Ch 18 Introduction to Ecology



Name Date Period

Ecology Unit

ANCHORS

• Describe ecological levels of organization in the biosphere

o Describe the levels of ecological organization (i.e., organism, population, community, ecosystem, biome, and biosphere)

o Describe characteristic biotic and abiotic components of aquatic and terrestrial ecosystems

• Describe interactions and relationships in an ecosystem

o Describe how energy flows through an ecosystem (e.g., food chains, food webs, energy pyramids)

o Describe biotic interactions in an ecosystem (e.g., competition, predation, symbiosis)

o Describe how matter recycles through an ecosystem (i.e., water cycle, carbon cycle, oxygen cycle, and nitrogen cycle)

o Describe how ecosystems change in response to natural and human disturbances (e.g. climate changes, introduction of nonnative species, pollution, fires)

o Describe the effects of limiting factors on population dynamics and potential species extinction

VOCABULARY

|Abiotic |A term that describes a nonliving factor in an ecosystem. |

|Agriculture |The artificial cultivation of food, fiber, and other goods by the systematic growing and harvesting of various organisms. |

|Aquatic |A term that describes an organism associated with a water environment. |

|Biochemical Conversion |The changing of organic matter into other chemical forms such as fuels. |

|Biogeochemical Cycles |The movement of abiotic factors between the living and nonliving components within ecosystems; also known as nutrient cycles|

| |(i.e., water cycle, carbon cycle, oxygen cycle, and nitrogen cycle). |

|Biome |A large area or geographical region with distinct plant and animal groups adapted to that environment. |

|Biosphere |The zone of life on Earth; sum total of all ecosystems on Earth. |

|Biotic |A term that describes a living or once‐living organism in an ecosystem. |

|Community (Ecological) |Different populations of organisms interacting in a shared environment. |

|Competition |When individuals or groups of organisms compete for similar resources such as territory, mates, water, and food in the same |

| |environment. |

|Consumer (Ecological) |An organism that obtains energy by feeding on other organisms or their remains. |

|Decomposer |An organism that obtains nutrients by consuming dead and decaying organic matter which allows nutrients to be accessible to |

| |other organisms. |

|Ecology |The study of the relationships between organisms and their interactions with the environment. |

|Ecosystem |A system composed of organisms and nonliving components of an environment. |

|Endemic Species |A species that is found in its originating location and is generally restricted to that geographic area. |

|Endosymbiosis |A theorized process in which early eukaryotic cells were formed from simpler prokaryotes. |

|Energy Pyramid |A model that illustrates the biomass productivity at multiple trophic levels in a given ecosystem. |

|Energy Transformation |A process in which energy changes from one form to another form while some of the energy is lost to the environment. |

|Environment |The total surroundings of an organism or a group of organisms. |

|Food Chain |A simplified path illustrating the passing of potential chemical energy (food) from one organism to another organism. |

|Food Web |A complex arrangement of interrelated food chains illustrating the flow of energy between interdependent organisms. |

|Habitat |An area that provides an organism with its basic needs for survival. |

|Isolating Mechanisms |Features of behaviors, morphology, or genetics which serve to prevent mating or breeding between two different species |

| |(e.g., temporal isolation, in which individuals are active at different times of the day, seasons, or mating periods; |

| |ecological isolation, in which individuals only mate in their specific habitat; behavioral isolation, when there are no |

| |sexual cues between representatives of the species; mechanical isolation, when there is no sperm transfer during an |

| |attempted mating; and gametic incompatibility, when there is sperm transfer without fertilization occurring). If mating can |

| |take place, there are four factors that prevent hybrid viability: zygotic mortality (fertilization but no zygote),hybrid |

| |non-viability (embryo is not viable), hybrid sterility (resulting adult is sterile), and hybrid breakdown (first generation |

| |is viable but future generations are not). |

|Limiting Factor |Chemical or physical factor that limits the existence, growth, abundance, or distribution of an individual organism or a |

| |population. |

|Nonnative Species |A species normally living outside a distribution range that has been introduced through either deliberate or accidental |

| |human activity; also can be known as introduced, invasive, alien, non-indigenous, or exotic. |

|Population |A group of individuals of the same species living in a specific geographical area and reproducing. |

