1

Chapter 11

Biodiversity

2

OUTLINE

• Biodiversity and the Species Concept

Varied Definitions

• Benefits of Biodiversity

• Threats to Biodiversity

Natural and Human-Caused Reductions

• Endangered Species Management

ESA

CITES

• Captive Breeding

3

BIODIVERSITY OF THE SPECIES CONCEPT

• WHAT IS BIODIVERSITY?

GENETIC DIVERSITY - measures the variety

of different versions of the same genes within

a species (gene pool)

SPECIES DIVERSITY - measures the number

of different kinds of organisms within a

community

ECOLOGICAL DIVERSITY - measures the

richness and complexity of a community

(food web complexity/levels/niches)

4

WHAT IS BIODIVERSITY?

• SPECIES DIVERSITY

SPECIES RICHNESS - total number of

species in a community

SPECIES EVENNESS -relative abundance of

individuals within each species

Community A Community B

*10 species * 10 species

*8-10 of each species * 2-10 of each species

5

WHAT ARE SPECIES?

• Definitions of Species (3)

1. REPRODUCTIVE ISOLATION - a.k.a....

BIOLOGICAL SPECIES CONCEPT

organisms that can breed in nature and

produce fertile offspring are a “species”

ie: Horses & Donkeys and Lions & Tigers, can

produce offspring (Mules and Ligers) BUT

they are sterile, therefore, Horses & Donkeys

and Lions & Tigers are different species.

6

WHAT ARE SPECIES?

Definitions of Species (3)

2. PHYLOGENETIC SPECIES CONCEPT - emphasizes the cladistic relationships (branches on a taxonomic tree)

defines a species as the smallest group of individuals on a phylogenetic tree

7

WHAT ARE SPECIES?

• Definitions of Species

3. EVOLUTIONARY SPECIES CONCEPT - defines species in terms of evolutionary

history based on genetic information.

8

MOLECULAR TECHNIQUES

• DNA sequencing and other molecular

techniques give insight into taxonomic and

evolutionary relationships.

GENOME - total DNA sequence that

characterizes a species

Species classification or even identification

of an individual can be done from samples

such as blood, fur, or feces.

Genome information is crucial in breeding

facilities to increase diversity around the

world.

9

HOW MANY SPECIES ARE THERE?

• Currently 1.5 million species identified

• Estimates range between 3-50 million

Recent data support an estimate of 4 to 6 million insect species alone.

Invertebrates make up ~70% of all known species, and probably most of those still to be discovered. Most are found in the tropics.

10

BIODIVERSITY HOTSPOTS

• Tropical rainforests and coral reefs are biodiversity hotspots.

34 hotspots (1.4% of world’s land area)

75% of the world’s most threatened mammals, birds and amphibians.

11

BIODIVERSITY HOTSPOTS • Hot spots are at significant risk due to human

disruption and potential loss of biodiversity

12

BENEFITS OF BIODIVERSITY

• FOOD

Wild plants could provide new sources of food

or more genetic diversity for existing crops.

• DRUGS AND MEDICINES

More than 50% of all prescriptions contain

some natural product.

Pharmaceutical companies actively prospect

tropical countries for products.

Resources often extracted without

compensation (BIOPIRACY).

Sharing profits provides an incentive to local

people to preserve native species.

13

BENEFITS OF BIODIVERSITY

• ECOLOGICAL BENEFITS

Soil formation

Waste disposal

Air and Water purification

Solar energy absorption and conversion

Biogeochemical and Hydrological cycles all

depend on biodiversity.

DIVERSITY CREATES STABILITY

We do not fully understand biological

communities. Loss of a seemingly

insignificant species can be damaging.

14

BENEFITS OF BIODIVERSITY

• AESTHETIC AND CULTURAL BENEFITS

Hunting, fishing, camping, hiking, etc.

USFWS estimates Americans spend $104 billion annually on wildlife-related recreation.

Ecotourism can be an important form of sustainable economic development. Especially in developing nations.

Existence (intrinsic) value - organisms have value in and of themselves.

15

THREATS TO BIODIVERSITY

• EXTINCTION – the elimination of a species

NATURAL CAUSES

- In undisturbed ecosystems, background

rate appears to be one species per decade.

