Question

Selection 2: The Environmental Impact of Rock Climbing
1 Rock climbing is a popular sport around the world. It requires minimal equipment and gives climbers the opportunity to challenge themselves in unique surroundings. However, the benefits of this extreme sport do not outweigh its potential to cause extreme harm to the natural world.
2 One threat comes from the chalk many climbers use to maintain a good grip while climbing. The chalk is made from magnesite that is mined from deep in the ground. Studies have shown that areas around these mines have high levels of magnesium in the soil. As a result, fewer microorganisms survive there. A 2020 study showed that the chalk caused harm to four species of ferns and mosses that live on rocks (Hepenstrick).
3 Beyond the use of chalk, rock climbers pose other threats to local plant life. Sometimes, climbers remove lichens to make their climb safer. Some of these cliffside plants may only exist in small areas of the country. Removing or damaging them could cause them to go extinct. Even careful climbers may cause destruction. One study at the University of Granada in Spain showed that frequently climbed areas had less plant life than other rock faces (Lorite).
4 Rock climbing can also disrupt animal habitats. Many bird species, including the peregrine falcon, nest on cliffs. Climbers who come too close to the nests may cause the mother birds to abandon their eggs. This is especially harmful for species that are threatened or endangered.
5 The research into the environmental effects of rock climbing is still in its early stages. However, early studies paint a clear picture. Rock climbing’s impact on local ecosystems is something all climbers should be aware of.
References
Hepenstrick, Daniel, et al. “The distribution of climbing chalk on climbed boulders and its impact on rock-dwelling fern and moss species.” Ecology and Evolution, 01 Oct. 2020.
Lorite, Juan, et al. “Rock climbing alters plant species composition, cover, and richness in Mediterranean limestone cliffs.” PLOS One, 2 Aug. 2017.

What is the main purpose of the in-text citations in paragraphs 2 and 3 of Selection 2?
A. to show why background information is important
B. to convince the reader that the author is correct
C. to explain the credibility of each source
D. to identify the source of specific details

Answer 1

D. The citations identify the sources of the specific study results and details mentioned (they show where the evidence comes from).