Lecture 23: Biogeography and Conservation Ecology

Question 1

Island Biogeography Theory givens

Answer 1

Immigration of individuals form mainland are constantly occurring

Deaths of individuals on the island are constantly occurring, at times causing extinction

Question 2

Theories of local species coexistence (how species pass biotic filter)

Answer 2

Niche differentiation
Janzen Connell
Neutral Theory

Question 3

Island Biogeography Theory

Answer 3

Immigration is higher if islands are close to the mainland
Extinction is higher if islands are smaller and population sizes of each species are thus smaller

Question 4

Niche differentiation

Answer 4

Lower overlap across species –> greater species richness
Lotka Volterra result: alpha, beta less than 1 helps with coexistence
Species with niche differences are more likely to coexist

Question 5

Janzen Connell Theory

Answer 5

Natural enemies prevent recruitment of offspring near their parents, thus facilitating coexistence among species

Ex. Specialist herbivores present seedings die
Specialist herbivores absent seedlings live

Question 6

Assumptions for Neutral Theory (hubbell)

Answer 6

Assume all species have equivalent vital rates (fecundity, survival)
Assume there is a constant number of individuals in the community
Once an individual dies, the open spot is filled at random by an existing individual

Question 7

Neutral Theory

Answer 7

All species equal, abundance will drift until you have a single species

Mechanisms that slow this march to extinction should increase diversity
- Proximity to other communities
- Number of individuals
- Area of the local community
- Speciation rate

Question 8

Criticisms of neutral Theory

Answer 8

Species are observably different
Distribution fitting is not great way to test mechanistic hypotheses

Question 9

Stable coexistence

Answer 9

When relative abundances of species are perturbed, mechanisms
direct them back.

Species tend to recover from low density

Niche differentiation, Janzen-Connell

Question 10

Unstable coexistence

Answer 10

When relative abundances of species are perturbed, nothing returns
them to the original state

Coexistence is maintained by immigration and speciation

neutral theory

Question 11

biodiversity can provide

Answer 11

stability

Question 12

Complementarity hypothesis

Question 13

Redundancy hypothesis

Question 14

Ecosystem functions

Answer 14

Plant productivity
Soil fertility
Water quality and availability
Atmospheric gas exchange
Resistance to disturbance

Question 15

Ecosystem services

Answer 15

Food and fuel production
Water purification
O2 and CO2 exchange
Protection from catastrophic
events like floods, tsunamis

Question 16

Richness is

Answer 16

species diversity

Question 17

Phylogenetic diversity is

Answer 17

genetic diversity

Question 18

Water availability is

Answer 18

Ecosystem diversity

Question 19

Conservation biology

Answer 19

scientific study of the phenomena that affect the maintenance, loss, and restoration of biodiversity

Question 20

Conservation

Answer 20

preservation and restoration of biodiversity

Question 21

Biodiversity

Answer 21

of individual species in a community
genetic diversity of each species
of communities
of ecosystems

Question 22

Rare species

Answer 22

low numbers
many ways to be rare

Question 23

Endemic species

Answer 23

rare
species found only in a certain area

Question 24

Threatened species

Answer 24

species at risk of becoming endangered in the near future

Question 25

Endangered species

Answer 25

species in danger of extinction locally or globally (biological definition)
species legally protected by Endangered Species Act (legal definition)

Question 26

Extinct species

Answer 26

locally or globally
no longer exist on Earth

Question 27

Reasons for preserving biodiversity

Answer 27

indirect economic benefits (ecosystem services)
direct economic benefits
aesthetic and recreational reasons

Question 28

Indirect economic benefits (ecosystem services) to why we should preserve biodiversity

Answer 28

carbon uptake and storage
erosion control nutrient uptake, which prevents downstream eutrophication
absorption of storm and hurricane energy

Question 29

Direct economic benefits to why we should preserve biodiversity

Answer 29

recreation

Question 30

Causes of loss of biodiversity

Answer 30

Land use change or habitat loss
Habitat degradation
Habitat fragmentation
Invasive species
Overexploitation
Conflicting human interests
Climate Change

Question 31

Land use change or habitat loss

Answer 31

Conversion of habitat to another use

Question 32

Habitat degradation

Answer 32

changes that reduce quality of habitat for many species

Question 33

Habitat fragmentation

Answer 33

breaking up of once-continuous habitat into series of patches

Question 34

Invasive species

Answer 34

species introduced
from outside their native range,
rapidly increasing in population size

Question 35

Overexploitation

Answer 35

fishing or
otherwise getting food from a
natural system at an unsustainable
rate

Question 36

Conflicting human interests

Answer 36

forest
management for deer or fowl versus
plant diversity, chickens versus
wolves.

Question 37

Climate change

Answer 37

Rapidly changing
temperature, rainfall, CO2
concentration, sea level all influence
ecosystems

Question 38

Think about problems to decrease biodiversity?

Answer 38

Biology is powerful (ability to adapt) and sensitive