Download Unit B: Interdependence and Relationships Among Organisms

Unit B: Interdependence and Relationships Among Organisms
Standards Addressed
During Unit
Overview
Students are immersed in opportunities to see first hand relationships among organisms. Students compare
the roles and relationships among organisms as they survive and transfer energy through the food web. They
investigate limiting factors in their local ecosystem and how they impact native populations. Students also get
a deeper understanding of their natural world as they see first hand human impact such as deforestation,
urbanization, desertification, erosion, air and water quality, changing the flow of water. Students study
interdependence of organisms as they are actively engaged in problem based learning in the field. Students
understand and practice safe research practices in the classroom laboratory.
Fundamental Skills:
 Knowledge of needs of living things including food, shelter, water, space.
 Background knowledge of characteristics of living things
Science laboratory safety practices including an SDS.
SC.7.L.17.1
SC.7.L.17.2
SC.7.L.17.3
SC.7.E.6.6
Highlighted Nature of
Science Standards
SC.7.N.1.1
SC.7.N.1.7
SC.7.N.1.2
SC.7.N.1.4
SC.7.N.1.3
SC.7.N.3.2
SC.7.N.1.5
SC.7.N.1.6
Coherence
In the grade prior students…
 Learn about seasonal changes in plants and animals: Florida vs. Other regions
 Flow of energy in a food chain (producers to consumers)
 Learn how animals (including humans) impact the environment

Learn various adaptations
o variations in life cycles
o Animal behaviors
o Physical characteristics
Not addressed in 6th grade
In the future grades students will…
 Discuss the characteristics of populations, such as number of individuals, age
structure, density, and pattern of distribution.
 Describe changes in ecosystems resulting from seasonal variations, climate
change and succession.
 Analyze how population size is determined by births, deaths, immigration,
emigration, and limiting factors (biotic and abiotic) that determine carrying
capacity.
 Recognize the consequences of the losses of biodiversity due to catastrophic
events, climate changes, human activity, and the introduction of invasive, nonnative species.
 Use a food web to identify and distinguish producers, consumers, and
decomposers. Explain the pathway of energy transfer through trophic levels
and the reduction of available energy at successive trophic levels.
Unit B: Interdependence and Relationships Among Organisms
Unpacking the Standards: What do we want students to Know, Understand and Do (KUD)
The purpose of creating a Know, Understand, and Do Map (KUD) is to further the unwrapping of a standard to assist PLCs in answering question #1, “What do we expect all students to learn?” It is important for PLCs to
study the standards in the unit to ensure that all members have a mutual understanding of what student learning will look and sound like when the standards are achieved
Unit B: Interdependence and Relationships among Organisms
How do organisms depend on each other and their environment to satisfy their basic needs?
Standards: SC.7.L.17.1 Explain and illustrate the roles of and relationships among producers, consumers, and decomposers in the process of energy transfer in a food web
SC.7.L.17.2 Compare and contrast the relationships among organisms such as mutualism, predation, parasitism, competition, and commensalism.
SC.7.L.17.3 Describe and investigate various limiting factors in the local ecosystem and their impact on native populations, including food, shelter, water, space, disease,
parasitism, predation, and nesting sites
SC.7.E.6.6 Identify the impact that humans have had on Earth, such as deforestation, urbanization, desertification, erosion, air and water quality, changing the flow of water.
Understand
“Essential understandings,” or generalizations, represent ideas that are transferable to other contexts.
A balanced ecosystem contains organisms that maintain specific roles and relationships.
Know
Do
Declarative knowledge: Facts, vocabulary, information.
Procedural knowledge: Skills, strategies & processes that are transferrable to other contexts.
1. Producers, consumers, and decomposers play specific roles in the
energy transfers within a food web.
2. Organisms establish relationships within a community. (Examples:
mutualism, parasitism, predation, competition, and commensalism.)
3. Limiting factors include: food, shelter, water, space, disease,
parasitism, predation, reproductive habitat such as nesting.
4. Human activity and natural events impact changes in the
environment, ex: deforestation, urbanization, desertification,
erosion, air quality, water quality, changing the flow of water.
1. Construct a food web that reflects the flow of energy within an
ecosystem.
2. Describe the relationships among the organisms within various
ecosystems.
3. Simulate and graph changes in population size over time as limiting
factors change. Research the impact of human and natural events,
including limiting factors on populations in an environment.
