Unit 1 - MSH - Complexity & Gap Dynamics

Question 1

definition: the process of development that over time, gradually and predictably changes the biological community

Answer 1

succession

Question 2

What drives succession forward? What replaces one community with another over time?

Answer 2

facilitation

Question 3

What is the broad framework of succession?

Answer 3

bare rock–> lichens–> small annual plants/ moss–> perennial herbs/grasses–> shrubs/shade-intolerant trees–> shade-tolerant trees

Question 4

What makes up the climax community in succession?

Answer 4

shade-tolerant trees

Question 5

What makes up the pioneer stages in succession?

Answer 5

bare rock, lichens, & small annual plants/moss

Question 6

What makes up the intermediate stages in succession?

Answer 6

perennial herbs/grasses & shrubs/shade-intolerant trees

Question 7

Where do we find primary succession?

Answer 7

mountain tops, glacial retreat, parking lots, granite outcrops

Question 8

Does the pumice plain experience primary or secondary succession? Why?

Answer 8

secondary; tephra, although nutrient poor, is still soil, things can put down roots, not solid bare rock but rock dust

Question 9

What was the succession process like on MSH?

Answer 9

lupine–> fireweed, pearly everlasting–> willows/red alder–> noble fir/Douglas fir/red cedar

Question 10

What makes up the pioneer stages in succession on MSH?

Answer 10

lupine & fireweed/pearly everlasting

Question 11

What makes up the intermediate stages in succession in MSH?

Answer 11

willows, red alder

Question 12

What makes up the climax community in succession in MSH?

Answer 12

noble fir/Douglas fir/red cedar

Question 13

Are all successional pathways the same? why?

Answer 13

no, random variation can lead to different outcomes

Question 14

definition: the “final” stage that will persist as a static ecosystem and will continuously regenerate itself

Answer 14

climax community

Question 15

Why are shade-tolerant trees often a part of the climax community?

Answer 15

they are able to grow underneath the shade that their parents are providing; the last stage is self-perpetuating; shade tolerant trees are able to regenerate themselves

Question 16

How does soil development change with succession?

Answer 16

soil accumulates in volume, depth, and nutrients over time

Question 17

What particular part of the soil changes with a good amount of time?

Answer 17

stratification - the development of layers

Question 18

With succession: over time, what increases?

Answer 18

complexity

Question 19

What does the succession progression look like in the Midwest/Northeast?

Answer 19

exposed rocks–> lichens and mosses–> annual weeds–> perennial weeds & grasses–>shrubs–>aspen, cherry & young pine forest–>beech and maple broadleaf forest

Question 20

What are 3 types of complexity we observe?

Answer 20

(1) structural - horizontal vs vertical
(2) soil complexity
(3) biodiversity - species richness

Question 21

What does vertical complexity mainly look at?

Answer 21

the layers of a forest

Question 22

What are the different layers of a forest with regards to vertical complexity?

Answer 22

soil–> forest floor–> understory/shrub layer–> sub canopy–> canopy

Question 23

Did the old growth forest on MSH have vertical complexity pre-eruption?

Answer 23

yes, almost every inch was full of life

Question 24

Did the blowdown zone have much vertical complexity post-eruption?

Answer 24

no, only a few plants on the forest floor and then really tall trees w/no leaves (not much in the middle)

Question 25

What does horizontal complexity mainly look at?

Answer 25

patchiness - how many different kinds of communities exist right next to each other

Question 26

Is complexity just based on time since eruption? What else is it based on?

Answer 26

distance from eruption: closer to greater: least vertically complex further away forest: more vertically complex

Question 27

Which type of farming, traditional or permaculture, has more vertical complexity? Why?

Answer 27

permaculture; traditional ag is very low to the ground while permaculture contains all different levels

Question 28

Which type of farming, traditional or permaculture, has more horizontal complexity? Why?

Answer 28

permaculture; permaculture has more patchwork in a small space while traditional ag just has a few species grown in longs rows

Question 29

Do ecosystems only change in one direction with succession?

Answer 29

no

Question 30

What can push change in the other direction with regards to succession?

Answer 30

a disturbance

Question 31

What acts in opposition to succession?

