Read the Article And Write 3 Pages Essay Including Few Deatils From The Chapters Which Are Attached Below.

BiodiversityandConservationBiology_Ch11.pdf

Home >Environmental science homework help >Read the Article And Write 3 Pages Essay Including Few Deatils From The Chapters Which Are Attached Below.

Lecture Outlines

ENVIRONMENT the science behind the stories

Chapter 11

Biodiversity and Conservation Biology

Lecture objectives  Characterize the scope of biodiversity on Earth.  Specify the benefits of biodiversity to humans.  Discuss today’s extinction crisis in geologic context.  Evaluate the primary causes of biodiversity loss.  Assess the science and practice of conservation

biology.  Analyze efforts to conserve threatened and

endangered species.  Compare and contrast conservation efforts above

the species level.

Will We Slice Through the Serengeti?  Each year, millions of wildebeest, zebras, and

antelope migrate across Africa during the change from wet to dry season.

 The Maasai, people native to this region, are semi-nomadic herders that have sustainably lived with the ecosystem for many generations.

 The area includes two protected areas that fall within the countries of Tanzania and Kenya.

 The reserves have effectively isolated people living in Northern Tanzania from the rest of the country, creating dire poverty.

 Tanzania’s president promised to build a paved commercial highway through the Serengeti, connecting these communities with cities to the East and ports on the Indian Ocean.

 This plan raised many concerns with conservationists:  Migration routes could be blocked.  Many animals would die from traffic collisions.  Poachers would have easier access.  Human development would be accelerated along the

edges of the reserves.  The East Africa Court of Justice blocked the plan,

and an alternative route that wrapped around the southern Serengeti was planned instead.

 In 2016, a new president announced plans to build an oil pipeline through the Serengeti, sparking many of the same protests.

Life’s Diversity on Earth  Biodiversity is the variety of life across all levels of

biological organization (genes through ecosystems).  A species is a set of organisms that share unique

characteristics and can breed and produce fertile offspring.

 Species diversity describes the number or variety of species found in a region.  Species richness describes the number of species.  Evenness or relative abundance describes how much

the species differ from each other in numbers of individuals.

 Genetic diversity includes differences in DNA composition among individuals.  Populations with little genetic diversity are more likely

to suffer inbreeding depression and be vulnerable to environmental change, as they lack the variants needed to help adapt to new conditions.

 Ecosystem diversity refers to the number and variety of ecosystems, communities, or habitats.

Biodiversity is unevenly distributed  Some groups of organisms include more species

than others.  Insects, for example, are the most diverse group of

organisms.

 Biodiversity also varies based on location.  Species richness generally increases as one

approaches the equator, a pattern called the latitudinal gradient in species richness.  Greater geographic area  More solar energy  Stability of tropical climates  Lack of disruptive glaciation events

 Species diversity also tends to increase in areas with more diverse habitats, such as ecotones.

 Structurally diverse habitats, like forests, also tend to be more biodiverse.

[Insert Figure 11.5, p. 273, 6e]

Many species await discovery  So far, about 1.8 million species of plants, animals,

and microorganisms have been identified.  Estimates for the total number range from 3–100

million.  Our species knowledge is incomplete because most

of the unknown species are small, such as bacteria, roundworms, fungi, and protists.  Other organisms may appear to be the same species,

but are found to be different under further examination.

Review Questions 1. The Serengeti contains savanna grassland, hilly

woodlands, seasonal wetlands, and rock outcroppings. What kind of diversity is this? a. Species diversity b. Genetic diversity c. Ecosystem diversity

Review Questions 2. Which of these best describes the latitudinal

gradient in species richness? a. There tends to be a greater number of species in

ecosystems closer to the equator. b. There tends to be a greater number of species in

midlatitudes. c. There tends to be a greater number of species in

ecosystems farther from the equator. d. The number of species is generally consistent

across all latitudes.

Benefits of Biodiversity  Biodiverse regions provide potential new or unused

food sources.  Wild relatives of crops we already use also provide

genetic diversity to protect against disease.

 This table lists promising new food sources from Central and South America.

Organisms provide drugs and medicines  About half of today’s pharmaceuticals are derived

from chemical compounds in wild plants.

