Test #3

Question 1

6 Life History Traits

Answer 1

Age @ Maturity
# and Frequency of reproductive events
Size and # of offspring
Parental care

Question 2

R vs K Strategies

Answer 2

R - emphasis on fast reproduction (mice)

S - emphasis on survival (whale)

Question 3

Pianka’s Pattern of Traits

Answer 3

R - Young and small @ 1st reproduction, few breeding events, many small offspring
S - Old and large @ 1st reproduction, many breeding events, few large offspring

Question 4

What are Grime’s Plant Strategies based upon?

Answer 4

Disturbance (destruction of living biomass) and Stress (Growth limitation due to unfavorable conditions)

Question 5

C stands for? Explain…

Answer 5

Competitors - low stress, rare disturbance - grow fast and outcompete others - Cattail

Question 6

S stands for? Explain…

Answer 6

Stress Tolerators - high stress, rare disturbance - slow growing, long living - Wintergreen

Question 7

R stands for? Explain…

Answer 7

Ruderals - low stress, frequent disturbance - short lived, fast-reproducing - foxtail barley

Question 8

No plants? Explain…

Answer 8

High stress, frequent disturbance - slow growing destroyed too frequently

Question 9

2 types of Community borders are?

Answer 9

Discrete - abrupt transitions - often coincide with steep changes or land use by humans
Continuous - gradual transitions

Question 10

Define: Ecotone

Answer 10

Transition zone of a continuous community

Question 11

Explain Clements Concept (Organismal Community)

Answer 11

• community unit hypothesis
• community as closely integrated entity of mutually independent organisms
• discrete borders
• predictable end point - climax community
• Evidence - he was raised in the prairies and viewed vastness of plains

Question 12

Explain Gleason’s Concept (individualistic/continuum)

Answer 12

• no single climax - continuum of communities
• Whittaker - continuous change of comm composition
• Evidence - elevation gradients in USA demonstrated that forests changed gradually in species comp without sharp boundaries

Question 13

2 Types of Functional Organization

Answer 13

• Guild - Share resource (nectar)

- Functional Group - Process resources in a similar way (fixing atmos N)

Question 14

Define: Niche

Answer 14

role of species in a comm - involves all env factors that limit distribution, growth and reproduction

Question 15

Define: Herbivory

Answer 15

Herbivores can have major impact on a community - outbreaks can weaken trees - BUT provides more light for herbs

Question 16

Define: Predation

Answer 16

Reduce herbivore populations - can lead to improved plant growth - ladybug larvae can be used as a mean for pest management in greenhouses

Question 17

Define: Competition

Answer 17

resources in limited supply are being competed for - competitive ability strongly influences species abundance and presence

Question 18

Define: Competitive Exclusion

Answer 18

Similar niches - one outcompetes the other when no variation in env

Question 19

Define: Competitive Release

Answer 19

a species can spread out when a competitor is eliminated

Question 20

Define: Mutualism

Answer 20

both partners benefit - mycorrhizae

Question 21

Define: Obligate Mutualism

Answer 21

Organisms cannot live apart

Question 22

Define: Parasitism

Answer 22

one partner benefits, the other dies - strangler figs gain support from trees, trees die

Question 23

Define: Commensalism

Answer 23

One partner benefits, not effect on other partner - liches supported on tree, not harmful for tree

Question 24

Define: Facilitation

Answer 24

Organisms interacting in positive ways - hemlock uses fallen logs to regenerate moss-rich forests

Question 25

Define: Fundamental Niche

Answer 25

Full range of env tolerances

Question 26

Define: Realized Niche

Answer 26

Range of tolerances restricted by others

Question 27

Define: Keystone Species

Answer 27

communities often have a dominant species for each trophic level - removal of keystone species results in a change in comm composition

Question 28

Explain: Connell's Intermediate Disturbance Hypothesis

Answer 28

- Species richness is at its highest at intermediate disturbance - High levels - species fail to establish - Low levels - competitively superior species suppress others

Question 29

Resource Control (bottom-up) vs. Consumer Control (top-down)

Answer 29

R - consumer abundance determined by food limitation | C - abundance of species limited by consumers

Question 30

Define: Tropic Cascade

Answer 30

- serial change of pop abundance across trophic levels from top-down - Ex)abundance of seed in a year - leads to increased pop of small rodents - leads to more food for predators

Question 31

Explain: Multiple Stable States (4 states)

Answer 31

- Stable - occurs when comm resides in a valley - Resilient - comm will return to valley when subject to small displacement - Change - if change occurs, comm may shift or move into another valley - New stable state - reversal of change may not result in a return to original valley, may make new valley

Question 32

Resilience vs Resistance

Answer 32

Resil - succession restores original comm | Resis - system can avoid being disturbed

Question 33

5 Types of Disturbances

Answer 33

- Micro - small scale - death of a tree - Large - affect entire comm - wildfire - Biological Agents - insects which erupt to high densities - spruce budworm - Invasive non-native pathogens - fungal - chestnut blight decimated american chestnut forest - Anthropogenic - small scale (harvesting trees) or large scale (forest clearing)

Question 34

Define: Succession

Answer 34

community level recovery - sedge meadow is a seral stage in succession following a collapse of a beaver dam

Question 35

Define: Seral Stages

Answer 35

sequence of community types

Question 36

Define: sere

Answer 36

seral stages together

Question 37

Define: Climax

Answer 37

final stage of succession

Question 38

5 Types of Climax

Answer 38

- Mono - all successions lead to same end point - Edaphic - related to local soil conditions - Disclimax - regular disturbance - Pyroclimax - regular disturbance in case of a fire - Polyclimax - multiple steady state endpoints

Question 39

Define: Hydrosere

Answer 39

begins with young lake after glacial melting - initial accumulation slow - may eventually turn into wetland

Question 40

Define: Lithosere

Answer 40

Succession on bare rock - after glacial retreat or volcano - begins with lichens, algae and moss

Question 41

Define: Psammosere

Answer 41

succession on sandy substrate - shore - moving substrate is a stressor to plants

Question 42

Explain: Facilitation, Tolerance and Inhibition Models

Answer 42

- F - earlier stages are required for later states to occur - liches create substrate for grasses that create substrate for trees - T - vary in ability to utilize and tolerate conditions and resources - colonizing species are displaced at later stages because they cannot tolerate shady conditinos - I - early successional species prevent/delay establishment of others - dense litter layer of grasses prevent establishment of trees

Question 43

Define: Serotiny

Answer 43

serotinous seeds stay for years on the plant - release triggered by an env factor - cones of pine trees release during heat of fire and seeds are shed - eventually seedlings will emerge and regenerate

Question 44

Define: Chronosequence

Answer 44

studying different ages - succession can last over centuries - can study by comparing different seres at different ages - be careful that sites and climatic conditions may differ over time

Question 45

Define: Palynology

Answer 45

Study of pollen grains in sediment

Question 46

Explain: Primary vs Secondary Succession

Answer 46

- P - succession in an initially abiotic env (landslide, volcano) - S - some life survives initial distubance - secondary starts with presence of organisms

Question 47

Explain: Comm structure and function change during succession

Answer 47

- OM & C decrease at disturbance but increase during succession - Disturbance leads to loss of N & K, increase P - levels return to normal during succession - Disturbance decreases transpiration - Disturbance reduces structural complexity