Questions for Limiting Factors Review
- What is a limiting factor?
The availability of resources.
- List 4 examples of limiting factors described in the reading and label if each would be considered abiotic or biotic.
- Food: biotic
- Water: abiotic
- Shelter: both
- Space: abiotic
- Analyze if limiting factors always decrease a population? Explain using the term competition (make sure to underline it).
Sometimes, limiting factors increase a population when they are in abundance. If plants grow, the competition for it decreases among herbivores.
- Evaluate if humans can be a limiting factor? Explain using a specific example from the reading.
Humans can greatly impact ecosystems, so technically they are a limiting factor. When humans turn land into houses, the animals that used to live there often die off.
- Summarize why there are so many white-tailed deer and use the term limiting factor, in your answer.
There are no predators for the white-tailed deer, so their main limiting factor is gone and there is an increase in population.
Questions for Forest Ecosystem
You will need to select Oregon for your state.
- State the type of growth the three species show when they begin to recover from fire:
After most of the species decrease, the trees would produce more nuts, which would attract the chipmunks and then the foxes gradually back.
- Explain if you predict the carrying capacity of squirrels to increase or decrease when the fox population is lowered by disease. Use competition and limiting factors in your explanation.
Squirrels should increase in population if the foxes decrease, because the squirrels’ predator has diminished. Competition is now not a problem and the limiting factor (predators) is gone.
- What is the limiting factor during the third scenario?
Water is the limiting factor, because there is a drought and the species decrease.
- Predict the distribution pattern of the three populations and justify why:
a. Trees: Random, because the tree can’t control where its offspring lives.
b. Chipmunks: Even, because squirrels like to avoid competition.
c. Foxes: Clumped, because foxes live together.
Questions for Review
- State the type of symbiosis between chipmunks and foxes is:
predator – prey.
- Identify the type of succession that occurs after forest or disease is:
- Click on “Introduced Species.” Explain how the introduction of Kudzu, a non-native vine, effects feeding relationships and biodiversity?
Nut production decreases as the Kudzu kills the trees, so the squirrels die off and the foxes decrease. Biodiversity is lowered.
- Eutrophication occurs when phosphorus and nitrogen are added to lakes and streams. How do these limiting factors get added?
Phosphorous and nitrogen in the soil gets washed down by rain (runoff) into lakes and streams.
- Draw/ copy and paste a picture of the steps that occur.
- Interpret the graph below to describe what occurred in this ant population. Use the terms carrying capacity, crash, and limiting factors.
The ant population appears to have increased due to an abundance in limiting factors, which caused it to reach its carrying capacity. This means the population is at the most it can handle for its location, so the population rises and crashes until it may eventually even out.
Population of Ants
Questions for Human Population
If you examine the growth of the human population you will notice that it is quite odd. It took over 1 million years for the world population to reach 1 billion. The second billion was added in 80 years, the third in 30 years, the fourth in 15 years, and in 1984 we were halfway toward adding our fifth billion (at a 10 year rate). In 1982 alone we added 82 million to our numbers, about 225,000/day. Like all populations, we have encountered limiting factors, but unlike other populations we have responded by overcoming these factors, rather than by reaching a balance with nature.
Let us take a look at the human population over the last four thousand years: In the year 2000 BC there were 108,000,000 people; by 1000 BC there were 120,000,000 people; in 1 AD the population was 138,000,000; in 1000 AD there were 275,000,000 people; in 1800 AD the population was 1,000,000,000. The population in 2000 AD was 6,200,000,000. The current population for August 18, 2008 was 6,717,706,969. Within the last year, the world’s population has crossed the 7 billion amount.
- Create a graph in Google Spreadsheets of the Data Table 1 to examine the change of the human population. Insert it into your edublogs post.
- Purpose two factors that could limit human population. Describe, for each, how humans have been able to overcome these limitations.
1) Availability of Water: Humans have designed water systems that allow even dry regions to acquire water through piping and water storage (wells, dams, aquifers).
2) Acquisition of Food: City-dwellers get their food shipped in from rural farms. Farmers and scientists have developed new techniques and equipment to expand the production rate of seasonal crops.
- National Geographic put together a short video analyzing the growth of the human population. Watch the video here. Select one of the facts from the video you find interesting, conduct research on that particular fact, and share your analysis below (AS Question).
Fact: In 1975, there were three “megacities.” These were New York City, Mexico City, and Tokyo. Right now there are 21 megacities.
The world’s megacities include (ranked by urban area population):
New York City
Rio de Janeiro
Santiago de Chile
*The largest city is Chongqing, which has more than 32 million people. It is a Chinese province (like Shanghei and Beijing).
“Megacities of the WorldVisit the Most Populated Cities on Earth.” The Most Populated Cities of the World. World Megacities. Web. 26 May 2012.
(Btw Mr. Rott, I love that video! Mr. Malone showed that to his journalism class last semester, it’s really well-made!)