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underground ni Riza

Total questions: 150

Worksheet time: 1hrs 15mins

Name
Class
Date
1.

Toxic runoff can pollute a stream and also

a)

create algae blooms

b)

pollute groundwater

c)

cause soil erosion

d)

produce acid rain

2.

Which most likely caused the changes observed in the data over time?

a)

decrease in the amount of recharge

b)

increase in the amount of precipitation

c)

decrease in irrigation for farming

d)

increase in water conservation efforts

3.

Which human activity directly affects the quality of freshwater resources?

a)

burning gasoline in car engines

b)

depleting the ozone layer

c)

throwing trash out of car windows

d)

allowing runoff from agricultural fields

4.

What is most responsible for the presence of groundwater in an area?

a)

movement of surface water through impermeable rock

b)

movement of surface water and precipitation through soil and rock

c)

movement of water from a confined aquifer into surface water

d)

movement of water from streams and rivers to watersheds

5.

A community upgrades its water purification and management systems. What lasting impact could this have on available freshwater?

a)

decrease in water demand

b)

increase in waterborne diseases

c)

increase in freshwater supply

d)

decrease in water levels

6.

A rural, forested area receives a lot of rain in a short amount of time. What would most likely cause potential flooding in the area?

a)

if the ground of the area is already saturated

b)

if the area has a large uncharged aquifer beneath it

c)

if the ground of the area is mostly sandy soil

d)

if the water level in the area is below the zone of saturation

7.

Which of the following make up part of Earth's groundwater?

a)

lakes

b)

rivers

c)

aquifers

d)

wetlands

8.

Which statement best describes a relationship between groundwater and surface water?

a)

Surface water is found in lakes directly above underground water sources

b)

There is no relationship between surface and groundwater

c)

Surface water percolates through soil to form groundwater

d)

Groundwater filters through soil to form surface water

9.

How could a long-term decrease in precipitation impact an area?

a)

increase the average water level of lakes

b)

decrease the amount of possible infiltration

c)

decrease the possible amount of damage to crops

d)

increase the amount of flooding

10.

Plants release water into the atmosphere through a process called

a)

evaporation

b)

infiltration

c)

precipitation

d)

transpiration

11.

A drainage basin or river basin is

a)

the land covered by floodwaters

b)

all streams that flow directly to the ocean

c)

the channel of a stream

d)

the land area that contributes water to a river

12.

Aquifers that allow for good groundwater flow have many open spaces between the rocks or sediments that are connected to each other. Describe the aquifer using the terms below.

a)

permeable and nonporous

b)

permeable and porous

c)

impermeable and porous

d)

impermeable and nonporous

13.

In the groundwater diagram, what process is happening at letter A?

a)

Precipitation

b)

Condensation

c)

Infiltration

d)

Evaporation

14.

In the groundwater diagram, which letter indicates the area where water is being added to the groundwater system?

a)

Arrow A

b)

Arrow B

c)

Arrow D

d)

Arrow C

15.

In the groundwater diagram, which process is happening at Arrow B?

a)

Water vapor is condensing to liquid water

b)

Liquid water is evaporating into the atmosphere

c)

Precipitation is running off across the land surface

d)

Liquid water is infiltrating into the groundwater system

16.

What is significant about the area labeled E in the groundwater diagram?

a)

it is a recharge zone for the confined aquifer

b)

it is a discharge zone for the confined aquifer

c)

it is the zone of aeration

d)

there is no significance to this area for the confined aquifer

17.

The layer of the diagram labeled C is which type of material?

a)

permeable layer

b)

aquifer

c)

porous layer

d)

impermeable layer

18.

What is the area where water enters the aquifer called?

a)

No fly zone

b)

Recharge zone

c)

Aquatard

d)

Replacement zone

19.

The boundary between the zone of aeration and the zone of saturation is called the

a)

watershed

b)

water table

c)

recharge zone

d)

well

20.

Which of the following has the lowest porosity?

a)

Sand

b)

Clay

21.

A land area that is covered with water for part of the year is called:

a)

river

b)

lake

c)

wetland

d)

wasted land

22.

Which of the following is a reason why wetlands are important?

a)

Wetlands block water from flowing

b)

Wetlands provide habitat for cactus

c)

Wetlands act as a filtering system

d)

Wetlands are a place where birds go to die

23.

