Bell-ringer: What do you think biodiversity encompasses?

Period 3 retake quiz

Biodiversity notes

Biosphere 2 video clip

Wrap-up: What was the point of the biosphere 2 experiment?

Environmental Science

In July 1991 eight “Biospherians” started a daring biodiversity experiment that called for the eight people to live in the airtight Biosphere 2 for two years.

Had a footprint of 13,000 square meters and enclosed 204,000 meters cubed

Housed simplified versions of a desert, savanna, tropical forest, wetland, and a small ocean

Hoped that the plants, animals, and other organisms in these simplified biomes would generate their air, food, and water

Spectacular failure

By January 1993 the O2 content dropped from 19% to 14% (close to minimum needed for humans)

CO2 concentration rose

Before the 2 year mark, O2 was added to prolong the experiment

After 3 years the atmospheric conc. of N2O reached 79 ppm (310 ppm in Earth’s atm)

Low levels reduce the production of vitamin B12 and can damage the human brain

Nonhuman populations also changed

Morning glory vines, added to reduce CO2, overran other plants despite weeding efforts

Water system became overloaded with nutrients and polluted the aquatic system

All pollinators died flowering plants could not produce food for the Biospherians

19 out of the 25 vertebrates species went extinct, as did most of the insects other than cockroaches

Cost about $200 million to build, and several million to operate/year

Failed for reasons that reflect the technical and scientific shortcomings of both the Biospherians and the wider ecological community.

Rise in CO2 was caused in part by microbial degradation of organic carbon in the soils

Human food production requires soils with high organic content

Biospherians must have forgot that respiration reduces oxygen levels

O2 levels reduced when CO2 combined with Ca in cement locking up original O2 in cement walls

Bell-ringer: Why did the biosphere 2 fail?

Notes

Biosphere video clip

Wrap-up: What is species richness?

Not possible to build a simplified ecosystem that can supply and recycle the food, water, and gases that people need

Illustrates the danger of losing biodiversity

Driving a wave of mass extinctions with little understanding of the implications for biogeochemical cycles, food webs, diversity, resistance, or resilience

Refers to the number and variety of living organisms

Umbrella term that encompasses all plants, animals, microorganisms, and ecosystems

Measured at three levels: Genetic diversity

Ecosystem Diversity

Species Diversity

Refers to the genetic information in the DNA of plants, animals, and microorganisms.

Genetic diversity is the raw material for natural selection, which plays an important role in evolution.

Describes the variety of ecosystems on Earth such as coral reefs, forests, and wetlands.

Also involves variation within ecosystems regarding the number and types of organisms, habitats, and ecological processes such as nutrient cycling.

Refers to the total number of living species

Currently biologists have identified about 1.7 million species, the majority of which are insects

New species are identified at the rate of about 300 per day

It is estimated that 10 million to 100 million species exist, but no one is quite sure.

One way to measure species diversity

Refers to the number of species present

An area with an especially large number of species is called a biodiversity hot spot

The second way to measure species diversity

Refers to the distribution of individuals among species and measures whether individuals are distributed evenly among species or represent a few of the many species present

Evenness decreases as the concentration of individuals in a few species increases

Costa Rican rain forest area of 14 km2

Has about 1500 plant species which is more than all of Great Britain ( 243,500 km2 )

In general, species richness is greatest near the equator and declines toward the poles

Observation: Species richness is greatest near the equator and declines toward the poles

Support: Species richness depends on the balance between the gain in new species and the loss of existing species

Areas gain species via speciation and immigration and loose species via extinction

Speciation: the process by which evolution generates new species

Immigration: occurs when new species spread into an area from elsewhere

Occurs when a species fails to reproduce and no individuals remain

Study done by Robert MacArthur and Edward O. Wilson

Found that the number of lizard species on Caribbean islands varies positively with the area of the island

**Species richness increases with island size**

Larger islands such as Cuba (100, 860 km2) have more lizard species than smaller islands such as Saba (13 km2)

This applies to not just lizards but also other animals, birds, and plants

Also applies to other environments like lakes and mountaintops

Tend to have fewer species Can be explained by immigration

Few new species arrive at islands that are far from the mainland or other islands because organisms or seeds must travel a long distance

The ability of organisms to reach new environments

Def: The distance a species can travel to find new environments

Lizards are not good swimmers – must hitch a ride on floating materials

Birds can fly – some over great distances

Light seeds can be blown over long distances, other seeds can float (coconuts)

A species that is restricted to a certain geographic region and is thought to have originated there

