Exam 11: Population Growth and Regulation

Species A is a nonreproductive shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. In year 0, 340 individuals were tagged. In year 1, 288 were still alive. In year 2, 250 were alive. In year 3, 200 remained. Suppose that the carrying capacity of this environment for species A is 500 individuals. How would you expect the growth rate to change over the next 5 years? If the carrying capacity for species A was 2,000, how would you expect the growth rate to change over the next 5 years?

Suppose you are constructing a life table for a population of a small perennial plant. Currently, there are 650 plants that are in age class 0, 347 in age class 1, 123 in age class 2, and 55 in age class 3. Based on previous work, the expected survival rates of plants are S₀ = 0.4, S₁ = 0.6, and S₂ = 0.8. - Assuming that the expected survival rates remain the same, about how many plants will be in age class 2 in 12 months?

Species A is a nonreproductive age shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. Data from the control, no wildfire site, documents that species A becomes reproductive in year 3. At the control site, there are 432 species A shrubs in year 3 and 523 in Year 4. What is species A's $\lambda$ ?

Which statement about population growth is true?

Which statement about life tables is false?

Refer to the table. . - The table shows the survivorship, fecundity, and life expectancies for U.S. females of various ages as of 2009. In 2009, how many more years was a 50-year-old woman expected to live?

Suppose populations of a beetle species follow the logistic equation for growth. If a population is at 3/4 of its carrying capacity and its (per capita) growth rate in the absence of density-dependent regulation is r, what is its growth rate now?

If there are 100 plants in a population in year 1, and 120 plants in the population in year 2, what is $\lambda$ ?

Refer to the table. The table shows the survivorship, fecundity, and life expectancies for U.S. females of various ages as of 2009. If approximately 1.5 million females were born in the United States in 2009, how many of them should we expect to live to at least age 90?

A continuously growing population of bears has a population size of 500 and its intrinsic rate of increase is r = 0.07 per year. Assuming that this rate of increase remains the same, about how long should it take for the population to reach 1,000? (Note: The natural logarithm of 2 is about 0.70.)

The country of Guatemala is currently experiencing rapid population growth, Greece is experiencing essentially zero population growth, and Germany is experiencing negative population growth. Assuming that age-specific fecundities are similar in these three countries, which of the following is most likely?

Population regulation occurs when

Species A is a nonreproductive shrub you have been studying for 3 years after a wildfire destroyed all the vegetation on your field site. In year 0, 340 individuals were tagged. In year 1, 288 were still alive. In year 2, 250 were alive. In year 3, 200 remained. The data from the control, no wildfire site, documents that species A becomes reproductive in year 3 with a $\lambda$ of 1.21. How many shrubs would you predict will be at the wildfire site in year 4?

Which statement about Pearl and Reed's application of the logistic growth curve to U.S. population growth is true?

Refer to the figure. Based on the figure, an acorn barnacle has _______ chance of surviving to age 5 when compared to a song thrush.

Suppose that researchers are studying the life history of a population of gorillas, a species in which individuals can live for several decades. They can assess the ages of the gorillas with high accuracy, but because of funding constraints, they are limited to three years of study. Which table will the researchers be able to construct?

Suppose you are constructing a life table for a population of a small perennial plant. Currently, there are 650 plants that are in age class 0, 347 in age class 1, 123 in age class 2, and 55 in age class 3. Based on previous work, the expected survival rates of plants are S₀ = 0.4, S₁ = 0.6, and S₂ = 0.8. -Assuming that the expected survival rates remain the same, about how many plants that are expected to be in age class 2 in 24 months?

Which statement about ecological footprints is false?

Which statement is not consistent with projected trends in human population growth?

Refer to the figure. Based on the figure, what is the approximate difference in the probability that a Gambian will survive to age 40 if she was born in the "hungry season" (July-October) compared with another time of the year?