4. Demonstrate and observe the effects of organisms on air and water
quality in a watershed and its ability to reduce or prevent flooding and
filter pollutants such as storm water runoff.
Performance Task: Students use evidence to support their claim as to which organisms within a local ecosystem will have the greatest survivability.
Students take pictures of organisms within their local environment. The collection of photo cards would be used for the class to create a local ecosystem key.
Students would conduct research by identifying relationships organisms have with others and the biotic and abiotic factors within the ecosystem. They identify
potential limiting factors for the population of organisms. They are scored with how thorough and complete their evidence is as to which organism would
survive the best.
http://www.cala.fsu.edu/files/Spec%204%20-%20Observing%20Limiting%20Factors%20-%204-5-13.pdf
Concept:
SC.7.L.17.1 Explain and illustrate the roles of and relationships among producers, consumers, and decomposers in the process of energy
transfer in a food web
Sample Scale
Score 4.0
In addition to Score 3.0, in-depth inferences and applications
that go beyond what was taught.
I can:
• describe the relationship between plants, the producers, and
fungi, the decomposers. How do fungi benefit plants? How do
plants benefit fungi?
Sample Performance Tasks
Students describe relationship between the producers and the
decomposers. How do fungi benefit plants? How do plants benefit fungi?
Students explain their critical role of energy transfer in a food web.
Students can explain what the effects are if an organism disappears.
Score 3.5
I can do everything at a 3.0, and I can demonstrate partial success at score 4.0.
Score 3.0
SC.7.L.17.1 Explain and illustrate the roles of and
relationships among producers, consumers, and decomposers
in the process of energy transfer in a food web
I can:
• draw a diagram and describe the transfer of energy in an
aquatic food web and a land food web with reference to
producers, consumers, decomposers, and predator/prey
relationships
Students construct a food web that reflects the flow of energy within an
ecosystem. Explain each role in the food web
Students make sample ecosystems in a bottle using layers of rock, leaves, sand,
soil, grass seed, and worms. (Also demonstrates how erosion can be
controlled.)
Score 2.5
I can do everything at a 2.0, and I can demonstrate partial success at score 3.0.
Score 2.0
I can:
•explain key concepts such as: food web, food chain,
producers, consumers, decomposers
Score 1.5
Score 1.0
Students can assemble a food web and explain their relationships.
Students can explain the difference between a food chain and a food web.
Students can use pictures of organisms and label those that are producers,
The student will perform basic processes, such as:
consumers and decomposers.
identifies examples of producers, consumers and
decomposers
I can do everything at a 1.0, and I can demonstrate partial success at score 2.0.
With help I can:
•define key vocabulary such as producers, consumers,
decomposers, food web, food chain, energy, energy transfer
Unit B: Interdependence and Relationships Among Organisms
Concept: Organization of a Food Web
SC.7.L.17.1
Explain and illustrate the roles of and relationships among
producers, consumers, and decomposers in the process of
energy transfer in a food web
Driving Questions:
Sample Formative Assessment Task:
How are the biotic and abiotic factors of an
ecosystem interrelated?
Draw a food web for an ecosystem in your
neighborhood.
What are the roles and relationships that occur
within a food web? oon its energy
Student Investigations:
Vocabulary:
abiotic, biotic producers, consumers, food web,
food chain, decomposers, community, population,
ecosystem, organism, *niche
*Notates FCAT 2.0 Science Glossary Term-Grade 8
Text Resources:
Fusion Digital Resources:
Roles in Energy Transfer, Interactions in Communities
Sciencesaurus:
pgs. 176-187, 194-200
Fusion Correlations:
TE: pgs. 666-679
SE: U10L2: pgs. 510-521
Lab Manual:
Quick Lab pgs. 468, 478, 481, 495
Interactive Food Chain (May help to introduce
before Food Web for struggling learners.)
http://www.sheppardsoftware.com/content/a
nimals/kidscorner/games/foodchaingame.htm
Food webs show feeding relationships among different
types of organisms. Those organisms each have a specific
niche. Which of the following best describes a function of
decomposers in food webs?
