Conservation Bio- Exam 1

Front 1

biological species

Back 1

A group of actually or potentially interbreeding populations that are reproductively isolated from other groups

Front 2

Biodiversity: Function

3 Hypothesis

Back 2

1. Rivet
2. Drivers and Passengers
3. Portfolio Effect

Front 3

Rivet Hypothesis

Back 3

Lose just one species and bad things start to happen

--> linear relationship

Front 4

Drivers and Passengers
Hypothesis

Back 4

Some species are more important ("drivers") and function will decrease if they are lost
--> high function relies on a few species!

Front 5

Portfolio Effect Hypothesis

Back 5

Having more species hedges against catastrophe

--> Need lots of species for a gain in function

Front 6

Ecoregion

Back 6

Relatively large unit of land or water containing a geographically distinct assemblage of species, natural communities and environmental conditions

Front 7

Types of Biodiversity

Back 7

-genetic
-phenotypic
-community
-ecosystem
-landscape
-species

Front 8

How do we measure/quantify biodiversity?

Back 8

Alpha - measured locally, between patches at the same site
Beta - measures uniqueness between 2 sites
Gamma - overall diversity for al ecosystems w/in a large region

Front 9

Genetic Diversity
3 levels

Back 9

1. W/in an individual
2. W/in a population
3. Among populations

Front 10

Gene pool

Back 10

# of alleles and their frequencies in a population

-changes in frequency occur from: mutation, drift, non-random mating

Front 11

Mutation

Back 11

errors in replication/substitutions of a nucleotide sequence

Front 12

Genetic Drift

Back 12

random fluctuation of gene frequencies due to CHANCE

Front 13

Gene Flow

Back 13

movement of genes from one populations to another
--> High exchange = low divergence

Front 14

Natural Selection

Back 14

differential survival and reproduction of different genotypes

Front 15

Ne =

Back 15

= effective population size

or # of breeding individuals

Size of an ideal pop that has the same properties with respect to genetic drift as our actual pop does

Front 16

Bottleneck Event: ability to bounce back

Back 16

Relies on
- higher initial population
- faster growth rate

Front 17

r =

N0=

Back 17

r = growth rate

N0= initial population size

Front 18

ESU - Evolutionarily Significant Unit

Back 18

-distinct populations are based on genetic diversity
-a population that is reproductively isolated from other
conspecific populations and represents an important component in the evolutionary legacy of
the species

Front 19

Fst

Back 19

comparing variation in the subpopulation (s) to the total population (t)

--> large Fst = distinct pops
0 = no variation

Front 20

Why does a loss of genetic diversity matter?

Negative effects of loss...

Back 20

- Inbreeding
- accumulation of deleterious alleles
- outbreeding
- random loss thru genetic drift

Front 21

Demographics

Back 21

intrinsic factors that contribute to a population's growth rate (r) or decline

BIDE

Front 22

Murray 1990

Back 22

Density-dependence is more important/has stronger effects at low and high population densities

Front 23

Allee Effect

Back 23

total failure in a population increase at low densities
- not enough #s for the population to survive
- some spec require high density pops for reproduction or finding a mate

Front 24

Sources

Sinks

Back 24

- areas w/ a lot of resources,
B>D

- D>B

Front 25

Metapopulation

Back 25

an overall network of populations linked by I and E
- organisms flow between patches
- patches can lose all species and recolonize
- habitat = patch, matrix = space between patches

Front 26

Matrix

Back 26

space between patches

--> very important for facilitating movement and recolonization

Front 27

k=

Back 27

=carrying capacity

--> k in an equations represents density-dependence

Front 28

lambda =

Back 28

= annual rate of change
=0 - no growth
<1 - population decline
>1 - population increase

Front 29

Environmental Stochasticity

Back 29

changes in abiotic (environmental) factors effects population growth rate
--> stronger effect on fast growing pops

Front 30

Results of a population model

Back 30

-mean time to extinction
- median (less susceptible to outliers/skew)
- distributional histogram

Front 31

Sensitivity analysis

Risk based

Back 31

effect of each vital rate on the overall growth rate

- evaluating change by creating different models with adjusted risks

Front 32

PVA

Back 32

Population Viability Assessment
- known demographics are used to asses extinction risk
- simpified representation of a complex system

Front 33

Good models have:

Back 33

- long-term demogrpahic data
- include stochasticity
- density-dependence
-uncertainty/error
- genetic effects

