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BIO1621 > Lecture 17/18/19/20: Biosphere/Biomes > Flashcards

Lecture 17/18/19/20: Biosphere/Biomes Flashcards

1
Q

what is the biosphere? what does it include?

A

it is the global ecosystem, the sum of all the planets ecosystems. includes every place where life exists:
- entire portion of Earth inhabited by life
- ranges from the atmosphere to the deep sea and rocks underground

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2
Q

what is “dispersal”?

A

when organisms move away from crowded areas or their birthplace to new areas

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3
Q

how does understanding dispersal help scientists?

A

helps them learn about how species are spread out and how they evolve in isolation

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4
Q

How do scientists test dispersal?

A

scientists look at cases where humans have accidentally or purposely moved a species to a new area

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5
Q

what makes a dispersal successful? what does it mean if its successful?

A

the species must survive and reproduce in the new location.
- successful dispersal means that the species could live in a wider area than it currently does

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6
Q

why do scientists study accidental cases of dispersal instead of purposely moving species around?

A

moving species to new places can disrupt local ecosystems

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7
Q

what contributes to the distribution of organisms?

A

behaviour and habitat selection

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8
Q

sometimes animals don’t spread to all the places they could live: instead, they _____

A

pick specific areas

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9
Q

what factors affect where organisms can survive/live?

A
  • biotic/abiotic factors
  • such as the absence of other important species
  • variation in water availability among habitats
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10
Q

what makes it harder for organisms to survive and reproduce?

A

negative interactions such as being hunted, getting diseases, or competing for resources

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11
Q

why do scientists sometimes remove predators from certain areas?

A

to see how it affects where prey species can live

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12
Q

most aquatic organisms are restricted to what environments?

A

freshwater or marine environments

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13
Q

how is temperature important in where an organism can live?

A

because it affects how organisms’ bodies work (biological processes).
- very few organisms can maintain an active metabolism in extreme heat/cold

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14
Q

terrestrial organisms face a nearly constant threat of what?

A

of desiccation (drying out) and have adaptations to allow them to obtain and conserve water

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15
Q

what does “photoperiod” mean?

A

the relative length of daytime and nighttime

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16
Q

what limits the distribution of photosynthetic organisms in aquatic environments?

A

light intensity

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17
Q

why does most photosynthesis in aquatic environments occur near the surface?

A

because theres more light near the surface. with every meter down, water absorbs a lot of red light and only a tiny bit of blue light

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18
Q

what provides the energy that drives nearly all ecosystems?

A

sunlight

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19
Q

why do some plants compete for shade?

A

in forests, tall trees create shade and the plants underneath have to compete for light

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20
Q

how does wind amplify the effects of temperature?

A

wind makes temps feel more extreme by speeding up heat loss through evaporation:
- For animals, wind cools them down faster by taking away body heat and moisture.
- For plants, wind causes them to lose water more quickly as it speeds up the process of water evaporating from their leaves.

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21
Q

in streams and rivers, what affects the water chemistry?

A

the substrate composition (the type of ground like sand and rocks)

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22
Q

what creates variety in land ecosystems?

3 examples, how does it affect the land?

A
  1. the physical structure
  2. acidity (pH)
  3. minerals in soil and rocks

affects where plants can grown and in return affects animals that rely on those plants, creating variety

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23
Q

what does “climate” mean?

A

it is the prevailing weather conditions in an area

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24
Q

what are the major components of climate?

A
  1. Temperature
  2. Water
  3. Sunlight
  4. Wind
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25
Q

what are the 2 scales that describe climate patterns?

A
  1. Macroclimate
  2. Microclimate
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26
Q

what levels are MACROclimate patterns on?

A

they are on global, regional, and local levels

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27
Q

what is a MICROclimate?

A

a small area with its own unique climate conditions, like under a tree or a rock (very fine patterns)

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28
Q

climate determines…

A

the makeup of biomes

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29
Q

what are biomes?

A

the major types of ecosystems

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30
Q

how are the global climate patterns determined?

A

by sunlight and Earth’s movement in space

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31
Q

What factors cause regional differences in climate? 2

A
  • bodies of water
  • topographic features (such as mountain ranges)
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32
Q

how do ocean currents influence climate along the coast?

