There Are Two Types of Things Present in an Ecosystem

Name DateHour

Vocab #8

ECO-
-LOGY
BIO-
-SPHER-
A-
ORG-
POPUL-
AUTO-
HETERO-
DETRI-
GEO-
MOLE-
-CULE
MACRO-
MICRO-
HYDR-
CONIF-
DECID-

INTRODUCTION TO ECOLOGY NOTES

Ecology- ______

______

Biosphere-______

______

Ecosystem- ______

______

Niche- ______

______

There are two types of things present in an ecosystem:

Living things are called ______factors.

Examples:______

______

Nonliving things are called ______factors.

Examples:______

______

Biotic and abiotic factors ______each other. Organisms change their

______and the environment changes the ______.

All organisms depend in some way on other living things and non living things in the environment.

No organism is isolated! The survival of all organisms depends on their interactions with

______in their surroundings and the

______of their environment.

Any disturbance in one aspect of an ecosystem affects ______

______.

Write-Up

From the Ecology Circle-Sit activity I learned that ______

Question: What will happen when a population of bears the size of our class hunts for food in their environment? How does the population size and the size of the environment affect the animal?

1.Hypothesis: ______
______

2. What will happen to the blind bear, the injured bear, and the mother with the young cubs? How will their impairments affect the hunt for food?

______

3. As a bear, what do you think some of the obstacles will be in your quest for finding food? ______

4. Total # of kilograms your bear ate: ______kg

Fill in the data table below:

Data Table 1—Amount of Food

Food / Nuts / Berries / Insects / Meat / Plants
# of Kilograms
Percentage

An actual bear’s diet will vary between areas, seasons, and years. For example, a bear in Alaska would more likely eat more meat (fish) and fewer nuts than a bear in Arizona. One similarity among black bears everywhere is that the majority of their diet is normally made up of a vegetative material. The following are estimates of total pounds of food one bear in 10 days:

Berries and fruits20 kg = 25%

Nuts20 kg =25%

Insects12 kg =15%

Meat 8 kg =10%

Plants20 kg =25%

Now that you know what a “healthy” bear diet consists of, explain how healthy you think your bear will be. Which foods were abundant in your bear’s diet? Which foods were deficient? ______
______
What is the term that ecologists use to describe things in the environment that limit the number of individuals that can live there? ______

How many bears survived? ______
Divide the total number of kilograms eaten by the 80 kg needed for an individual bear to survive a 10-day period: ______/ 80 = ______
How many bears could the habitat support? ______
What is the term that ecologists use to describe the maximum number of individuals an environment can support? ______
Was there a discrepancy between the number of bears that survived and the number of bears the habitat could support? ______
Explain why there might be a difference between the number of bears that survived and the number of bears the habitat could support even if it did not occur in this situation.

______

How will limiting the size of the bear population affect the hunt for food for the bears that hunt? ______

Based on this information, why do you think wildlife managers permit hunting? Can hunting benefit some populations? Explain. ______
______
What do you think will happen if only half the class hunted with the same amount of food available?______

Conclusion: Write a paragraph answering the following questions:

What will happen when a population of bears the size of our class hunts for food in their environment?
How did the population size and the size of the environment affect the animal?
Include the following terms in your answer: competition, population, carryingcapacity and limiting factor. (Underline each term.)

______

NOTES

Population: ______

CHARACTERISTICS OF POPULATIONS

Population density: ______

High Population Density Pic A
Describe: / Low Population Density Pic A
Describe:
High Population Density Pic B
Describe: / Low Population Density Pic B
Describe:

Island Hopping Worksheet

(from

Read the paragraph below, then scan the map and table. Answerthe questions that follow.

