The fynbos shrubland is a diverse habitat found only in South Africa. It is adjacent to the Afro-temperate forest, with...
GMAT Information and Ideas : (Ideas) Questions
The fynbos shrubland is a diverse habitat found only in South Africa. It is adjacent to the Afro-temperate forest, with almost no transition space between the two distinct habitats. Plants in the fynbos have uniquely thin and long root systems that spread out over large distances to absorb nutrients from the soil. Ecologists transplanted tree seedlings from the forest into plots in the fynbos. Seedlings in plots isolated from the roots of fynbos plants exhibited a growth rate five times greater than that of the seedlings in plots in close proximity to the roots of fynbos plants.
Based on the text, what role do fynbos roots most likely have in maintaining the border between the fynbos shrubland and the Afro-temperate forest habitats?
Step 1: Decode and Map the Passage
Passage Analysis Table
| Text from Passage | Analysis |
|---|---|
| "The fynbos shrubland is a diverse habitat found only in South Africa." |
|
| "It is adjacent to the Afro-temperate forest, with almost no transition space between the two distinct habitats." |
|
| "Plants in the fynbos have uniquely thin and long root systems that spread out over large distances to absorb nutrients from the soil." |
|
| "Ecologists transplanted tree seedlings from the forest into plots in the fynbos." |
|
| "Seedlings in plots isolated from the roots of fynbos plants exhibited a growth rate five times greater than that of the seedlings in plots in close proximity to the roots of fynbos plants." |
|
Passage Architecture & Core Elements
Main Point: The fynbos shrubland maintains a sharp boundary with the adjacent forest through the competitive advantage of its specialized root systems.
Argument Flow: The passage establishes the unique characteristics of fynbos habitat and its sharp border with forest, then presents experimental evidence showing that fynbos roots significantly inhibit the growth of forest plants, explaining how this boundary is maintained.
Step 2: Interpret the Question Precisely
What's being asked? The role that fynbos roots play in maintaining the border between two habitats
What type of answer do we need? A mechanism or function that explains how the roots create/maintain habitat separation
Any limiting keywords? "most likely" indicates we need to infer based on the evidence provided
Step 3: Prethink the Answer
- The experimental evidence shows forest seedlings thrive when isolated from fynbos roots (5x growth rate) but struggle when near fynbos roots
- This suggests fynbos roots prevent forest plants from succeeding in the fynbos area
- We also know fynbos plants have root systems that "spread out over large distances to absorb nutrients from the soil"
- The right answer should explain how fynbos roots prevent forest plants from establishing in the fynbos area, maintaining that sharp boundary
- Claims fynbos roots physically damage forest plant roots
- The passage shows growth differences based on proximity, not root damage
- No evidence of physical damage is provided
- Suggests fynbos roots create a physical barrier
- The passage describes nutrient absorption, not physical blocking
- Physical barriers wouldn't explain why isolated seedlings grow so well
- Explains that fynbos roots are so effective at nutrient absorption that forest plants can't get enough nutrients to thrive
- Directly connects to the passage's description of fynbos roots spreading wide "to absorb nutrients from the soil"
- Perfectly explains the experimental results: forest seedlings thrive when isolated from this competition but struggle when competing with fynbos roots for nutrients
- Focuses on how roots help fynbos plants rather than how they affect forest plants
- Doesn't explain the border maintenance mechanism