Wetlands help control flooding by

a)

absorbing runoff from heavy rains

b)

quickly releasing water

c)

providing natural water filtration

d)

collecting water behind dams

24.

What do we call the land area that supplies water to a river system?

a)

recharge

b)

watershed

c)

valley

d)

runoff

25.

Wetlands are important because

a)

all of these choices

b)

they support many species

c)

they protect areas from floods

d)

they help filter water of toxins and excess nutrients

26.

What could happen to the water table if several houses sharing a well started pumping water at a high rate at the same time?

a)

the wells will overflow

b)

the water table may rise

c)

the well will be completely dry

d)

the water table may fall

27.

Water can move through soil because of the soil’s

a)

not well-sorted materials

b)

permeability

c)

impermeability

d)

porosity that is low

28.

What is an area called when the soil is totally filled up with water?

a)

unsaturated zone

b)

permeable

c)

saturated zone

d)

impermeable

29.

Materials that do not allow water to pass through easily are called

a)

impermeable

b)

permeable

c)

saturated

d)

unsaturated

30.

There are lakes that store water for humans to use; these are called

a)

watersheds

b)

aquifers

c)

ponds

d)

reservoirs

31.

The source of human drinking water in urban areas is

a)

an aquifer

b)

lake water that is cleaned at a treatment plant

c)

lake and river water that is cleaned at a treatment plant

d)

river water that is cleaned at a treatment plant

32.

What percent of water on Earth is considered freshwater?

a)

3

b)

97

c)

2

d)

1

33.

A well pipe should be ______ of an aquifer.

a)

at the bottom

b)

above the top

c)

any part

d)

toward the middle

34.

Which of the following contains more of Earth’s water?

a)

oceans

b)

lakes

c)

glaciers

d)

rivers

35.

The source below the ground that provides water from underground is called

a)

a reservoir

b)

water treatment plant

c)

aquifer

d)

an unsaturated zone

36.

Why is water from an aquifer more likely to be cleaner than from other sources?

a)

it receives water directly from precipitation

b)

it rises to the surface near lakes

c)

it forms where fresh and salt water meet

d)

pollutants can be filtered by rock and soil deep in the Earth

37.

Which property of water explains why rock and soil particles often sink to the bottom of the saturated zone?

a)

density

b)

cohesion

c)

adhesion

d)

surface tension

38.

What allows water to accumulate in the saturated zone?

a)

condensation

b)

precipitation and infiltration

c)

precipitation

d)

run-off

39.

People in rural areas obtain drinking water from

a)

rivers and lakes

b)

rivers

c)

wells drilled into reservoirs

d)

wells drilled into aquifers

40.

Wastewater is disinfected using

a)

UV light only

b)

bacteria

c)

a filter

d)

chlorine and/or UV light

41.

Septic tanks are used for

a)

storing waste

b)

storing water

c)

cleaning water for human use

d)

holding water for human consumption

42.

After wastewater is treated at a wastewater treatment plant, it is piped to homes to be used.

a)

True

b)

False

43.

Water vapor forms drops on the outside of a glass; this represents which part of the hydrologic cycle?

a)

sublimation

b)

evaporation

c)

transpiration

d)

condensation

44.

The water table is located

a)

at the top of the saturated zone

b)

at the top of the unsaturated zone

c)

at the bottom of the saturated zone

45.

Saturated zone

a)

has spaces filled with water

b)

has empty spaces

46.

The water table level

a)

is lower when it rains

b)

is higher when it rains

c)

is the same height always

47.

What is the most common method for removing groundwater?

a)

building a water tower

b)

accessing the water table by use of low-grade explosives

c)

a well bored into the zone of saturation

d)

damming up a river

48.

Sand is _______ meaning that water can pass through easily.

a)

permeable

b)

solid

c)

impermeable

d)

soft

49.

Water from precipitation soaks down through permeable rock and soil layers. These layers contain air as well as water, so they are not filled with water. This top layer is the

a)

unsaturated zone

b)

saturated zone

50.

A place where the water table intersects the ground surface and where a natural flow of groundwater results is called

a)

an aqueduct

b)

a spring

c)

a fissure

d)

a geyser

51.

This is a picture of what? Refer to the picture provided on the worksheet.

a)

Artesian well

b)

Permeable rock

c)

spring

d)

Impermeable rock

52.