The Turks and Caicos Islands consist of about 30 islands, eight of which are inhabited. They lie in the NorthAtlantic Ocean, southeast of the Bahamas, and are split into two main groups, the Caicos Islands and the Turks Islands, separated by the Columbus Channel. The islands feature spectacular coral reefs, beaches, and historical sites, but are relatively undeveloped. The main businesses are tourism, offshore financial services, fishing, and construction. Lobster and conch are the main exports. The economy grew at a rate of 13.9 percent in 1998 and 8.7 percent in 1999. Much of the land is arid; only about 2 percent of the land is useful for agriculture. Most items need to be imported, resulting in a fairly high cost-of-living. Tourism is centered in Providenciales; many islanders are moving there from other islands. The territory’s only hospital is located on Grand Turk. The table below provides information on the size and population of each of the major islands. Use this information to answer the questions below.

Calculate the population density (number of people per square mile) of each island and fill in that column of the table.

Island / Approximate
Population / Area
(square miles) / Population Density
(people/square mile)
Grand Turk / 6,000 / 7
East Caicos / 0 / 18
Middle Caicos / 275 / 48
North Caicos / 1,500 / 41
Providenciales / 8,000 / 30
Salt Cay / 200 / 1
South Caicos / 1,200 / 8
West Caicos / 0 / 9

(a) Which island has the largest population? ______

(b) The smallest?______

What percentage of the eight major islands are inhabited? ______

The islands’ capital, Cockburn Town, is located on Grand Turk. It has a population of about 3,800. What fraction of the population of the people living onGrand Turk live in Cockburn Town? ______

What is the total population of the eight major islands?______

Which island is the largest? ______

How much larger is it than the second largestisland? ______

What is the total area of the eight major Islands? ______

Which island has the highest populationdensity? ______

Which island has the lowest population density? ______

The total population of all of the Turks and Caicos Islands, including two smallinhabited islands not listed in the above table, was estimated at 17,502 in 2000.The total area of all the islands is approximately 166 square miles. Estimate thetotal population, total area, and average population density of the 22 islands notlisted in the table. Explain your calculations.

Total population = ______

Total area = ______

Avg Pop Density = ______

POPULATION GROWTH

Things that affect population growth:

Natality (Birth rate)
Mortality (Death rate )

Question: What happens to the population when natality is greater than mortality?

Answer: ______

Question: What happens to the population when mortality is greater than natality?

Answer: ______

Immigration: moving ______an area (hint: )
Emigration: ______an area (hint: )

CARRYING CAPACITY AND LIMITING FACTORS

Carrying capacity:______

______

Here is what a graph looks like when a population has reached carrying capacity:

Limiting factor: ______
______

TWO TYPES OF POPULATION GROWTH

Exponential: ______

AKA: ______

Here is an exponential curve graph:

This graph means that: ______
______

Logistic: ______

AKA: ______

Here is a logistic curve graph:

This graph means that: ______
______

A student grew a yeast culture on sterilized nutrient medium in a closed dish for 5 days. Each day, she took the same size sample from the dish and placed it on a special slide used for counting microorganisms. She examined the samples under a microscope and drew the following illustrations of her observations over the course of the investigation. Each dot represents 10 yeast cells.

Why did the student use sterilized medium and keep the dish closed? ______

What problem was this student investigating? ______
______
During which two-day period was population growth most rapid? ______
At what point did the population reach the carrying capacity of the culture dish? ______
______
What factors probably limited the growth of the yeast population? ______
______
How could the student change the investigation so that the carrying capacity of the yeast’s environment is increased? ______
______
What steps could the student take to ensure the accuracy of her results? ______
______

Which graph best illustrates the growth of the student’s yeast population?

Deer: Predation or Starvation

Introduction: In 1970 the deer population of an island forest reserve about 518 square kilometers in size was about 2000 animals. Although the island had excellent vegetation for feeding, the food supply obviously had limits. Thus the forest management personnel feared that overgrazing might lead to mass starvation. Since the area was too remote for hunters, the wildlife seervice decided to bring in natural predators to control the deer population. It was hoped that natural predation would keep the deer population from becoming too large and also increase the deer quality (or health), as predators often eliminate the weaker members of the herd. In 1971, ten wolves were flown into the island.

