BiodiversityBiodiversity

Environmental ScienceEnvironmental Science

A World Rich in BiodiversityA World Rich in Biodiversity

BiodiversityBiodiversity, , short for biological diversity, is the short for biological diversity, is the variety of organisms in a given area, the genetic variety of organisms in a given area, the genetic variation within a population, the variety of variation within a population, the variety of species in a community, or the variety of species in a community, or the variety of communities in an ecosystem.communities in an ecosystem.

Certain areas of the planet, such as tropical Certain areas of the planet, such as tropical rainforests, contain an extraordinary variety of rainforests, contain an extraordinary variety of species and are call species and are call biodiversity hot spotsbiodiversity hot spots

Humans need to understand and preserve Humans need to understand and preserve biodiversity for our own survival.biodiversity for our own survival.

Unknown DiversityUnknown Diversity

The number of species known to science is about 1.7 The number of species known to science is about 1.7 million, most of which are insects. However, the actual million, most of which are insects. However, the actual number of species on Earth is unknown.number of species on Earth is unknown.

Scientists accept an estimate of greater than 10 million Scientists accept an estimate of greater than 10 million for the total number of species; ( 4.5 mill-500 mill !!)for the total number of species; ( 4.5 mill-500 mill !!)

Levels of DiversityLevels of Diversity

Biodiversity can be studied and described at Biodiversity can be studied and described at three levels: species diversity, ecosystem three levels: species diversity, ecosystem diversity, and genetic diversity.diversity, and genetic diversity.

Species diversitySpecies diversity refers to all the differences refers to all the differences between populations of species, as well as between populations of species, as well as between different species.between different species.

Ecosystem diversityEcosystem diversity refers to the variety of refers to the variety of habitats, communities, and ecological processes habitats, communities, and ecological processes within and between ecosystems.within and between ecosystems.

Levels of DiversityLevels of DiversityGenetic diversityGenetic diversity refers refers to all the different to all the different genes contained within genes contained within all members of a all members of a population.population.

A A genegene is a segment is a segment of DNA that is located of DNA that is located in a chromosome and in a chromosome and that codes for a that codes for a specific hereditary specific hereditary trait.trait.

Benefits of BiodiversityBenefits of Biodiversity

Biodiversity can affect the stability of Biodiversity can affect the stability of ecosystems and the sustainability of ecosystems and the sustainability of populations.populations.

Every species is probably either dependent on Every species is probably either dependent on or depended upon by at least one other species or depended upon by at least one other species in ways that are not always obvious.in ways that are not always obvious.

When one species disappears from an When one species disappears from an ecosystem, a strand in a food web is removed. ecosystem, a strand in a food web is removed.

Species are Connected to Species are Connected to EcosystemsEcosystems

A A keystone specieskeystone species is a species that is critical is a species that is critical to the functioning of the ecosystem in which it to the functioning of the ecosystem in which it lives because it affects the survival and lives because it affects the survival and abundance of many other species in its abundance of many other species in its community.community.

Species are Connected to Species are Connected to EcosystemsEcosystems

An example is the sea otter. The loss of An example is the sea otter. The loss of the sea otter populations led to an the sea otter populations led to an unchecked sea urchin population, which unchecked sea urchin population, which ate all the kelp leading to the loss of kelp ate all the kelp leading to the loss of kelp beds along the U.S. Pacific Coast. beds along the U.S. Pacific Coast.

Species and Population SurvivalSpecies and Population Survival

The level of genetic diversity within populations The level of genetic diversity within populations is a critical factor in species survival.is a critical factor in species survival.

Genetic variation increases the chances that Genetic variation increases the chances that some members of the population may survive some members of the population may survive environmental pressures or changes.environmental pressures or changes.

Small and isolated populations are less likely to Small and isolated populations are less likely to survive such pressures.survive such pressures.

Species and Population SurvivalSpecies and Population Survival When a population shrinks, its When a population shrinks, its

genetic diversity decreases as genetic diversity decreases as though it is passing through a though it is passing through a bottleneck.bottleneck.