18 – 1 Introduction to Ecology Pages 359-362

■ Ecology – study of interactions between organisms and the living and non-living components of their environment

18-2 Ecology of Organisms Pages 363-365

A. Ecosystem Components

1. Abiotic – the nonliving components of an ecosystem

• Sunlight (affects photosynthesis), temperature (affects metabolism), water supply, oxygen supply, minerals, soil/rocks, pH

2. Biotic – the living components of an ecosystem

• Ex: Plants, Animals, Protists, Fungi, Bacteria

B. The Niche

1. Habitat - the physical area in which an organism lives (includes climate, topography, soil and water chemistry, plant and animal life, etc.)

2. Niche – the way of life of a species (includes its habitat, feeding habits, reproductive behavior, etc.)

18-3 Energy Transfer Pages 366-369

A. Producers (Autotrophs): organisms that can capture energy and use it to make organic molecules (ex. glucose, food, etc.)

■ Can capture energy from the sun (solar energy) or from chemosynthesis and store it in the bonds of sugars, making it available to the rest of the community.

■ Examples – plants, algae (protists), some bacteria

B. Consumers (Heterotrophs): Rely on other organisms for energy and nutrients by using oxygen to break bonds in sugar and release its energy through cellular respiration

■ Types of Consumers:

1. Herbivores: plant -eaters

2. Carnivores: meat-eaters

3. Omnivores: combination-eaters

4. Detritivores and decomposers: recycle nutrients within the ecosystem by breaking down nonliving organic matter

C. Energy Flow

■ When one organisms eats another, molecules are metabolized and energy is transferred

■ Trophic level: indicates the organism’s position in a sequence of energy transfers

■ Producers always occupy the 1st trophic level of any community.

|Food Chain |Food Web |

|linear series of feeding relationships |Sets of interrelated food chains |

| | |

■ In general, only about 10% of the energy available at any trophic level is passed to the next; most of the rest is LOST to the environment as heat.

■ List two food chains from the food web on the previous page:

1)

2)

■ What would happen if all of the plants were removed?

■ What would happen if all of the hawks were removed?

18-4 Ecosystem Recycling Pages 371-374

As energy and matter flow through an ecosystem, matter must be recycled and reused. These substances pass between the living and non-living worlds though biogeochemical cycles.

A. Water Cycle:

• Ground water - water found in soil or in underground formations of porous rock

• Transpiration - process by which water evaporates from leaves of plants in terrestrial ecosystems

• Evaporation - adds water to the atmosphere (liquid to gas)

• Precipitation - the process by which water leaves the atmosphere

B. Carbon Cycle:

• Carbon is the building block of all living things

• Fossil fuels - Carbon-rich fuel from ancient animals and plants

• Photosynthesis - Energy (sun)+ Water + Carbon dioxide( Glucose + Oxygen

• Cellular Respiration - Glucose+ Oxygen( carbon dioxide + water + Energy (ATP)

• Decomposition - Breakdown of matter by bacteria and fungi

C. Nitrogen Cycle:

• Organisms need nitrogen to make proteins and nucleic acids

• Most plants can only use nitrogen in the form of nitrate

• Nitrogen fixation - process of converting nitrogen gas into nitrate; done by bacteria/lightning

• Denitrification - bacteria break down decaying organisms and release the nitrogen they contain back into the atmosphere

D. Phosphorous Cycle:

• Phosphorous is a component of DNA, RNA, and molecules that store energy (ATP)

• Phosphorous cycle is the movement of phosphorous from the environment to organisms, and then back to the environment

• Phosphorus is mainly found in water, soil, rocks, and sediments (no gas state)

