Environmental Constraints: Water, Temperature, Wind, Salt, And Toxins

Question 1

Examples of abiotic stress factors

Answer 1

temperatures, water, radiation, chemical stress, mechanical stress

Question 2

Drought avoidance

Answer 2

desert annuals complete life cycle rapidly after rain (live fast die young)

Question 3

Drought deciduous

Answer 3

lose leaves during dry season, typically expansive belowground

Question 4

Drougt tolerant adaptations

Answer 4

Invest heavily in root systems
more but smaller stomata
thick and tough leaves
enter domat state during drought
increase solutes to increase osmotic potential

Question 5

Flooding adaptations

Answer 5

switch to glycolysis to avoid oxygen requirements during ATP synthesis
roots may have aerenhyma (hollow chambers that allow oxygen to flow through plants

Question 6

Temperature classifications for plants

Answer 6

Chilling sensitive
Freezing sensitive
Freezing tolerant

Question 7

Chilling sensitive

Answer 7

injury below 10-15 C. Change in membrane stucture inhibits cellular function

Question 8

Freezing sensitive

Answer 8

Injury below 0 C. Creation of ice crystals cause physical damage to cells

Question 9

Freezing tolerant

Answer 9

supercooling prevents cellular contents from freezing up to a point

Question 10

What determines distribution of species (temp)

Answer 10

Huge variation in temperature as a function of latitude and altitude

Question 11

Dwarfing

Answer 11

Decreased investment in vunerable woody areas, causing plant to grow closer to the ground

Question 12

Leaf adaptations to cold temperatures

Answer 12

thicker, tougher leaves
waxy coating to reduce water loss
reduction in photosynthesis

Question 13

Acclimation response to cool temps

Answer 13

change in fatty acid membrane to increase chilling resistance
change chemical compensation in leaves to avoid freezing
enter dormant state with senescence of leaves

Question 14

dominant type of trees in lack of freezing lands

Answer 14

broad evergreen leaves

Question 15

dominant type of trees in freezing winters

Answer 15

deciduous broad-leaved species

Question 16

dominant type of trees in freezing temps with short growing season

Answer 16

evergreen coniferdominance

Question 17

Primary effect of heat on photosynthesis

Answer 17

effeciency of photosynthesis declines above 25 C or C3 plants (slows)

Question 18

How is heat injury tied with water limitation?

Answer 18

temp greater than 40 C cause plants to cease transpiration cooling to conserve water

Question 19

How do plants cool down?

Answer 19

Transpiration cooling
long wave radiation emission
convective cooling
heliotrophic sun tracking
life history strategies to avoid hottest part of year

Question 20

Physical damage from wind

Answer 20

windthrow
abrasion by windborne particles
“flagging” shape in woody plants (lost branches on one side)
desiccation by dry winds

Question 21

Adaptations to wind

Answer 21

dwarfing/cushion growth forms
hairy leaf surfaces or thick waxy cuticle to protect more sensitive parts from flying particles

Question 22

Ionic toxicity

Answer 22

Injury from osmotic effect or direct toxic effect of ions caused by salts

Question 23

Example of plant with salinity resistance

Answer 23

Salt cedar (salt accumulates in foliar gland and then are deposited on soil surface)

Question 24

A plant adapted to salinity is often also adapted to _________

Answer 24

drought

Question 25

Common source of acute short term toxicity

Answer 25

acid deposition from fossil fuel combustian

Question 26

What does acute short term toxiticy cause?

Answer 26

direct injury to leaf surface acidified soils aluminum toxicity (acid rain) loss of important cations

Question 27

Ecological impacts of toxicity

Answer 27

chronic/long-term toxin exposure can lead to adaptation serpentine soils lack nutrients and often have high nickle, cobalt, and chromium concentrations diverse endemic flora

Question 28

trade off

Answer 28

whn increasing performance of one feature, organism must decrease another

Question 29

Examples of important tradeoffs

Answer 29

annual vs perenial evergreen vs deciduous growth rate vs defense seed size vsseed dispersial seed size vs seed number

Question 30

Functional types (strategies)

Answer 30

gymnosperms angiosperms dicots monocots

Question 31

Life history

Answer 31

organism's lifetime pattern of growth, development, and reproduction common history life patterns recognized as functional types

Question 32

Functional groups

Answer 32

graminoids forbs shrubs trees vines nitrogen fixers

Question 33

Graminoids

Answer 33

grasses and grasslike plants monocots with extensive fiberous root systems imprecise foragers renew above-ground biomass annually

Question 34

Forbs

Answer 34

Herbaceous dicots with fibrous and/or taproots with 2 common growth forms prostrate/rosette and erect

Question 35

Prostrate/rosette

Answer 35

grows close to ground and only grows up when it is going to flower

Question 36

Erect

Answer 36

shoots up in stem, is tall, and has lots of leaves coming off stem

Question 37

Shrubs

Answer 37

Plants that accumulate above-ground woody tissue and is typically around 4.5m tall

Question 38

trees

Answer 38

tall woody plants that are better at competing for light than shrubs but require more resource avability. Typically taller than 4.5m

Question 39

vines

Answer 39

often woody climbing plants that are unable to support themselves due to thin stems

Question 40

Nitrogen fixers

Answer 40

fix nitrogen through rhizobia or other bacterial associations and can exhibit multiple forms

Question 41

competitive CSR classification

Answer 41

Need high nutrient levels fast growing utilize resource avalibility

Question 42

stress tolerant CSR classification

Answer 42

slow growing to avoid nutrient loss can tolerate low nutrients and harsh environments maximize traits to maintain structure (not to grow quick)

Question 43

ruderal CSR classification

Answer 43

fast growing but not competitive finish life cycle fast rapidly colonize sites maximize seed output often annual weeds

Question 44

How does the CSR triangle seperate plants?

Answer 44

along gradient of competitive intensity, environmental stress, and disturbance frequency/intensity

Question 45

what drives roots vs shoots allocations?

Answer 45

relative requirements for soil resources and light

Question 46

why is total root biomass so much higher in grasslands?

Answer 46

More perenial species, so they have more time to accumulate roots

Question 47

Fast-slow economic spectrum in leaves

Answer 47

Invest more in leaves and they will be more efficent/last longer, but u will grow slower Invest minimally in your leaves and you can grow fast, but leaves will be more suseptible to damage and resource leaking

Question 48

Height trade off

Answer 48

taller plants are better at capturing light, but more suseptable to damage

Question 49

seed trade off

Answer 49

bigger seeds allow better establishment, but dont disperse as far