Relatively little ability to disperse and often found in a single place

1.) Allopatric speciation Occurs when a population becomes geographically

isolated from its parent population then accumulates genetic or behavioral changes that differentiate from the original population

2.) Sympatric speciation New species may arise within the parent population

Scenario 1: A few individuals may find their way to a new island

Scenario 2: A large population may be separated into smaller subpopulations by the formation of a new mountain, land bridge, or some other barrier

Both processes isolate the subpopulation which makes it different than parent population

Difference from the parent population that accumulate due to isolation may be driven by random changes in the gene pool

These random changes are known as genetic or random drift

Changes may also be from natural selection which favors traits different than those favored in the original location

Rose from the ocean about 3 million years ago

May have accelerated allopatric speciation of snapping shrimp

Before the land bridge the shrimp where found in both the western Caribbean and the eastern Pacific

After the land bridge they changed genetically and behaviorally on each side

If male and female shrimp from either side of the land bridge are put in the same tank they do NOT BREED

They snap at each other

The inability to produce offspring makes them TWO DIFFERENT SPECIES

New species arise within the parent population

May be powered by mutations that occur during cell division

Different species could also interbreed to from a new species

Modern wheat plant Produces the flour for our bread

Offspring of earlier wheat plants and a wild grass

Home to nearly 200 species of cichlid fish

Less than 1 million years old leads scientists for hypothesize that the rapid speciation was driven by exploitation of new food resources and habitats

Important for ecosystem function

Makes important contributions to human well-being as a source of insurance, genetic knowledge, and ecosystem services

Argues that nonhuman species have value in and of themselves and have the right to exist independent of their usefulness to humans.

Human-centered perspective on the relationship between humans and other species hold that other species exist for human use, and their importance is determined by their value to humans.

Based on ethical beliefs – cannot be reconciled by science

Ex.) In 1999 there was ethical debate about destroying the last known sample of the smallpox virus

Could the extinction of the smallpox virus be justified on the basis of reducing human suffering?

Statement that some animals are more equal than others

This also applies to biodiversity

Southeastern portion of the US

Digs burrows that can reach 2 meters below the surface

Depth were microclimate remains relatively constant year-round

These burrows not only protect the tortoise but also many other species (indigo snake & burrowing owl)

Species whose presence and numbers control the integrity of a community or ecosystem and allow that system to persist within its nature range of environmental conditions

Ex.) Gopher Tortoise

Experiment where scientists added phosphorus and nitrogen fertilizers to two lakes

Adding fertilizer retained top-level predators such as largemouth bass and increased NPP, which allowed the lake to remove carbon from the atmosphere

Added same amount of fertilizer but removed all top-level predators including largemouth

Bass feed on smaller fish such as fathead minnows

Fathead minnows and other small fish eat zooplankton, which allowed the fertilizer to increase the algae population

The algal bloom caused the lake to become eutrophic, which cause it to emit CO2

Largemouth are a KEYSTONE SPECIES!!!

Noncritical species

Loss of them would have a relatively small effect on an ecosystem

Insurance: spreads the potential effects of risk When you buy insurance, you sign a contract that

entitles you to compensation should some event happen

To maintain insurance you make payments that are called an insurance premium

You pay the premium w/o knowing whether or not the event that triggers compensation will occur

Society bought insurance by supporting the International Rice Research Institute

Used funds from international organizations such as the Food and Agriculture Organization of the UN and the World Bank to preserve seeds from rice varieties that were considered uneconomic.

Applies to varieties that produce lower yields than varieties currently grown by famers

There was no immediate economic reason to preserve the seeds of uneconomic varieties

Potential value lay in the future, when some unknown aspect of their genetic diversity could be of economic value

Some varieties’ resistance to the grassy stunt virus, which first appeared in the 1970s

Virus threatened much of the Asian rice harvest

In some years, the virus eliminated nearly a quarter of the potential yield

IRRI launched a breeding program by growing rice from uneconomic seeds it had preserved

Hoped that one variety had a genetic component that would allow it to resist the grassy stunt virus

After several years they identified a resistant variety

Variety would have been extinct if IRRI hadn’t saved the seeds!

Allows farmers to practice agricultural techniques that are highly productive but would be too risky w/o insurance

Modern farmers plant a few highly productive varieties of corn, wheat, or rice over large areas generates large amounts of money and food

Risk: Genetically identical food source that could be wiped out by the same disease!

