Ecology Test Three

Front 1

Resources -

Back 1

Limited -
Limited by a single resource that is most scarce
Shared -
Resources (Niche) = competition

Front 2

Interference -

Back 2

Direct aggressive interaction between individuals

Front 3

Exploitation -

Back 3

Consumption and deplietion of resources

Front 4

Intraspecific -

Back 4

Competition with members of own species (conspecifics)

Front 5

Interspecific

Back 5

Competition between individuals of two species (heterospecifics)

Front 6

Competition results in -

Back 6

Survivorship
Growth
Reproduction

And ultimately -
Distribution
Evolution

Front 7

Similar requirements =

Back 7

similar niches

Front 8

Niche as defined by J. Grinnell -

Back 8

an organisms home where it lives
potential distribution in the absence of any interspecific interactions (predation, competition)

Front 9

Niche by Charles Elton -

Back 9

Species to members of human community
Across communities there are similar roles (doctor, lawyer, etc.)
Each species has a role
Some roles exist across multiple communities
(dominant producer, top vertebrate carnivore)

Front 10

G. G. Gause Competitive Exclusion

Back 10

Two species with identical niches cannot coexist indefinitely. One will have higher fitness and eventually exclude the other

Front 11

Conditions for CES

Back 11

Rare species not favored demographically
Species have opportunity to compete
Environment is spatially and temporally constant
long enough time has passed for exclusion
Growth limited by one resource
No immigration

More of these - bigger number of species that can coexist

Front 12

Realized niche -

Back 12

includes interactions such as competition that may restrict the potential envrionments where a species may live

Front 13

Example of physical separation of niches -

Back 13

Barnacles

Front 14

Criteria for demonstrating character displacement -

Back 14

Sympatric vs. allopatric character differences
Differences must be heritable
Differences must NOT be due to founder effect
Character must have known effect on resource use
Competition must be demonstrated and must be correlated with character similarity
Differences in character must not be due to differences in resource availability

Front 15

Predators -

Back 15

Kill prey immediately after attacking them
Consume several or many prey over a lifetime

Front 16

Herbivores/Grazers -

Back 16

Don't typically kill prey
Only partially consume individuals
Consume several prey over a lifetime

Front 17

Parasites -

Back 17

Typically do not kill prey
Only consume part of prey
Attack only one or very few prey over a lifetime

Front 18

Parasitoids -

Back 18

Kill prey over prolonged period
Young consume most of prey (from inside out)
Attack only one or very few prey in a lifetime
Mainly Hymenoptera and Diptera

Front 19

Pathogens

Back 19

Cause disease (debilitation sometimes severely) in hosts

Front 20

Exploitation result in -

Back 20

Some form of fitness decrease

Front 21

Conditions for CES

Back 21

Rare species not favored demographically
Species have opportunity to compete
Environment is spatially and temporally constant
long enough time has passed for exclusion
Growth limited by one resource
No immigration

More of these - bigger number of species that can coexist

Front 22

Realized niche -

Back 22

includes interactions such as competition that may restrict the potential envrionments where a species may live

Front 23

Example of physical separation of niches -

Back 23

Barnacles

Front 24

Criteria for demonstrating character displacement -

Back 24

Sympatric vs. allopatric character differences
Differences must be heritable
Differences must NOT be due to founder effect
Character must have known effect on resource use
Competition must be demonstrated and must be correlated with character similarity
Differences in character must not be due to differences in resource availability

Front 25

Predators -

Back 25

Kill prey immediately after attacking them
Consume several or many prey over a lifetime

Front 26

Herbivores/Grazers -

Back 26

Don't typically kill prey
Only partially consume individuals
Consume several prey over a lifetime

Front 27

Parasites -

Back 27

Typically do not kill prey
Only consume part of prey
Attack only one or very few prey over a lifetime

Front 28

Parasitoids -

Back 28

Kill prey over prolonged period
Young consume most of prey (from inside out)
Attack only one or very few prey in a lifetime
Mainly Hymenoptera and Diptera

Front 29

Pathogens

Back 29

Cause disease (debilitation sometimes severely) in hosts

Front 30

Exploitation result in -

Back 30

Some form of fitness decrease

Front 31

Algal bacterial populations -

Back 31

Reduced by caddisfly larvae

Front 32

Exploitation and abundance -

Back 32

Prickly Pear cactus in australia - Moth found to be effective predator. Reduced by 3 orders of magnitude in 2 years.

Front 33

Examples of predator prey -

Back 33

Lynx and snowshoe hare
Hudson's Bay Company measured the furs brought in

Front 34

Predators can account for -

Back 34

60-98% of mortality during peack densities

Front 35

Lotka -

Back 35

Moth and butterfly larvae and parasitoids

Front 36

Volterra -

Back 36

Marine fish populations

Front 37

Lotka Volterra assumes host population -

Back 37

Grows exponentially, and population size is limited by parasites, pathogens, and predators.

