Question 29·Medium·Cross-Text Connections
Text 1
In a 2005 conference paper, climate scientist Dr. Amita Singh argues that reforesting degraded land with single-species plantations of fast-growing eucalyptus trees is “the most efficient pathway to sequester atmospheric carbon in the coming two decades.” Citing computer models, she concludes that such monoculture plantations can “capture up to 30 % more carbon per acre than any mixed forest of comparable age.”
Text 2
A decade later, ecologist Prof. Martin Roberts publishes a field study of 40 reforestation sites across three continents. Roberts reports that while young eucalyptus monocultures do absorb carbon quickly, by year 15 many show declining soil quality and slower growth, resulting in less total carbon storage after year 25 than mixed-species stands. He writes, “Short-term gains touted by earlier modeling studies ignore long-term soil dynamics and biodiversity losses; diverse forests ultimately sequester more carbon and support healthier ecosystems.”
Based on the two texts, how would Prof. Roberts in Text 2 most likely respond to Dr. Singh’s claim in Text 1 that eucalyptus monocultures are “the most efficient pathway” for carbon sequestration?
For cross-text connection questions, first summarize the key claim in Text 1 in your own words, then summarize how Text 2 treats the same issue, especially noting time frame, tone, and main evidence. Decide if the second author agrees, disagrees, or partially agrees with a twist, and identify the specific reason for that stance. Finally, eliminate choices that (1) ignore clear parts of the second text (like its long-term data), or (2) introduce new topics the second author never mentions (such as economics or absolute claims about all models), and select the option that best captures both the agreement and the disagreement between the two texts.
Hints
Clarify the first author’s position
Reread Text 1 and underline how Dr. Singh describes the efficiency of eucalyptus monocultures compared with mixed forests and what kind of evidence she uses.
Focus on time frame in Text 2
In Text 2, pay attention to what Roberts says happens in the early years of eucalyptus plantations versus what happens by year 15 and after year 25.
Determine the nature of Roberts’s response
Ask yourself: Does Roberts totally agree, totally disagree, or partly agree but qualify Singh’s claim? Look for any places where he seems to accept part of her idea but then challenge it with his field results.
Eliminate answers that add new topics
Be wary of choices that bring in ideas Roberts never mentions, such as economic costs or blanket statements about all computer models.
Step-by-step Explanation
Pin down Dr. Singh’s main claim in Text 1
Focus on what Dr. Singh is actually arguing, not the details of her methods.
She says that reforesting degraded land with single-species, fast-growing eucalyptus plantations is "the most efficient pathway" to pull carbon out of the atmosphere over the next two decades. She backs this up with computer models that say these monocultures can "capture up to 30% more carbon per acre" than any same-age mixed forest.
So Text 1’s core idea: eucalyptus monocultures are more efficient at carbon sequestration than mixed forests, at least according to models and within a roughly 20-year window.
Understand what Roberts’s data show in Text 2
Now look closely at Roberts’s real-world field study in Text 2.
He reports that:
- Young eucalyptus monocultures do absorb carbon quickly.
- But by year 15, many sites show declining soil quality and slower growth.
- As a result, after year 25, these monocultures have less total carbon storage than mixed-species stands.
- He concludes that short-term gains from earlier modeling studies ignore long-term soil dynamics and biodiversity losses, and that diverse forests ultimately sequester more carbon.
So Roberts agrees about the early rapid growth, but he disagrees about which system is better in the long run.
Decide how Roberts would respond to Singh’s "most efficient pathway" claim
Ask: If Roberts read Singh’s statement that eucalyptus monocultures are "the most efficient pathway," how would he react?
Based on Text 2:
- He would likely acknowledge that they look very efficient at first, because his own data show rapid early carbon uptake.
- But he would challenge calling them "most efficient" overall, because by 25 years, mixed forests store more carbon and have healthier soils and biodiversity.
- He would also say that Singh’s models left out crucial long-term ecological processes, so they overstate the advantage of monocultures.
So his response is partly agreeing (short-term) but disagreeing overall due to long-term evidence.
Match that nuanced stance to the answer choices
Now test each option against what you just understood about Roberts:
- A) He would fully endorse the claim... This says he fully agrees and that eucalyptus plantations "consistently outperform" mixed forests, but Text 2 clearly says that after year 25, mixed forests store more carbon, so he would not fully endorse Singh.
- B) He would contend that the claim is irrelevant because economic costs... Roberts never talks about money or economic feasibility; he focuses on ecological processes (soil, growth, biodiversity). So this adds a new idea not in the text.
- C) He would dismiss the claim outright... because computer models cannot predict carbon storage at any timescale. He doesn’t say models can’t predict at any timescale; he says earlier modeling studies ignored long-term soil and biodiversity effects. That’s a specific criticism, not a total rejection.
- D) He would concede that monocultures sequester carbon rapidly at first but argue that they overlook long-term soil decline, so their overall efficiency is overstated. This exactly matches Text 2: he concedes fast early carbon uptake, but uses his long-term data on soil decline and lower total carbon after 25 years to argue that calling monocultures "most efficient" is overstating their true effectiveness.
Therefore, the correct answer is: D) He would concede that monocultures sequester carbon rapidly at first but argue that they overlook long-term soil decline, so their overall efficiency is overstated.