Name:_____________________________________________________Period:____Date:_______________
I. VOCABULARY:

_____________________- The scientific study of interaction between organism and their environments.
o Environments:
 ________________________–all the living organism that inhabit an environment
 ________________________– the nonliving parts of the environment
 Ex: air currents, temperature, moisture, light, and soil

______________________– is a group of organisms of one species that interbreed and live in the same
place at the same time
o Organisms compete for food, water, mates.
 Determines how large each population can become

_____________________- The interacting system of a biological community and its nonliving
environment.

________________________– is a collection of interacting populations
o A change in one population in a community will cause changes in the other populations

__________________________- Place where an organism lives;
o Even in the same ecosystem, different organisms differ in their habitats.
II. SPECIES RELATIONSHIPS:

____________________- Organisms that produce their own food are called _________________.
o Ex: Plants
o all of the species of the ecosystem depend on autotrophs for nutrients and energy.

___________________________- They obtain food by eating other organisms.
o All the organisms that cannot make their own food (and need autotrophs) are
called____________________________.
o There are different levels of consumers:
 Those that feed directly from producers, i.e. organisms that eat plant or plant products
are called___________________________.
 ___________= a role that an organism has in the environment (based on what they
EAT!)
1. __________________________- consumer that eats only plants
Ex: grasshoppers, mice, rabbits, deer, beavers, moose, cows, sheep
2. ________________________________- consumer that eats only other animals.
Ex: Foxes, frogs, snakes, hawks, and spiders.
3. ________________________________– consumer that eats the remains of dead animals.
Ex: vultures, buzzards, crows, ants, beetles
1
4. __________________________- eats both plants (acting as primary consumers) and meat (acting as
secondary or tertiary consumers).
Ex: Bears --They eat insects, fish, moose, elk, deer, sheep as well as honey, grass
5. ________________________- organisms that break down the remains of other organisms.
o Found at the bottom of the food web.
Ex: Bacteria, yeast, fungi, worms and many insects
III. RELATIONSHIPS FOR SURVIVAL:

________________________– permanent, close association between two or more organisms of
different species
o 3 types:
1. ________________________– one species benefits and the
other species is neither harmed nor helped
Ex: an orchid growing on the branch of a larger plant
2. _______________________– relationship that is beneficial to
both species
Ex: acacia trees (provides food/shelter for ants) and ants
(protect tree by attacking any herbivore)
3. _______________________– one species benefits at the
expense of the other species
Ex: ticks, tapeworms live on or in the organism
IV. MATTER & ENERGY IN ECOSYSTEMS:

_______________________- Show one prey-predator relationship and how each
living thing gets its food.
o Some animals eat plants and some animals eat other animals.
o Ex: Trees/shrubs  giraffes  lions
o Each link in this chain is food for the next link.
o Always starts with plant life and ends with an animal.
o ____________________________-link represented by each organism
in a food chain;
 Represents a feeding step in the transfer of ____________and matter in an ecosystem.
 All energy in an ecosystem originates with
the___________.

Plants transform solar energy into chemical
energy (food) via photosynthesis

This is consumed by plant-eating animals, which
are in turn consumed as food.
 The total energy transfer from one trophic level to the
next is only about _______, the other 90% is lost as
___________
2

Heat is lost by:
1. Organisms fail to capture and eat ________food available at the trophic level below them
2. Not all food that is captured and eaten __________________________
3. Digested food is _______________by the organism as a source of energy.

