Lecture 4

Biodiversity

Biodiversity

- also called biological diversity

- consists of the forms of life that can best survive Earth’s conditions

- includes genetic diversity, species diversity & ecological diversity

Genetic Diversity- variability in the genetic makeup among

individuals within a single species

Species Diversity- the variety of species on Earth

- ~ 1.4 million species described

Ecosystem Diversity

- also called ecological diversity

- variety of forests, deserts, grasslands, streams, lakes, oceans and other biological communities

Aquatic Ecosystems

Aquatic ecosystems include:

- Wetlands

- Mangrove Forests

- Coral Reefs

Wetland

- an area of land covered all or part of the year with salt water or fresh water

(excludes lakes, ponds, streams)

Mangrove Forests

- dominated by mangrove trees

- warm tropical climates

- live partly submerged in coastal wetlands

- habitat for ~ 2,000 species

MANGROVE ROOTS – A Microhabitat

SEAGRASSES• stabilize sediments – provide cleaner waters• absorb nutrient before waters reach coral reefs• food source• habitat (among leaves) and microhabitat (on leaf surface)

Coral Reefs

- found in warm, tropical and subtropical oceans

- coastal, shallow waters

- habitat for many marine plants & animals

- protect shoreline from erosion

POSITION OF CORAL REEFS – EQUATORIAL REGION (IN GREEN)

• net benefit / yr (World Resources Institute Global Compilation 2008):

Worldwide: $US 29.8 billion / yr Caribbean: $US 3.1 – 4.6 billion / yr (largest share from dive tourism)

Importance of Biodiversity

- we are dependent on the rich variety of genes, species and ecosystems, for example:

◦ food

◦ medicine

◦ wood

◦ energy

◦ industrial chemicals

◦ raw materials

8 Main Areas of Biodiversity Importance

• Ecosystem Stability

• Genetic Reserves

• Medicinal

• Agricultural

• Industrial

• Aesthetic

• Ethical

• Religious / Spiritual

Threatened Species• any species – animal, plant, fungi etc. – which is vulnerable to extinction in the near future.

• according to the IUCN (International Union for the Conservation of Nature) there are three categories of threatened:

1.Vulnerable2.Endangered 3.Critically endangered

Threatened SpeciesVulnerable: the least critical of the three categories; species are likely to become endangered unless circumstances threatening its survival and reproduction improve e.g. cheetah, lion, polar bear, komodo dragon

Threatened Species

Endangered: faces a very high risk of extinction in the near future e.g. blue whale, giant panda, tiger.

Threatened Species

Critically Endangered: faces an extremely high risk of extinction in the immediate future e.g. Mountain Gorilla, Javan Rhino.

Extinction- complete disappearance of a species from Earth

- Jamaican Examples:

Jamaica rice rat

Giant yellow galliwasp

Jamaican Parauque

Black-capped Petrel

Examples of Jamaica’s Threatened Species

Yellow-billed Parrot

Black-billed Parrot

Giant Swallowtail

Butterfly

Jamaican Iguana

Jamaican Hutia

Jamaican Boa / Yellow Snake

Characteristics of Endangered Species

• extremely small, localised range

• require a large territory to survive

• living on islands (in isolation)

• low reproductive success

Characteristics of Endangered Species cont’d

• specialised breeding areas

• specialised feeding habits

The 3 Main Human Causes of Extinction

• Habitat Destruction

• Biotic Pollution

• Hunting

Habitat Destruction- the greatest threat to most wild species

Biotic Pollution- introduction of foreign or exotic species into

an ecosystem in which it did not evolve

Conservation Biology

- aims to investigate human impact on biodiversity

- develops practical approaches to prevent species extinction

- develops compromises between conservation priorities & human needs

In Situ Conservation

- on-site preservation

- preservation of natural populations in the wild

- best strategy for the long-term protection of biodiversity

Ex Situ Conservation

- off-site preservation

- includes:

artificial insemination

in vitro fertilisation

captive breeding programmes

zoos

NATURAL RESOURCE VALUATION

NATURAL RESOURCE VALUATION

- Process of placing monetary values on natural environmental resources, their services, including those that are not usually accounted for by the market

- Does not value biodiversity for its own sake but for services provided.

RESOURCE VALUATION cont’d

Services may be estimated in various ways such as:

- Direct market price.

Decline in the value of fish catch between 1975 and 2000 cost the country an estimated US$1.6 billion(Sary, Munro and Woodley, 2003)

RESOURCE VALUATION cont’d

- Damage cost avoided. • Models have been used to estimate the role of coral

reefs in preventing wave damage.

• The reef in Discovery Bay being severely degraded would result in 100 structures including two hotels, a church and an airfield being flooded during a storm event within a 25 year period.

RESOURCE VALUATION cont’d

- Travel costs. • Visitors pay money to travel to Jamaica and to stay in hotels.

Damage to beaches would reduce visitation to Jamaica and thus tourism revenue.

• It has been estimated that at the end of 10 years, current erosion rates at the beaches in Negril, Montego Bay and Ocho Rios will cause an annual loss in value of US$19 million.

• If beaches degrade further this value could increase to US$33 million per year.

RESOURCE VALUATION Cont’d

- Costs people are willing to pay for measures to save a natural resource.

Sewage treatment plants provide the services of easier waste disposal and cleaner water for swimming and beach use.

In Barbados a survey revealed that persons living near where a new sewage treatment plant was to be constructed were willing to pay US$178 per household per quarter while those outside the area were only willing to pay US$11 per household.