A

by heating or cooling the air above the ocean currents which moves along the lands along the coasts

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33
Q

coastal areas are usually more _____ than areas inland

A

humid (moist)

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34
Q

how do oceans and big lakes help the climate?

A

helps keep the climate more balanced in nearby areas and makes heat less extreme

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35
Q

what happens to cool/dry ocean breezes in certain regions?

A

they are warmed when they move over land and absorb moisture. This creates a hot/rainless climate inland

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36
Q

in the northern hem, which facing slope receives more sunlight, north or south? what does this mean?

A

south-facing slopes, creates warmer and drier climates

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37
Q

mountains change how much ______, _____, and _____ different areas get.

A

sunlight; heat; rain

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38
Q

as you go up a mountain, it gets…

A

colder

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39
Q

what happens when warm wet air comes towards a mountain? what side does the rain fall on?

A
  • the air is pushed upward by the mountain
  • as it rises, it cools down, and the moisture in the air turns into rain
  • the rain falls on the windward side (the side of the mountain facing the wind)
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40
Q

what happens after the rainfall on a mountain (when the air loses its moisture in rain)? what does it create?

A
  • its moves over the top of the mountain and down the other side, becoming dry and warm
  • this creates a rain shadow on the leeward side
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41
Q

what is a rain shadow?

A

a dry area on the opposite side of the mountain

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42
Q

where are desserts or dry regions often found (which side of mountain)?

A

the leeward side of mountain ranges

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43
Q

what do seasonal changes in wind patterns influence?

A
  • ocean currents
  • sometimes bringing cold, nutrient-rich water up from deep in the ocean
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44
Q

in summer and winter, many lakes form…

A

layers of water at different temperatures

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45
Q

in spring and fall, lakes go through a…

A

turnover where the water mixes

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46
Q

what happens during a “turnover” in lakes?

A

the water mixes, switching oxygen to the bottom and nutrients to the surface

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47
Q

what do scientists look at to understand today’s climate changes?

A

they look at what happened after the last Ice Age

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48
Q

what happened as it got warmer (Ice Age)?

A

the glaciers melted and trees spread farther north

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49
Q

how do scientists track where the trees spread over time?

A

they look at fossil pollen found in lake and pond sediments

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50
Q

scientists can guess how a species’ range will change with global warming by…

A

studying its current climate limits

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51
Q

How can we tell if trees will keep up with climate change?

A

Check if they can spread their seeds fast enough.

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52
Q

what are the two types of aquatic biomes?

A
  1. Freshwater: lakes, wetlands, streams, rivers
  2. Marine: coral reefs, open zone (pelagic zone), coastal areas (intertidal zones), ocean floor (marine benthic), and estuaries
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53
Q

what are estuaries?

A

areas where freshwater mixes with saltwater (areas of transition between river and sea)

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54
Q

how do scientists separate freshwater and marine biomes?

A

based on their salt levels. marine biomes have higher salt levels

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55
Q

what type of aquatic biome has more salt in it, marine or freshwater?

A

marine, about 3% salt

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56
Q

where is the majority of earth’s water?

A

oceans. they contain about 97% of earths water

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57
Q

which biomes occupy the largest part of the biosphere?

A

aquatic biomes

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58
Q

what creates most of Earth’s rainfall?

A

water evaporating from oceans

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59
Q

which organisms in marine biomes help produce much of earth’s oxygen?

A

algae and photosynthetic bacteria

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60
Q

What are freshwater biomes connected to as they flow through their environments?

A

the surrounding soil and living organisms

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61
Q

what is the photic zone?

A

the open water zone at the top of the water, has enough light for plants to do photosynthesis

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62
Q

what is the aphotic zone?

A

the deep water zone near the bottom, much darker, very little light

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63
Q

what is the benthic zone?

A

the substrate at the bottom of any aquatic biome

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64
Q

the benthic zone is home to organisms called…

A

benthos

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65
Q

what do benthos feed mostly on?

A

detritus (dead organic material) that falls down from the water above, the photic zone

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66
Q

what is the littoral zone?

A

the shallow, well-lit, nearshore area of a lake/pond/ocean

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67
Q

how are layers of temperatures in lakes created?

