Exam 25: Global Ecology

DeLucia and colleagues have shown that increasing carbon dioxide has led to increased NPP in a pine forest. If this result can be generalized, it suggests that forests could be a _______ of anthropogenic carbon and thus tend to _______ the greenhouse effect.

Refer to the map. The map shows the changes in NPP (per year) between 1982 and 1999. Which place has seen the largest increase in NPP?

Which statement best describes our current understanding of the relationship between CO₂ levels and photosynthetic activity?

Refer to the figure. Computer models observed global temperature changes with and without anthropogenic forces, proving that humans have indeed played a major role in observed warming. Using the figure, what year did anthropogenic factors start making a significant impact?

Refer to the figure. The figure shows the temperature (in °C, relative to modern temperature) and the concentrations of carbon dioxide (in ppm) and methane (in ppb) over the past 400,000 years. -Relative to the average over the last 400,000 years, concentrations of CO₂ during the warm interglacial periods in this time period have been _______, and concentrations of methane have been _______.

Refer to the figure. The figure shows mean annual global temperature anomalies between 1880 and 2019. -Prior to 1970, over which 20-year period did the global temperature rise the most?

Refer to the figure. The figure shows the temperature (in °C, relative to modern temperature) and the concentrations of carbon dioxide (in ppm) and methane (in ppb) over the past 400,000 years. -According to various lines of evidence, our species emerged about 160,000 years ago. At that time, temperatures were about _______°C cooler than they are now, and the carbon dioxide level was about _______ ppm.

Why is there a net flow of carbon from the atmosphere to the oceans?

The potential for harmful effects from the loss of the shielding benefits of ozone is strongest

Anthropogenic release of carbon has primarily been from the _______ pool to the _______ pool.

Refer to the figure. Figure 1 Suppose a researcher is experimenting with an invention that might affect global climate. This researcher builds a model to predict how the invention might impact global temperatures and global atmospheric composition over time. The results of the model are shown in Figure 1. -Based on the predictions of the model, answer the following questions: a) How will the invention affect global temperatures? b) How will the invention affect global atmospheric composition? c) Based on the data, does this invention remove CO₂ or block sunlight?

Dust from the Gobi Desert can cross the Pacific Ocean and fall on the remote, tropical oceanic islands of Hawaii. What direct impact will this dust most likely have on nutrient cycling in the terrestrial ecosystems of Hawaii?

Refer to the figure. Individual species vary in their response to climate change. What is the best explanation for what is happening to communities in the European Alps as a result of climate change?

Which statement regarding the oceanic pool of carbon is false?

Refer to the figure. The figure shows the relationship between the mean number of species per plot and the deposition of inorganic nitrogen in kilograms per hectare per year. Within the scope of this experiment, the deposition of each kilogram per hectare of nitrogen reduced plot species diversity by about _______ species.

Which statement about the stratospheric ozone layer is false?

Too much ozone in the lower atmosphere is harmful to organisms and ecosystems because it

Ozone in the _______ is beneficial because it acts as a shield that blocks mainly _______ radiation.

Between 1880 and 2012, the average annual global surface temperature

As nitrogen input increases, _______ increases at first and then decreases at high levels of nitrogen input.