An aquifer is a(n)

a)

underground layer of rock or sediment that holds water

b)

type of hot spring from which water periodically erupts

c)

place where groundwater bubbles or flows out of cracks in the rock

53.

A well in which groundwater rises because of pressure is called a(n)

a)

spring

b)

oil well

c)

geyser

d)

artesian well

54.

Groundwater is often obtained by drilling a well to reach below the water table.

a)

True

b)

False

55.

Artesian wells rely on pressure to bring water to the surface.

a)

False

b)

True

56.

Materials that allow water to pass through them easily are

a)

impermeable

b)

saturated

c)

permeable

d)

unsaturated

57.

What is the primary source of recharge for underground aquifers?

a)

River water seepage

b)

Rainwater infiltration

c)

Ocean water intrusion

d)

Evaporation from soils

58.

Which of the following best describes the term aquifer?

a)

A layer of rock or sediment that holds groundwater

b)

A layer of rock that is impermeable to water

c)

A type of soil that is always dry

d)

A surface water body that feeds into rivers

59.

What will occur as a result of garbage being placed on the surface of the old dump?

a)

The garbage will become fun to swim with.

b)

The groundwater under the dump will dry up.

c)

The groundwater under the dump will reverse direction.

d)

The groundwater under the dump will become polluted.

60.

Fertilizer can seep through the ground to reach groundwater. What effect can it have?

a)

Fertilizer can cause groundwater to freeze.

b)

It will seep into the school.

c)

Fertilizer can cause groundwater to become undrinkable.

d)

Fertilizer can cause groundwater to reverse flow.

61.

The photo shows rusting barrels floating in shallow river water. How will the rusting barrels in this stream affect the surface water in the watershed?

a)

The barrels will alter the course of the surface water that reaches the river.

b)

The barrels will not affect the surface water that reaches the river.

c)

The barrels will be fun for Mrs. Glassmann to ride down the river.

d)

The barrels will pollute the surface water that reaches the river.

62.

What will happen if local groundwater makes contact with the barrels in this stream?

a)

You can drink the water.

b)

The groundwater will become less clean.

c)

The groundwater will react by flowing back under the ground.

d)

The groundwater will not be affected.

63.

When an area is experiencing drought, humans may excessively pump groundwater out of aquifers. All of the following are effects of this excessive pumping EXCEPT —

a)

Water quality decreasing.

b)

Groundwater depleting.

c)

Soil collapsing.

d)

Dottie’s waterbowl.

64.

Runoff will affect local watersheds in all of the following ways EXCEPT —

a)

By introducing acid rock drainage to the lake and stream.

b)

By increasing the number of animals that live in the lake or stream.

c)

By contaminating the lake with heavy metals.

65.

Which of the following is the most likely cause of algal bloom?

a)

Humans dumped their trash directly into the pond, causing the water to become unclean.

b)

Acid rain transported pollution from nearby bodies of water through the water cycle.

c)

A seasonal algal cycle caused the water to have too many organisms living in it.

d)

Fertilizers from nearby fields drained into the pond, causing an excess of nutrients.

66.

Which of the following organisms do NOT benefit from the runoff?

a)

Fish, swimming near the shore of the beach.

b)

Crop plants, getting nutrients that normally wash out of the soil.

c)

Microscopic organisms that cause the red tide.

d)

Humans, using the fertilizer to produce more crops.

67.

The volume of Earth’s groundwater is estimated to be 50 times the volume of freshwater found on Earth’s surface. Sometimes, communities use groundwater faster than the water can renew itself. What effect does this have on these communities?

a)

Communities have to relocate to areas with more groundwater.

b)

Communities must stop using water until the groundwater is replenished.

c)

Communities must dig deeper wells to reach a lower water table.

d)

LMS is forced to use reclaimed water only.

68.

What does the red dye represent in the model?

a)

Rainwater.

b)

Dottie’s water.

c)

Surface water.

d)

Pollution caused by humans.

69.

A new human community was built near the aquifer at some point in the last ten years. In which year was the community most likely built?

a)

Year 7

b)

Year 5

c)

Year 3

d)

Year 0

70.

The model shows an aquifer. When an area is experiencing drought, humans may excessively pump groundwater out of aquifers like this one. All of the following are effects of this excessive pumping EXCEPT -

a)

water quality decreasing

b)

soil collapsing

c)

groundwater depleting

d)

the water table rising

71.