A

sunlight heats the top layer of water but deeper layers stay cold

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68
Q

how is community distribution determined in aquatic biomes?

What decides where communities live in aquatic biomes?

A
  • the depth of the water
  • distance from shore
  • open water vs near bottom
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69
Q

how do oceans impact global climate and winds?

A

through their temperature, which influences both

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70
Q

why does light fade as you go deeper underwater?

A

because water absorbs and scatters sunlight, making less light reach the deeper layers.

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71
Q

what is the name of the layer that separates warmer surface water from colder deeper water?

A

the thermocline

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72
Q

where do most plankton and many fish live in marine environments?

A

in the photic zone (upper layer)

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73
Q

What’s the main difference between a lake that is oligotrophic and one that is eutrophic?

A

Oligotrophic lakes have clear, nutrient-poor water, while eutrophic lakes are foggy looking and nutrient-rich.

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74
Q

Where in a lake would you find the most plant growth?

A

In the shallow, sunlit area near the shore, called the littoral zone.

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75
Q

Why are wetlands considered highly productive?

A

They support a wide variety of species and have rich soil and water nutrients

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76
Q

What type of freshwater bodies move continuously in one direction?

A

Streams and rivers

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77
Q

Where do streams and rivers start?

A

In cold, clear areas called headwaters.

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78
Q

What is a unique feature of the intertidal zone?

A

It is regularly submerged and exposed by tides

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79
Q

where do most glowing fish live?

A

the aphotic zone

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80
Q

what are oligotrophic lakes?

A

they are deep, lack nutrients, lots of oxygen, good water clarity, and little life

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81
Q

what are eutrophic lakes?

A

shallow, lots of nutrients, less oxygen, less clear water, more life, highly productive

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82
Q

what is the limnetic zone?

A

the open surface water

83
Q

what are mesotrophic lakes?

A

moderate in nutrients and oxygen, with a balanced amount of life

84
Q

what does open surface water refer to?

A

refers to the area of a lake or ocean away from the shore, and close to the surface. well lit

85
Q

what are wet lands?

A

areas covered with sufficient water to support aquatic plants

86
Q

what do wetlands include?

A

marshes, bogs, and swamps

87
Q

why is the water and soil of wetlands low in dissolved oxygen?

A
  • high organic production
  • still or slow-moving
  • the decomposition of organic matter uses up oxygen
88
Q

what are headwaters?

A

the beginning or source of a river/stream. they are cold, clear, turbulent and swift

89
Q

What mainly determines nutrient content in headwaters?

A

the terrain and vegetation of the area

90
Q

what is the oceanic pelagic biome?

A

the open, deep water in the middle of the ocean, away from the coast, where currents keep it in constant motion

91
Q

the open ocean has ___ oxygen levels and ____ nutrient levels

A

high; low

92
Q

where do coral reefs grow? which zone?

A

in clear, warm tropical waters with lots of sunlight. PHOTIC ZONE

93
Q

what lives inside corals and helps them grow?

A

mutualistic algae

94
Q

how are coral reefs threatened?

4 examples

A
  • collecting
  • overfishing
  • pollution
  • global warming
95
Q

what is the marine benthic zone?

A

the seafloor below the surface waters. ground is covered by sand, rocks, or mud. most of it is in complete darkness

96
Q

what is the abyssal zone?

A

deepest parts of the ocean, around 3-6,000 m below ocean surface
- high water pressure
- no sunlight
- very cold

97
Q

what are the primary producers called in benthic zone communities?

A

chemoautotrophic prokaryotes

98
Q

what are chemoautotrophic prokaryotes? how do they support other life forms

A

bacteria and archaea that make their own energy from chemicals rather than sunlight.
- they use chemosynthesis
- support others by providing energy

99
Q

what is a climograph?

A

a chart that shows the average temperature and precipitation for an area throughout the year

100
Q

what is stratification?

A

the layering of plants in an ecosystem, creating different habitats that support various species
EX:
- canopy in a forest (top layer)
- grass layer in a grassland

101
Q

what is the ecotone?

A

the area of intergradation
- transition area between two different ecosystems/biomes
- ex: space between a forest and a grassland

102
Q

what are coral reefs formed by?

