Context and question: The elimination of wolves from Yellowstone National Park had profound impacts on the trophic pyramid. Without predation, herbivores began to over-graze many woody browse species, affecting the area's plant populations. In addition, wolves often kept animals from grazing in riparian areas, which protected beavers from having their food sources encroached upon. The removal of wolves had a direct effect on beaver populations, as their habitat became territory for grazing. Furthermore, predation keeps hydrological features such as creeks and streams in normal working order. Increased browsing on willows and conifers along Blacktail Creek due to a lack of predation caused channel incision because they helped slow the water down and hold the soil in place.
Why were plant populations affected after wolves were eliminated from Yellowstone?
Answer: Without predation, herbivores began to over-graze many woody browse species
Context and question: With increasing environmental concerns about synthetic coatings (such as PFOA) and the higher prices of hydrocarbon based petrochemicals, there is a focus on zein (corn protein) as a coating for paper in high grease applications such as popcorn bags.
What is newly used as a coating in high grease applications?
Answer: corn protein
Context and question: After Hurricane Katrina in 2005, Beyonce and Rowland founded the Survivor Foundation to provide transitional housing for victims in the Houston area, to which Beyonce contributed an initial $250,000. The foundation has since expanded to work with other charities in the city, and also provided relief following Hurricane Ike three years later.
What other hurricane did Beyonce's foundation help with?
Answer:
Hurricane Ike