Community Ecology Each species has a particular ecological niche or role that it plays in an ecosystem.

Community Ecology

• Each species has a particular ecological niche or role that it plays in an ecosystem.

r-Selected Species

Cockroach Dandelion

Many small offspring

Little or no parental care and protection of offspring

Early reproductive age

Most offspring die before reaching reproductive age

Small adults

Adapted to unstable climate and environmental conditions

High population growth rate (r)

Population size fluctuates wildly above and below carrying capacity (K)

Generalist niche

Low ability to compete

Early successional species

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

• Similar climate 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

Cockroaches: Nature’s Ultimate Survivor

• Appeared in the geologic record 350 million years ago.

• Classic r-strategist = “generalist”• Eat almost anything including algae,

dead insects, salts in tennis shoes, electrical cords, glue, paper, soap, and weaker cockroaches.

• Some species can go for months without food, last a month without water, withstand massive doses of radiation, one species can even survive being frozen for 48 hours.

• High reproductive rates (1 female can produce 10 million offspring in one year)

• Carry viruses that cause hepatitis, polio, typhoid, and salmonella.

• 60% of the 12 million Americans suffer from asthma are allergic to cockroaches, dead or alive.

Fewer, larger offspring

High parental care and protection of offspring

Later reproductive age

Most offspring survive to reproductive age

Larger adults

Adapted to stable climate and environmental conditions

Lower population growth rate (r)

Population size fairly stable and usually close tocarrying capacity (K)

Specialist niche

High ability to compete

Late successional species

ElephantSaguaro

K-Selected Species

The Giant Panda: Specialized and Endangered

• Classic k-strategist = specialist

• Feeds exclusively on bamboo (1/3 of body weight)

• Habitat fragmentation has created “habitat islands” of bamboo in southwestern China due to human encroachment.

• 12 protected reserves in China.

Why Are Panda Faced With Extinction?

• Illegal poaching (pelt brings in $40,000-60,000).• Only one cub per female survives each year.• Gestation period = 22 months• Picky about mates. Find each other through

scent, become isolated due to habitat fragmentation.

• Habitat islands interrupt natural migration to adjacent areas when bamboo population crashes in local areas.

• Approximately 700 panda left between zoos and the wild.

Panda Babies

• Five giant panda cubs were born in captivity in 2005: one at Washington, D.C.'s National Zoo and two pairs of twins (one of which is pictured above) at China's Wolong panda reserve.

• US pays 1 million/year to China to have Mei Xiang on exhibit for a ten year period. All offspring will be sent back to China.

What Are Indicator Species?

• Indicator species serve as early warnings of damage to a community.

• Birds and butterflies are migratory and are excellent indicators of the environment. They do not return to areas along their migratory routes where deforestation has occurred or where broad spectrum pesticides have been applied.

• Amphibians are also a universal indicator of environmental degradation as they respire through their skin.

Why Are Amphibians Vanishing?

• Appeared in the fossil record about 350 million years ago.

• Frogs and toads have been around for 150 million years (indicates adaptability)

• Last 20 years nearly 3,000 species of frogs and toads have disappeared.

Reasons for Global Amphibian Declines

• Global climate change (Costa Rican golden toads)• Dehydration weakens amphibians, susceptible to fatal

diseases.• Introduction of non-native predatory fish into aquatic

habitats.• Pollution (air, water, soil)– respire through skin.• Consume insects that take up pesticides

(bioacumulation/biomagnification).• Eggs sensitive to increases in UV radiation – endocrine

blockers)• Consumption of frog legs (delicacy).• Loss of habitat.

Indicator Species

• As indicator species, amphibians may be sending us an important message about the health of the global environment.

• They don’t need us, but we and other species need them.

Golden toads – once prevalent in Costa Rica’s cloud forest have disappeared.

Indicator Species on Long Island

Why Should We Care About Indicator Species?

• They give clues that the environmental health is deteriorating in parts of the world such as habitat loss and degradation, pollution, UV exposure, and climate change.

• They provide ecological services (niche) in biological communities. ie. Amphibians eat more insects including mosquitoes than birds. They provide a food source for higher trophic levels.

• Amphibians especially provide a storehouse of pharmaceutical products waiting to be discivered (economic goods and services).

What Are Keystone Species?

• A keystone species holds a community together, when it disappears, so does the biological community. Elimination of a keystone species dramatically alters the structure and function of a community.

