Unit 1 - Mount St Helens Background Info

Question 1

What defines an ecosystem?

Answer 1

pre & post eruption

Question 2

What defines a species as members of populations that actually or potentially interbreed in nature, NOT according to similarity of appearance?

Answer 2

biological species concept

Question 3

What defines all of the individuals of a SINGLE species that interact?

Answer 3

population

Question 4

What defines all of the populations of LIVING things that interact in a place?

Answer 4

community

Question 5

What defines a biological community of interacting organisms and their physical environment (biotic and abiotic components)?

Answer 5

ecosystem

Question 6

How does a community differ from an ecosystem?

Answer 6

community is based solely on organisms and within an ecosystem the physical environment is included

Question 7

What are some ways that ecosystems are defined by organisms (biotic)?

Answer 7

(1) Biodiversity
(2) Biomass (NPP - net primary productivity)
(3) Species interactions
(4) Invasive or keystone species

Question 8

What are some ways that ecosystems are defined by their environment (abiotic)?

Answer 8

(1) Climate - averages & seasonality
(2) geology - bedrock, water, soils, topography
(3) disturbance - natural, human & scale, frequency

Question 9

What are some components of soil that we can study?

Answer 9

(1) pH levels
(2) nutrients
(3) composition (sand, silt, clay, organic matter)
(4) depth

Question 10

What are some common examples of landforms?

Answer 10

mountains, cliffs, valleys, plains

Question 11

Scales and frequency levels of the following:
(1) tornadoes
(2) hurricanes
(3) thunderstorms

Answer 11

(1) large scale / low frequency
(2) large scale / low frequency
(3) small scale / high frequency

Question 12

Definition: how much land is covered in a natural disaster

Answer 12

scale

Question 13

definition: how often a natural disaster occurs

Answer 13

frequency

Question 14

Is there a defined size of an “ecosystem”?

Answer 14

no

Question 15

Are there boundaries dividing ecosystems?

Answer 15

no

Question 16

Why are there no boundaries in an ecosystem?

Answer 16

because of migration - animals can continuously fly in & out

Question 17

Where is the location of MSH?

Answer 17

Washington state

Question 18

What mountain range is MSH also a part of?

Answer 18

cascade mountains

Question 19

How would you described the biome of MSH?

Answer 19

temperate rainforest

Question 20

What do biomes classify ecosystems by?

Answer 20

primarily their vegetation type

Question 21

What biome is the temperate rainforest fairly similar to? And in what way are they similar?

Answer 21

tropical rainforest & they both have annual precipitation

Question 22

How does the temperate rainforest mainly differ from the tropical rainforest?

Answer 22

cooler temperatures

Question 23

Describe common characteristics of the Pacific NW Climate?

Answer 23

(1) mild & wet year round
(2) lots of snow in the mountains
(3) infrequent fire
(4) VERY infrequent volcanic events

Question 24

What region of the US is MSH located in?

Answer 24

Pacific NW

Question 25

What changes as you go up in elevation?

Answer 25

(1) temperature (2) animals (3) biomass and soil nutrient levels (4) precipitation

Question 26

Is there more rain at the bottom or tops of mountains?

Answer 26

top

Question 27

What impact does changing elevation have on biological communities?

Answer 27

(1) changes in biomes / ecosystems in a condensed fashion (tropical RF, temperate RF, taiga, tundra, polar ice) (2) relationship between latitude and altitude

Question 28

What is the biodiversity of mountains like?

Answer 28

very HIGH - all different kinds of ecosystems represented

Question 29

definition: the variety of different kinds of life you will find in one area--the variety of animals, plants, fungi, and even microorganisms

Answer 29

biodiversity

Question 30

What was the "old growth" forest of MSH like pre-eruption?

Answer 30

had never been logged, very diverse, includes lots of wildlife, but NOT necessarily undisturbed

Question 31

What was the soil of MSH like pre-eruption?

Answer 31

"rich" with lots of available nutrients suitable for plant life

Question 32

Was MSH a homogeneous ecosystem pre- eruption?

Answer 32

NO - Mountains have lots of different ecosystems that change with elevation

Question 33

definition: an ecosystem that has indistinguishable features and looks exactly the same all over

Answer 33

homgeneous

Question 34

How does the top of a mountain compare to the bottom?

Answer 34

top: colder, more rain, thinner air, poor soil, less / smaller plants, fewer animals bottom: mild/warmer, less rain, richer soil, more large and small plants, more animals

Question 35

When was the date and time of the MSH eruption?

Answer 35

May 18th, 1980 at 8:32 AM

Question 36

The MSH eruption went directly up what side of the mountain?

Answer 36

North side

Question 37

What was unique about the southern slopes of the mountain?

Answer 37

they experienced so little damage that they looked almost identical to pre-eruption

Question 38

What were the 3 main areas of disruption on MSH?

Answer 38

(1) Pyroclastic flow / pumice plain (2) Blow down zone / lateral blast (3) Scorch zone

Question 39

What main area of MSH is being described here: -most damaged area -pumice covering all the ground -NOTHING in this area survived -covered up with 6' of tephra/ash

Answer 39

pumice plain

Question 40

Describe the destruction of MSH.

