Also in 2025 Practice Test B English, question 32.
Passage Using Fire to Keep a Prairie Healthy
Using Fire to Keep a Prairie Healthy
Inside the 40,000-acre Joseph H. Williams Tallgrass Prairie Preserve in northern Oklahoma, herds of bison roam on the scenic land that is home to hundreds of different species of plants and animals. While one of the greatest threats to the prairie is wildfire, the use of controlled fires is actually an effective way to protect this idyllic landscape.
Fires that are started by lightning or other natural circumstances are inevitable, and the results can be disastrous. However, hundreds of years ago the American Indian people who inhabited the Great Plains area between Minnesota and Texas realized that these fires could also be helpful. The bison in the area seemed to prefer grazing on tender new grass on the recently burned land rather than on grass in the unburned areas. The American Indian people began to deliberately burn areas of land for bison to graze on, which enticed the herds away from the people’s crops.
Today conservationists at the Tallgrass Prairie Preserve and farmers in the Great Plains continue to use controlled burns for land management. Intentionally burning a portion of land can dramatically improve the quality of the vegetation that regrows there. The fires burn away weedy undergrowth and help limit the overcrowding of shrubs and trees in the burn area, creating less competition for water and nutrients. Additionally, the process of burning excess plant matter adds nitrogen, an essential element for plant growth, to the soil.
One common target of controlled burns at the preserve and the surrounding area is the invasive red cedar tree. A single red cedar tree can consume up to 40 gallons of water per day, taking this vital resource away from other plant life. These tall trees also cast shade that prevents sunlight from reaching the plants beneath them. The fast-growing red cedar trees tend to crowd out prairie grasses, the primary food source for wild and domestic animals that make the prairie their home. An imbalance in one component of the prairie’s ecosystem affects the entire web of life. Controlled burns help maintain this ecosystem’s delicate balance.
Of course, these controlled fires are intended to burn only a portion of an area. A total burn, which is a risk with an uncontrolled wildfire, would destroy all wildlife as well as the crops farmers plant for income. The key to using controlled fires is knowing which areas of land to burn and when. Conservation experts at the preserve employ the “patch-burn” approach, meaning they rotate which portion of land is burned each year. They study the land to find out which areas would most benefit from being burned, and then they arrange about a dozen burns over one-third of the land. This patch burning contains the fire within a specific area and allows animals in the burn area to safely relocate. The following year, conservationists will burn a different section of the preserve, while the land burned the previous year regrows healthier than before.
Researchers have tracked and studied the variety of plant species and animals that live on the preserve, and their studies show that the patch-burn approach has restored biodiversity to the area by promoting the growth of species that were at risk of being crowded out. The patch-burn system is so successful that the conservationists at the preserve provide training to prairie farmers about conducting controlled burns on their own land. Burning land to make it healthy may seem counterintuitive, but strategic controlled fires have helped the prairie sustain life for hundreds of years and, with careful management, will continue to do so.
Question
According to the passage, how did fires started by natural causes prompt American Indians to begin practicing controlled burns?
- Aby drawing animals in to the area to feed on the new growth sprouting from the burned land
- Bby destroying tall trees and reducing the shade that had hindered the growth of planted crops
- Cby burning off excess vegetation and increasing the availability of nutrients for the remaining plants
- Dby causing changes to the bison’s migration habits as bison herds fled from the wildfires on the prairie
Show the answer
Correct answer: A
The question asks how observing the effects of the fires started by natural causes prompted American Indians to begin practicing controlled burns.
A. CORRECT. In paragraph 2, the author states that American Indians observed bison “grazing on tender new grass on the recently burned land rather than on grass in the unburned areas.” These observations prompted the practice of controlled burns as a means of enticing “the herds away from the people’s crops.”
B. Incorrect. Although the author mentions in paragraph 4 that the primary targets of a controlled burn are red cedar trees and that “these tall trees also cast shade that prevents sunlight from reaching the plants beneath them,” this detail supports why conservationists use controlled burns today, not what initially prompted the use of controlled burns.
C. Incorrect. While the author states in paragraph 3 that “the process of burning excess plant matter adds nitrogen, an essential element for plant growth, to the soil” and that “intentionally burning a portion of land can dramatically improve the quality of the vegetation that regrows there,” these details do not explain the initial observations that prompted American Indians to practice controlled burning.
D. Incorrect. While paragraph 2 mentions that bison moved to a new area to graze because they preferred the “tender new grass on the recently burned land,” there is no indication in the passage that bison changed their migration habits in order to flee wildfires.
Question analysis
This key-details question about an article on controlled burns at an Oklahoma tallgrass prairie preserve asks how fires started by lightning or other natural causes led American Indians to begin burning land on purpose. Students must find the passage's account of that early practice, and since the article describes several effects of fire, each choice has to be checked against what those first observers actually saw.
