PTE Core Reading Test 1

For centuries, the dense canopy of tropical rainforests has guarded secrets that scientists are only beginning to uncover. These ecosystems, though they cover a relatively small fraction of the planet's surface, are home to more than half of the world's plant and animal species. The reasons for this extraordinary biodiversity remain a subject of active research, but the stable, warm, and humid climate certainly plays a part, allowing organisms to thrive year-round without the harsh seasonal swings found in temperate regions.

The rainforest is structured in distinct layers, each supporting its own community of life. At the very top, the emergent layer consists of the tallest trees, which rise above the rest and are exposed to the full force of sunlight and wind. Below this lies the canopy, a dense roof of leaves where the majority of rainforest species live. Further down, the understorey receives only filtered light, while the forest floor remains dim and humid, carpeted with decomposing matter that recycles nutrients back into the soil.

Despite their richness, rainforests are increasingly under threat from logging, agriculture, and climate change. Scientists warn that the loss of these habitats could lead to the extinction of countless species before they are even documented. Protecting rainforests, therefore, is not merely an environmental concern but also a matter of preserving knowledge that could benefit medicine, agriculture, and our understanding of life itself.

According to the passage, why do most rainforest species live in the canopy?

1. A.It is the layer that contains the tallest emergent trees.
2. B.It forms a dense roof of leaves that supports the majority of species.
3. C.It receives only filtered light from above.
4. D.It is carpeted with decomposing matter that recycles nutrients.

The correct answer is shown in your review when you finish the test.