why is biodiversity important? - willis'...

Why is Biodiversity Important?

Species

Richness:

How many

species are in an

area

Why Maintain Diversity?

Ecosystem Services!

Oxygen creation

(phytoplankton)

To reduce floods and erosion

(vegetation)

To generate fertile soil…

To pollinate…

To cycle nutrients…

Bleeding Tooth

Fungus

To control agricultural pests!

Why We Need Species?

Economic Goods!

Why We Need Species?Sources of Food

Aspirin Codeine

Why We Need Species?Sources of Medicines

Provide us with recreation

Ecotourism: giving $$ to a country to view their environment.

Why We Need Species?

# of Species?

• 1.3 million catalogued

• ≈ 8.7 ± 1.3 mill

–Undiscovered: insects, fungi,

bacteria

• 1973 -illegal to import or trade products of E.S.

unless used for science (USFWS)

• Species on list cannot be “taken”, threatened,

killed, harmed: habitat can’t be harmed

Threatened Species

Species has few individuals and is

near becoming endangered.

Gelada Baboon

Grizzly Bear

Northern Spotted Owl

• Threatened-US ESA Habitat loss in Canada and No. US!

• Need old growth forest, top predators, and are specialists.

Species has fewer individuals; at risk

of becoming extinct.

Endangered Species

White Abalone

Barred Bandicoot

Case Study: California Condor• Scavenger bird;

eats dead

carcasses.

• 2005 = 273

individs.

• Endangered: low

birth rates, late

sexual maturity,

poaching, lead

poisoning, DDT,

and power lines.

X Ray shows bottle caps and

metal shards

Intrinsic Characteristics of E. S.

• Extremely localized/require LARGE territory

• Low birth rates

• Island species/extreme specialists

• Low adaptability

• Late sexual maturity

Species no longer exists on Earth.

1,138 documented today since 1600

Extinct Species

Tecopa Pupfish, CA

Yangtze River Dolphin• AKA Bajii

• Last sighting 2004

• Causes: heavy transportation on

river, overfishing,

dams, collision w/ boats, H2O

pollution.

Case Study: Passenger Pigeon• 200 yrs ago 3-5

billion

–world’s most abundant bird

–1 flock =10 mi wide, 100 mi long)

• Killed for its meat

• Martha died in 1914.

Types of Extinctions

• Background

extinction: 3-

30 species

die/yr

• Caused by

natural

selection.

• Mass Extinction:

1000’s spcs

die/yr

• Caused by

dramatic env.

change.

• 5-6 so far

• Humans causing

6th ??

• Too many people!

• Weak/no laws

• High consumption rates

Root Causes of Extinction

Humans Cause Extinction

Habitat Loss/ Habitat Fragmentation

Humans Cause Extinction

Hunting/Poaching

Humans Cause Extinction

Overfishing

Humans Cause Extinction

Capture and Sale of Exotics

2.5 million birds

caught illegally / yr

1 bird in store = 10 deaths in

transit

Humans Cause Extinction

Global Climate Change

Introduction of Non-Native Species –species that does not belong in area.

Humans Cause Extinction

Cane Toad Zebra Mussels in Great Lakes

Iceplant at Beach

Non-Natives/Exotics• Cause problems w/ native

species because:

1. Can usually outcompete

natives

2. Eat same food resources

as natives

3. No natural predators in

new area.

4. Reproduce w/ no limits on

growth.

Amer. Bullfrog in

CA

Crayfish in CA

International Laws

• CITES - Convention on the International

Trade of Endangered Species

–Created by IUCN

–Prohibits trade of live specimens or

products of 900 species on list

CITES

• Uses appendices

for classification.

• Appendix 1:

endangered.

• Appendix 2:

threatened.

• An org. can be on

both CITES and US

ESA!

Squirrel Monkey: App II

Ring-Tailed Lemur: App I

IUCN’s

Red List

• Assess

conservation

status of global

species.

• Use Critically

Endangered,

Endangered, and

Vulnerable.

Common Hippo: Vulnerable

Angel Shark: Crit. Endang.

International

Whaling Commission

• Regulates whaling

• Bans on gill-netting, purse seines

• Japan/Finland/Iceland no sign!

Marine Mammal Protection Act

• 1972, All marine mammals are protected • Prohibits "take” of marine mammals in U.S. waters and by U.S. citizens on the high seas