In this century, human impacts have

accelerated that rate, causing perhaps

hundreds to thousands of extinctions

annually.

(we don’t know for sure because we

haven’t discovered all species yet)

16

NATURAL EXTINCTION

• Fossil record suggests more than 99% of all species ever in existence are now extinct.

• Periodically, the Earth has experienced mass extinctions.

ORDOCICIAN - 444 mya

- 85% of species died out

DEVONIAN - 370 mya

- 83% of species died out

PERMIAN PERIOD - 250 mya

- 95% of marine species and nearly half of all plant and animal families died out

17

NATURAL EXTINCTION

END OF TRIASSIC - 210 mya

- 80% of species died out

END OF CRETACEOUS - 65 mya

- Dinosaurs and 50% of existing genera disappeared. 76% total

QUARTERNARY – PRESENT DAY

- 33-66% of species have or are dying out

18

ACCELERATING EXTINCTION RATES

• Humans are accelerating the natural extinction

rates by 100 to 1000x.

If present trends continue, between 22% and

47% of all plants species will become extinct

within 50 years. Animals dependent upon

them would also go extinct.

This is equivalent to other mass extinctions

like the Cretaceous extinction.

THIS IS THE FIRST TIME IN HISTORY THAT

ONE SPECIES IS CAUSING THE EXTINCTION

OF ANOTHER

19

HUMAN-CAUSED LOSSES IN BIODIVERSITY

• Acronym HIPPO summarizes the issues:

1. Habitat destruction

2. Invasive species

3. Pollution

4. Population (human)

5. Overharvesting

20

1. HABITAT DESTRUCTION

• HABITAT DESTRUCTION – 50% of End.Spe.

Biggest reason for current increase in extinction is habitat loss

- Conversion of forest & grasslands to farmland, pastures, cities, etc.

Only 1/5 of remaining forest is old growth.

- Loss of habitat due to mining, dams, destructive fishing practices

- Habitat is fragmented into small, scattered plots due to roads, development

- Draining of wetlands, flooding from dams

21

• INVASIVE SPECIES

Invasive (exotic) organisms thrive in new

territory where they are free of usual

predators, diseases, or resource limitations

that limited them in original habitat.

- Over past 300 years, approximately 50,000

non-native species have become

introduced into the U.S.

At least 4,500 are free-living.

15% cause environmental and/or

economic damage.

2. INVASIVE SPECIES

22

2. INVASIVE SPECIES

• EXAMPLES OF INVASIVE SPECies

Kudzu vine – introduced as ornamental from

Japan, covering the south east

Purple loosestrife – introduced as ornamental

from Europe, displaces native vegetation

Zebra mussels – introduced in ballast water

to the Great Lakes, outcompeting natives for

food, economic damage to powerplants

• ISLAND’S ARE PARTICULARLY SUSCEPTIBLE

generally high in coevolution between

species, and lack of predation

ie: New Zealand, Galapagos, Madagascar

23

2. INVASIVE SPECIES

24

METHODS TO CONTROL INVASIVES

ERADICATION METHODS – removal of

individuals, usually time consuming and

expensive

- Biological Controls – introduction of

predators or parasites (a slippery slope!)

- Mechanical Controls – physically removing

individuals

- Ecological Controls – ie: using fire to kill

off non-native plant species (natives would

survive as they are adapted to fire),

draining lakes to kill off invasives

25

3. POLLUTION

• POLLUTION

PESTICIDES – kill off target pests and many

other species, and bioaccumulate/magnify

PLASTICS – don’t decompose, they photo-

degrade with UV light over many years

CHEMICAL CONTAMINATION

- Lead, Mercury, PCB’s also can

bioaccumulate/magnify – leading to

disease processes

Effects of Global Warming on ecosystems

Effects of Acid Rain

26

BIOACCUMULATION vs BIOMAGNIFICATION

• BIOACCUMULATION - Contaminants increase

in concentration in individual organisms

• BIOMAGNIFICATION - Contaminants increase in

concentration in the food chain

27

4. HUMAN POPULATION

• HUMAN POPULATION

Human population growth and resource use.

~1804 = 1 billion people.

2016 = 7+ billion people.

