1 biodiversity. 2 biodiversity includes a variety of factors genetic diversity – genetic...

22
1 Biodiversity

Upload: silas-moore

Post on 13-Dec-2015

249 views

Category:

Documents


2 download

TRANSCRIPT

1

Biodiversity

2

BIODIVERSITY

• Includes a variety of factors Genetic Diversity – genetic variability

within a species Species Diversity – variety of different

species- Species Richness - Total number of species in a community.

Ecological Diversity – variety of abiotic and biotic factors

3

Factors That Increase Biodiversity

• Diverse habitat• Moderate environmental disturbance• Small variations in environmental

conditions• Middle stages of succession• Evolution

4

Factors That Decrease Biodiversity

• Environmental Stress• Large environmental disturbance• Extreme environmental conditions• Introduction of alien species• Geographic isolation• Severe limitation of essential

resources

5

How Many Species Are There ?

• Currently 1.7 million species identified.

• Estimates range between 3-50 million. May be 30 million insect species. Invertebrates make up 70% of all

known species, and probably most of yet to be discovered species.

• Tropical rainforests and coral reefs are biodiversity hotspots. NA and Europe only contain 10-15%.

6

Biodiversity Hotspots

7

BENEFITS OF BIODIVERSITY

• Food As many as 80,000 edible wild plant

species could be utilized by humans.• Drugs and Medicines

> ½ of all prescriptions contain some natural product.

8

Benefits of Biodiversity

• Ecological Benefits Soil formation, waste disposal, air and water

purification, nutrient cycling, solar energy absorption, and biogeochemical and hydrological cycles

• Aesthetic and Cultural Benefits Cultural diversity linked to biodiversity. USFWS estimates Americans spend $104

billion annually on wildlife-related recreation.

Ecotourism Intrinsic value.

9

THREATS TO BIODIVERSITY

• Extinction - Elimination of a species. Natural Causes

- In undisturbed ecosystems, ~ one species per decade.

In this century, human impacts have accelerated that rate, causing perhaps hundreds to thousands of extinctions annually.

10

Human-Caused Threats to Biodiversity

• Habitat Destruction Biggest reason for current increase

in extinction- Habitat fragmentation divides populations into isolated groups

Northern Spotted Owl

11

Habitat Fragmentation

12

Human-Caused Reductions in Biodiversity

• Alien Species Thrive in new territories-free of

predators, diseases, or resource limitations that limited them in original habitat.

13

Human-Caused Reductions in Biodiversity

• Pollution Pesticides Lead

• Population Human population growth

- Resource Use• Overharvesting

American Passenger Pigeon Whales

14

Human-Caused Reductions in Biodiversity

• Commercial Products and Live Specimens Wildlife smuggling is very profitable.

- Leopard fur / Rhinoceros horns U.S. Annual pet trade in wild species:

- 2 million reptiles- 1 million amphibians and mammals- 500,000 birds- 128,000,000 tropical fish

Cyanide released above coral reefs.

15

Human-Caused Reductions in Biodiversity

16

Human-Caused Reductions in Biodiversity

Predator and Pest Control• Many animal populations have been

greatly reduced or exterminated because they are regarded as dangerous to humans or livestock. Animal control costs $20 million in

federal and state funds annually.- 700,000 birds and mammals annually.

100,000 coyotes

17

Solutions to Protecting Wild Species

• Endangered Species Act-1973 Conservation of threatened and

endangered plants and animals and the habitats in which they are found

Endangered- are those considered in imminent danger of extinction.

Threatened are those likely to become endangered, at least locally, in the near future.

18

Endangered Species Act

• Regulates the following 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

19

Endangered Species Act

• Currently, U.S. has 1,300 species on its Endangered and Threatened lists, and about 250 candidate species waiting for consideration. Number 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.

20

Recovery Plans

• Once a species is listed, USFWS is required to propose a recovery plan detailing the rebuilding of the species to sustainable levels. Total cost of all current plans = $5

billion.- Some have been very successful.

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

21

Solutions to Protecting Wild Species

• International treaties Convention on International Trade in

Endangered Species (CITES)- Bans hunting, capturing and selling of

endangered and threatened species • Egg pulling-collecting wild eggs laid by

critically endangered species and hatching them in zoos or research centers

• Captive breeding-bred in captivity with the aim of reintroducing the offspring into the wild

• Wildlife Management Population management plans Saving critical habitat especially for

migratory species

22