A. to recycle nutrients into soil
B. to convert solar energy into food
C. to provide food for secondary consumers
D. to compete with secondary consumers for oxygen
Videos:
http://www.pbslearningmedia.org/resource/td
c02.sci.life.oate.decompose/decomposers/
http://www.riverventure.org/charleston/resou
rces/pdf/food%20web%20game.pdf
Resources
Student Misconceptions:
Deeper Learning Opportunities:
Watershed Ambassador’s Program:
See SWFWMD website to order free publications, water
testing kits and apply for a SPLASH Grant
http://www.nextgenscience.org/sites/default/files/MSESS_Watershed_Study_version2.pdf
Scientific Argumentation:
ADI: Life Science 6-8 Lab 11: Food webs and Ecosystems:
Which member of an ecosystem would affect the food
web the most if removed.
http://sciencenetlinks.com/lessons/cycle-of-life-1-foodchain/
Research Ideas:
http://www.rff.org/research/topics
http://www.cala.fsu.edu/ies/performance_assessment_specificati
ons/
Concept: Environmental Relationships
Driving Questions:
Sample Formative Assessment Task:
(E-PBL Environmental Problem Based Learning)
.
What types of wetland and upland ecosystems are
found at Starkey Park or Cross Bar Ranch?
SC.7.L.17.2
Compare and contrast the relationships among organisms such as
mutualism, predation, parasitism, competition, and commensalism.
Mangrove trees are common to the Florida Everglades. The
tree roots serve as a place for freshwater oysters to attach
when the tide is high, as shown in the picture below. The
What are the roles and relationships of living organisms oysters are protected from predators when attached to the
within local upland and wetland ecosystems?
roots underwater.
Student Investigations:
Vocabulary:
biodiversity, uplands, wetlands, mutualism, parasitism,
predation, competition, commensalism, *percolation,
*infiltration, symbiosis
* Notates FCAT 2.0 Science Glossary Term-Grade 8
Galapagos field researchers journal with
examples of organisms
http://www.nsta.org/publications/interactive/galapago
The oysters to not harm the trees nor do they provide any
s/activities/tortoise.html
benefit to the trees. Which of the following relationships is
most similar to the relationship between the mangrove trees
and the oysters?
Activities:
A. African ants living in acacia trees feed on leaf-eating insects
http://www.pbs.org/wgbh/nova/education/activities/2 found on the tree.
B. Spider crabs are camouflaged by the green-brown algae growing
609_abyss.htm
Live Link:
on their shells.
C. A whale is unaffected by the attached remora fish feeding on the
whale’s leftover food.
D. Bees fly from one flowering plant to another gathering nectar
and pollinating the flowers. Voca
http://sdnhm.org/oceanoasis/teachersguide/activity11.ht
mlbulary
Resources
Text Resources:
Student Misconceptions:
Fusion Digital Resources:
Deeper Learning Opportunities:
Watershed Ambassador’s Program:
Interactions in Communities,
Sciencesaurus:
pgs. 176-187, 194-200
See SWFWMD website to order free publications, water testing
kits and apply for a SPLASH Grant
Fusion Correlations:
TE: pgs. 680-692
SE: U10L3: pgs. 522-531
Lab Manual:
Quick Lab pgs. 468, 478, 481, 495
http://www.nextgenscience.org/sites/default/files/MSESS_Watershed_Study_version2.pdf
Research Ideas:
http://sciencenetlinks.com/search/?csrfmiddlewaretoken=6e76101ed
677e96ac52b740f4f619dd0&q=parasitism
Article:
https://student.societyforscience.org/article/some-otterswear-red-algae
http://www.rff.org/research/topics
http://www.cala.fsu.edu/ies/performance_assessment_specifications
/
Can’t We All Get Along:
Relationships in the Ecosystem
Can’t We All Get Along:
Relationships in the Ecosystem
In terrestrial ecosystems there are many examples of
producer/consumer relationships. In the forest, many species of
plants produce seeds. Mice eat these seeds (producer/consumer
relationship #1). A snake might eat the mouse, which will
indirectly give it some of the sun’s energy (producer/consumer
relationship #2). Finally, a snowy owl might eat the snake.
Again, it will indirectly get the sun’s energy (producer/consumer
relationship #3). Whatever the consumer is and whichever
ecosystem it lives in, it can get direct or indirect energy from the
producers.
Can’t We All Get Along:
Relationships in the Ecosystem
Predators are a special type of consumer. In order to be a
predator, one must hunt and kill its food, or prey. In the oceans,
one of the top predators is the Great White Shark. This fish is
designed to eat, having rows and rows of teeth. It will hunt
down and eat seals, large fish, squid, and even injured whales.