A

the calcium carbonate skeletons of coral animals

103
Q

in many biomes, the dominant plants depend on ______ ________

A

periodic disturbance

104
Q

what is more the norm in nature, change or stability?

A

change

105
Q

how do hurricanes help create habitats in a way?

A

they can clear spaces for new plants

106
Q

how does snow help create new plants?

A

snow in forests breaks branches and lets other plants grow in gaps

107
Q

why are natural events like wildfires essential in areas like grasslands, savannas, chaparral, and forests?

A

many plants need them to grow

108
Q

the major terrestrial biomes include… (8)

A
  • tropical forest
  • desert
  • savanna
  • chaparral
  • temperate grassland
  • coniferous forest
  • temperate broadleaf forest
  • tundra
109
Q

where are tropical forests found?

A

close to the equator

110
Q

in which terrestrial biome is animal diversity the highest in?

A

tropical forests

111
Q

what does the vegetation include in deserts?

A

sparse, includes succulents like cacti and deeply rooted shrubs

112
Q

where are deserts found?

A

in a band near 30° N and S latitudes, and in the interior of continents

113
Q

where are savanna’s found?

A

equatorial and subequatorial regions

114
Q

do deserts have rain?

A

low rainfall, highly variable

115
Q

does the savanna have rain?

A

yes, seasonally

116
Q

many desert animals are ______. why?

A

nocturnal; so they can avoid the heat

117
Q

what does the savanna vegetation consist of?

A

grassland with scattered trees

118
Q

what element is important in maintaining savanna biomes?

A

fire

119
Q

what animals are commonly in the savanna?

A

large herbivorous mammals

120
Q

is there rain in chaparrals?

A

yes, highly seasonal precipitation

121
Q

what does the vegetation look like in chaparrals?

A
  • shrubs
  • small trees
  • high diversity of grasses and herbs
122
Q

what makes temperate grasslands ideal for agriculture?

A

deep fertile soils

123
Q

what have most grasslands in North America and Eurasia been converted to?

A

farmland

124
Q

What role do natural disturbances play in maintaining biomes?

A

They create gaps for new species and maintain ecological balance, as seen in forests with hurricane disturbances or grasslands with wildfires.

125
Q

What distinguishes temperate broadleaf forests from coniferous forests?

A

Temperate broadleaf forests have more diverse plant and tree species that lose leaves seasonally, while coniferous forests are dominated by evergreen trees

126
Q

Why do deserts have low vegetation density?

A

The limited and unpredictable rainfall supports only sparse vegetation adapted to conserve water

127
Q

What is the main factor that creates patchiness in biomes?

A

Natural disturbances, like hurricanes or wildfires, create patches with different plant and animal communities

128
Q

How do chaparral plants adapt to frequent fires?

A

fire-resistant seeds or can quickly regrow after a fire

129
Q

How does periodic flooding benefit certain biomes?

A

Flooding deposits nutrients and supports plant growth, especially in biomes like wetlands

130
Q

Why is high water clarity important for coral reefs?

A

Clear water allows sunlight to reach the algae within coral, which need light for photosynthesis

131
Q

what is the biggest land biome on Earth called?

A

the Confierous Forest, aka Taiga

132
Q

what are the seasons like in the Coniferous forest?

A

long and cold winters
short and wet summers

133
Q

what is destroying these coniferous forests quickly? what may happen?

A

logging.
- old trees might disappear soon

134
Q

where is taiga found on Earth?

A

northern parts of earth. Ex: Canada, Russia, Ireland

135
Q

what kind of seasons do the Temperate Broadleaf forests have?

A
  • cold winters
  • hot summers
  • plenty of rain
136
Q

what is a “canopy”? what does it do?

A

the upper layer of trees in a forest, formed by their branches and leaves.
- blocks sunlight from reaching the ground
- creates shade

137
Q

what does a deciduous tree (in the Northern Hemisphere Broadleaf Forest) do in the winter? why?

A

drops their leaves and becomes dormant (inactive, resting state).
- this helps them save their energy

138
Q

what do animals do in temperate broadleaf forests during winter months?

A

hibernate or migrate to warmer climates

139
Q

how much does the Tundra cover of Earth’s land surface?