Answer 31

disturbance

Question 32

How does disturbance lead to horizontal complexity?

Answer 32

disturbance allows succession to be constantly occurring at different stages and scales, forming more patches

Question 33

What type of complexity does a disturbance cause more of?

Answer 33

horizontal - forms patches

Question 34

definition: when little disturbances happen gradually and accumulate over time this will lead to more patches that exist in different successional stages

Answer 34

dynamic equilibrium

Question 35

What two things together over a period of time create an ecosystem in dynamic equilibrium?

Answer 35

succession & disturbance

Question 36

What is the early-successional forest of MSH?

Answer 36

willows/red alder

Question 37

What is the late-successional forest of MSH?

Answer 37

noble fir/Douglas fir/red cedar

Question 38

What is the term for an ecosystem that is in a constant state of flux/change due to disturbance and succession?

Answer 38

dynamic equilibrium

Question 39

What are two important characteristics of dynamic equilibrium?

Answer 39

(1) develops over time (2) contains patches in DIFFERENT successional stages

Question 40

What type of complexity increases with small-scale disturbances?

Answer 40

horizontal

Question 41

A forest in ________ might have a patch of climax community (red cedar trees) next to a patch of grass.

Answer 41

dynamic equilibrium

Question 42

In dynamic equilibrium: overall high ______ complexity some patches with high _____ complexity and some with low _____ complexity depending on successional stage

Answer 42

horizontal; vertical

Question 43

What happens to biodiversity over time with succession?

Answer 43

increases - more species in different layers

Question 44

What happens to biodiversity when we add disturbance (dynamic equilibrium)?

Answer 44

increases - many different biological communities right next to each other in equilibrium

Question 45

What is the first species that secondary succession starts with?

Answer 45

small annual plants (completely skips bare rock and lichen stage)

Question 46

Why are some places more biodiverse than others?

Answer 46

(1) time - succession and dynamic equilibrium develop over time (2) ecosystem complexity - horizontal and vertical; topographic (3) more energy in the system

Question 47

Where does energy in an ecosystem come from? In what locations is this energy most abundant?

Answer 47

sun/solar energy - most abundant in places near the equator

Question 48

Why do mountains have such high biodiversity?

Answer 48

dynamic equilibrium at different elevations & contains different biomes in a condensed fashion

Question 49

How does species richness at the equator compare to that at the poles?

Answer 49

equator: very high poles: extremely low

Question 50

More energy in the system = more _____

Answer 50

biodiversity

Question 51

What is the relationship between number of plant species and degrees Latitude increasing from 0 out N or S?

Answer 51

negative - further from equator, less plant species present

Question 52

What are two main reasons that biodiversity is advantageous to a place?

Answer 52

higher resistance & resilience

Question 53

What is the main ecological reason for why biodiversity is important?

Answer 53

the more biomass in an ecosystem, then less likely to be impacted as heavily by disturbances

Question 54

What is the relationship between the number of plant species before a drought and change in biomass?

Answer 54

negative; more plant species = lower change in biomass

Question 55

As the number of species increases, the amount of biomass lost in a disturbance _____.

Answer 55

decreases

Question 56

definition: total weight of all the LIVING things in an area

Answer 56

biomass

Question 57

definition: ability to prevent impacts from disturbances

Answer 57

resistance

Question 58

Do ecosystems with high biodiversity change drastically with a minor disturbance? Why?

Answer 58

no because of more species leading to redundancy; if one species is lost, another can fill in its position

Question 59

If there is 0 change in biomass, then an ecosystem is completely ______ to disturbance (impossible).

Answer 59

resistant

Question 60

definition: ability to recover after a disturbance

Answer 60

resilience

Question 61

Ecosystems with ___ biodiversity recover faster from disturbances.

Answer 61

high

Question 62

Why are ecosystems with high biodiversity more resilient to disturbances?

Answer 62

as a community accumulates species, there is a higher chance of any one of them having traits that enable them to adapt to a changing environment

Question 63

definition: ecosystems are more CONSISTENT over long periods of time

Answer 63

stability

Question 64

higher biodiversity = more ______

Answer 64

stability

Question 65

Why is high biodiversity important to the stability of an ecosystem?

