19- Biodiversity and Society

Question 1

what does biodiversity mean?

Answer 1

= variability of life on earth and ecological complexes of which they are part
(not only what is there, but the processes that keep them going)

Question 2

what does diversity mean?

Answer 2

= a mathematical index of how to calculate the abundance and number of species in a system

Question 3

differences between biodiversity and diversity

Answer 3

Diversity is used as more of a ‘formula’, biodiversity is used in a more political sense to describe a number of things

Question 4

what is the current extinction rate compared to the background extinction rate

Answer 4

current extinction is 1000x more than background

Question 5

why are island species more vulnerable to extinction?

Answer 5

• small geographic range
• low population numbers
• native species that have evolved without contact with new invasive species are often unable to compete/ defend themselves

Question 6

what are the big 5 mass extinctions in history

Answer 6

1. End Ordivician
2. Late Devonian
3. End Permian
4. End Triassic
5. End Cretaceous
   - think about these relative to current rates of extinction.. (how dramatic the past was relative to today)
   - today’s extinction rate is really fast

Question 7

why should we care about conservation?

Answer 7

1. Ethics/ value of life
2. Medical reasons
3. Ecosystem services
   - direct (resources)
   - indirect (environment modification)
   - lifestyle (recreation)
4. Culture

Question 8

examples of medical reasons (reasons for conservation)

Answer 8

1. Plants provide medicine to humans.
   - rosy periwinkle treats leukemia
   - aspirin comes form plants
2. Plants provide medicine to animals.
   - chimps will swallow barbed leaves –> go through digestive track and hook onto worms/ parasites
   - red colubus monkey eat bitter bark.. why? to help with stomach pain

Question 9

examples of indirect services (reasons for conservation)

Answer 9

1. Climate control:
   - trees keeps cities cool
2. Physical stability:
   - taking away trees = no supporting structure for the soil = mudslides
   - coral reefs provide protective barrier + control waves

Question 10

examples of cultural reasons (reasons for conservation0

Answer 10

Wildlife and landscapes as expression of culture (part of identity).
- China protecting the panda –> successful conservation efforts
But sometimes they work in the other way
- cultural practice of hunting

Question 11

growth of tourism

Answer 11

1. tourism is the second largest industry in the world
2. adventure tourism is the fastest growing segment of the tourism industry
3. in developing countries, tourism makes up 1/3 of their trade in goods and services

Question 12

specific cases of the value of tourism

Answer 12

1. Kenya = $835 million from tourism

2. Costa rica = $1.7 billion from tourism

Question 13

pros and cons tourism

Answer 13

• most tourism –> money does NOT go towards local
• locals have little incentive to conserve
• money from tourism can be exploited or stolen by higher up officials
• the good thing is that tourism stops tea plantation from happening (which is a big threat to deforestation)

Question 14

what is the darwin/macarthur model

Answer 14

• increasing species richness increases the stability of ecological function
• implies that species occupy a “niche” ecological function
• assumes that species can be continually added to a community without saturating it
• assumes that the strength and breadth of ecological functions do not vary among species

Question 15

what is the idiosyncratic model

Answer 15

• ecological function varies idiosyncratically as species richness
• argues that you can’t determine a species value, so you have to protect everything
• if you remove something –> you don’t know what will happen

Question 16

what is the rivet model

Answer 16

• assumes that ecological function space is small
• therefore as species are added to an ecosystem, their functions begin to overlap –> allows ecological function to persist despite the loss of a limited number of species
• however, the increase of stability gained by adding new species decreases as functional space becomes more and more crowded
• like rivets on an airplane: if you pull one or two off –> nothing happens
• but once you pull of the critical rivet –> the wing of the plane falls off

Question 17

what is the passengers and drivers model

Answer 17

• ecological function is unevenly distributed among species
• some species have huge impacts (drivers) and some have minimal impact (passengers)
• the addition of drivers increases the stability of the system, while passengers have little or no effect
• related to keystone species

Question 18

what is a keystone species

Answer 18

= a species on which other species in an ecosystem largely depend, if it were removed the ecosystem would change drastically
- ex: when sea otter populations declined from overhunting –> sea urchin population increased –> overharvested kelp –> fish population declined

Question 19

idea of multiple stable states

Answer 19

• ecosystems can move between states (ex: savanna to forest to grassland)
• as soon as you go over the ‘peak’ –> will roll downhill and shift dramatically

Question 20

3 regeneration methods to restore ecology

Answer 20

1. enrichment planting
2. pine plantation
3. simply fire protection

Question 21

how fast is the forest regenerating in Africa?

Answer 21

• very slowly (or not at all)

Question 22

how fast are animal species recovering in africa?

Answer 22

• in about 10 years: recovery of almost all animals

- the only species that hasn’t come back is the blue monkey (don’t know why)