2050 some estimate we will reach 10 billion.

28

5. OVERHARVESTING

• OVERHARVESTING / OVERHUNTING

COMMERCIAL FISHING - All major fish

stocks are expected to collapse within 50

years (tuna, sharks, codfish, pollock, salmon)

BUSHMEAT TRADE – wild animals being

killed for food – subsistence and/or

commercially

PET TRADE – fish, birds, reptiles, wild cats,

primates – ~ 80% do not survive capture and

transport to destination

BLACK MARKET – animal parts sold illegally

(tusks, horns, skins, teeth) – many are used

in Traditional Chinese Medicines

29

5. OVERHARVESTING

• Commercial Products and Live Specimens

Wildlife smuggling is very profitable.

- Fur, horns, live specimens, folk medicine

- Leopard fur coat = $100,000

- Mature cactus = $1,000

- 5 million wild birds sold worldwide each year an additional 3 million are caught but die before reaching market

128 million tropical fish sold annually in U.S.

- Cyanide released above coral reefs to stun fish. A single diver can kill all life on 200 sq. meters of coral reef in one day.

30

5. OVERHARVESTING

Pet trade

80% of

wild

animals

die before

being sold

Cyanide

fishing is

killing reefs in

the

Philippines

and Indonesia.

Bush meat

more than

1 million tons

of wild animals

are sold for

human food

annually.

31

5. OVERHARVESTING

• HUNTING AND FISHING LAWS

By 1890’s, most states had enacted some hunting and fishing laws.

- General idea was pragmatic, not aesthetic or moral preservation.

- In general, regulations have been extremely successful.

White tailed deer

Wild turkey

Snowy egret

American alligator

32

CLASSIFYING ENDANGERED SPECIES

VULNERABLE are those that are naturally

rare or have been locally depleted to a level

that puts them at risk.

THREATENED are those likely to become

endangered, at least locally, in the near

future.

ENDANGERED are those considered in

imminent danger of extinction.

EXTINCT IN THE WILD are those which only

exist in captivity (zoos, breeding facility)

EXTINCT are those with no surviving

individuals

33

ENDANGERED SPECIES ACT - 1973

• ESA regulates a wide range of activities involving endangered species:

Taking (harassing, harming, pursuing, hunting, shooting, killing, capturing, or collecting) either accidentally, or on purpose

Selling

Importing into or Exporting out of the U.S.

Possessing

Transporting or Shipping

• Prohibitions apply to whole organisms, body parts, and products made from the organisms.

34

ENDANGERED SPECIES ACT

• Currently, U.S. has ~ 1,300 species on its Endangered and Threatened lists, and about 400 candidate species waiting for approval.

Numbers reflects more about human interests than actual status

- Invertebrates make up 75% of all species, but only 9% of T/E list.

Listing process is extremely slow; at least 18 species have gone extinct since being nominated for protection.

$150 million per year. Mostly for species of human interest or environmental need

35

OTHER IMPORTANT LAWS TO KNOW!!

• LACEY ACT – 1900 - 1st Federal US law that required permits for transporting wildlife across state lines. Each State had their own wildlife laws that weren’t always the same.

• MAGNUSON-STEVENS FISHERY CONSERVATION AND MANAGEMENT ACT – (SUSTAINABLE FISHERIES ACT) – 1996 – manages fisheries from 9-200 nautical miles off the coast. Impose limits in this area.

• MARINE MAMMAL PROTECTION ACT – 1972

Protects all marine mammals in US waters

36

OTHER IMPORTANT LAWS TO KNOW!! • CITES – 1975 – Convention on International

trade in Endangered Species of Wild Flora and Fauna – Controls trade of individual species.

Appendix I – endangered – trade is prohibited

Appendix II – threatened – trade is limited

Appendix III – protections vary by country

• UNESCO – United Nations Educational, Scientific and Cultural Organization - developed idea of BIOSPHERE RESERVES – protected areas that limit human impact to protect biodiversity. 600+ exist in the world.

37

“SPECIAL” SPECIES

• Some endangered species merit special attention.