The results of this program are shown in the following table. The Population Change is the number of deer born minus the number of deer that died during that year. Fill out the last column for each year (the first has been calculated for you).

Year / Wolf Population / Deer Population / Deer Offspring / Predation / Starvation / Deer Population Change
1971 / 10 / 2,000 / 800 / 400 / 100 / +300
1972 / 12 / 2,300 / 920 / 480 / 240
1973 / 16 / 2,500 / 1,000 / 640 / 500
1974 / 22 / 2.360 / 944 / 880 / 180
1975 / 28 / 2,224 / 996 / 1,120 / 26
1976 / 24 / 2,094 / 836 / 960 / 2
1977 / 21 / 1,968 / 788 / 840 / 0
1978 / 18 / 1,916 / 766 / 720 / 0
1979 / 19 / 1,962 / 780 / 760 / 0
1980 / 19 / 1,982 / 790 / 760 / 0

Graph the deer and wolf populations on the graph below. Use one color to show deer populations and another color to show wolf populations.

Analysis

Describe what happened to the deer and wolf populations between 1971 and 1980. ______
What do you think would have happened to the deer on the island had wolves NOT been introduced? ______
______

The Lesson of the Kaibab

Introduction: The environment may be altered by forces within the biotic community, as well as by relationships between organisms and the physical environment. The carrying capacity of an ecosystem is the maximum number of organisms that an area can support on a sustained basis. The density of a population may produce such profound changes in the environment that the environment becomes unsuitable for the survival of that species. For instance, overgrazing of land may make the land unable to support the grazing of animals that lived there.

Background:

Before 1905, the deer on the Kaibab Plateau were estimated to number about 4000. The average carrying capacity of the range was then estimated to be about 30,000 deer. On November 28th, 1906, President Theodore Roosevelt created the Grand Canyon National Game Preserve to protect the “finest deer herd in America.”

Unfortunately, by this time the Kaibab forest area had already been overgrazed by sheep, cattle, and horses. Most of the tall grasses had been eliminated. The first step to protect the deer was to ban all hunting. In addition, in 1907, The Forest Service tried to exterminate the predators of the deer. Between 1907 and 1939, 816 mountain lions, 20 wolves, 7388 coyotes and more than 500 bobcats were killed.

Signs that the deer population was out of control began to appear as early as 1920 – the range was beginning to deteriorate rapidly. The Forest Service reduced the number of livestock grazing permits. By 1923, the deer were reported to be on the verge of starvation and the range conditions were described as “deplorable.”

The Kaibab Deer Investigating Committee recommended that all livestock not owned by local residents be removed immediately from the range and that the number of deer be cut in half as quickly as possible. Hunting was reopened, and during the fall of 1924, 675 deer were killed by hunters. However, these deer represented only one-tenth the number of deer that had been born that spring. Over the next two winters, it is estimated that 60,000 deer starved to death.

Today, the Arizona Game Commission carefully manages the Kaibab area with regulations geared to specific local needs. Hunting permits are issued to keep the deer in balance with their range. Predators are protected to help keep herds in balance with food supplies. Tragic winter losses can be checked by keeping the number of deer near the carrying capacity of the range.

Graph the deer population data.

Deer Population Per Year

1905 / 1910 / 1915 / 1920 / 1924 / 1925 / 1926 / 1927 / 1928 / 1929 / 1930 / 1931 / 1935 / 1939
4,000 / 9,000 / 25,000 / 65,000 / 100,000 / 60,000 / 40,000 / 37,000 / 35,000 / 30,000 / 25,000 / 20,000 / 18,000 / 10,000

During 1906 and 1907, what two methods did the Forest Service use to protect the Kaibab deer? ______
______
Were these methods successful? Use the data from your graph to support your answer.
______
Why do you suppose the population of deer declined in 1925, although the elimination of predators occurred? ______
______
Why do you think the deer population size in 1900 was 4,000 when it is estimated that the plateau has a carrying capacity of 30,000? ______
______

Based on these lessons, suggest what YOU would have done in the following years to manage deer herds.