The water table is located

a)

at the top of the saturated zone

b)

at the top of the unsaturated zone

c)

at the bottom of the saturated zone

72.

The saturated zone

a)

has spaces filled with water

b)

has empty spaces

73.

The water table level

a)

is lower when it rains

b)

is the same height always

c)

is higher when it rains

74.

What is the most common method for removing groundwater?

a)

damming up a river

b)

accessing the water table by use of low-grade explosives

c)

building a water tower

d)

a well bored into the zone of saturation

75.

Sand is ________, meaning that water can pass through easily.

a)

permeable

b)

impermeable

c)

solid

d)

soft

76.

Water from precipitation soaks down through permeable rock and soil layers, so they are not filled with water. This top layer contains air as well as water. This top layer is the

a)

unsaturated zone

b)

saturated zone

77.

A place where the water table intersects the ground surface and where a natural flow of groundwater results is called

a)

a geyser

b)

an aquatard

c)

a spring

d)

a fissure

78.

This is a picture of what?

a)

artesian well

b)

permeable rock

c)

spring

d)

impermeable rock

79.

A type of hot spring from which the water periodically erupts is a(n)

a)

geyser

b)

underground layer of rock or sediment that holds water

c)

underground layer of rock or sediment that holds water

d)

place where groundwater bubbles or flows out of cracks in the rock

80.

A well in which groundwater rises because of pressure is called a(n)

a)

artesian well

b)

spring well

c)

dry well

d)

geyser

81.

Groundwater is often obtained by drilling a well to reach below the water table.

a)

True

b)

False

82.

Artesian wells rely on pressure to bring water to the surface.

a)

True

b)

False

83.

Materials that allow water to pass through them easily are

a)

saturated

b)

unsaturated

c)

impermeable

d)

permeable

84.

What is the primary source of recharge for underground aquifers?

a)

rainwater infiltration

b)

ocean water intrusion

c)

river water seepage

85.

Which of the following best describes the term aquifer?

a)

a layer of rock or sediment that holds groundwater

b)

a surface water body that feeds into rivers

c)

a type of soil that is always dry

d)

a layer of rock that is impermeable to water

86.

People can obtain groundwater by drilling a well

a)

into an aquifer

b)

into the unsaturated zone

c)

into the impermeable layer above the water table

87.

The top of the saturated zone is known as the

a)

aquifer

b)

unsaturated zone

c)

water table

d)

spring rock

88.

Groundwater naturally bubbles to the surface at

a)

lakes

b)

artesian wells

c)

springs

d)

aquifers

89.

When people obtain groundwater from an aquifer by drilling into a well below the water table

a)

well

b)

spring

c)

aquifer

90.

New water that enters an aquifer

a)

recharge

b)

unsaturated zone

c)

water table

d)

pores

91.

Spaces between particles of sediment in the ground

a)

pores

b)

well

c)

spring

d)

aquifer

92.

Material that allows water to pass through

a)

saturation zone

b)

permeable

c)

impermeable

d)

aquifer

93.

Which is the best way to get water from an aquifer with a well?

a)

Drill above the water table.

b)

Drill below the impermeable rock.

c)

Drill below the water table.

d)

Drill into the unsaturated zone.

94.

Which describes materials that have large and connected pores, such as sand and gravel?

a)

impermeable

b)

unsaturated

c)

permeable

d)

saturated

95.

Knowing the water table depth helps you reach which of the following?

a)

groundwater

b)

granite

c)

springs

d)

pores

96.

Where can the water table be found?

a)

in the unsaturated zone

b)

between layers of impermeable rock

c)

in the clay

d)

at the top of the saturated zone

97.

Which paragraph in the section "Invisible, But Drinkable" explains the various ways that groundwater is used?

a)

Paragraph 1

b)

Paragraph 4

c)

Paragraph 3

d)

Paragraph 2

98.

What is the primary source of recharge for underground aquifers?

a)

Rainwater infiltration

b)

River water seepage

c)

Ocean water intrusion

d)

Evaporation from soil

99.

Which of the following best describes the process of water moving through soil and rock to reach an aquifer?

a)

Percolation

b)

Evaporation

c)

Condensation

d)

Transpiration

100.

How does surface water reach the ocean?

a)

By being pumped from underground reservoirs

b)

Through rivers, streams, and runoff from precipitation

c)

Through underground tunnels

d)

By evaporation from the ocean floor

101.

