SCIENTIFIC THINKING An ecologist studying plants in the desert performed the following experiment. She staked out two identical plots, which included a few sagebrush plants and numerous small, annual wildflowers. She found the same five wildflower species in roughly equal numbers on both plots. She then enclosed one of the plots with a fence to keep out kangaroo rats, the most common grain-­eaters of the area. After two years, to her surprise, four of the wildflower species were no longer present in the fenced plot, but one species had increased dramatically. The control plot had not changed. Using the principles of ecology, propose a hypothesis to explain her results. What additional evidence would support your hypothesis?

About a third of insect species measured are in decline, meaning that their populations are shrinking due to habitat destruction, pollution, and other factors. Predict how this change affects the bee pollination of crops such as apples and almonds.

Suppose that a two-acre lawn on your college's campus is allowed to undergo succession. Describe how species traits, species interactions, and the site's history might affect the community that develops.

There are fewer lions in Africa's Serengeti than there are zebras. This is principally because .a. zebras tend to drive off lions;b. lions compete directly with cheetahs, whereas zebras do not have any competitors;c. zebras have mutualists that increase their population, whereas lions do not;d. there is less energy available in zebras to support the lion population than there is in grass to support the zebras;e. zebras are a keystone species, whereas lions are not

A team of 102 scientists spent a year surveying a small area of the San Lorenzo rain forest in Panama to count the number of species of arthropods living there. After collecting 129,494 specimens—using nets, traps, shovels, tree-climbing harnesses, helium balloons, and other creative gear—it took the team eight years to sort and identify the arthropods.Rather than measuring the entire 6000-hectare (ha) forest, the researchers sampled arthropod diversity by intensively collecting as many arthropods as they could in 12 plots that measured 20m×20msquare. If 1ha=10,000m2,, how many hectares of forest did they sample in all?a. 20m×20m×12=4800hab. 4800m2×10,000m2/1ha=48,000,000hac. 20m×20m=400had. 4800 m^2 x 1ha/10,000 m^2 = 0.48 ha

A team of 102 scientists spent a year surveying a small area of the San Lorenzo rain forest in Panama to count the number of species of arthropods living there. After collecting 129,494 specimens—using nets, traps, shovels, tree-climbing harnesses, helium balloons, and other creative gear—it took the team eight years to sort and identify the arthropods.The graph below shows some of the data for the major arthropod groups collected. Notice that the scale on the y axis is logarithmic to make both small and large numbers legible on the same graph. For example, there are about 400 species of spiders, but only 40 species of bees. About how many arthropods were found in total? About what percentage of these were beetles?

"In a classic study, John Teal measured energy flow in a salt marsh ecosystem. The table below shows some of his results.a. What percentage of the energy in sunlight was converted into chemical energy and incorporated into plant biomass? What term describes this new biomass?b. What percentage of the energy in plant biomass was incorporated into the bodies of the primary consumers? What became of the rest of the energy (see Figure 37.16A)?c. How much energy is available for secondary consumers? Based on the efficiency of energy transfer by primary consumers, estimate how much energy will be available to tertiary consumers."

A team of 102 scientists spent a year surveying a small area of the San Lorenzo rain forest in Panama to count the number of species of arthropods living there. After collecting 129,494 specimens—using nets, traps, shovels, tree-climbing harnesses, helium balloons, and other creative gear—it took the team eight years to sort and identify the arthropods.A team of 102 scientists spent a year surveying a small area of the San Lorenzo rain forest in Panama to count the number of species of arthropods living there. After collecting 129,494 specimens—using nets, traps, shovels, tree-climbing harnesses, helium balloons, and other creative gear—it took the team eight years to sort and identify the arthropods.Use the data in the graph to analyze the following statements. Select True or False for each statement, then correct any false statements to make them true.T/FAll taxa shown in the graph are insects.T/FAll taxa shown in the graph have segmented bodies and limbs.T/FAll taxa shown in the graph are terrestrial.T/FIf the researchers had sampled for mollusks, they probably would have found almost as many species as they did for arthropods.

Lyme disease is caused by infections of the bacterium Borrelia burgdorferi (stained blue in inset, among red blood cells) which is transferred to humans via blood-sucking bites from the tick, Ixodes scapularis. Lyme disease can cause flu-like symptoms in the short term and more serious illnesses in the long term, if not treated. Why is Lyme disease on the rise in eastern North America?Researchers have measured a positive correlation between forest fragmentation and incidence of Lyme disease. According to the theory of island biogeography, how do you predict fragmentation will affect species richness?