Let's take a look at how a topic currently in the news--species extinction--is treated in recent articles from the three different types of publications.
Clements, Christopher F., et al. "Effects of Recent Environmental Change on Accuracy of Inferences of Extinction Status." Conservation Biology 28.4 (2014): 971-81. Research Library. Web. 1 June 2015.
“The rate at which a population declines to extinction can play an important role in determining how accurately a method for inferring extinction performs (Rivadeneira et al. 2009; Clements et al. 2013). Where species persist at low density for a lengthy period (and thus are rarely observed), estimates are worse than when the species falls rapidly to extinction” (Clements, et al. 972).
This quoted excerpt from a peer-reviewed article in a scholarly journal (Conservation Biology) shows several characteristics of a scholarly article:
Dolesh, Richard J. "Debate Over the Purpose of Conservation Heats Up." Parks & Recreation 12 2014: 28-9. Research Library. Web. 1 June 2015.
“The issue of who conservation is for is not just a philosophical or theoretical debate by ivory-towered academics. It has very real meaning to all of us in the field of parks and recreation. Increasingly, parks are viewed as protectors of biodiversity. A recent report by the World Wildlife Fund, the 2014 Living Planet Index, identifies the shocking loss of the word's vertebrate wildlife species - more than 50 percent in the past 40 years” (Dolesh 29).
This quotation shows signs that this article is from a trade periodical (Parks & Recreation) because
Borenstein, Seth. "Plants, Animals Going Extinct 1,000 Times Faster Than They Did before Humans, New Study Finds." U.S.News & World Report 05 2014: 1. Research Library. Web. 1 June 2015 .
“Species of plants and animals are becoming extinct at least 1,000 times faster than they did before humans arrived on the scene, and the world is on the brink of a sixth great extinction, a new study says. The study looks at past and present rates of extinction and finds a lower rate in the past than scientists had thought. Species are now disappearing from Earth about 10 times faster than biologists had believed, said study lead author noted biologist Stuart Pimm of Duke University” (Borenstein 1).
This quotation shows qualities of an article from a popular news magazine (U.S. News & World Report) because