What is the process of water seeping into the ground called?

a)

percolation

b)

exfiltration

c)

evaporation

d)

infiltration

102.

What is the water table?

a)

The water table is a type of board game played with water

b)

The water table is a scientific term for the level of water in a glass

c)

The water table is a type of furniture used for dining

d)

The level below which the ground is saturated with water

103.

How might groundwater become contaminated?

a)

Contamination of groundwater is caused by excessive rainfall

b)

Human activities such as industrial waste, agricultural runoff, and improper disposal of chemicals and waste

c)

Groundwater contamination is a result of volcanic activity

d)

Groundwater becomes contaminated due to natural processes

104.

What are some advantages of using surface water as a water source?

a)

Surface water is readily available and can be easily accessed for various uses

b)

Surface water is difficult to access and not readily available

c)

Surface water is not suitable for various uses

d)

Surface water is expensive to use and maintain

105.

What are some disadvantages of using groundwater as a water source?

a)

Reduced risk of contamination

b)

Increased water quality

c)

Potential contamination and depletion of aquifers

d)

Enhanced aquifer recharge

106.

How does human activity impact surface and underground water?

a)

Human activity has no impact on surface and underground water

b)

Surface and underground water are not affected by human activity

c)

Human activity can impact surface and underground water through pollution, over-extraction, and changes in land use

d)

Human activity only has a positive impact on surface and underground water

107.

What is the name of the area of groundwater where it is saturated?

a)

Zone of Saturation

b)

Water Table

c)

Zone of Aeration

108.

What is the area underground where there is not any water?

a)

Water

b)

Zone of Aeration

c)

Zone of Saturation

109.

The name of the area that is the upper level of the zone of saturation:

a)

Water Table

b)

Zone of Aeration

c)

Zone of Saturation

110.

Water stored below the Earth's surface is called:

a)

Bogs

b)

Groundwater

c)

Water in the ground

111.

When water soaks the ground it becomes groundwater through what process?

a)

Runoff

b)

Infiltration

c)

Transpiration

112.

The amount of space between soil is:

a)

Permeability

b)

Porosity

113.

The ability of a liquid to flow through a substance is:

a)

Porosity

b)

Permeability

114.

A material with a high porosity has:

a)

Little space

b)

A lot of spaces

115.

A substance has a low permeability when:

a)

Water can flow through easily

b)

Water can't flow through easily

116.

Water that seeps into the ground into spaces between bits of rocks and soil is called:

a)

Groundwater

b)

Spring

c)

Water table

d)

Aquifer

117.

What is a hole dug below the water table that water seeps into?

a)

Well

b)

Spring

c)

Reservoir

d)

Aquifer

118.

What is the top of the water-filled spaces in the ground called?

a)

Reservoir

b)

Groundwater

c)

Water Table

d)

Well

119.

What is an underground layer of rock or soil filled with water called?

a)

Spring

b)

Aquifer

c)

Reservoir

d)

Well

120.

What is a place where groundwater seeps out of the ground called?

a)

Well

b)

Spring

c)

Reservoir

d)

Aquifer

121.

What are sources of water pollution?

a)

All of these

b)

Runoff water and groundwater

c)

Industry and household waste

d)

Precipitation as acid rain

122.

What do we call the land area that supplies water to a river system?

a)

Recharge

b)

Watershed

c)

Valley

d)

Runoff

123.

What do we call water that flows over the ground surface rather than soaking in?

a)

Runoff

b)

Recharge

c)

Tributary

d)

Discharge

124.

What mechanism controls the flow of water in runoff?

a)

Permeability

b)

Porosity

c)

Temperature

d)

Gravity

125.

What mechanism controls the flow of water in runoff?

a)

Gravity

b)

Porosity

c)

Temperature

d)

Permeability

126.

An aquifer is a(n):

a)

Place where groundwater bubbles or flows out of cracks in the rock

b)

Type of hot spring from which the water periodically erupts

c)

Underground layer of rock or sediment that holds water

d)

Well in which water rises because of pressure

127.

A well in which groundwater rises because of pressure is called a(n):

a)

Spring well

b)

Geyser well

c)

Artesian well

d)

City well

128.

Which well(s) end(s) in a saturated zone?

a)

4 and 5

b)

1 and 2

c)

1, 3 and 5

d)

Only 3

129.

