Services (NMFS) U.S. Fish and Wildlife Services (USFWS) Decisions must be based on biological facts only Between 1973-2006 the # on the ES list went

from 92 to 1260 Once a species is on ES list a plan is put in to

place to help recovery.

Protecting Wild Species: Legal and Economic Approaches

Encouraging private landowners to protect endangered species Habitat conservation plans

Part of critical habitat is allowed to be destroyed in exchange for taking steps to protect species (setting aside part of habitat, pay to relocate species, pay government to purchase suitable habitat elsewhere)

Safe harbor agreements: Voluntary candidate conservation

agreements:

Protecting Wild Species: The Sanctuary Approach

Since 1903 there are 544 refuges More then ¾ of refuges serve as vital wetlands

for migratory birds More then 1/5 of endangered and threatened

species have habitats in refuges Harmful activities occur in about 60% of

refuges Invasive species are a huge threat Too much fishing and hunting and use of boats

and off road vehicles cause damage

Protecting Wild Species: The Sanctuary Approach National Refuge System Improvement Act (1997)

insuring that the biological diversity and integrity and environmental health of the system are maintained.

Gene banks, botanical gardens, and wildlife farms Gene banks:

Cons: some seeds can’t be kept in a bank, expensive, accidental destruction could destroy seeds

Botanical gardens: Cons: too little storage capacity and funding to preserve rare

and threatened species Wildlife farms:

Zoos and Aquariums Long term goal to reintroduce endangered and threatened

species into the wild Most don’t have money to successfully help threatened or

endangered species but are still beneficial because of educational opportunities.

Reconciliation Ecology

Find ways to share the places we dominate with other species

Examples: For pollinators: Have communities agree

not to spray pesticides, plant gardens of flowering plants, build nesting areas

Use native vegetation- reduce the need for water, and mowing (pollution)

Roof top gardens

Fig. 11-21, p. 246

• Do not buy furs, ivory products, and other materials made from endangered or threatened animal species.

• Do not buy wood and paper products produced by cutting remaining old-growth forests in the tropics.

• Do not buy birds, snakes, turtles, tropical fish, and other animals that are taken from the wild.

• Do not buy orchids, cacti, and other plants that are taken from the wild.

• Spread the word. Talk to your friends and relatives about this problem and what they can do about it.

What Can You Do?

Protecting Species