______________________- model used to express feeding relationship among the members of a
community.
o A group of interlinked ____________________
o Illustrates:
1. Who eats who?
2. ______________ = energy flow through the community
3. Functional feeding groups
4. Important ecological interactions
V. Differences between a food web & food chain:
1. ____________________ONLY show one prey-predator relationship. The source of food is also often
____________________with many animals adapting to changes in the season by eating different types
of food.
2. ____________________show a better picture of interrelationships between plants and animals.
VI. How Pollution Can Affect Organism:

__________________________= The process of increasing a chemical concentration through the food
chain (Examples: DDT and PCB)
o Animals that eat other animals have HIGHER levels of contaminants than animals that eat plants.
o Some contaminants are persistent - once they are in the animal's body, they stay there for a long time.
o So when smaller animals are eaten by bigger animals, all the contaminants stored in their tissues are
then ____________________to the bigger animal.
3
o The result of biomagnification is that animals ____________________________________
o The top predators at the end of a long food chain
may accumulate concentrations of a toxic chemical high
enough to cause serious deformities or death even though
the concentration of the chemical in the open water is
extremely low.
o The concentration of some chemicals in the fatty
tissues of top predators can be millions of times higher than
the concentration in the open water.
4
VII. Nutrient Cycles
 The Water Cycle
1. Water cycles between the oceans, atmosphere and land.
A. Water enters the atmosphere as__________________________, a gas, when water evaporates from
the ocean or other bodies of water.
o
Evaporation—the process by which water changes from a _____________ to a __________.
B. Water can also enter the atmosphere by evaporating from the leaves of plants—Transpiration.
C. Precipitation--________________,___________________, ______________, or ___________
o
The sun heats the __________________________________.
o
Warm, moist air rises and cools.
o
Eventually, the water vapor condenses into tiny droplets that form __________________.
o
When the droplets become large enough, the water return to Earth’s surface.
D. Run-off—Precipitation runs along the surface of the ground until it enters a river or a stream that
carries the run-off back to an ________________ or lake.
E. Seepage—Rain also seeps into the soil, some of it deeply enough to become ___________________.
Water in the soil enters plants through the ________________________, and the water cycle begins
anew.
Condensation
Condensation
Precipitation
Transpiration
Seepage
Precipitation
Evaporation
Surface Run-off
Ground Water
5
 The Carbon Cycle
1. Every__________________________ molecule contains the element ___________________.
A. Carbon and oxygen form ___________________________ gas (CO2), an important component of the
_______________________________________.
B. Carbon dioxide is taken in by plants during ___________________________________ and is given
off by plants and animals during _________________________________.

Cellular respiration is a process where cells transform chemical energy (sugar) into a useable form of
energy (____________).
2. Four main types of processes move carbon through its cycle:
A. Biological processes, such as_________________________________, _______________________,
and ____________________________, take up and release carbon and oxygen.
B. Geochemical processes, such as ___________________ and volcanic activity, release carbon dioxide
into the atmosphere and oceans.
C. Mixed biogeochemical processes, such as the burial and decomposition of
________________________________________ and their conversion under pressure into _______
and ____________________________(fossil fuels), store carbon underground.
D. Human activities, such as ____________________, cutting and ___________________ forests, and
burning ___________________________ (car emissions, electricity), release carbon dioxide into the
atmosphere.
Burning of
Fossil Fuels
CO2 in Atmosphere
Cellular Respiration
Photosynthesis
Coal and Petroleum
Decomposition of
dead organisms
6
 The Nitrogen Cycle
1. All organisms require nitrogen to make ______________________, which in turn are used to build
_______________________.
A. Nitrogen gas makes up 78% of Earth’s _______________________________.
B. Nitrogen containing substances such as ____________________ (NH3), _________________ (NO2-),
and _____________________ (NO3-) are found in the wastes produced by many organisms and in
dead and _____________________organic matter.
C. Nitrate is major component of plant ________________________________.
2. Nitrogen gas is the most abundant form but only certain ______________________ can use this form.
A. Such bacteria live in the __________ and on the _______________ of plants (Legumes- soybeans,
clover, alfalfa).
B. These bacteria convert nitrogen gas into ammonium-- ______________________________________
C. Other bacteria in the soil convert ammonia into ________________and _______________.
3. Once the nitrites and nitrates are available,______________________ (plants) can use them to
make_________________________.
o
____________________then eat the producers and reuse the nitrogen to make their own proteins.
4. When organisms die, ________________________________return nitrogen to the soil as ammonia.
5. Other soil bacteria convert nitrates into nitrogen gas--_________________________________. This
process releases nitrogen into the atmosphere once again.
Nitrogen Gas in Atmosphere
Denitrification
(Nitrates  nitrogen)
Nitrogen Fixation
(Nitrogenammonium)
Decomposers
return ammonia
to soil
Nitrates
(NO3-)
Nitrites
(NO2-)
7
VIII. A Change in Communities OVER Time: SUCCESSION

