Neotropical coastal mangrove forests are usually zonal, with certain

Question 3

The question is asking us to identify an area where Davis' paradigm (i.e. his theory) does NOT apply. Let's start by nailing down the paradigm that Davis came up with.

According to Davis’ paradigm:

• Shoreline is extended in a seaward direction because of the “land-building” role of mangroves
• Mangroves extend the shoreline by trapping sediments over time.

Let's now consider (A):

The passage tells us that Davis came up with his paradigm in "a study of Florida mangrove forests." So we'd definitely expect his paradigm to apply to the Florida mangrove forests he studied, since he developed his theory by observing them.

You raise an interesting question -- maybe someone else studied the Florida mangrove forests before Davis? The passage doesn't give us a definite answer on this question. But luckily for us, the answer to that question isn't relevant. Because either way, we'd expect Davis' paradigm to apply to this area, so (A) is out.

Let's now consider (E):

According to the passage, Davis' paradigm predicts that mangroves can extend shorelines by trapping and accumulating sediments. So if few sediments can accumulate, the shoreline would not be extended. Since Davis' paradigm would not apply in this case, (E) is correct.

I hope that helps!

1. The primary purpose of the passage is to (D) discuss hypotheses that attempt to explain the zonation of coastal mangrove forests.
The passage introduces the concept of zonation in neotropical coastal mangrove forests and discusses the historical research on mangrove forests without exploring the causes of the distributions. It then presents J.H. Davis' hypothesis on plant succession and challenges its universal application. Finally, it explores the role of salinity and its effects on mangroves as a possible explanation for the various distribution patterns. The passage primarily aims to discuss different hypotheses that explain the zonation of coastal mangrove forests.
2. According to the passage, the earliest research on mangrove forests produced (B) descriptions of species distributions suggesting zonation.
The passage states that the earliest research on mangrove forests produced descriptions of species distribution from shore to land, implying the presence of zonation. It does not mention random patterns, reclassification of species, or confirmation of the "land-building" role of mangroves. Therefore, the correct answer is descriptions of species distributions suggesting zonation.
3. It can be inferred from the passage that Davis' paradigm does NOT apply to (E) a shoreline in which few sediments can accumulate.
The passage mentions that Davis' succession paradigm, which suggests the extension of the shoreline through the "land-building" role of mangroves trapping sediments over time, applies in areas where weak currents and weak tidal energies allow the accumulation of sediments. However, it implies that on stable coastlines where few sediments can accumulate, the distribution of mangrove species results in different patterns of zonation, and the "land-building" does not occur. Therefore, the correct answer is a shoreline in which few sediments can accumulate.
4. Information in the passage indicates that the author would most probably regard which of the following statements as INCORRECT? (C) Species of plants that thrive in a saline habitat require salt to flourish.
The passage mentions that mangroves can thrive in salinities as high as 2.5 times that of seawater, but it states that they do not require salt. Instead, they are metabolically efficient in high salinity environments, which excludes plants adapted to lower salinities. Therefore, the author would regard the statement that species of plants that thrive in a saline habitat require salt to flourish as incorrect.

Hi,

I am still not clear why option D is incorrect for the 4th question. Please help.

Thanks

GMATNinja

Here's choice (D) in the 4th question.

(D) Plants with the highest metabolic efficiency in a given habitat tend to include other plants from that habitat.

That choice conflicts with what the passage says, as you noticed.

However, the choice is written incorrectly. It's supposed to be

(D) Plants with the highest metabolic efficiency in a given habitat tend to EXCLUDE other plants from that habitat.

Bunuel question 4 choice (D) needs to be edited as outlined above.

Thank you MartyTargetTestPrep, edited as suggested.

MartyTargetTestPrep thanks for replying. Really appreciate your help here. But nowhere in the passage it is mentioned that plants with highest metabolic efficiency exclude other plants. Can you please help me understand how this choice is incorrect?

Thanks