- Grade level
- Grade 7 reading and task
- Compared with grade 7
- At grade 7 Finding a stated cause in an informational text is regular grade 7 reading. The answer sits in one short paragraph, but the article describes several effects of fire, old and new, and the choices draw on them, which keeps the demand typical.
- Estimated difficulty
- Straightforward: two steps or one careful reading.
- Thinking it demands
- Depth of knowledge 2, skills and concepts · mainly understand
- What makes it hard
- Evidence
- Answered from one paragraph or stanza
- Reading level
- Passage: about grade 11, 598 words; question and choices: about grade 9, 86 words.
- Students, last 30 days
- Not enough answers yet to show (it takes 10).
Why it is hard, traps and wrong answers (shows the answer)
Why it is hard
The stem points to one short paragraph, but the article goes on to list many more benefits of fire, and two wrong choices borrow them: shade cleared from under red cedars and nutrients returned to the soil. Both are true of controlled burns today, not of what the Great Plains peoples first noticed. Students who return to paragraph 2 and restate the bison’s taste for freshly burned grass find the answer quickly.
Every choice must be checked minor Choosing the answer
Two wrong choices name real benefits of burning from later paragraphs, cedar shade removed in paragraph 4 and nutrients freed in paragraph 3, so each must be tested against what the early peoples saw. (Embretson & Wetzel, 1987)
Reading between the lines minor Working it out
Paragraph 2 never says the bison’s grazing caused the practice; students connect “realized that these fires could also be helpful” to the preference for burned land and the deliberate burns that follow. (Graesser, Singer & Trabasso, 1994; Kintsch, 1998)
Strategy: Go to the paragraph about the Great Plains peoples of hundreds of years ago, restate in your own words what they noticed after natural fires, and test each choice against that observation.
Traps
- Wrong part of the text: A choice is true of another paragraph, stanza or speaker than the one asked about.
- True but not the answer: A choice says something accurate about the text that does not answer this question.
- Twists what the text says: Uses the text's topic and ideas but changes what it says: who did it, how much, when, or why.
The wrong answers, classified
B Wrong part of the text (Kirsch & Mosenthal, 1990)
Borrows paragraph 4’s red cedars, whose shade blocks sunlight from the plants beneath them, and adds “planted crops,” though that shade explains modern burns, not the first deliberate ones.
C True but not the answer (King et al., 2004; Embretson & Wetzel, 1987)
States paragraph 3’s real benefits, weedy undergrowth burned away and nitrogen added to the soil, but the article gives them as reasons for burning today, not as what the early peoples observed.
D Twists what the text says (King et al., 2004)
Remembers that bison moved onto burned land but turns their preference for “tender new grass” into herds fleeing wildfire, a change in migration the passage never describes.
Working it out, step by step
Figure out what the question asks
This question asks about a cause. Long ago, fires started by lightning gave American Indians an idea. They began to burn land on purpose. You need to find what they saw that led them to do it. A controlled burn is a fire that people set and keep inside a planned area.
Find the right paragraph
Paragraph 2 tells this part of the story. It says the people “realized that these fires could also be helpful.” Then it says what they noticed: “The bison in the area seemed to prefer grazing on tender new grass on the recently burned land rather than on grass in the unburned areas.”
Put it in your own words
Grazing means eating grass. After a fire, soft new grass grew, and the bison liked it best. So the people began to burn land on purpose. The new grass pulled the herds to that land. That kept the bison away from the crops. The paragraph says the burning “enticed the herds away from the people’s crops.” Enticed means tempted or drew.
Check each choice
- A is right. The burned land drew animals, the bison, to eat the new grass.
- B is wrong. The shade of tall trees comes from paragraph 4. It explains why people burn red cedars today, not how burning began.
- C is wrong. Burning off weeds and adding nutrients come from paragraph 3. Nutrients are what plants need to grow. These are reasons for burning today.
- D is wrong. The bison moved toward the fresh grass. The passage never says herds fled from fires.
Watch out: C is true about controlled burns. But the question asks what first gave the people the idea. Paragraph 2 says it was the bison.
Choose the answer
The early people saw bison come to burned land to eat the new grass. So the answer is A: “by drawing animals in to the area to feed on the new growth sprouting from the burned land.”
Why this answer and not the closest wrong one
C is the closest wrong answer, because it names real good effects of fire. But paragraph 3 gives those as reasons people burn land “today.” The question asks how burning began hundreds of years ago. Paragraph 2 says it began when people watched bison feed on burned land.
More questions like this
The original DOE question
The passage “Using Fire to Keep a Prairie Healthy” as printed (page 41)