September 1845 leaves on potato plants turned black and curled, then rotted

Cause was an airborne fungus (phytophthora infestans) transported from ships travelling from N. America to England

Winds from southern England carried the fungus to Dublin

A single infected plant could infect thousands more in just a few days

Potatoes dug out of the ground at first looked edible but shriveled and rotted within days

By October 1845, news of the blight reached London

Prime Minister sent scientists to determine the outlook over half of Ireland’s potato crop might perish due to “wet rot”

Static electricity from newly arrived locomotive trains

Mortiferous vapors from volcanoes emanating from the center of the earth

Divine punishment for the “sins of the people”

Judgment against abusive landlords and middlement

Prime Minister repealed England’s long-standing Corn Law (made corn really expensive to foreign countries)

English gentry and politicians raised a fuss and would not allow it to happen with fear of losing their fortune

Prime Minister secretly purchased two shipments of inexpensive Indian corn directly from America to be distributed to Irish

Needed to be digestible corn meal so it had to be ground and there were not enough mills in a nation of potato farmers

Irish found corn unsuitable when compared to potatoes lacked vitamin C (led to scurvy) and was hard to digest causing diarrhea

Single greatest threat to biodiversity

Large-scale alteration of natural ecosystems by humans

Examples: Deforestation and reforestation

Urbanization

Desertification and conversion to agriculture Wetland drainage, irrigation and degradation due to

overgrazing

The change of land quality

In the last 3 centuries it has eliminated nearly 20% of earth’s forests, altered 8% of earth’s grassland, and expanded croplands by nearly 500%

Reduces biodiversity by eliminating habitats in a given biome

The breakup of a continuous habitat, ecosystem, or land use type into smaller areas

Breaking up forest into smaller fragments generates longer edges, which create transition zones between different land covers

Can help species diversity by creating areas that support species that cannot exist in either of the adjacent land covers

Yet in many cases it disrupts ecosystem process

Expose forest species to unfavorable conditions such as:

Stronger winds

Temperature changes

Increased incidence of fire

Increased predation & competition from exotic species and pests

Edges increase the damage and death rates of trees living in the Amazon forest – up to 500m from an edge

Only 39% of the loss of habitat from 1978-1988 was caused by forest clearing, the rest occurred through fragmentation and edge effects

Plants and animals often come along with people who travel

Ex.) Polynesians brought rats to Easter Island

No terrestrial vertebrates were present before humans arrived

When they displace indigenous species or spread into habitats where they were not previously common

79 alien species caused $97 billion in damages between 1901 and 1991

Currently is set to be $138 billion a year

Ex.) Zebra mussels $5 billion per year

The original habitat of a species, where they evolve with other species

A variety of predatory, parasitic, and disease organisms often keep the populations in check

The new environment that a species is introduced into

Previously limiting factors are no longer in place allowing them to spread

The population of an alien species can grow rapidly if the number of pathogens if leaves behind in its native range exceeds the new pathogens it accumulates in its naturalized range

On average, plants living in their naturalized range had 84 % fewer fungi and 24 % fewer virus species than did individuals liing in their native range.

What does this mean? EASIER TO BECOME INVASIVE!

A term that refers to any species that is in danger of extinction throughout all or a significant portion of its range

Endangered plant species are most abundant where biomass is relatively low

Availability of phosphorus has increased in some areas which has led to a decrease in plant biodiversity

Humans hunt and harvest many plant and animal species

If the rate of hunting/harvesting exceeds the max. sustainable yield, the populations could decline

This can lead to EXTINCTION!

The arrival of aboriginal human populations in Australia about 30,000 years ago contributed to the extinction of many large mammals

Marsupial lions

Kangaroos that reached 8 feet tall

Hunting now extends well beyond the need for food

Def: The process in which people try to reduce the populations of species that compete with humans for crops or game.

Ranchers complained that their livestock was being killed off by wolves, mountain lions, and eagles

U.S. federal and state governments used to pay hunters to kill top-level predators

Illegal killing or collecting of plants and animals.

Examples:

Rhino horns can sell for thousands of dollars in the Middle/Far East (daggers/medicine)

Bright Blue Hyacinth Macaw (world’s largest parrot) sells for up to $8,000

If society is willing to spend money to preserve biodiversity, how can this money be directed to save the greatest amount of biodiversity?

Society to allocate its preservation efforts so that the benefits associated with the last species saved equal the effort spent saving it

Scientists have developed four criteria to choose among efforts to preserve biodiversity:

1. Examines how distinct a species is

2. Examines the usefulness of a species

3. The degree to which human actions can reduce the probability that a species will go extinct

4. Society must evaluate the cost of preserving a species

Higher priority is given to unique species

Ranking based on their potential contribution to the growing collection of genetic knowledge

Genetically unique species may contain info that is not available in other species

Can be either commercial value (wild salmon) or the degree to which humans like the species (bald eagle, panda, etc.)