Even if such a population is Even if such a population is able to increase again, there able to increase again, there will be inbreeding within a will be inbreeding within a smaller variety of genes.smaller variety of genes.

The members of the The members of the population may then become population may then become more likely to inherit genetic more likely to inherit genetic diseases.diseases.

Medicinal UseMedicinal Use

About one quarter of the drugs prescribed in the About one quarter of the drugs prescribed in the United States are derived from plants, and United States are derived from plants, and almost all of the antibiotics are derived from almost all of the antibiotics are derived from chemicals found in fungi.chemicals found in fungi.

New chemicals and industrial materials may be New chemicals and industrial materials may be developed from chemicals discovered in all developed from chemicals discovered in all kinds of species.kinds of species.

The scientific community continues to find new The scientific community continues to find new uses for biological material and genetic diversity.uses for biological material and genetic diversity.

Agricultural UseAgricultural UseMost of the crops produced around the world Most of the crops produced around the world

originated from a few areas of high biodiversity.originated from a few areas of high biodiversity.

Most new crop varieties are hybrids, or crops Most new crop varieties are hybrids, or crops developed by combing genetic material from developed by combing genetic material from other populations.other populations.

History has shown that depending on too few History has shown that depending on too few plants for food is risky. Famines have resulted plants for food is risky. Famines have resulted when an important crop was wiped out by when an important crop was wiped out by disease. disease.

FOOD!!FOOD!!

Mangosteen from Mangosteen from Indonesia supposedly Indonesia supposedly the best tasting fruit… the best tasting fruit… but only found in but only found in tropical regions- not tropical regions- not harvested and harvested and shipped overseas for shipped overseas for profit. Is that good or profit. Is that good or bad?bad?

Ethics, Aesthetics, and RecreationEthics, Aesthetics, and Recreation

Some people believe that we should preserve Some people believe that we should preserve biodiversity for ethical reasons. They believe biodiversity for ethical reasons. They believe that species and ecosystems have a right to that species and ecosystems have a right to exist whether or not they have any other value.exist whether or not they have any other value.

People also value biodiversity for aesthetic or People also value biodiversity for aesthetic or personal enjoyment such as keeping pets, personal enjoyment such as keeping pets, camping, picking flowers, or watching wildlife.camping, picking flowers, or watching wildlife.

EcotourismEcotourism is a form of tourism that supports the is a form of tourism that supports the conservation and sustainable development of conservation and sustainable development of

ecologically unique areas.ecologically unique areas.

ExtinctionExtinctionThe extinction of many species in a small The extinction of many species in a small

amount of time is called a amount of time is called a mass extinctionmass extinction..

The last mass extinction event occurred when The last mass extinction event occurred when the dinosaurs disappeared.the dinosaurs disappeared.

Scientists warn that we are in the middle of a Scientists warn that we are in the middle of a mass extinction event now.mass extinction event now.

The current mass extinction is different from The current mass extinction is different from previous ones because it is being caused by previous ones because it is being caused by humanshumans

Species Prone to ExtinctionSpecies Prone to Extinction An An endangered speciesendangered species is a is a

species that has been species that has been identified to be in danger of identified to be in danger of extinctionextinction

A A threatened speciesthreatened species is a is a species that is likely to become species that is likely to become endangered in the foreseeable endangered in the foreseeable future.future.

The major causes of extinction The major causes of extinction today are the destruction of today are the destruction of habitats, the introduction of habitats, the introduction of non-native species, pollution, non-native species, pollution, and the over-harvesting of and the over-harvesting of species.species.

Habitat Destruction and Habitat Destruction and FragmentationFragmentation

As human populations As human populations grow, we use more land grow, we use more land to build homes and to build homes and harvest resources. harvest resources.

In the process, we In the process, we destroy and fragment the destroy and fragment the habitats of other species.habitats of other species.

It is estimated that habitat It is estimated that habitat loss causes almost 75 loss causes almost 75 percent of the extinctions percent of the extinctions now occurring.now occurring.