The great white shark sits at the top of the food web and is a top
consumer.
All organisms interact with each other in some way. Some make
food that is eaten by others, some get eaten, and some even live
their entire lives inside another organism. Whatever the
relationship, all living things on Earth are dependent upon each
other for their survival.
In terrestrial ecosystems, predators include
lions, snakes, hawks, and even the shrew.
Each of these animals hunts down prey, kills
it, and eats it. Freshwater ecosystems can also
have predators. Many birds eat the fish and
shellfish that live in freshwater lakes and
ponds. They swoop down out of the air and
Three ways that organisms can relate to each other include:
parasite/host, consumer/producer, and predator/prey. Each of
these can exist in freshwater, marine, and terrestrial
environments.
snatch them up to eat them.
Consumers like this shrew get their
energy from eating other things.
Birds, mammals, and fish are all
Freshwater, marine, and terrestrial
types of consumers.
ecosystems all have organisms that are always
interacting with each other. Some of these relationships are very
one sided (as in the predator/prey and parasite/host), but they
are essential for the survival of all living things. As energy is
transmitted through the food web, some organisms can even
play multiple roles. There are times when an animal, like a
snake, may be a predator, but then when an owl eats it, it
becomes prey.
All these relationships keep ecosystems in balance and energy
being transferred.
Discovery Education Science
© Discovery Communications, LLC
Parasites are common
in all ecosystems
around the world, but
they thrive in warmer
conditions. Parasites
are not just problems
for people. They exist
naturally in
ecosystems, infecting
many different species
Mistletoe is actually a parasite that grows
of animals. Even
on other species of trees. It takes
plants can be infected
nutrients from its host plant.
by parasites. Many
different types of organisms can be parasites, including bacteria,
protists, plants, and animals. A parasite species may be specific
to a single host species or may infect a group of related
organisms. For example, hookworms have evolved hook-like
structures on their mouths that allow the worms to attach firmly
to mammalian intestinal walls. Hookworms infect a variety of
mammals, taking nutrients directly from the host.
Another very common parasite in all types of environments is
the tapeworm. The host, which could be a fish in freshwater and
ocean ecosystems and a cow in terrestrial ecosystems, gets
infected when it swallows the tapeworm eggs. The eggs pass
through the digestive tract and implant themselves into the
intestine wall of the animal. Here, the tapeworm will absorb
nutrients that the host should get, and use them for its own
metabolism. Over time, the host will weaken because of the lack
of nutrition. At this point, the tapeworm needs to release its
eggs into the environment so that it can carry on.
Discovery Education Science
© Discovery Communications, LLC
In freshwater and marine ecosystems, water is used to transport
the eggs to the next host. The eggs float around until another
organism accidentally consumes them. Reproduction in a
terrestrial ecosystem is a bit more difficult. The eggs are often
consumed when a grazing animal takes a drink from an infected
pond or other water source. Unlike in aquatic ecosystems, the
eggs may sit around longer in terrestrial ones.
A consumer is any organism that gets its energy from eating, or
consuming, another organism. Familiar images of consumers
include lions eating gazelles, and birds, like this roadrunner,
munching on a lizard. These animals are
called carnivores because they eat meat.
Other consumers are called herbivores.
They eat plants and plant-like organisms.
Herbivores could include deer and giraffes
in terrestrial ecosystems, ducks and some
fish in freshwater ecosystems, and some
fish and manatees in ocean ecosystems.
A producer is an organism that makes food
Consumers get their energy from
eating other things. Birds,
for itself through the process of
mammals, and fish are all types of
photosynthesis. This process takes energy
consumers.
from the sun, combines it with water and
carbon dioxide, and creates sugars. Many types of plants live in
all ecosystems. Terrestrial producers include trees, rose bushes,
and grass. Freshwater producers include diatoms, pondweed,
and reeds, and ocean producers include salt grasses, seaweeds,
and diatoms.
Producers are considered the bottom of the food chain. This
means that all of the upper levels (the consumers) rely on the
producers for their energy. Take for example a top land
predator, the polar bear. In the Arctic, the waters are loaded
with microscopic algae, making tons of food from the sun. This
algae is eaten by small fish. Larger fish eat the small fish, which
are then eaten by leopard seals. When a polar bear eats the
leopard seal, it is, indirectly, getting the energy from the sun. A
great producer/consumer relationship!