___________________= orderly, natural changes that take place in the communities of an ecosystem
o The community of organisms inhabiting an area ________________changes.
o __________________________________ since it can take decade or centuries for one type of
community to completely succeed another.
Figure 1: Succession of plant species on abandoned fields in North Carolina. Pioneer species
consist of a variety of annual plants. This successional stage is then followed by communities of
perennials and grasses, shrubs, softwood trees and shrubs, and finally hardwood trees and shrubs.
This succession takes about 120 years to go from the pioneer stage to the climax community.

___________________________________= establishment of a community in an area of exposed rock that
does not have any topsoil.
o Ex: ______________flowing from a volcano destroys everything in its path, but when it cools it
forms new land
o Ex: ________________gradually deposit silt along their banks, creating new soil in which plants
can take root.
o After some time, primary succession slows down, and the community becomes fairly_________.


A stable, mature community that undergoes little of NO succession is called
a________________________________.
_________________________________= the sequence of community changes that takes place when a
community is disrupted by natural disasters or human actions

Ex: Hurricanes, forest fires, farmers abandoning fields
IX. Biomes

____________________= a large group of ecosystems that share the same type of climax community

Two factors that will determine which biome will be dominant on land:
1. ____________________
2. ____________________
8
2) World Biomes:
1) ____________________________________
 Characteristics: treeless, long cold winters, little winter sun, poor soil, little rain (less than
5 in)
 __________________________________________– permanently frozen ground
 Location: Canada, Russia, Alaska
 Vegetation: grasses, moss, lichen
 Animals: insects, fox, rodents, caribou, reindeer
2) ________________________________________
 Characteristics: coniferous forest, poor soil, long severe winter
 Location: Canada, N. Europe, N. Asia
 Vegetation: pine, fir, hemlock, spruce
 Animals: rabbits, lynx, caribou, moose, woodpecker
3) _________________________________________________(where we live!)
 Characteristics: deciduous trees, 4 seasons, vegetation exhibits seasonal changes
o ___________________________________– trees lose leaves in winter
 Location: East US, Europe
 Vegetation: Maple, Oak, Birch, Hickory
 Animals: bear, deer, robin, raccoon
4) _________________________________________________________________
 Characteristics: warm, wet, humid, most diversity, up to 17 feet of rainfall annually
 Location: islands, equatorial regions
 Vegetation: broad lush plants, flowers, vines, palms, fruit trees
o lush with many layers in the canopy that support an incredible
___________________of life.
 Animals: monkey, sloth, frogs, snakes, parrots
5) ___________________________________________________
 Characteristics: ideal growing season, good soil quality, little precipitation does not
support trees, but grasses and herbs are present in great abundance.
 Location: central regions
 Types:
o Prairie – US
o Steppe – Russia
o Savanna – Serengeti
o Pampas - Argentina
 Vegetation: grass, grains, crops, wildflowers
 Animals: bison, prairie dogs, birds, lions, elephants
6) _________________________________________________
 Characteristics: dry & arid, less than 10 in of rainfall
 Location: SW US, N. Africa, Middle East
o Hot Deserts- Mojave, Sahara
o Cold Desert- Gobi
 Vegetation: Plant cover is sparse, and characterized by drought tolerant brushes,
succulent (cacti, creosote bushes)
 Animals: rodents(gerbils, jerboas and kangaroo rats), snakes, lizards, scorpions, turtles,
hawks
9
X. Population Dynamics