Answer 40

230 square miles of forest were blown done & scorched up to 17 miles away from MSH

Question 41

What is tephra/ash?

Answer 41

rock dust

Question 42

Was tephra very suitable for plants after the eruption?

Answer 42

no, its different from normal volcanic ash in that it does not contain many nutrients in it

Question 43

What made MSH different from a normal volcano?

Answer 43

lateral explosion - directed sideways rather than upward and NO magma was involved, it was tephra

Question 44

What main area of MSH is being described here: -shattered trees - big wave of heat killed all trees -wasn't much ABOVE ground that survived

Answer 44

blowdone zone / lateral blast

Question 45

What main area of MSH is being described here: -outermost reach of impact -some trees managed to stay up but all of their leaves were blown off -plants among the forest floor survived in this area

Answer 45

scorch zone

Question 46

Why did some plants survive in the scorch zone?

Answer 46

the timing of the eruption left a layer of snow over the slopes still & this snow pact protected everything a certain level above ground

Question 47

What two things will affect the order of reestablishment on MSH?

Answer 47

(1) what can reach the area first (2) what can survive there

Question 48

The first to reestablish in the pumice plain will need to be the first that can _____ & ______.

Answer 48

reach; survive

Question 49

What are some example of organisms that will reestablish in the MSH pumice plain first?

Answer 49

insects - live low to ground; feed off dead plant matter birds - they can fly, migrate into pumice plain small rodents - feed on insects smaller plants / shrubbery bacteria

Question 50

How are plants able to move/migrate?

Answer 50

seed dispersal

Question 51

definition: how seeds/spores are spread from the parent plant

Answer 51

dispersal

Question 52

What is a negative consequence of seed dispersal?

Answer 52

plants spend a lot of time & energy making/dispersing their seeds

Question 53

What is the purpose of parents taking a lot of time & energy to disperse seeds?

Answer 53

to reduce competition for resources among parents & offspring

Question 54

How is pollen dispersal different from seed dispersal?

Answer 54

pollen is used for fertilization - combines genes of separate plants & is sexual reproduction

Question 55

What are the 4 main ways that plants disperse seeds?

Answer 55

(1) wind (2) water (3) animal (4) gravity

Question 56

What is the main benefit of wind dispersed seeds?

Answer 56

very long dispersal distance

Question 57

What is the main benefit of animal dispersed seeds?

Answer 57

the digestion of the fruit leads to fertilized soil

Question 58

What is a negative of animal dispersed seeds?

Answer 58

(1) takes a lot of energy to create desirable fruit (2) dispersion distance varies

Question 59

What is a specific form of gravity dispersal that includes pods that shoot out seeds from them?

Answer 59

ballistic dispersal

Question 60

How is the dispersal distance for water dispersed seeds?

Answer 60

variable (can be a splash or long-distance)

Question 61

What is a negative of gravity dispersed seeds?

Answer 61

short dispersal distance (seeds roll down a hill)

Question 62

What is a pro of seeds dispersing close to their parents?

Answer 62

probability of survival is higher (environments already suitable for that species)

Question 63

What is the purpose of a seed coat?

Answer 63

to protect seed from environment

Question 64

definition: embryo sack wall surrounding a seed

Answer 64

seed coat

Question 65

definition: food storage area of a seed (largest part)

Answer 65

cotyledon

Question 66

What are the benefits of a thick seed coat?

Answer 66

(1) protects seeds from getting eaten by an animal/insect (2) protects from temperature / atmospheric conditions - prevents inside from drying out / becoming to waterlogged or wet

Question 67

What are the negatives of a thick seed coat?

Answer 67

(1) take a lot of energy to create (2) may have shorter dispersal distance

Question 68

What are the benefits of a thin seed coat?

Answer 68

(1) disperses easily

Question 69

What are the negatives of a thin seed coat?

Answer 69

(1) not as much protection from outside environment

Question 70

What is the purpose of the cotyledon of a seed?

Answer 70

to store food as fats and oils (think peanuts)

Question 71

What are the advantages of having a large cotyledon?

Answer 71

(1) can store more energy (2) seed can last longer before sprouting (germination) (3) more likely to survive (4) can grow quickly to overtop competitors (5) can't disperse far - suitable environment (adv?)

Question 72

What are the advantages of having a small cotyledon and seed coat?

Answer 72

(1) can produce MANY more seeds (2) longer dispersal distance

Question 73

What does the concept of evolutionary trade-offs explain?

Answer 73

(1) a pool of energy can be allocated in different ways (2) there are advantages and disadvantages of each selection (3) its impossible to have the best of both worlds

Question 74

How do we see evolutionary trade-offs with regards to large seeds?

Answer 74

can't have a massive amount of large seeds

Question 75

What type of relationship occurs between seed size and seed number (fecundity)?

Answer 75

inverse

Question 76

What type of relationship occurs between per capita seedling survivorship and seed size?

Answer 76

direct

Question 77

Per capita = per _______

Answer 77

individual

Question 78

per capita survivorship = probability of survival for _____ seed

Answer 78

one

Question 79

Is there one best strategy for small vs large seeds?

Answer 79

No, both can have = fitness levels (total survivorship

Question 80

definition: the ability to pass on genes to subsequent generations (amount surviving to reproduce)

Answer 80

fitness