Erwin and Scott used an insecticidal spray to remove insects from the top section of an L. seemannii tree and collect them from the forest floor. Using the data collected, Erwin projected that this entire tree, from top to bottom, is host to about 600 unique arthropod species, which were not found on any other tree species. While the researchers also identified 900 beetle species from the top section, the vast majority of them were known to be found on many other tree species. If there are approximately 50,000 species of tropical trees, and assuming that every tree hosts a similar number of unique species, which of the following would be the best quantitative method to roughly estimate the total number of arthropod species, globally?
A) Estimate the species density and then multiply by 50,000. B) Multiply 600 by 50,000. C) Multiply 50,000 by 900. D) Add 900 to 600, and then multiply by 50,000.
A parasitic fungus, Geomyces destructans, has decimated millions of bats in the United States since it was first observed in upstate New York in 2006. The disease has been named white-nose syndrome because of the white fungal hyphae that cover the bat upon infection. It is believed that this fungus was introduced from Europe by tourists entering into caves with hibernating bat populations. Which prediction most likely reflects changes that will occur in natural communities as a result of massive bat mortality?
A) increased animal populations as a result of niche availability B) increased rodent populations as a result of an increase in flying insect populations C) increased flying insect populations D) decreased bird populations as the spread of the fungus infects other closely related species
Suppose you attend a town meeting at which some experts tell the audience that they have performed a cost-benefit analysis of a proposed transit system that would probably reduce overall air pollution and fossil fuel consumption. The analysis, however, reveals that ticket prices will not cover the cost of operating the new system. As a biologist, you know that if ecosystem services had been included in the analysis, the experts might have arrived at a different conclusion. Which of the following best explains why ecosystem services are rarely included in economic analyses?
A) Federal laws of the United States exclude their inclusion in any cost benefit analysis. B) They have a low value and are usually not cost effective. C) Ecosystem services only take into account abiotic factors that affect local environments. D) Their cost is difficult to estimate, and people take them for granted.