1915: ______
______
1923: ______
______
It is a criticism of many population ecologists that the pattern of population increase and subsequent crash of the deer population would have occurred even if the bounty had not been placed on the predators. Do you agree or disagree with this statement. Explain your reasoning. ______
______
What future management plans would you suggest for the Kaibab deer herd? ______
______

Define symbiosis: ______

WHATAVORES?

All organisms require energy to survive. The major source of energy on Earth comes from the ______.

Humans and other animals cannot stand out in the sun in order to gain energy. So how do we get energy?

Plants are adapted to turn energy from the sun into a food source. Through the process of ______, plants use energy from the sun to make ______. These sugars are then stored inside of the plant.

Then an organism, such as a cow eats the plant. Organisms that eat plants are called ______. When the herbivore eats the grass, it eats the stored sugars that provide energy.

The herbivore is later eaten by another organism (a human eating a cow, for instance). Organisms that eat meat are called ______. When the carnivore eats another organism, it gains the sugars that provide energy.

Organisms that eat both plants and animals are called ______.

THE CHAIN GANG

Producer / Consumer
Autotroph / Heterotroph

→→→

______

Primary
consumer / Secondary
Consumer / Tertiary
Consumer / Quaternary
Consumer

Torrens River Food Web

The Torrens River starts in the Adelaide hills as several small creeks which join to form one larger creek. As it winds its way down the hills to the city, more and more water is added. It generally only flows in winter when the rainfall is sufficient, and it dries up into small waterholes during the summer. A weir is used to hold water permanently in the city. It is surprising how many organisms rely on the river for their existence.

Algae can be observed growing in the water, as well as water ribbons (Triglochin procerum). On the water edge, fluffy topped reeds such as the common reed (Phragmites australis) and the bulrush (Typhus sp.) grow. Water boatman observed swimming in the water. They are eating the algae and reeds. Mosquito larvae also eat the algae while the fresh water snail eats both the algae and water ribbons. A long necked tortoise pokes its nostrils above the water. The tortoise eats the algae too, as well as feeding on snails, boatman and yabbies. The water boatman provides food for many species including fish, frogs, diving beetles and dragonfly larvae. The yabbies are scavengers, feeding on rotting plant and animal matter, while bacteria also help break down this dead material by digesting it and recycling nutrients in the food web. The mosquito larvae are considered a delicacy for frogs (such as the common froglet) and several varieties of fish (such as the big-headed gudgeon or the congolli).

Birds are in abundance along the waterway. Pacific black ducks are feeding on fish, dragonfly larvae and diving beetles, while the occasional visiting pelican feeds on fish, frogs, and dragonfly larvae. Black swans make a beautiful sight, bending their elegant necks to forage under the water grazing on the water ribbons, snails and an occasional fish. The white-faced heron makes a meal of the fish and frogs. The purple swamp hen runs quickly from the bulrushes where it feeds on the tender growth of the bulrushes and also makes its nest. On the bank a blue-tongue lizard is sunning itself in a warm rock. It snaps at the dragonflies and diving beetle and beware the unwary frog, the lizard will sometimes eat them too.

Divide the organisms into the following categories:

Producers / 1st Order Consumer / 2nd Order Consumer (and higher)

Now complete your food web

It is best to start with the producers and build up. Complete the arrows to show the flow of energy. You may need to read through parts of the text again.

Which of the organisms contain chlorophyll? Are they producers or consumers? How do you know? ______
Which organisms feed on algae? ______
______
Which organisms feed on fish? ______
______
Find a food chain from your web with at least 4 organisms. Place them in the pyramid with the producer at the bottom and the highest order consumer at the peak. Estimate numbers of organisms for each level (their population) in that habitat. It should decrease as it goes higher. Infer or explain why this happens.