lecture 07 - resource constraints: temperature

Question 1

what is a macroclimate?

Answer 1

large-scale climate patterns that prevail over entire regions

Question 2

what is a microclimate

Answer 2

small-scale climate patterns that can deviate from macroclimate patterns

Question 3

how are microclimates determined

Answer 3

landscape, vegetation or small-scale topography features

Question 4

how does elevation influence microclimate

Answer 4

elevation can cause different plants to grow

Question 5

how does aspect influence microclimate

Answer 5

depending on north or south facing, each side may or may not receive as much sunlight as the other

Question 6

north aspect

Answer 6

slopes exposed to the north receive less solar radiation, higher snow loads, and hence more water. water availability is sufficiently high for a forest to grow

Question 7

south aspect

Answer 7

slopes exposed to the south receive more solar radiation, lower snow loads, and hence less water. water availability is too low for a forest to grow. grasses and shrubs prevail.

Question 8

how does vegetation influence microclimate

Answer 8

by casting shade, trees and shrubs. in the understory, temperatures are cooler, and evaporation is decreased

Question 9

how does surface colour influence microclimate

Answer 9

lighter colours reflect light so that the surface and surroundings do not increase in temperature

darker colours absorb light so that the surface and surroundings increase in temperature

Question 10

what is albedo?

Answer 10

reflectivity of a landscape = how much light is reflected and does not get absorbed

Question 11

how do boulders and burrows influence microclimate

Answer 11

some organisms have adapted to live under rocks or underground in burrows. burrows and rocks create shade and allow inhabiting animals to avoid heat during the day

Question 12

why do water temperatures fluctuate less than air temperatures

Answer 12

larger bodies of water tend to be more stable as it has a higher capacity for absorbing heat energy. heat is absorbed by water as it evaporates.

Question 13

what is the range of tolerance

Answer 13

the range of an environmental condition in which the organism can live. organisms perform best at an optimum performance range of environmental conditions in the absence of interactions with other species.

Question 14

why do organisms express physiological stress at the niche margins of a limiting factor

Answer 14

they use more energy to sustain their body and health

Question 15

law of tolerance

Answer 15

the abundance and distribution of an organism can be determined by the deviation between location conditions and the optimum set of conditions for a species.

Question 16

what is the range of tolerance in plants

Answer 16

temperature is a limiting factor of photosynthesis in plants

Question 17

principle of allocation

Answer 17

organisms have limited amounts of energy (how much we can take and how much we can use to keep body alive) when an organism allocates energy to one function, it reduces the energy available to other functions

Question 18

evolutionary tradeoffs

Answer 18

adapting to one set of environmental conditions generally reduces fitness in other environments

Question 19

what are the things and organism do when they are at the margins of their tolerance?

Answer 19

die
migrate
acclimate
adaptations to extreme temperatures

Question 20

allocation using death

Answer 20

avoid extreme temperatures giving all energy to reproduction. organism dies but the offspring have a chance to live

Question 21

allocation using migration

Answer 21

avoid extreme temperatures by migrating to warmer regions, advantages of migration outweigh the costs of migrating (energy wise)

Question 22

allocation using acclimation

Answer 22

physiological or morphological changes in an organism in response to changes in the environment. NOT adaptation but the ability to acclimate IS and adaptation (phenotypic plasticity)

Question 23

define acclimation

Answer 23

physiological or morphological changes in response to changes in the environment within an individuals lifetime. generally reversible as conditions change.

Question 24

define adaptation

Answer 24

an evolutionary process that changes anatomy, physiology, or behaviour across generations and on a genetic level. NOT reversible.

Question 25

plant adaptations to cold temps

Answer 25

dark coloured leaves
cushion growth form (closer to ground = more heat)
leaf and flower orientation
smaller surface-area ratio

Question 26

plat adaptations to hot temps

Answer 26

decrease contact with the ground
open growth form (tall + elongated so more air surrounds them and heat gets taken by the wind)
reduced leaves
light surface

Question 27

poikilotherms

Answer 27

body temperature varies with environment

Question 28

homeotherms

Answer 28

body temperature relatively constant regardless of environment

Question 29

ectotherms

Answer 29

control body heat using EXTERNAL energy

Question 30

endotherms

Answer 30

control body temperature using INTERNAL energy

Question 31

why be endothermic?

Answer 31

allows organisms to live in environments in which the average temp is lower than their body temp