KEYSTONE SPECIES - species has major effect

on other members of community (wolf)

INDICATOR SPECIES - tied to specific

communities or successional stages (tadpole)

UMBRELLA SPECIES - require large blocks of

undisturbed habitat (spotted owl)

FLAGSHIP SPECIES - attractive organisms to

which people react emotionally (panda)

• Notable successes include bald eagle, alligator,

whooping crane

38

RECOVERY PLANS

• Once a species is listed as endangered, the USFWS is required to propose a recovery plan detailing the rebuilding of the individual species to sustainable levels.

Takes many years, is expensive, and is subject to political interference

Once a species is endangered, much of its habitat and ability to survive is already often compromised.

39

RECOVERY PLANS

• Opponents have continually tried to require economic costs and benefits be incorporated into planning.

In 1978, construction of Tellico Dam in Tennessee threatened a fish called the snail darter. A federal committee was given the power to override the ESA for economic reasons.

Sometimes economic interests are in conflict. Commercial and sport fishing for salmon in Columbia River is worth 1 billion per year, but farmers and electric utilities want the dams that provide irrigation and hydroelectric power.

40

PRIVATE LAND AND CRITICAL HABITAT

• 80% of habitat for more than half of all listed

species is on non-public property.

Supreme Court has ruled destroying habitat

equates to “taking”.

- USFWS has been negotiating Habitat

Conservation Plans (HCP) with private

landowners.

Landowners allowed to harvest

resources or build on part of land as

long as endangered species benefits

41

REAUTHORIZING ESA

• Endangered Species Act officially expired in 1992.

• Farmers, loggers, miners, ranchers, developers have tried to prevent its reauthorization.

• Scientists think we should focus on continent-wide preservation of ecosystems that support maximum biodiversity rather than individual species.

• Gap analysis - seeks out unprotected landscapes rich in species – to protect multiple species at once.

42

GAP ANALYSIS

a holistic approach to

managing ecosystems

and species.

• J. Michael Scott –

Conservation biologist

• This biodiversity map

of the island of Hawaii

shows areas of high

species richness that

are not protected in

any preserve and

preserves that have

scenic and

recreational value, but

little in the way of

species protection.

43

HABITAT PROTECTION

• R.E. Grumbine (conservation biologist)

suggests 4 principles:

Protect enough habitat for all native species

in a given region

Manage at regional scale large enough to

accommodate natural disturbances

Plan over a period of centuries

Allow for human use at a level that does not

result in significant ecological degradation

44

SPECIES SURVIVAL PLANS

• CAPTIVE BREEDING PROGRAMS in zoos & botanical gardens are one method of saving threatened species.

Repositories of genetic diversity

- Most mammals in North American zoos are now produced from captive-breeding programs.

Reintroduction programs

But many species do not reproduce in captivity, and there are not enough zoos to maintain every species.

45

SPECIES SURVIVAL PLANS

• CAPTIVE BREEDING PROGRAMS in zoos & botanical gardens are one method of saving threatened species.

ARTIFICIAL INSEMINATION (sperm from one male can be used in several females)

CROSS INCUBATION (eggs laid by one bird are hatched by another)

EMBRYO TRANSFER (embryos are implanted into other females to be raised)

ARTIFICIAL INCUBATION (wild eggs are collected and young released soon after hatching)

46

SPECIES RESTORED BY CAPTIVE BREEDING

Nene Goose

California

Condor

Arabian Oryx Black-footed

Ferret

Golden-lion

Tamarin

47

SPECIES SURVIVAL PLANS

• Zoos/gardens have limited space

How many can/should we save? Should we

preserve pathogens? Parasites?

Continued inbreeding of zoo specimens may

lead to fertility and infant survival problems.

Natural habitat may disappear while we are

busy conserving the species itself.

• Another alternative is to attempt to save species

in the wild by saving large parcels of land.

Provide funding for protection in native

habitats

48

SPECIES SURVIVAL PLANS

• THERE MUST ALWAYS BE A BALANCE

BETWEEN WILDLIFE AND HUMAN LIFE.

• TRADEOFFS EXIST TO SAVE A SPECIES

Monetary costs to save the species

Economic losses if industry is affected

Public desire to save or not to save a species

Indigenous/Cultural uses must be considered

Ecotourism can benefit both wildlife and the

indigenous people of an area through economic

gains that would be lost without the wildlife.