Front 38

Utida -

Back 38

Found reciprocal interactions in adzuki bean weevils and a parasitoid wasp over several generations.

Front 39

Lab experiments recreating curve-

Back 39

Led to the extinction of one population within a relatively short period.

Front 40

Best way to do this -

Back 40

Paramecium experiments
Need refuges in order to do that.

Front 41

Protection in Numbers -

Back 41

Living in large groups provides a refuge
Prey reduce individual probability of being eaten by living in dense populations

Front 42

Life history characteristics -

Back 42

The reproductive habit of some tree species where populations produce large seed crops (fruits) synchronously in some years and small seed crops otherwise

Front 43

Predator satiation by Janzen -Australian tree -

Back 43

Seed predation is a major selective force favoring mast crop production

Front 44

O'Dowd and Gill -

Back 44

Eucalyptus trees disperse seeds at the same time which reduces losses to ants

Front 45

Predator Satiation Periodical Cicadas -

Back 45

Emerge as adults every 13-17 years
Huge densities
1,063,000 cicadas emerged from 16 ha study site
50% emerged during four consecutive nights
Losses to birds was only 15% of production

Front 46

Periodical Cicadas Effects of Resource Pulse -

Back 46

Increased amounts of soil microbes, fungi and soil nitrogen
Faster growing trees
Bigger seeds in some flowering plants

Front 47

Types of refuges -

Back 47

Space
Numbers
Size

Front 48

Size as a Refuge -

Back 48

Large individuals ignored by predators - serves as a refuge
Mayflies tried to make themselves look bigger in the face of stoneflies
In terms of the foraging theory - large size makes it unprofitable to attack.

Front 49

Competition
Predation
Herbivory
Parasitism
Disease

Back 49

Species
A - B
- -
- +
- +
- +
- +

Front 50

Mutualisms -

Back 50

Evolve if benefits outweigh costs
Plants and Fungi
Mycorrhize = fungus roots
VAM = Vesicular-Arbuscular Mycorrhizae
Aka endomycorrhizae
Ectomycorrhizae

Front 51

Why mycorrhizae -

Back 51

plant benefits - water and nutrients

Fungus benefits - food (energy) from exudates

Front 52

Defensive Mutualism -

Back 52

Ants and Acacia - lowers shoots with herbivorous insects

Front 53

Coral -

Back 53

Zooxanthellae + coral + crustaceans
Corals occupied b pistol shrimp and crabs are attacked less frequently than are corals without these crustaceans

Front 54

Indigenous African woodpeckers and indegenous African tribe -

Back 54

Honey guide = 3.2 hours to find nest
Without = 8.9 hours

Front 55

Commensalism -

Back 55

One species benefits from another without damaging it

Front 56

Honey guide when getting closer -

Back 56

Time between stops declines -
Perches lower and lower to the ground

Front 57

Summary -

Back 57

Commensalism and mutualism are similar in the sort of possible benefits
Plants exhibit many kinds of mutualisms, almost always they must give up energy (energy is often one benefit gained by a mutualist even without plants)
Environment affects the kinds of mutualisms that can develop
Costs must be less than benefits for mutualism to evolve

Front 58

Species Richness -

Back 58

Number of different species in a given area.

Front 59

Species evenness -

Back 59

Relative abundance of species in a given habitat, biotope, community or assemblage.

Front 60

Shannon Weiner Index -

Back 60

Quantifies Species Diversity
Weaknesses -
Can't tell if differences due to richness or evenness
Can't compare unequal sample sizes use rarefaction

Front 61

Quantification of Species Diversity -

Back 61

Rank abundance curves - plot relative abundance vs. abundance rank (most to least)

Front 62

Food web trophic levels -

Back 62

rarely exceed 4 or 5
Energy flow hypothesis
Dynamic stability hypothesis

Front 63

Proportion of organisms in each trophic level relatively constant

Back 63

Ratio of prey to predator is roughly 2-3:1

Front 64

Stability of community structure depends on -

Back 64

strength of interactions

Front 65

Experimentally removing a species -

Back 65

powerful tool in unraveling the workings of a food web

Front 66

General expectations?

Back 66

predator - prey
competitor - competitor

Front 67

Direct effects -

Back 67

Removal of one species releases others from competition or predation or, if it is a plant, results in decrease in herbivores

Front 68

Indirect effects -

Back 68

Removal of one species does not result in changes in linked species due to compensatory effects within the food web

Front 69

Keystone Species -

Back 69

A species that exerts a large, stabilizing influence throughout an ecological community, despite its relatively small numerical abundance

Front 70

Dominant Species -

Back 70

Ecological cominance is teh degree to which different species in an ecological community predominate. In most communities, one or a few species are most numerous, or form the bulk of the biomass - these are the dominant species. Most ecological communities are defined by their dominant species.