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Today – finish biodiversity (Chapter 23) – start conservation biology (Chapter 25) Wednesday – conservation biology Friday – quiz! – conservation biology Monday – historical biogeography (Chapter 24) Wednesday – ecosystem management (outside reading)

Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

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Page 1: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Today– finish biodiversity (Chapter 23)– start conservation biology (Chapter 25)

Wednesday– conservation biology

Friday– quiz!– conservation biology

Monday– historical biogeography (Chapter 24)

Wednesday– ecosystem management (outside reading)

Page 2: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Conservation Biology - a mission-oriented science that focuses on protecting and restoring biodiversity

Biodiversity

1. All forms of life

2. All levels of organization (subpopulation to biosphere)

3. All interactions among forms of life and the environment

Page 3: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Where is the biodiversity?

• Endemic species – restricted to a small region– isolated areas (islands, mountain ranges)– product of unique habitat, climate features

Page 4: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Biodiversity hotspots - areas with a high concentration of endemic species, experiencing rapid habitat loss

Page 5: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Hotspots:– 1.4% of the land area– 44% of vascular plant species– 35% of terrestrial vertebrate species

• But…– 20% of the human population, which is…– growing at 1.8% per year (vs. 1.3%

worldwide)– each hotspot has already lost 70% of its

vegetation

Page 6: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Current Status of Biodiversity• 1.4 million described species, possibly

10 million in total

• Background extinction rate – rate of species loss in the absence of human activities– fossil record: species survive 1-10 million

years– one year: one species has a 1 in 1-10

million chance of going extinct– total: 1 extinction per year

Page 7: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Mass extinction – loss of large number of species– usually due to catastrophic volcano or

meteor impact– very rare (5 times in 3 billion years)

• Current rate of extinction???

Page 8: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 9: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Some estimates for current rate:– 1 species per hour– 1 million species total, so far– 10% of all species so far– 8.8% of all species– 27,000 species per year– 20% of neotropical plant species– 100 to 10,000 times the background rate

Page 10: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Numbers of threatened/endagered species:– 5,188 vertebrates (9%)– 1,992 invertebrates (0.17%)– 8,321 plants (2.89%)– 2 lichens (0.02%)

• Since 1600, ~1000 species have gone extinct (probably many more)

Page 11: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Why do species go extinct?

2 separate processes:

1. Something causes a large population to decline.

2. Small populations go extinct.

Page 12: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Causes of species declines

1. Habitat destruction and fragmentation

2. Introduced species

3. Exploitation and overharvesting

4. Pollution

5. Climate change

Page 13: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

USA

Page 14: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

1. Habitat destruction and fragmentation

Fragmentation – disruption of extensive habitats into small, isolated patches

Page 15: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 16: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 17: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 18: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 19: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 20: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 21: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Relaxation – loss of species from isolated habitats over time

Area

S

Page 22: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Edge effects – negative impacts adjacent to habitat boundaries

• Forest edges:– more sunlight– drying– high winds– tree mortality– invasive species– more predators

Page 23: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 24: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Core area

Edge area

• Core area – part of a patch not impacted by edge effects

• Patch size is not always the best predictor of patch quality

Page 25: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

2. Introduced species

• Humans are constantly moving species between continents, islands

– deliberate or accidental

• Most serious impacts on islands– low species diversity– few native predators– animals lack anti-predator defenses,

resistance to diseases

Page 26: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 27: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Characteristics of invasive species– pioneer species– high dispersal rates– found in disturbed habitats, but…– some can invade undisturbed communities

• Why are invasives successful?– no diseases, herbivores, parasites,

predators– better competitors than native species

Page 28: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Introduced diseases – exploit lack of evolved resistance– Dutch elm disease – American elm– Chestnut blight – American chestnut– avian malaria – Hawaiian birds– Rinderpest – African ungulates– chytrid fungus – amphibians

Page 29: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 30: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Net result of invasive species– homogenize ecological communities

around the world– drive native, endemic species extinct

Page 31: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

3. Exploitation and overharvest

• Direct exploitation for food– overfishing– “bycatch” in fisheries – killing non-target

species (birds, marine mammals)– “bush meat” – harvest of wild animals for

food• can be sustainable, but often not• threatens many large mammals, primates

Page 32: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 33: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Global trade in wildlife– birds, orchids, cactus, primates – captured for gardens, pets, zoos, etc.

• Many species driven extinct before hunting/harvest regulations were in place– passenger pigeon, island tortoises, marine

mammals

Page 34: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Exam

• Definitions, compare-contrast – 5 points each (20 points per page)

• 5 questions – 12 points per question

• bonuses – 3 points each

• dropped the question with the lowest score

• Average grade = 86

Page 35: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Causes of species declines

1. Habitat destruction and fragmentation

2. Introduced species

3. Exploitation and overharvesting

4. Pollution

5. Climate change

Page 36: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

4. Pollution

• Most important for aquatic systems– chemical pollutants– acid precipitation

• Bioaccumulation – process by which toxin concentrations increase in living tissues

– concentrations increase through the food chain

Page 37: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 38: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 39: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

5. Climate change

Page 40: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 41: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 42: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 43: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Why do small populations go extinct?

• Demographic stochasticity – chance events that occur at small populations size– failure to breed or survive– failure to find a mate– skewed sex ratio

Page 44: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Dusky Seaside Sparrow

Page 45: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Environmental effects – unpredictable events that reduce survival or reproduction– droughts, floods, fires, storms

• Genetic effects at small population size– inbreeding– genetic drift– random mutations

Page 46: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Extinction vortex – combination of genetic, environmental and demographic factors that drive a small population to extinction

Page 47: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Heath hen

• 1700 – throughout the northeast coast

• 1907 – 50 left on Martha’s Vineyard

• 1915 – 2000 birds

• 1916 – fire

• 1917 – goshawk invasion

• 1920’s – poultry disease

• 1927 – 13 birds, mostly males

• March 11, 1932 – last known sighting

Page 48: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 49: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 50: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 51: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

• Minimum viable population – smallest population has a specified probability of surviving for a certain time– usually 95% chance of surviving for 100

years

• How big?– at least 50 individuals to avoid

demographic stochasticity– at least 500 individuals to avoid genetic

effects– realistically > 1000 but varies by species

Page 52: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Reasons for protecting biodiversity

1. Intrinsic – valuable for its own sake

2. Instrumental – beneficial to humans

Page 53: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Instrumental Reasons for Protecting Biodiversity

1. Economic benefits– food– drugs– cultivated crops– ecotourism

Page 54: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

2. Ecosystem services – quantifiable services that an ecosystem provides to humans

– often very valuable economically

Examples:– moderating climates– mitigating floods and droughts– eliminating waste and toxins– pest control– pollination

Page 55: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Pollinators

• Insects pollinate 2/3 of crop species– ~25% of foods consumed

• U.S.: $20 to 40 billion in agriculture

• Evidence that many pollinators are declining– bats– honeybees

hummingbirds

Page 56: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

3. Maintenance of ecosystem function

• How many species can you safely remove?

• How do you ensure maximum productivity in managed or natural ecosystems?

Page 57: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

More diverse ecosystems are more stable

Page 58: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 59: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 60: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday
Page 61: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Diversity-productivity relationship

• How are plant species richness and primary productivity related?

• 3 possibilities:

Page 62: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday

Why would productivity increase with richness?

• Greater odds of encountering a super-productive species

• Complementarity – use of different resources by different species

Page 63: Today –finish biodiversity (Chapter 23) –start conservation biology (Chapter 25) Wednesday –conservation biology Friday –quiz! –conservation biology Monday