The biosphere is a natural Earth system maintained by things like plants and animals.
True
False
True
Consider the following scenario:
When vegetation is removed from a stream valley, flowing water from precipitation causes soil erosion and loss of nutrients. This causes more vegetation to die. With less vegetation to hold soil in place, flowing water causes even more erosion and nutrient loss, which then causes more plants to die.
This is an example of a ________ feedback.
a. runaway
b. natural system
c. positive
d. negative
c. positive
Which of the following is TRUE about systems?
a. Positive feedbacks work to maintain stability in systems.
b. A natural system can reach its ecological tipping point if it gets caught in a negative feedback loop.
c. Outputs cannot be converted into inputs.
d. Inputs flow through processes to create outputs
d. Inputs flow through processes to create outputs
Forests also have an important role in the global nitrogen cycle. According to the results from Templer's research, how might that change in the future?
a. Under higher global temperatures, trees will convert nitrogen into nitric acid.
b. Under higher global temperatures, tree roots will pull more nitrogen from the soil, reducing available nitrogen.
c. Under higher global temperatures, tree roots won't absorb as much nitrogen from the soil and more nitrogen might runoff into waterways.
d. Under higher global temperatures, trees will release more nitrogen into the air.
c. Under higher global temperatures, tree roots won't absorb as much nitrogen from the soil and more nitrogen might runoff into waterways.
What variable is Templer changing in her experimental forest plots?
a. Cooling the plots
b. Increasing wind exposure
c. Increasing ground water
d. Warming the plots
d. Warming the plots
Because scientists cannot actually precisely measure a process like soil erosion over the entire earth, they must ____.
a. extrapolate conclusions from the most available sampling
b. prove their hypotheses without the use of external measurements
c. use statistical sampling and mathematical models to produce estimates
d. rely on peer review to provide consensus on the validity of the hypothesis
e. focus on developing sound scientific theories with correlating data