Front 34

Deterministic models

Back 34

- have no stochasticity or DD
If there is no annual variability or fluctuation then the pop will move to a stable rate of growth and stable age distribution

Front 35

Stochastic models

Back 35

- No stable annual growth rate of age distribution
- demographic rates exhibit annual fluctuation
--> more stochasticity = a wider range of potential outcomes

Front 36

Adding density-dependence to a model

Back 36

- limits the growth capacity of the population
- maximum pop size is smaller

Front 37

Elasticity (in a model)

Back 37

- measures the contribution that each matrix element makes to the stable growth rate

Front 38

Species Invasions

Direct Impacts -

Back 38

-change in biodiversity
- reduction in abundance
- change in biotic interactions
- change in behavior, morphology , genetics

Front 39

Species Invasions

Indirect Impacts -

Back 39

- change in trophic relationships
- change in biotic interactions
- change in habitat structure/nutrient cycling

Front 40

Landscape -

Back 40

- a heterogeneous area containing a mosaic of patches
- influenced by physical template and the abiotic environment

Front 41

Corridor -

Back 41

facilitates movement between patches

Front 42

Influences on Landscape:
4

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1. Physical template, abiotic factors
2. Sum of small-scale events
3. Biotic interactions
4. Disturbances

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Disturbance

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- relatively discrete event that disrupts ecological processes and/or changes niche characteristics

Front 44

Factors of a disturbance that contribute to landscape and landscape change

Back 44

- frequency
- predictability
-magnitude
-synergirms

Front 45

Anthropogenic Disturbance

Back 45

- can cause permanent change!
- introduces novel/unprecidented disturbances (system hasn't evolved to deal w/ these)
- disturbance suppression

Front 46

Fragmentation + Disturbance

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- synergistic relationship
- increased edges from fragmentation lead to an increase in disturbances

Front 47

Importance of Disturbances

Back 47

- create and maintain landscape patterns
- species diversity

Front 48

MTE

Back 48

mean time to extinction

Front 49

Prediction vs Projection

Back 49

Predictions
- hard to make
- short term
Projections
- long term
- easier to make

Front 50

Habitat fragmentation-

Back 50

- loss or reduction in area, change in habitat configuration

Front 51

Lande Scenario

Back 51

Most species are driven to extinction before genetic factors have time to impact them
-demographic factors cause the extinction NOT loss of genetic diversity
- small pop don't have time to experience genetic losses

Front 52

Frankham's view

-importance of genetics

Back 52

-effects of the loss of genetic diversity (decrease in diversity) does increase risk of extinction
- effects can occur on an ecological time scale, leaving small pop's more susceptible

Front 53

Fragment (why it isn't just a patch)

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-reduction of size and connectivity on a shorter time scale
- no rich internal structure
-sharply delineated edges
-"fragment features" = roads

Front 54

Effects of fragmentation

Back 54

- intitial exclusion
- crowding from density increase
- sensitivity
- isolation (physical and genetic)

Front 55

Effects of roads (fragmentation)

Back 55

- mortality
- behavioral changes
-changes in drainage/habitat alterations

Front 56

Changes in processes (due to fragmentation)

Back 56

- increased predation
- decreased mutualism
- changes in abundance/trophic relationships
- nutrient availability/cycling

Front 57

Species richness-

Back 57

- # of organisms present in an area

Front 58

Species diversity -

Back 58

-species are weighted by some measure of their importance

Front 59

Structurally complex community-

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- more ways to exploit resources, greater variety of microclimates

Front 60

Hot spot-

Back 60

- area of unusually high endimism

Front 61

Founder effect-

Back 61

- when a few individuals establish new populations, the genetic constitution of which depends upon the genes of the founders

Front 62

Demographic bottleneck-

Back 62

- when a pop experiences a severe, temporary reduction in size. Decrease in genetic diversity.

Front 63

Genetic drift-

Back 63

-random change in gene frequencies

Front 64

Inbreeding depression-

Back 64

-reductions in fecundity, offspring size, growth or survivorship, changes
in age at maturity, physical deformities

Front 65

Density-dependent factors-

Back 65

- B and D are influenced by population density

Front 66

3 options for persistence in a fragmented landscape

Back 66

1. Species survives or thrives
2. Survives by maintaining viable populations (small home ranges)
3. Species is highly mobile