1. Studies over many years and by many different researchers have shown that only 10% of the energy captured by photosynthesis is transferred to the next trophic level, primary consumers. Similarly, the transfer of energy between any trophic level and the next has been shown to be 10% (Infographic 22.4). The biogeochemical cycles that continually renew supplies of clean water, oxygen, essential nutrients (nitrogen and phosphorus), and carbon also are powered by the sunâs energy (Infographic 23.9). The amount of energy delivered to the Earth remains nearly the same from year to year and is called the solar constant. Explain how energy flow and the rates of the biogeochemical cycles relate to the carrying capacity of an ecosystem. [45]
2. Prepare a schematic of the hydrologic cycle that shows the major sinks, flows, drivers and processes in the cycle. Indicate the relative amounts of freshwater and saltwater and briefly explain why all the Earthâs water has not become salty. [40]
3. If the Earthâs water supply is finite, how can global warming cause sea levels to rise? Hint: There are several mechanisms but donât fall into a common trap. Do this experiment! Put ice in a glass and fill the glass till it is ready to overflow. Set the glass on a table and let the ice melt. What did you observe? [15]
1. Studies over many years and by many different researchers have shown that only 10% of the energy captured by photosynthesis is transferred to the next trophic level, primary consumers. Similarly, the transfer of energy between any trophic level and the next has been shown to be 10% (Infographic 22.4). The biogeochemical cycles that continually renew supplies of clean water, oxygen, essential nutrients (nitrogen and phosphorus), and carbon also are powered by the sunâs energy (Infographic 23.9). The amount of energy delivered to the Earth remains nearly the same from year to year and is called the solar constant. Explain how energy flow and the rates of the biogeochemical cycles relate to the carrying capacity of an ecosystem. [45]
2. Prepare a schematic of the hydrologic cycle that shows the major sinks, flows, drivers and processes in the cycle. Indicate the relative amounts of freshwater and saltwater and briefly explain why all the Earthâs water has not become salty. [40]
3. If the Earthâs water supply is finite, how can global warming cause sea levels to rise? Hint: There are several mechanisms but donât fall into a common trap. Do this experiment! Put ice in a glass and fill the glass till it is ready to overflow. Set the glass on a table and let the ice melt. What did you observe? [15]