Discovery Education Science
© Discovery Communications, LLC
Video: Symbiosis, Mutualism and Commensalism
https://www.youtube.com/watch?v=zSmL2F1t81Q
Concept: Limiting Factors
Driving Questions:
Sample Formative Assessment Task:
(E-PBL Environmental Problem Based Learning)
SC.7.L.17.3.
What are limiting factors and how do they affect
individual species and populations within a
Describe and investigate various limiting factors in the local ecosystem
and their impact on native populations, including food, shelter, water,
space, disease, parasitism, predation, and nesting sites.
community?itnergy?
Student Investigations:
Activities:
Winn Bee Foraging Activity
Vocabulary:
limiting factors- food, shelter, water, space, disease,
threatened, endangered, extinct species
Limiting factors challenge and simulation
https://www.heart.org/idc/groups/heartpublic/@wcm/@fc/documents/downloadable/
ucm_306499.pdf
http://www.wolfquest.org/classroom_activitie http://www.tamdistrict.org/cms/lib8/CA01000875/Centri
city/Domain/654/Limiting%20factors%20Activity%20GP1
s.php
3.pdf
Videos:
https://www.youtube.com/watch?v=QI2ixJeIxEU
Resources
Text Resources:
Student Misconceptions
Deeper Learning Opportunities:
Fusion Digital Resources:
Natural Resources, Florida’s Ecosystems, Human
Impact on Land, Human Impact on Water, Human
Impact on Atmosphere, Protecting Earth’s Water,
Land, and Air
Sciencesaurus: pgs. 176-187, 194-200
Fusion Correlations:
TE: pgs. 696-709 SE: U10L4: pgs. 534-547
Lab Manual: Quick Lab pgs. 468, 478, 481, 495
Watershed Ambassador’s Program:
See SWFWMD website to order free publications,
water testing kits and apply for a SPLASH Grant
AASCollections
The Ups and Downs of Populations Students will
analyze population graphs, collect data to
generate their own population graph, and
experience limiting factors and their impact on
carrying capacity in a small deer population.
–
Science
Net
Links
http://sciencenetlinks.com/search/?csrfmiddlewaretoke
n=6e76101ed677e96ac52b740f4f619dd0&q=parasitism
Biodiversity- Discussions, Blogs, and Journals
http://www.rff.org/research/subtopics/biodiversity
http://www.nextgenscience.org/sites/default/files/
MS-ESS_Watershed_Study_version2.pdf
Research Ideas
http://www.cala.fsu.edu/ies/performance_assessment_spec
ifications/
Concept: Human Activity
Driving Questions:
Sample Formative Assessment Task:
(E-PBL Environmental Problem Based Learning)
What effects can human and natural factors in one area of
SC.7.E.6.6. Identify the impact that humans have had on Earth, a watershed have on the quantity and quality of surface
such as deforestation, urbanization, desertification, erosion, air and water and groundwater on the rest of the watershed?
water quality, changing the flow of water.
SC.7.N.3.2Identify the benefits and limitations of the use of
scientific models.
How can water quality testing be used to determine the
health of a wetland ecosystem?e o
Deforestation occurs when large areas of trees are cut
down. Which of the following impacts on the
environment would result from deforestation?
A. increased erosion
B. colder temperatures
C. excess ground moisture
D. greater oxygen production Vo
How do we identify, monitor and improve conditions in our
environment to positively impact our watershed? o
Imagine a location that contains large populations of
trees, flowers, beetles, worms, fungi, bacteria and
Student Investigations:
other small insects. Explain in a short essay what might
happen to the soil if the entire population of trees were
Websites:
www.ecokids.ca/pub/eco_info/topics/frogs/chain_reaction suddenly removed?