A

20%

140
Q

what is the “tundra”? (location, seasons, animals, vegetation)

A

a cold biome that covers big parts of the arctic:
- found in arctic regions near north pole
- extremely cold, long winters and short, mild summers
- permafrost is common and restricts plant roots
- small plants, like mosses, grasses, lichens, and tiny shrubs
- inhabits musk oxen, caribou, reindeer, migratory birds

141
Q

what are the differences between tundra and alpine tundra?

A

tundra is cold because of its location near the poles, whereas alpine is cold because of its elevation on mountains.

142
Q

what is “the alpine tundra”? (location, seasons, animals, vegetation)

A

cold biome found at the top of mountains:
- found on high mountains all over the world
- cold temperatures but due to latitude (not longitude)
- not permafrost but soil is very thing and rocky
- small plants, like mosses, grasses, lichens, and tiny shrubs
- fewer large animals live there year round

143
Q

why do birds use the tundra in summer?

A

for nesting

144
Q

do a lot of people live in the arctic tundra?

A

no- sparsely settled by humans

145
Q

what has the focus become in arctic tundra recently?

A

mineral and oil extraction (drilling)

146
Q

what is “population ecology”?

A

the study of populations in relation to the environment, including environmental influences on the population (such as density, distribution, age structure, and size)

147
Q

what is a population?

A

a group of individuals of a single species that live in the same general area

148
Q

why do members of a population have a high likelihood of interacting with and breeding with one another?

A

because they use the same resources and face the same environment

149
Q

how can populations change over time?

A

by natural selection.
- as individuals with helpful traits survive, reproduce, they pass those traits to future generations, making them more common.

150
Q

what are the population characteristics? 2

A

size and geographical boundaries

151
Q

in what ways could a population be spaced out as a group (dispersion)? 3

A
  • uniform (penguin)
  • random (flowers)
  • clumped (elephant herd)
152
Q

what is “population density”?

A

number of individuals that are in a given space (per unit area or volume)

153
Q

what is the “dispersion of a population”?

A

how individuals are spread out in a given area

154
Q

why do ecologists normally estimate population density/size?

A

its impractical to count every individual in a population

155
Q

how do ecologists estimate population density/size?

A

they use sampling methods:
- like counting individuals in a random small areas and averaging the results to extrapolate the population size in the entire area

156
Q

when does the sampling method work best (for ecologists when estimating population size/density)?

A

when the habitat is similar throughout (homogeneous habitat)

157
Q

what is a homogeneous habitat?

A

when the habitat is similar throughout

158
Q

what is the mark-recapture method?

A

a sampling technique
- trap and tag animals, record them, and let them go
- later on, traps are set again to see how many are tagged/untagged
- this helps estimate population size
- assumes tagged/untagged animals are equally likely to be trapped, but this may not be true always

159
Q

what do the values represent in the following formula: N = [M x S]/R

A

N = population size estimate
M = marked individuals released
S = size of second sample
R = marked animals recaptured

160
Q

how does a population grow? 2

A
  1. birth
  2. immigration (movement of individuals into a population)
161
Q

how does a population decrease? 2

A
  1. death
  2. emigration (movement of individuals out of a population)
162
Q

what does immigration and emigration represent? what could it create?

A

exchanges between populations (gene pool exchange)
- creates mutations

163
Q

what causes/changes population density?

cause and change used interchangeably

A

the addition or removal of individuals

164
Q

some populations are described by ____ _____

hint: area

A

geographic range

165
Q

what does “geographic range” mean?

A

the area inhabited by a species, can vary greatly depending on species

166
Q

what does “least concern” mean in relation to geographic range?

A

“Least concern” means a species is not at risk of extinction and has a wide or stable geographic range.

167
Q

what does “vulnerable” mean in relation to geographic range?

A

limited area, at risk of threats

168
Q

what does “critically endangered” mean in relation to geographic range?

A

extremely small or fragmented range, super high risk of extinction

169
Q

what are important population characteristics? what does it provide? 1

A
  1. variations in local density
    - provides insights into environmental and social interactions
170
Q

how a population is spaced out is called population _______.

A

dispersion

171
Q

why would a population be clumped?