American Alligator – a Keystone Species

• Largest North American reptile; only humans are their predator.

• Hunted nearly to extinction for exotic meat, and leather to make shoes and pocketbooks, and for sport.

Ecological Niche of American Alligator

• Dig gator holes that collect freshwater during the dry season which serve as refuges for aquatic life, and supply freshwater and food for many animals.

Ecological Niche of American Alligator

• Alligator nesting mounds serve as nesting and feeding sites for herons and egrets

Ecological Niche of American Alligator

• Alligator eat large numbers of predatory gar fish and help maintain healthy numbers of game fish such as bass and bream.

Ecological Niche of American Alligator

• As alligators move from gator holes to nesting sites, they keep areas of open water free of invading vegetation. This helps to maintain healthy ecosystems with flowing water.

American Alligator Protection• In 1967, the US

Government placed the American alligator on the Endangered Species List, which protected it from hunting.

• By 1975, the American alligator populations rebounded successfully.

Status of the American Alligator.

• In 1977, the US Fish and Wildlife Service (DOI), down-listed the American alligator to a threatened species in Florida, Louisiana, and Texas.

• Limited kills with a license are permitted. Recreational lotteries are held in the Florida Everglades each year by FWS.

• Alligator farms established to fulfill the market for alligator goods.

Why Should We Protect keystone Species?

• They play critical roles in the cross pollination of angiosperms (bees, hummingbirds, bats).

• Top predator keystone species help regulate the population numbers of other species.

• The loss of keystone species can lead to population crashes and extinctions of other species that depend on it for ecological services.

E.O. Wilson

• “The loss of a keystone species is like a drill accidentally striking a power line. It causes lights to go out all over”

The Good News Is…

• Conservation Efforts on the rise –

• President Theodore Roosevelt (1901-1909) “the Golden Age of Conservation”

• 1903 he established the first federal refuge at Pelican Island off the east coast of Florida to protect the endangered brown pelican.

Roosevelt

• T. Roosevelt also tripled the size of the forest reserves and transferred administration from Department of the Interior (USDOI) to Department of Agriculture (USDA.

• 1905, Congress created the US Forest Service to manage and protect forest reserves. Roosevelt appointed Gifford Pinchot as its first chief.

• 1907, Roosevelt reserved 16 million acres of land. Congress was trying to ban Executive orders for forest reservation. Roosevelt did this defiantly the day before Congress’ ban became law!

Pinchot• (1905) Pinchot pioneered

scientific management of forest resources on public lands, using the principles of sustainable yield and multiple use.

• This same year, the Audubon Society was founded to preserve the nation’s bird species.

Conservation Split• Conservationists became the “wise-

use movement” – and believed that all public lands should be managed “wisely” and scientifically to provide needed goods and services for the country.

• Preservationists lead by John Muir (founder of Sierra Club) believed that remaining wilderness areas on public lands should be left untouched.

Preservationists

• Aldo Leopold – began the Wilderness Society in 1935.

• Leopold helped draft the Wilderness Act of 1964 and lobbied Congress for it’s passage.

University of Idaho

Department of Philosophy

Environmental Philosophy

Wilderness Act of 1964

• Wilderness Act of 1964: directed the Secretary of the Interior, within 10 years, to review every roadless area of 5,000 or more acres and every roadless island (regardless of size) within National Wildlife Refuge and National Park Systems and to recommend to the President the suitability of each such area or island for inclusion in the National Wilderness Preservation System, with final decisions made by Congress. The Secretary of Agriculture was directed to study and recommend suitable areas in the National Forest System.

US National Park Service• 1912, Congress created the US

National Park Service.• 1916, Congress passed the

National park System Organic Act – declared that the parks were to be maintained in a manner that leaves them unimpaired for future generations and established the National Park Service (DOI).

• Stephen Mather was the first Director of NPS. He began establishing grand hotels and other tourist facilities in parks with spectacular scenery to encourage tourism by allowing private concessionaires to operate facilities within the parks.

Long Island’s National Parks and National Wildlife Refuges’

• Fire Island National Seashore• Floyd Bennett Field• Jamaica Bay• Wortheim• Amagansett• Oyster Bay (JFK Bird Sanctuary)• Lido Beach• Elizabeth Morton• Target Rock (Caumsett State

Park)• Seatuck• Conscience Point

Aldo Leopold

• “We abuse land because we regard it as a commodity belonging to us. When we see land as a community to which we belong, we may begin to use it with love and respect”