Answer 65

species with high genetic diversity and many populations adapted to a wide variety of conditions are more likely to be able to withstand weather disturbances, disease, and climate change

Question 66

What is the term that refers to the capability of a natural system to apply self-regulating mechanisms so as to return to a steady state after a disturbance?

Answer 66

stability

Question 67

Under what conditions is an ecosystem said to possess ecological stability?

Answer 67

if its capable of returning to its equilibrium state after a disturbance or does not experience unexpected large changes in its characteristics over time

Question 68

If an ecosystem is stable for a long period of time, what will happen to complexity and biodiversity?

Answer 68

increase

Question 69

Why are stable ecosystems not characterized as static?

Answer 69

they still experience changes and add complexity with minor disturbances

Question 70

Increased biodiversity, increased _______, increased ______ (positive feedback loop).

Answer 70

complexity, stability

Question 71

What is an example how organisms in an ecosystem with great biodiversity have higher stability>

Answer 71

organisms rely on more than one type of food, so if a food source gets wiped out by a disturbance, they have others to rely on

Question 72

What are 2 major advantages to a population?

Answer 72

(1) genetic diversity (2) ecosystem complexity

Question 73

What are some other disciplines that the ideas of resilience and stability span across?

Answer 73

ecological and social

Question 74

definition: openings in a forest canopy (due to a disturbance) where new trees can grow

Answer 74

forest gaps

Question 75

What is the advantage of a forest gap?

Answer 75

increased sunlight reaches the forest floor for plants to take advantage of

Question 76

What is the goal when trying to fill the gap?

Answer 76

to reach the canopy

Question 77

Why do trees want to reach the canopy?

Answer 77

increased fitness - more energy

Question 78

Is there an evolutionary trade off with short vs long-term strategies?

Answer 78

yes

Question 79

definition: a situation in which evolution cannot advance one part of a biological ecosystem without distressing another part of it

Answer 79

evolutionary trade off

Question 80

Explain how colored feathers are an evolutionary tradeoff?

Answer 80

pro: they help attract mates con: they are more easily spotted by predators

Question 81

What type of trees are the first species to come in and establish in a gap that forms?

Answer 81

early successional trees (hares)

Question 82

What type of trees can establish underneath an existing canopy and slowly make their way to the canopy themselves?

Answer 82

late successional trees (tortoises)

Question 83

What are 4 traits involved with trees?

Answer 83

(1) maximum growth rate (2) persistence (3) shade tolerance (4) longevity

Question 84

definition: how fast a tree is able to grow given ideal conditions (some trees are better at growing faster than others)

Answer 84

maximum growth rate

Question 85

definition: how little growth a tree can sustain without dying (all about height of a tree)

Answer 85

persistence

Question 86

definition: how much light a tree requires in order to live (maintain a positive carbon balance)

Answer 86

shade tolerance

Question 87

definition: max life-span of a tree

Answer 87

longevity

Question 88

What is the trade off between maximum growth rate and persistence?

Answer 88

an early successional tree that can grow at fast speeds also can be likely to die very quickly

Question 89

Early successional trees (high/low): max GR: persistence: shade tolerance: longevity:

Answer 89

high low low low

Question 90

Late successional trees (high/low): max GR: persistence: shade tolerance: longevity:

Answer 90

low high high high

Question 91

What is the relationship between shade tolerance & max growth rate?

Answer 91

negative

Question 92

Do shade tolerant trees grow fast?

Answer 92

no - they are slow steady growers

Question 93

example of evolutionary tradeoff: although late successional trees can live longer, they can't grow very _____

Answer 93

fast

Question 94

What is the relationship between shade tolerance and lifespan?

Answer 94

positive

Question 95

Over very long periods of time, which kinds of trees will accumulate in the canopy? Why?

Answer 95

shade tolerant trees because they can live a long time (high longevity) and can regenerate themselves

Question 96

example of evolutionary tradeoff: although early successional trees have a high growth rate, they can't _____ for very long (low _____)

Answer 96

survive; longevity

Question 97

What is the order of tree species on MSH from early successional (1) to late successional (4)?

Answer 97

(1) red alder (2) noble fir (3) Douglas fir (4) red cedar