Ex. Florida PantherEx. Florida Panther

Habitat FragmentationHabitat Fragmentation

2020

Habitat LossHabitat Loss

Nonnative species that move, or are moved, into a new ecosystem

Often have competitive edge against native speciesAvenues of Human Introduction

ColonizationHorticulture and AgricultureAccidental Transport

Exotic Species

Invasive SpeciesInvasive Species

Even familiar organisms such Even familiar organisms such as cats and rats are considered to as cats and rats are considered to be exotic species when they are be exotic species when they are brought to regions where they brought to regions where they never lived before.never lived before.

When exotic species threaten When exotic species threaten native species that have no native species that have no natural defenses against them, natural defenses against them, they are called they are called invasive speciesinvasive species

2323

OverexploitationOverexploitationWhen the harvest is so great that the When the harvest is so great that the

population becomes severely reduced population becomes severely reduced in numbersin numbers

The market forces driving the harvest:The market forces driving the harvest:– Exotic PetsExotic Pets– Hunting / PoachingHunting / Poaching– Over-Harvesting FisheriesOver-Harvesting Fisheries

Hunting, Harvesting, and PoachingHunting, Harvesting, and Poaching

Excessive hunting can Excessive hunting can also lead to extinctionalso lead to extinction– Ex. Passenger PigeonsEx. Passenger Pigeons

Thousands of rare Thousands of rare species worldwide are species worldwide are harvested and sold for harvested and sold for use as pets, houseplants, use as pets, houseplants, wood, food, or herbal wood, food, or herbal medicine.medicine.

PoachingPoaching is is the illegal is is the illegal harvesting of fish, game, harvesting of fish, game, or other species.or other species.

Smuggling bird eggsSmuggling bird eggs

Hyacinth macaw goes for Hyacinth macaw goes for $10,000$10,000

PollutionPollution

Pesticides, cleaning Pesticides, cleaning agents, drugs, and agents, drugs, and other chemicals used other chemicals used by humans are by humans are making their way into making their way into food webs around the food webs around the globe.globe.– Ex. Bald Eagles and Ex. Bald Eagles and

DDTDDT

Reasons why biodiversity is Reasons why biodiversity is threatenedthreatened

H – habitat loss and fragmentationH – habitat loss and fragmentationI – invasive speciesI – invasive speciesP - pollutionP - pollutionP – human population growthP – human population growthO – overexploitationO – overexploitation

Areas of Critical DiversityAreas of Critical Diversity

Some areas of the world have a greater Some areas of the world have a greater number of endemic species than othersnumber of endemic species than others

An An endemic speciesendemic species is a species that is is a species that is native to an area and is found only there.native to an area and is found only there.

Areas of high biodiversity include tropical Areas of high biodiversity include tropical rain forests, coral reefs, and tropical rain forests, coral reefs, and tropical islands islands Biodiversity HotspotsBiodiversity Hotspots

Captive Breeding ProgramsCaptive Breeding Programs

When a species is clearly When a species is clearly on the verge of extinction, on the verge of extinction, people can start a captive people can start a captive breeding programbreeding program

Species are bred in Species are bred in captivity, with the hopes captivity, with the hopes of reintroducing of reintroducing populations to their populations to their natural habitats.natural habitats.

Ex. California CondorEx. California Condor

Preserving Genetic MaterialPreserving Genetic Material One way to save the One way to save the

essence of a species is essence of a species is by preserving its genetic by preserving its genetic material.material.

Germ plasmGerm plasm is hereditary is hereditary material (chromosomes material (chromosomes and genes) that is usually and genes) that is usually contained in seeds, contained in seeds, sperm, eggs, or pure sperm, eggs, or pure DNA.DNA.

Many botanical gardens Many botanical gardens and zoos act as germ and zoos act as germ plasm banks.plasm banks.

Other Efforts to Preserve SpeciesOther Efforts to Preserve Species

Zoos, wildlife parks, aquariums, and botanical Zoos, wildlife parks, aquariums, and botanical gardens, are living museums of the worldgardens, are living museums of the world’’s s biodiversity.biodiversity.