The materials that make up Aquifers A and B are:

a)

Impermeable

b)

Permeable

130.

Which types of aquifers are in the most danger of becoming contaminated by pollutants?

a)

Aquifers confined by a permeable layer

b)

Unconfined aquifers

131.

What is the water that fills the cracks and spaces in underground soil and rock layers called?

a)

Precipitation

b)

Snow

c)

Water Table

d)

Groundwater

132.

An underground layer of rock or sediment that holds water?

a)

Reservoir

b)

Watershed

c)

Groundwater

d)

Aquifer

133.

The land area that supplies water to a river system is called a

a)

water table

b)

watershed

c)

trailer of house

134.

Because they have large connected pores, materials such as sand and gravel allow water to pass through. This is known as

a)

impermeable

b)

permeable

135.

Water from precipitation soaks down through permeable rock and soil layers. This top layer is called the

a)

saturated zone

b)

unsaturated zone

136.

At some depth, the water reaches a level where the pores in the ground are saturated with water, called the

a)

saturated zone

b)

unsaturated zone

137.

An underground layer of permeable rock or sediment that holds water and allows it to flow is called an

a)

Ocean

b)

Aquifer

c)

Water shed

d)

Water table

138.

What is ecological succession?

a)

The removal of all living organisms from an area

b)

The process of one community replacing another as a result of changing abiotic and biotic factors

c)

The destruction of a habitat due to natural disasters

d)

The introduction of new species into an existing ecosystem

139.

What is primary succession?

a)

The recovery of an ecosystem after a disturbance such as fire or flood

b)

The process by which pioneer species are replaced by intermediate species

c)

The establishment of a community in an area that does not have topsoil

d)

The initial establishment of a community in an area with existing soil

140.

Which organisms are among the first to appear during primary succession?

a)

Intermediate species

b)

Lichens and some mosses

c)

Mature trees and shrubs

d)

Small weedy plants

141.

What role do pioneer species play in primary succession?

a)

They are the final species to appear in a climax community

b)

They are responsible for the introduction of animals to the ecosystem

c)

They prevent soil erosion by establishing a root system

d)

They secrete acids that help break down rocks to form soil

142.

What is a climax community?

a)

A stable, mature community with little change in the number of species

b)

The initial stage of an ecosystem with pioneer species

c)

A community that is disturbed by natural events like fire or flood

d)

A community that changes rapidly with a high number of species

143.

How does secondary succession differ from primary succession?

a)

Secondary succession is unpredictable, while primary succession is orderly

b)

Secondary succession occurs with soil present, while primary succession starts without soil

c)

Secondary succession involves only animal species, while primary succession involves only plant species

d)

Secondary succession occurs without soil, while primary succession requires soil

144.

What are two things mentioned in the reading that can happen that might affect an ecosystem?

a)

Urban development and deforestation

b)

Climate change and pollution

c)

Overfishing and acid rain

d)

Natural disasters and invasive species

145.

Define ecological succession.

a)

The process by which the structure of a biological community evolves over time

b)

The study of interactions between organisms and their environment

146.

What is primary succession?

a)

The replacement of one community by another at a single location over a period of time

b)

Succession that begins in an area where no biotic community previously existed

c)

The final stage of succession, remaining relatively unchanged until destroyed by an event such as fire or human interference

d)

Succession that occurs on surfaces where an ecosystem has previously existed

147.

Describe an example of primary succession.

a)

A new community developing after a forest fire

b)

Grasses growing on a sand dune that was previously occupied by shrubs

c)

A forest developing on a newly formed volcanic island

d)

A garden growing in an abandoned urban lot

148.

What is a pioneer species?

a)

A species that prevents other species from entering an ecosystem

b)

A species that is dominant in the final stage of succession

c)

The first species to colonize previously disrupted or damaged ecosystems

d)

A species that is introduced to an ecosystem by human activity

149.

How long might it take for an ecosystem to become balanced?

a)

Many decades to several centuries

b)

A few months to several years

c)

A few weeks to a couple of months

d)

Several years to many decades

150.

What happens when an ecosystem is in equilibrium?

a)

The ecosystem is highly susceptible to invasive species

b)

The ecosystem's community structure does not change much over time

c)

The ecosystem begins the process of primary succession

d)

The ecosystem experiences rapid changes and high species turnover