 Bioprospecting is searching for organisms that might provide new foods, medicines, or other products.  This includes animals that

are endangered and may go extinct before the substances can be discovered.

Biodiversity provides ecosystem services  Biodiversity provides many free benefits, including:  Food, fuel, fiber, and shelter  Air and water purification  Waste decomposition  Climate stabilization (reduction in droughts, floods,

etc.)  Pollination of plants  Controlling pests and diseases  Maintaining genetic diversity for crop varieties and

livestock  Cultural and aesthetic benefits

Biodiversity helps maintain ecosystem function  Biodiversity increases the resilience of an

ecosystem—its ability to withstand disturbance, recover from stress, or adapt to change.  If a keystone species like a top predator is lost,

consequences will cascade down the entire food chain.  If an ecosystem engineer is lost, the entire structure

of an ecosystem can change.  The removal of elephants from some of Africa’s

savannas has caused scrubby vegetation to overgrow, turning them into scrub forests.

Biodiversity boosts economies through tourism and recreation  Visitors to natural areas spend money at local

businesses, hire locals as guides, and support parks that employ residents.  For Tanzania, ecotourism provides a quarter of all

foreign money entering the economy.

People value connections with nature  A biologist named Edward O. Norton suggested that

human beings share an instinctive love for nature and feel an emotional bond with other living things.  He called this biophilia.

 Others believe that a lack of outdoor experiences and direct contact with wild organisms contributes to the emotional stress, angst, and anxiety felt by many young people.

Biodiversity Loss and Extinction  The alteration of ecosystems creates “winners” and

“losers” among the world’s animals and plants.  Humans have a tendency to change ecosystems to

that they are more similar to each other, more open in structure, and more polluted.  This favors generalists, which can adapt to the

changing conditions and harms specialists that rely on mature, stable ecosystems.

 Organisms that benefit from human development also tend to be geographically widespread, small and fast-reproducing, and lower on the food chain.

Biodiversity loss involves population declines  As a population shrinks, it loses both genetic

diversity and geographic range.  Both make the population vulnerable to further

declines.  The United Nations Environment Programme

(UNEP) developed the Living Planet Index as a way to express how large the average population size of a species is now compared to a baseline year of 1970.

 The Living Planet Index fell by 52% between 1970 and 2010 primarily because of biodiversity losses in tropical regions.

Extinction is irreversible  Extinction occurs when

the last member of a species dies and the entire species ceases to exist.

 Extirpation is the loss of a species from one area, but not the entire world.  The black rhino has been

extirpated from most of its historic range but is not yet extinct.

 Human impact is responsible for most extirpation and extinction today, but these process do also occur naturally.

 The background extinction rate is the pace at which organisms independently go extinct.  Based on the fossil record, scientists estimate this

rate at an average of 1 out of every 1–10 million mammal and marine animal going extinct each year.

Earth has experienced five mass extinction events  Mass extinction events are ones that eliminated at

least half of the species on the Earth.  Five have already occurred, and we are in the midst

of the sixth due to human impacts.

We are setting the sixth mass extinction in motion  The current extinction rate

is 100–1000 times greater than the background rate.  This includes many North

American birds, such as the ivory-billed woodpecker.

 The International Union for Conservation of Nature (IUCN) maintains the Red List, all species facing high risks of extinction.

 The 2016 Red List reported these animals were threatened with extinction:  22% (1197) of mammal species  13% (1375) of bird species  20% (944) of reptile species  31% (1994) of amphibian species  16% (2073) of fish species

 For other groups, not enough data is available to make global assessments.

Several major causes of biodiversity loss stand out  Habitat loss is the greatest threat to biodiversity

today.  Humans have

altered, degraded, or destroyed habitat through urban sprawl, farming, grazing, clearing forests, and damming rivers.

 Habitat loss most commonly occurs through gradual, piecemeal degradation called habitat fragmentation.  This makes habitats smaller, and prevents movement

of organisms between habitats.  The proposed Serengeti

highway would have caused habitat fragmentation.

 Habitat loss has affected every biome, with wetlands being especially threatened.

 Habitat loss is the primarily source of the population declines in more than 80% of threatened birds and mammals.