But, these kinds of facilities rarely have enough But, these kinds of facilities rarely have enough resources or knowledge to preserve more than a resources or knowledge to preserve more than a fraction of the worldfraction of the world’’s rare and threatened s rare and threatened species.species.

Ultimately, saving a few individuals does little to Ultimately, saving a few individuals does little to preserve a species as captive species may not preserve a species as captive species may not reproduce or survive again in the wild.reproduce or survive again in the wild.

Preserving Habitats and Preserving Habitats and EcosystemsEcosystems

Priority is now given to protecting entire Priority is now given to protecting entire ecosystems rather than individual species.ecosystems rather than individual species.

By saving the ecosystem, most of the species By saving the ecosystem, most of the species in an ecosystem are saved instead of just the in an ecosystem are saved instead of just the endangered ones.endangered ones.

When possible large areas are preserved for When possible large areas are preserved for two reasons:two reasons:1.1. Small areas are in danger from natural disastersSmall areas are in danger from natural disasters2.2. Some animals need a large range to find foodSome animals need a large range to find food

Endangered Species Act of 1973Endangered Species Act of 1973

Under the first provision of the Endangered Under the first provision of the Endangered Species Act, the U.S. Fish and Wildlife Service Species Act, the U.S. Fish and Wildlife Service (USFWS) must compile a list of all endangered (USFWS) must compile a list of all endangered and threatened species in the United States. As and threatened species in the United States. As of 2002, 983 species of plants and animals were of 2002, 983 species of plants and animals were listed.listed.

The second main provision of the act protects The second main provision of the act protects listed species from human harm.listed species from human harm.

The third provision prevents the federal The third provision prevents the federal government from carrying out any project that government from carrying out any project that jeopardizes a listed species.jeopardizes a listed species.

CITESCITES

Convention on International Trade in Convention on International Trade in Endangered Species (CITES) Endangered Species (CITES)

The CITES treaty was the first effective effort to The CITES treaty was the first effective effort to stop the slaughter of African elephants being stop the slaughter of African elephants being killed by poachers who would then sell the ivory killed by poachers who would then sell the ivory tusks.tusks.

In 1989, the members of CITES proposed a total In 1989, the members of CITES proposed a total worldwide ban on all sales, imports, and exports worldwide ban on all sales, imports, and exports of ivory, hoping to put a stop the problem.of ivory, hoping to put a stop the problem.

The Biodiversity TreatyThe Biodiversity Treaty

The The Biodiversity TreatyBiodiversity Treaty is an is an international agreement aimed at international agreement aimed at strengthening national control and strengthening national control and preservation of biological resources.preservation of biological resources.

The treatyThe treaty’’s goal is to preserve s goal is to preserve biodiversity and ensure the sustainable biodiversity and ensure the sustainable and fair use of genetic resources in all and fair use of genetic resources in all countries.countries.

Private OrganizationsPrivate OrganizationsMany private organizations work to protect Many private organizations work to protect

species worldwide, often more effectively than species worldwide, often more effectively than government agencies.government agencies.– World Wildlife FundWorld Wildlife Fund – sustainable use of resources – sustainable use of resources

and wildlife protectionand wildlife protection

– Nature ConservancyNature Conservancy – has purchased land to turn – has purchased land to turn into nature preserves in 29 countriesinto nature preserves in 29 countries

– Conservation InternationalConservation International – identifies biodiversity – identifies biodiversity hot spots (Jeff Corwin in Madagascar)hot spots (Jeff Corwin in Madagascar)

– Greenpeace InternationalGreenpeace International – organizes direct and – organizes direct and sometimes confrontational actionsometimes confrontational action

Balancing Human NeedsBalancing Human NeedsAttempts to protect species often come into Attempts to protect species often come into

conflict with the interests of the people.conflict with the interests of the people.

Sometimes an endangered species represents a Sometimes an endangered species represents a source of food or income. source of food or income.

Many people donMany people don’’t understand how important t understand how important biodiversity is to stable ecosystems.biodiversity is to stable ecosystems.

Many conservationists feel than an important Many conservationists feel than an important part of protecting species is educating people on part of protecting species is educating people on the value of biodiversity.the value of biodiversity.