A

b/c
- able for their growth (micro organsims)
- effectiveness of certain predators (wolves)
- mating reasons

172
Q

when does dispersion “uniform” occur?

A

when individuals are evenly spaced
- ex. birds
- ex. some plants. secrete chemicals that disallow other competitors to grow near them

173
Q

why would a population be uniformly dispersed?

A
  • territoriality
  • avoid overcrowding
  • competition for resources
  • ensure access to food and mates
174
Q

what is random dispersion of a population?

A

the distribution was random/unpredictable.
- how/why they got there was random
- ex. wind blowing plant seeds

175
Q

are random patterns common in nature?

A

no

176
Q

what is demography?

A

the study of the vital stats of pops and how they change over time
- birth/death rates
- looks specifically at females
- looks at factors that affect the density/dispersion patterns

177
Q

what is a “life table”?

A

CHAT: shows how a population survives at different ages
SLIDE: age specific summary of the survival pattern of a population

178
Q

what is the best way to construct a life table?

A

to track a group of same-age individuals from birth until they pass away

179
Q

what is a cohort?

A

a group of same-age individuals

180
Q

what are people really interested in when looking at the life table?

A

the curves generated from that data

181
Q

what are survivorship curves?

A

a graphic way of representing the survival data in a life
CHAT:
- graphs that show how many individuals in a population survive at different ages. They help us understand patterns of survival, like if most die young, live long lives, or die evenly over time.

182
Q

what are the 3 types of survivorship curve? what do they look like? what do they mean?

A
  1. High:
    - relatively flat at the start then drops steeply as age gets bigger (looks like an N)
    - fewer offspring (babies) and provide significant care to ensure longer survival
  2. Steady:
    - constant mortality over time
    - diagonal line downwards
    - don’t have a higher risk of dying at any specific age but instead face consistent challenges throughout their lives
  3. Low:
    - drops slowly at the start, then flattens out (looks like a L)
    - rely on producing large numbers of offsprings (babies) to ensure some survive in challenging environments
    - little parental care
183
Q

who follows the type 1 line (high survivorship)?

A

large mammals, primates, and humans

184
Q

who follows the type 2 line (steady survivorship)?

A

rodents, invertebrates, annual plants, birds, reptiles

185
Q

who follows the type 3 line (low survivorship)?

A

fishes, long-lived plants, marine invertebrates, insects, amphibians

186
Q

a “stair-stepped” survivorship curve is often seen in crabs due to mortality during molts. T or F?

A

T

187
Q

how do I create a life table?

A

count how many individuals die at each age and figure out

188
Q

what does stair-stepped curve mean?

A

higher changes of dying during molting (when they shed their shell)

189
Q

what determines population size when there’s no immigration or emigration?

A

reproductive rates

190
Q

why do studies usually focus on females?

A

since they give birth to offspring

191
Q

what does a reproductive table show?

A

how many offsprings females produce at different ages

192
Q

what processes add individuals to a population?

A

birth and immigration

193
Q

what type of dispersion pattern occurs when individuals are evenly spcaed?

A

uniform

194
Q

which of the following best describes a type 1 survivorship curve: a) High death rates early in life, then stable survival
b) Constant mortality throughout life
c) Low death rates in early and middle life, then steep decline
d) Unpredictable survival patterns

A

C

195
Q

in random dispersion, the position of individuals is influenced by:

A

no strong interactions among individuals

196
Q

immigration and emigration have no impact on population size. T or F?

A

F

197
Q

which dispersion is the most common pattern in nature?

A

clumped

198
Q

Which of the following is NOT a key process in population density?
a) Immigration
b) Emigration
c) Mortality
d) Adaptation

A

D

199
Q

Which factor can increase a population’s geographic range?
a) Increased reproduction rates
b) Habitat expansion
c) Competition for resources
d) High mortality rates

A

B

200
Q

Population density only decreases through emigration. T or F?

A

F. also decreases with mortalities

201
Q

what does emigration mean?

A

refers to individuals leaving a population or moving to another location. removing

202
Q

what does immigration mean?

A

refers to individuals moving into a population from another location. adding

203
Q

whats the diff between immigration and emigration?

A

IMM:
individuals move INTO a population = + size

EM:
individuals move OUT of a populations = - size

BIO1621 (8 decks)

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