 Pollution harms organisms in many ways.  Air pollution degrades forests and affects the

atmosphere and climate.  Noise and light pollution affect the behavior and

habitat use of animals.  Water pollution directly harms fish and amphibians.  Agricultural runoff affects the food webs of aquatic

ecosystems.  Persistent pollutants like heavy metals directly poison

people and wildlife.  Plastic in the ocean can strangle, drown, or choke

marine animals.

 Our growth in population and consumption is also leading us to remove species at faster rates than they can reproduce.  Valuable trees, like teak and mahogany, are

disappearing quickly.  Gorillas and other primates killed for “bush meat”

could face extinction.  Many ocean fish stocks are overharvested.  Thousands of sharks are killed each year for their

fins.

 Poaching is the illegal killing of wildlife for meat or body parts.  The illegal trade for wildlife products has lead to steep

population declines for many animals, including tigers, rhinoceros, and elephants.

 Invasive species, non-native species introduced to new environments, can proliferate and displace native species.

 Species native to islands are particularly vulnerable, as they have been isolated from new parasites, predators, and competitors.

 Climate change is also hurting biodiversity, with the warming temperatures causing some animals to shift their ranges to be closer to the poles or higher in altitude.  Organisms

already living in these places, such as the polar bear, have nowhere left to go, and are especially vulnerable.

A mix of causes threatens many species  For many species, multiple factors are conspiring to

cause declines.  The worldwide collapse of amphibians is an example

of a “perfect storm” of causes from habitat loss to pollution to disease.

Review Questions 3. Many factors lead to species extinction and

extirpation, but what is the biggest? a. Poaching b. Invasive species c. Pollution d. Habitat loss and fragmentation

Review Questions 4. Which of these characteristics would you expect to

see in a species that is the most vulnerable to human degradation of ecosystems? a. Geographically widespread b. Small and fast-reproducing c. Low on the food chain d. Specialists

Conservation Biology: The Search for Solutions  Conservation biology is a study that seeks to

understand the loss, protection, and restoration of biological diversity.

Conservation biology responds to biodiversity loss  Conservation geneticists determine how small a

population can become and how much genetic variation it can lose before encountering inbreeding depression.  By determining this size, they can help wildlife

managers make plans for increasing the size of a population.  Small and isolated populations are the most

vulnerable, so they get special attention.

Endangered species are a focus of conservation efforts  The Endangered Species Act of 1973 offers

protection to species that fall within two categories:  Endangered, or in danger of becoming extinct in the

near future  Threatened, likely to become endangered soon

 The ESA forbids the U.S. government and citizens from taking actions that destroy individuals within identified species.  As of 2016, 1229 species were listed as endangered

and 367 were listed as threatened.

 An early success of the ESA is the recovery of the bald eagle, peregrine falcon, brown pelican, and other birds following the ban of DDT in 1973.

 Federal authorization for spending under the ESA expired in 1992 and has not been re-authorized since.  As a result, a number of species judged in need of

protection have not been added to the law.  A common perception of the law is that it imperils the

livelihoods of some, such as loggers in the Pacific Northwest that have reduced timber harvesting due to the endangered northern spotted owl and marbled murrelet.

 The ESA does not always stop development projects —it can promote cooperation with landowners.  Habitat conservation plans allow the landowner to

harm some individuals of a species if the overall habitat is improved.  A safe harbor agreement is a promise that the

government will not pursue additional action if the landowner pursues actions that assist in the species’ recovery.

 A recent battle took place between federal officials, cattle ranchers, and oil and gas drillers over the potential listing of the greater sage grouse as endangered.  A voluntary campaign

was waged to lessen impacts on grouse populations, which federal officials deemed adequate to conserve the species.

International treaties promote conservation  The 1973 Convention on International Trade in

Endangered Species of Wild Fauna and Flora (CITES) bans the international transport of the body parts of rare species.

 The Convention on Biological Diversity is a treaty that provides funding and incentives for conservation in developing countries.  Successes include promoting ecotourism at the

Serengeti National Park, promoting sustainable crops like shade-grown coffee, and discouraging the use of pesticide-intensive farming.

Captive breeding, reintroduction, and cloning are being pursued  Zoos and botanical gardens have become centers

for captive breeding, where endangered individuals such as black rhinos are bred and raised with the intention of reintroducing their progeny into the wild.  65 plant and animal

species now exist only in captivity.