Name Date Period

X BIO ECOLOGY STUDY GUIDE – CHAPTER 18

CHAPTER 18 – INTRODUCTION TO ECOLOGY

ecology interdependence biosphere ecosystem

community population biotic factor abiotic factor

1. You go on a field trip to a farm, using the terms from the word bank above, identify the various units below:

a. The herd of cattle that live on the farm (2 answers): population/biotic

b. The amount of rainfall that the farm receives: abiotic

c. The entire farm, including livestock and the soil, sunlight, etc.: ecosystem

d. The chickens, ducks, horses, cows, etc. (2 answers): community/biotic

2. Distinguish between a habitat and a niche.

Habitat: physical area in which an organism lives

Niche: way of life of a species, includes its habitat, feeding habits, reproduction habits

3. According to the graph on pg. 367, which ecosystem has the greatest net primary productivity?

Tropical rain forest

The least? Open ocean & desert

4. How does a food chain differ from a food web?

Food chain: specific sequence in which organisms obtain energy

Food web: all of the interrelated food chains in an ecosystem

5. What would happen to the other organisms in the food web below if you removed the grass (producer)?

[pic]

They would not survive because there is no primary food source

6. What percentage of the total energy consumed in one trophic level is available to the next? 10%

Why is this so low? because some avoid getting eaten, some molecules can’t be used, E used by prey can’t be used by predators, no transformation is 100% efficient.

7. What five substances pass through biogeochemical cycles?

Water, carbon, oxygen, nitrogen, phosphorus

8. Label the diagram below with the following terms: evaporation(2X), transpiration, precipitation (2x), runoff, movement of H2O vapor by wind:

What is being cycled in the diagram?

Water

9. What are the two main processes of the carbon cycle?

Photosynthesis and respiration

How are these related? (remember way back to chapters 6 & 7)

products of one are the reactants of the other

10. What contributes to the increase in atmospheric carbon?

burning fossil fuels and other organic matter

11. How does atmospheric nitrogen get converted into a useable form?

Nitrogen Fixation

What organisms do this?

Nitrogen - Fixing bacteria and lightning

12. Why is phosphorus an important material to animals?

it is essential to animals so they can form bones, teeth, and molecules (DNA, RNA)

13. Where is phosphorus mainly found? in rocks

19-1 Understanding Populations Pages 381-384

A. Population ecology: studies changes in population size and the factors that regulate populations over time

B. Populations are affected by three things: size, density, and dispersion

1. Population size: number of individuals

2. Population density: the number of individuals of a species per unit area or volume (Ex: number of earthworms per cubic meter of soil)

3. Population dispersion: how the population is spread out in a given area (Ex. Clumps, uniform, or random)

19.2 Measuring Populations Pages 385-389

A. Population Growth Rate

▪ Determined by the following equation:

Growth rate = rate of individuals gained – rate of individuals lost

or

(birth rate + immigration rate) – (death rate + emigration rate)

▪ Growing populations have a positive growth rate; shrinking populations have a negative growth rate.

B. Exponential growth model: the rate of population growth under ideal conditions

▪ As the population size grows, more individuals are added during each interval

▪ Graphing this data gives a J-shape curve

▪ Exponential growth can NOT continue indefinitely

▪ Eventually, one or more environmental factors will limit growth

• Ex: space and food supply

C. Logistic growth model: idealized population growth that is slowed by limiting factors as the population size increases

▪ Results in formation of an S-shape curve

▪ Carrying capacity (K) - maximum population size that a particular environment can sustain

▪ K varies depending on the species and the resources available

▪ Limiting Factors to growth = predators, parasites, food sources, water & space

▪ Emphasizes that resources are finite

▪ At low populations, resources are abundant and the population is able to grow nearly exponentially

▪ Population stabilizes at the carrying capacity when the birth rate equals the death rate

Name Date Period

X BIO ECOLOGY STUDY GUIDE – CHAPTER 19

CHAPTER 19 – POPULATIONS

1. According to the graph on the right, during which time period (1, 2, 3, or 4) does:

a) the population show negative growth? ___4____

b) the population show positive growth? 1 (little) & 2 (most)

c) the population show no growth? __3__

2. How is population growth rate determined?

By subtracting death rate from birth rate GR = BR - DR

3. What four processes determines a population’s growth rate? Identify which two add individuals and which two subtract individuals from the population.