/index.cfm
Vocabulary:
Show students interactive and have them list changes
they see:
Watershed Interactive:
http://techalive.mtu.edu/meec/module01/whatiswatershe http://www.citylab.com/tech/2013/05/terrifyingd.htm
fascinating-timelapse-30-years-human-impact-earthArticles:
gifs/5540/
http://www.nationalgeographic.com/earthpulse/food-andwater.html
watershed, wetland, upland, ecosystem, ground
water, storm water runoff, deforestation,
urbanization, desertification, erosion, air quality,
water quality, recharge, filtration, sinkhole, acidic,
*pH, Prescribed burn, water quality, pine forests, https://student.societyforscience.org/article/plastic-trashgopher tortoise *niche,*transparent, *saturation, travels-arctic-waters
*temperature
Designing an Ecosystem
Notates FCAT 2.0 Science Glossary Term-Grade 8
Design an Ecosystem-SeaWorld Classroom Activity
Resources
Student Misconceptions:
Text Resources:
Fusion Digital Resources:
Natural Resources, Florida’s Ecosystems, Human Impact
on Land, Human Impact on Water, Human Impact on
Atmosphere, Protecting Earth’s Water, Land, and Air
Sciencesaurus:
pgs. 176-187, 194-200
Fusion Correlations: TE: pgs. 260-271, pgs. 272-284, pgs.
288-302, pgs. 304-317, pgs. 318-332
Deeper Learning Opportunities:
Watershed Ambassador’s Program:
See SWFWMD website to order free publications,
water testing kits and apply for a SPLASH Grant
http://www.nextgenscience.org/sites/default/files/
MS-ESS_Watershed_Study_version2.pdf
Research Ideas:
http://www.rff.org/research/topics
SE: U4L1: pgs. 198-205; U4L2: pgs. 206-217; U4L3: pgs.
218-231; U4L4: pgs. 232-243; U4L5: pgs. 244-264
http://www.cala.fsu.edu/ies/performance_assessment_spec
ifications/
Lab Manual:
Quick Lab pgs. 468, 478, 481, 495
http://sciencenetlinks.com/search/?q=urbanization
&content_types=All
Close Reading Exemplar: Living Like Weasels
Predator/Prey Relationships Beneath the Waters
of Cocos Island
Sudden Changes in
Ecosystems
Land ecosystems on Earth include the desert, tundra, forest,
rain forest, and grassland. Scientists classify land ecosystems
based on their climate, land, and species. The land and its features
are called terrain.
Argument Driven Inquiry Life Science 6-8: Lab 12
Matter in Ecosystems: How Healthy are your
Local Ecosystems?
For example, the climate in most deserts is very hot and dry. Desert
terrain is generally sandy or rocky. In contrast, the climate in the
tundra is very cold. The ground is frozen all year round. Different
types of plants and animals live in the desert and the tundra. For
example, cacti live in the desert. They can survive in hot
temperatures without much water. Polar bears live in the tundra.
They have thick fur to keep them warm.
The climate, terrain, and living things in a
land ecosystem can sometimes change.
They can change quickly from natural
events or human activity. People change the
land in tropical rain forests by
deforestation. Deforestation is the removal
of trees and other plants from an area.
People use trees from rain forests as
lumber. They also build buildings and farms
on the cleared land.
Sudden Changes in Ecosystems
Deforestation is a big issue in many
rain forests around the world.
Deforestation changes a land ecosystem.
Plants in a rain forest die when they are cleared out. Animals that
use trees for shelter and food must find somewhere else to live.
These animals include birds, frogs, lizards, and monkeys. However,
deforestation leaves few places for these animals to move to.
Because of the lack of food and shelter, many animals do not
survive after deforestation.
Fires can also change a land ecosystem. People can sometimes
cause fires. However, fires also happen naturally from lightning.
Grasslands are generally dry land ecosystems. Because they are dry,
fires often happen there. The fires can kill all the grasses in an area.
They can also kill insects, mice, lizards, and other animals that do
not escape. When the fire burns the grasses, it destroys the food
source for many animals. Animals such as bison feed or graze on
grasses. These animals will have to move to another area to find
food.
Fires can also change a grassland ecosystem in a positive way. For
example, after a fire birds feed off the many insects that did not
survive. The fire burns the tops of the grasses, but it does not harm
their roots. Therefore, the grasses are able to regrow.
Many animals depend on grasses for food. Fires are a
natural way to maintain grasslands as grazing areas for
animals.
Deforestation and fires both cause major changes to
ecosystems. You may have seen ecosystems change on a
smaller scale. Perhaps you have seen land cleared for a
new neighborhood, road, or shopping center. In many
cases, the land is cleared of all trees and is flattened.
These events change the terrain of the ecosystem. They
also change the number and types of organisms that are
able to live there.
Grassland fires damage the
ecosystem, but they have some
positive effects, too.
© 2007 Discovery Communications, LLC
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