 The California condor was a victim of hunting and lead shot poisoning, dwindling to only 22 individuals by 1982.  Captive breeding programs have released 268

condors into the wild, with 167 still in captivity.  Lead shot poisoning is still a problem, although

California is banning lead shot as of 2019.

 A new idea is to take DNA from an endangered species, insert it into an egg from a related species (that lacks a nucleus), and implant it into a female.  Several mammals have been cloned in this way, and

scientists believe that extinct species may be recovered from DNA in preserved body parts.

Forensics can help to protect species  Forensic science is the analysis of evidence to

make an identification or answer a question relating to a crime.

 Conservation biologists are using forensics to trace the geographic origin of organisms or body parts recovered from the black market.

 Forensics has also been used to identify if whale meat sold at Asian markets is from an endangered species or a protected area.

Several strategies help to protect habitats, communities, and ecosystems  The protection of umbrella species helps to protect

many others.  The wildebeest of the Serengeti, for example, have a

huge range. Protecting them results in the protection of many other species, as well.

 Environmental organizations use large charismatic vertebrates as flagship species to promote conservation.  The symbol of the World Wildlife Federation, for

example, is a giant panda.

 Biodiversity hotspots are regions that support a great number of species that are found nowhere else.  Defined as harboring at least 1500 endemic plant

species and having already lost 70% of habitat area.

 Parks and preserves are protected areas that seek to maintain habitats and ecological services.  May still be affected from illegal logging, poaching,

and resource extraction.  Areas of the ocean are also beginning to be set

aside for similar reasons.  Ecosystems can also be restored by re-establishing

the natural processes that were interrupted by human development.  U.S. restoration efforts have focused on the Illinois

prairie, Florida Everglades, and southeastern longleaf pine forests.

 In Kenya, efforts are being made to restore the heavily deforested Mau Forest Complex, an area that contains the watershed for the Maasai Mara Reserve.

Community-based conservation is growing  In the past, conservationists from developed

countries would work to preserve ecosystems while neglecting the needs of the local people.

 Today, community-based conservation actively engages local people such as the Maasai.  The Maasai had been forcibly evicted from the

Serengeti and forbidden from hunting wildlife, but are now given some authority over wildlife management.

 This approach will be vital to preserve biodiversity in the face of growing future human populations.

Review Questions 5. Which is the U.S. law that forbids the harming of

any species identified as endangered or threatened? a. CITES b. The Endangered Species Act c. Convention on Biological Diversity d. Safe Harbor Act

Slide Number 1
Lecture objectives
Will We Slice Through the Serengeti?
Slide Number 4
Slide Number 5
Life’s Diversity on Earth
Slide Number 7
Slide Number 8
Slide Number 9
Biodiversity is unevenly distributed
Slide Number 11
Slide Number 12
Many species await discovery
Review Questions
Review Questions
Benefits of Biodiversity
Slide Number 17
Organisms provide drugs and medicines
Slide Number 19
Biodiversity provides ecosystem services
Biodiversity helps maintain ecosystem function�
Biodiversity boosts economies through tourism and recreation
People value connections with nature
Biodiversity Loss and Extinction
Slide Number 25
Biodiversity loss involves population declines
Slide Number 27
Extinction is irreversible
Slide Number 29
Earth has experienced five mass extinction events
We are setting the sixth mass extinction in motion
Slide Number 32
Slide Number 33
Several major causes of biodiversity loss stand out
Slide Number 35
Slide Number 36
Slide Number 37
Slide Number 38
Slide Number 39
Slide Number 40
Slide Number 41
Slide Number 42
A mix of causes threatens many species
Review Questions
Review Questions
Conservation Biology: The Search for Solutions
Conservation biology responds to biodiversity loss
Endangered species are a focus of conservation efforts
Slide Number 49
Slide Number 50
Slide Number 51
Slide Number 52
International treaties promote conservation
Captive breeding, reintroduction, and cloning are being pursued
Slide Number 55
Slide Number 56
Forensics can help to protect species
Slide Number 58
Several strategies help to protect habitats, communities, and ecosystems
Slide Number 60
Slide Number 61
Slide Number 62
Community-based conservation is growing
Review Questions