What are the odds that the species will go extinct if society does nothing?

If some effort is expended, will that effort lower the probability of that species going extinct?

It doesn’t make sense to help a species unlikely to go extinct or one that will definitely become extinct regardless of intervention

Conservation efforts for some species may be small compared with the effort required to save others

Try to preserve the greatest biodiversity for the least cost

Policy makers have 3 general approaches to preserving biodiversity:

Legal protections

Ecosystem protections

Market-based mechanisms

Endangered Species Act of 1973 Authorizes the US Fish and Wildlife Service and the

National Marine Fisheries Service to protect endangered and threatened species

Prohibits hunting or commercial harvesting

Mandates habitat protections

Any threat supersedes all economic activities regardless of their value

Any species that is likely to become an endangered species in the foreseeable future throughout all or a significant portion of its range.

Once listed, they compete for federal and state funds aimed at preservation

Unfortunately large sums have been spent to protect “popular” species (bald eagle) and much less has been spent on other species (lizards, amphibians, etc.)

1973 Convention on International Trade in Endangered Species

At the start of 2006, more than 160 parties had entered the convention

Monitors and regulates international trade of endangered plants and animals (products made from them)

Effectively reduced trade in ivory, pelts, and other products that threaten certain species

Ex situ conservation: maintaining a species away from its habitat

Breeding animals in zoos or aquariums

Storing genetically diverse plants in seed banks

In situ conservation: efforts to preserve species in functioning ecosystems Preserving habitat

Convention on Wetlands of International Importance 1971 540 listed wetlands covering 32 million hectares

Signed 1972 in Paris

Convention designates protected areas as World Heritage Sites

Ex.) Everglades National Park in Florida

Ex.) Archaeological remains in Petra, Jordan

Almost 100 world heritage sites throughout the world

1993 set a goal of preserving 10% of the land surface that is covered by each of the fourteen major biomes

In 2003, they announced that protected areas covered 11.5% of Earth’s land surface in 9 out of the 14 biomes

Private organizations that pursue activities to relieve suffering, promote the interests of the poor, protect the environment, provide basic social services, or undertake community development

Raise money and make agreements with national governments to preserve land

Joins with governments, private corporations and individuals, nonprofit organizations, and indigenous people to purchase land they deem critical to biodiversity

Managed with respect to land and marine conservation, freshwater supplies, global climate change, fire, and invasive species

As of 2005 117 million acres of land, 5,000 miles of rivers, and established over 100 marine conservation projects

Species whose range falls outside of protected species

Most live in tropical areas

Range of many species does not coincide with protected areas

Scientists recommend that global network of protected areas be expanded based on geographic patterns of biodiversity

Some efforts to preserve biodiversity use market forces

Provides economically valuable goods and services

If policy can make consumers pay for these goods and services, these payments would serve as an incentive to preserve biodiversity

One of the most successful market-based mechanisms to preserve biodiversity

Tourism contributing to the conversation of natural environments that is planned, developed, and operated with local communities in a way that contributes to the well-being of local communities

Entrance fee is currently $5, questionnaire filled out by foreign tourists indicated that an entrance fee of about $47 would maximize the funds earned by local inhabitants

Local people cannot use for agriculture, so extra fees would help them out

Uncertainty about who owns the genetic info of biodiversity

Constant struggle between government and pharmaceutical companies

Agreement has been made between pharmaceutical companies and nations with high biodiversity

One of world’s largest drug companies recently paid $1.35 million to Costa Rica for the rights to the genetic info of local species

Allows Merck to comb local forests, looking for species with characteristics that can be used to produce marketable drugs

Should Merck be successful, Costa Rica would get a royalty

A market where goods or services are sold illegally

High price provides an incentive for poaching

Lack of legal market means there is no economic incentive to preserve the endangered species’ habitat

Caused by prohibiting the hunting or trade of an endangered species tends to drive up the price for a species

If a well-regulated market can be established, prices for the protected species can be reduced

Landowners will be willing to set aside habitat for endangered species

Bee Ted talk: http://www.huffingtonpost.ca/2016/03/15/honey-nut-cheerios-bee-missing_n_9473778.html

Small pox reading: http://www.npr.org/sections/health-shots/2014/05/09/310475511/keep-or-kill-last-lab-stocks-of-smallpox-time-to-decide-says-who