Births (+) Deaths (-) Immigration (+) Emigration (-)

4. Which of the following is true in the exponential model of population growth?

A) Population growth continues indefinitely.

B) Population growth stops at the carrying capacity.

C) Population growth increases and then decreases.

D) The immigration rate falls with increasing population size.

5. On the diagram below, label the following: # of individuals, time, carrying capacity, exponential growth, logistic growth.

A Exponential Which line is more typical of a population in nature? B

B Logistic

Why? Because it depicts the carrying capacity of the ecosystem

Why is growth initially so slow?

Because the population is so small and only a few females are producing young

20-1 Species Interactions Pages 399-404

A. Communities contain interacting populations of many species

B. 3 major types – predation, competition, and symbiosis

1. Predation - predator eats all or part of an individual ( the prey

• Adaptations of predators: venom, flesh-cutting teeth, sticky webs, speed

• Adaptations of prey: camouflage, chemical defenses (plants & animals), mimicry (resembles another species) , thorns, spines

2. Competition - Limited resources force competition among living things in same niche

• All competition almost always produces a winner and a loser (dies out)

• Ex: two species of paramecium kept in same culture…one species out competed the other.

3. Symbiosis = “together living”

• Any relationship where 2 species live in close association with each other

• 3 main types of symbiotic relationships: mutualism, parasitism, commensalism

▪ Mutualism (“win-win”): both benefit

▪ ex: sea anemone and clown fish. Clown fish gets a protected home and the anemone gets a defender when attacked

▪ Parasitism (“win-lose”): one benefits at the harm of the other (host)

▪ ex: Tapeworm inside a human. Tapeworm absorbs digested food of host, the host’s cells starved for nutrition.

▪ Commensalism (“win-no harm/help”): one benefits while the other is neither harmed nor helped

▪ ex: Barnacles on a whale. Barnacles benefit by motion of whale and the movement of food particles over them. No benefit or harm comes to the whale.

Directions: Complete the following graphic organizer.

[pic]

Directions: Identify the interaction being described.

1. Today I am in the central part of Africa. I spent the day observing the warthog and the oxpecker (a species of bird). The oxpecker was observed on the backs of the warthogs, where it appears to be feeding on something. On closer observation of the skin of a tranquilized warthog and later the stomach contents of an oxpecker, it appears that the oxpecker is eating ticks from the skin of the warthog.

2. Today I am in Tanzania, located in East Africa. I spent most of today observing grazing cape buffalo. I noticed that cattle egrets (a species of bird) were concentrated in those areas where cape buffalo were grazing. Upon closer observation, it was seen that the cattle egrets were feeding on insects that were flushed from the vegetation by the grazing cape buffalo.

3. Today I am in South America. I have been observing tomato hornworm caterpillars for a few days now. A braconid wasp was observed paralyzing the caterpillar. The wasp then deposited its eggs on the caterpillar.

4. Today I am in Yellowstone National Park to estimate the size of the gray wolf population in the park. I saw four wolves successfully kill a deer. They swiftly separated her from the small heard and attacked her from two different directions. The rest of the deer herd ran away to safety. The wolves immediately began eating the deer.

5. Today I am in Costa Rica. I spent the day observing a tree called the bull’s horn acacia. A certain species of stinging ant appears to live in the hollow thorns of these trees. The ants are observed feeding on sugar produced by nectarines on the tree and also on the protein-rich swellings called Beltian bodies that grow at the tips of leaflets. The ants are observed attacking anything that touches the tree.