All species occur in groups called _________________________________________

______________________________________________ = factors that are biotic or abiotic that
keep a population from continuing to increase indefinitely
2 Types of Population-Limiting Factors:

density-independent factors

density-dependent factors
 ______________________________________________________ = Any factor in the environment that
does not depend on the number of members in a population per unit area

Usually ______________________ (natural phenomena)

Ex:




Weather events (tornadoes, floods, hurricanes)
Fire
Human alterations of the landscape
Air, land, and water pollution
 ______________________________________________________= Any factor in the environment that
depends on the number of members in a population per unit area

Usually _________________________

Ex:




Predation
Disease- (high population density--> disease quickly spreads)
Parasites
Competition – food, space limitations
 The ______________________________________________________(PGR) explains how fast a given
population grows.
 ________________________________________________________occurs when the growth rate is
proportional to the size of the population.

__________ populations grow exponentially until some limiting factor slows the population’s
growth.
10
 The population’s growth slows or stops following exponential growth, at the population’s
__________________________________________________.

A population stops increasing when the number of births is less than the number of deaths or
when emigration exceeds immigration.

____________________________________________ = The maximum number of individuals
in a species that an environment can support for the long term.
 limited by the energy, water, oxygen, and nutrients available.
 Population exceeds carrying capacity- deaths outnumber births because resources are not
available to support all individuals
11
Food Web Worksheet
Identify the:
1. Producers (2)
2. Primary Consumers (4)
3. Secondary Consumers (4)
4. Herbivores (3)
5. Carnivores (4)
6. Omnivores (1)
7. What elements are missing from this
food web? ______________________
8. All energy in an ecosystem originates with the _______________.
9. The total energy transfer from one tropic level to the next is only about _______%, the
other ______% is lost in the form of heat.
10. A tick feeds on the blood of a rabbit. What type of symbiosis is this? ________________
11. A squirrel eats the berries and spread the berry-plants seeds in its feces. What type of
symbiosis is this? ______________________________
12. Barnacles adhering to the skin of a whale. What type of symbiosis is this?
_________________
13. Look at the food web above. What would happen if a disease killed the entire grasshopper
population?
12
FARM AREA FOOD WEB & CHAIN:
Directions:
1) Construct a food web using the animals listed below in the box. This ecosystem represents a farm
area. The corn is the main source of food for many of the herbivores in the area. You do not have to
draw pictures; you can just use the animal names and draw arrows between them.
o CORN
o SNAKE (eats: mouse, squirrel)
o CATERPILLAR (eats: corn)
o DEER (eats: corn)
o CROW(eats: corn, snake, mouse, caterpillar)
o MOUSE (eats: corn, caterpillar)
o COUGAR (eats: deer, mouse, snake, squirrel)
o SQUIRREL (eats: corn)
o DECOMPOSERS (microorganisms)
2) What niche do the caterpillar, squirrel & deer have in this ecosystem? ____________________
3) What niche does the cougar have in this ecosystem? __________________________
4) Construct a food chain using 3 organisms from above (remember you must start with a producer!).
13
Nutrient Cycles Worksheet
Cycle Identification: Write the correct cycle (water, carbon, nitrogen) next to the following
descriptions.
_________________________1. Bacteria and plants help to transform a nutrient
_________________________2. Precipitation and transpiration are a part of this cycle.
_________________________3. Carbon dioxide plays an important role
_________________________4. Legumes are important part of this cycle
_________________________5. Cellular respiration and photosynthesis play a key role in this cycle
Short Answer: Using your notes, correctly answer the following questions.
1) What is transpiration?
2) What process occurs when soil bacteria convert nitrates into nitrogen gas?___________________
3) What process occurs when bacteria converts nitrogen gas into ammonium?___________________
4) Explain one way that legumes are different from other plants when dealing with the nitrogen cycle?
5) List some examples of legumes. _________________________________________________
6) What are 3 processes that move carbon through a cycle?
7) Where (and in what form) is the majority of the Earth’s carbon found?
8) What are 2 ways that water can enter the atmosphere?
9) What are 3 ways that water can enter lakes, streams and/or oceans?
14
Biome Identification
Directions: Based on the information provided, determine which biome (temperate forest, tundra, taiga, desert,
rainforest, grassland) is being described.
This Biome has an average rainfall of 15-25 cm per year. Its temperature range is between -34⁰ and 12⁰C. The
plant species here are short grasses and shrubs, while the animals are caribou, reindeer, polar bears, birds,
insects, wolves, salmon and trout. Geographically it is located south of the polar ice caps in the Northern
