Question

Which of the following statements accurately describes how nutrients enter ecosystems?

1. Chemical weathering of rocks contributes to nutrients entry
2. Biological fixation of atmospheric oxygen is a primary way nutrients enter ecosystems.
3. Deposition of nutrients from the atmosphere through rain or wind-blown particles facilitates nutrient entry.
4. Fertilization is a significant nutrient input, especially in unmanaged ecosystems.

• A. None of these
• B. 4 only
• C. 2, 4
• D. 1, 3

Answer 1

Answer:

D. 1, 3

• Nutrient cycling involves the entry of nutrients to ecosystems, their internal transfers between plants and soils, and their loss from ecosystems.

• Nutrients enter ecosystems through the chemical weathering of rocks, the biological fixation of atmospheric nitrogen, and the deposition of nutrients from the atmosphere in rain, wind-blown particles, or gases.

• Fertilization is an additional nutrient input in managed ecosystem.

• Internal cycling processes include the conversion of nutrients from organic to inorganic forms, chemical reactions that change elements from one ionic form to another, biological up-take by plants and microorganisms, and exchange of nutrients on surfaces within the soil matrix.