6. Today I am located off the coast of Southern Florida, where I have been scuba diving for a few days in order to observe sharks. Remoras (a species of fish) are observed travelling attached to a shark. They appear to feed on scraps of food dropped by the shark as it eats. The shark does not seem to notice the presence of the remoras.

7. Today I am scuba diving in the coastal area of Kenai Fjords National Park in Alaska. I observed sea otters eating sea urchins. It was amazing to see the sea otter pick up the spiny sea urchins in their paws and crush the shells with their blunt teeth. The soft body was eaten and the spiny shell was quickly discarded.

8. Today I am located at my lab in upstate New York. I have been observing a fir tree found in the forest behind my lab for a few weeks. The tree seems to be dying and a species of mistletoe appears to be growing on the fir tree.

20-2 Patterns in Communities (Succession) Pages 407-410

A. Succession: a progressive, predictable ecological change in a community over time

A. Primary Succession: Begins with no remnants of the previous community

• Pioneer species are first to colonize barren land

– Ex: lichen (fungus and algae) turn rock into soil, turn N2 gas into useful nitrogen forms, and add organic material to the soil

B. Secondary Succession: occurs after a major event disturbs a community (fire, flood, earthquake, hurricane, human activity like forest clearing or farming)

• SOIL survives the disturbance, plants re-colonize the area faster than in primary succession, herbivores can move in and make use of the food supply. Then, carnivores can move in

• If ecosystem is healthy, it may be restored to its natural state prior to disturbance (the “climax” community) BUT sometimes the impact is so traumatic, a full recovery through succession is not possible

Name Date Period

X BIO ECOLOGY STUDY GUIDE – CHAPTER 19

CHAPTER 20 – COMMUNITY ECOLOGY

1. What is predation?

When individual of one species (predator) eats all or part of an individual of another (prey)

2. List four examples of adaptations that predators have evolved.

Acute sense of smell, venom, heat sensitive pits, sticky webs of spiders, teeth that cut flesh.

3. List four examples of adaptations that prey have evolved to avoid predators.

Deceptive markings, fleeing, hiding or resembling other objects, chemical defenses

4. What is a symbiosis?

Relationship in which 2 dissimilar organisms live together in a close association

5. List and explain the three types of symbiotic relationships.

a) Parasitism: 1 organism (the parasite) benefits (obtains nutrients) from the host (who is harmed)

b) Commensalism: one benefits, the other neither benefits nor is harmed

c) Mutualism: both benefit from living together

6. What is ecological succession?

The gradual, sequential replacement of populations in an area

7. Distinguish between primary and secondary succession.

Primary: the sequential replacement of populations in an area that has not previously supported life (i.e. bare rocks, sand dunes)

Secondary: the sequential replacement of populations in disrupted habitats that have not been totally stripped of soil and vegetation (i.e. and area that was flooded, destroyed by fire, etc.)

8. Distinguish between pioneer species, seral community, and climax communities.

Pioneer species: the first species to colonize a new habitat

Seral community: the intermediate communities that arise

Climax community: final community, a community that will remain stable as long as the area is undisturbed

21-1 Terrestrial Biomes Pages 417-422

B. Biomes: large climatic regions that contain a number of smaller but related ecosystems within them

– Characterized by similar plant and animal species

|Biome |Temperature/Rainfall |Predominant Plant Species |Predominant Animal Species |

|Tropical Forest |25°C-27°C |Broadleaf evergreen trees and shrubs |Insects, colorful birds, apes, monkeys,|

| |200-400cm | |predatory cats |

|Temperate Forest |6°C-28°C |Broadleaf deciduous trees and shrubs |White-tailed deer, foxes, raccoons, |

| |75-125cm | |squirrels, black bears, birds (blue |

| | | |jays, cardinals) |

|Taiga |-10°C-14°C |Needle-leafed evergreen trees |Moose, bears, lynx |

| |35-75cm | | |

|Desert |24°C-34°C |Succulent plants; scattered grasses and|Camel, ground squirrel, jack rabbit |

| | ................
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