Hemisphere. Abiotic factors are soggy summers, permafrost as well as it being cold and dark much of the year.
What Biome is this?
This biome gets about 38-51 cm of rain each year. Its average temperature is between -68⁰ and 32⁰C. Plant
species found here are spruce and fir trees, as well as deciduous trees and small shrubs. Animal species found
here are birds, moose, beavers, deer, wolverines and mountain lions. The geographic location of this biome is
the northern part of North America, Europe and Asia. Abiotic factors that impact this biome are summers being
short and moist, winters being long, cold and dry.
What Biome is this?
Approximately 75 – 150 cm of rainfall on this biome each year. The average temperature range is -30⁰ to 30⁰C.
Plants that thrive in this biome are oak, beech and maple trees, as well as shrubs. Animal varieties are squirrels,
rabbits, skunks, birds, deer, foxes and black bears. Geographically, this biome is south of the taiga in eastern
North America, eastern Asia, and Europe. Well-defined seasons, hot summers and cold winters define this
biome.
What Biome is this?
15 – 26 cm of precipitation fall on this biome annually. The temperature ranges can be as high as 20⁰ to 49⁰C,
and as low as 2⁰ to 26⁰C. Plant species found here are cacti, Joshua trees, and succulents. Animal species
found here are lizards, bobcats, birds, tortoises, cats, antelope, pygmies and desert toads. Geographically, this
biome is found on every continent except Europe. Abiotic factors that influence this biome are varying
temperatures and low rainfall.
What Biome is this?
50 – 150 cm of rain fall on this biome each year. The temperature fluctuates only modestly between 24⁰ and
49⁰C. Grasses and scattered trees are the backdrop to lions, hyenas, cheetahs, elephants, giraffes, zebras, birds
and insects. Africa, South America, and Australia are locations to go if you want to visit this biome. Abiotic
factors that influence the makeup of the biome are hot and rainy summers, as well as cool and dry winters.
What Biome is this?
125 to upwards of 660 cm of rainfall cover this biome. Temperatures range between 20 ⁰ and 34⁰C. Plant
species found here are broadleaf evergreens, bamboo, fig and coconut trees. Animals that feed off of and live
on these plants are chimpanzees, Bengal tigers, elephants, orangutans, bats, toucans, sloths, and cobras. This
biome is located in Central and South America, southeastern Asia, western Africa, as well as northeastern
Australia. Abiotic factors that influence this biome are that it is humid all year, as well as hot and wet.
What Biome is this?
15
Populations Dynamics Worksheet
1) What is the difference between density-independent factors and density-dependent
factors?
2) List 2 density-independent factors.
a. ________________________________________
b. ________________________________________
3) List 2 density-dependent factors.
a. ________________________________________
b. ________________________________________
4) List 2 factors can limit the carrying capacity of a population?
a. ________________________________________
b. ________________________________________
5) Which type of population growth model does the graph on
the right represent? __________________
6) Using the graph below, why does the population growth level
off at 10,000?
16
Ecology Review Worksheet
Vocabulary Matching:
___1. Feeds on dead organisms
___2. Study of how living things relate to each other and to their
environment
___3. Step in the passage of energy and matter through an ecosystem
___4. Relationship between organisms in which one benefits and the other
is neither harmed nor benefited
___5. Relationship between organisms in which one organism benefits and
the other is harmed
___6. Breaks down dead organisms
___7. Simple model for showing how matter and energy move through an
ecosystem
___8. Place where an organisms spends its life
___9. The role an organism has in an ecosystem (carnivore, omnivore, etc)
___10. Manufactures food using energy from the sun; makes their own
food
A. food web
B. mutualism
C. succession
D. niche
E. heterotroph
F. commensalism
G. autotroph
H. scavenger
I. community
J. trophic level
K. decomposer
L. ecology
M. food chain
N. parasitism
O. habitat
P. carrying capacity
___11. Obtains energy and nutrients from autotrophs
___12. Network of interconnected food chains
___13. Group formed by several populations
___14. Relationship between organisms in which BOTH organisms benefit
___15. Orderly, natural changes that take place in the communities of an ecosystem
___16. The maximum number of individuals in a species that an environment can support for the long
term.
Short Answer:
Provide the correct answers.
1) All energy originates with the ______________.
2) A stable, mature community that undergoes little or NO succession is called a
____________________________________________.
3) A forest fire destroys 10,000 acres of a forest and new grasses are starting to grow. This is an
example of______________________________________________.
4) _______________________________________ is the establishment of a community in an area
of exposed rock that does not have any topsoil.
5) The process of increasing a chemical concentration through the food chain is called
___________________________________.
17
6) A large group of ecosystems that shares the same type of climax community is called a
___________________.
7) The total energy transfer from one tropic level to another is about _______%.
8) List two biotic factors in an environment.
a. ____________________________________
b. ____________________________________
9) List two abiotic factors in an environment.
a. ____________________________________
b. ____________________________________
10) What two factors determine where each biome is located on the earth?
a. ____________________________________
b. ____________________________________
11) The clownfish has shelter in the sea anemone and the sea anemone get food that the fish brings.
What type of symbiosis is taking place between a clownfish and sea anemone? Why?
12) A tree provides a habitat for lichens, allowing it to receive ample sunlight. What type of symbiosis is
taking place between a tree and lichen? Why?
13) A dog is infected with heart worms that weaken the heart muscles. What type of symbiosis is taking
place between a dog and heart worm? Why?
14) Look at the following food chain: Plant  insect small bird  hawk
a. How does energy flow in the food chain?
Biome Identification:
Desert, Taiga, Tundra, Rainforest, Temperate Forest, Grassland
_______________________1. The biome where we live (Pennsylvania)
_______________________2. Has a lot of reptiles and rodents; succulents (cati)
_______________________3. Receives about 17 feet of rain per year!
_______________________4. Little precipitation; does not support trees, but grasses and herbs are
abundant
_______________________5. Vegetation exhibits 4 seasonal changes
_______________________6. Lies below the tundra and has different species of fir and spruce trees
_______________________7. Permafrost is present
18
Unit Learning Map (7 days):
Ecology
Mrs. Sim
Class: Biology B: PA standard: 3.3.10: Explain the structural an functional similarities
and differences found among living things
Optional
Instructional Tools:
Unit Essential Question(s):
Nutrient Cycles Activity
Biome Stations Activity
M&M Ecosystems Lab
How are organisms
affected by the abiotic &
biotic factors in the
environment?
Concept
Concept
Concept
Concept
Food Webs
Nutrient Cycles
Succession
&
Biomes
Lesson Essential Questions:
Lesson Essential Questions:
Lesson Essential Questions:
Lesson Essential Questions:
1) What
characteristics
identify each biome
on the Earth?
How can you
compare the
different models
used to quantify
the growth of a
population?
How does energy
flow through the
ecosystem?
How do nutrients
cycle through the
ecosystem?
Vocabulary:
Ecology
Biotic factors
Abiotic factors
Population
Community
Ecosystem
Habitat
Producer
Consumer
Herbivores
Carnivores
Scavengers
Decomposers
Niche
Food chain
Food web
Tropic levels
Symbiosis
Commensalism
Mutualism
Parasitism
Biomagnification
Vocabulary:
Denitrification
Nitrogen fixation
Legumes
Transpiration
2) What stages are
involved in an
ecosystem changing
over time?
Vocabulary:
Succession
Primary succession
Secondary succession
Climax community
Biomes
Tundra
Permafrost
Taiga
Temperate Forest
Tropical Rainforest
Grassland
Desert
Population Dynamics
Vocabulary:
Density-independent factors
Density-dependent factors
Exponential growth
Carrying capacity
19
Ecology Vocabulary:
1) Ecology = the scientific study of interaction between organism and their environments
2) Biotic factors = all the living organism that inhabit an environment
3) Abiotic factors = the nonliving parts of the environment
4) Population = a group of organisms of one species that interbreed and live in the same
place at the same time
5) Ecosystem = the interacting system of a biological community and its nonliving environment
6) Community = is a collection of interacting populations
7) Habitat = place where an organism lives
8) Producer = organisms that produce their own food are called autotrophs
9) Consumer = they obtain food by eating other organisms
10) Herbivores = consumer that eats only plants
11) Carnivores = consumer that eats only other animals
12) Scavengers = consumer that eats the remains of dead animals
13) Omnivores = eats both plants (acting as primary consumers) and meat (acting as secondary or tertiary
consumers)
14) Decomposers = organisms that break down the remains of other organisms
15) Niche = a role that an organism has in the environment (omnivore, carnivore, herbivore, etc.)
16) Food chain = shows only one prey-predator relationship and how each living thing gets its food
17) Food web = shows a better picture of interrelationships between plants and animals
18) Tropic levels = link represented by each organism in a food chain
19) Symbiosis = permanent, close association between two or more organisms of different species
20) Commensalism = one species benefits and the other species is neither harmed nor helped
21) Mutualism = relationship that is beneficial to both species
22) Parasitism = one species benefits at the expense of the other species
23) Biomagnification = the process of increasing a chemical concentration through the food chain
24) Succession = orderly, natural changes that take place in the communities of an ecosystem
25) Primary succession = establishment of a community in an area of exposed rock that does not have any
topsoil.
26) Secondary succession = the sequence of community changes that takes place when a community is
disrupted by natural disasters or human actions
27) Climax community = a stable, mature community that undergoes little of NO succession is called
28) Biomes = a large group of ecosystems that share the same type of climax community

Two factors that will determine which biome will be dominant on land: Temperature and precipitation
20
28) Tundra = treeless, long cold winters, little winter sun, poor soil, little rain (less than 5 in); Permafrost
29) Permafrost = permanently frozen ground; found in the Tundra
30) Taiga = coniferous forest, poor soil, long severe winter
31) Temperate Forest (where we live!) = deciduous trees, 4 seasons, vegetation exhibits seasonal changes
32) Tropical Rain Forest = warm, wet, humid, most diversity, up to 17 feet of rainfall annually
33) Grassland = ideal growing season, good soil quality, little precipitation does not support trees, but
grasses and herbs are present in great abundance.
34) Desert = dry & arid, less than 10 in of rainfall; succulent plants
35) Limiting Factor = Factors that restrict the number or reproduction of a population within a community.
36) Density-independent factors = Any factor in the environment that does not depend on the number of
members in a population per unit area; usually abiotic ( Ex: weather events, fire, human alterations of
the landscape, pollution)
37) Density-dependent factor = Any factor in the environment that depends on the number of members in a
population per unit area; usually biotic (predation, disease, parasites, competition)
38) Exponential growth occurs when the growth rate is proportional to the size of the population.
39) Carrying capacity = The maximum number of individuals in a species that an environment can support
for the long term.
40) Denitrification = Soil bacteria convert nitrates into nitrogen gas; releases nitrogen into the atmosphere.
41) Nitrogen fixation = when bacteria converts nitrogen gas into ammonium.
42) Legumes = type of plants (clover, soybeans, alfalfa) that have nitrogen-fixing bacteria associated with
their root nodules that can convert nitrogen in the soil to ammonium.
43) Transpiration = when water evaporates from the leaves of plants
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