NR 501 FINAL EXAM QUESTIONS AND CORRECT ANSWERS GRADED A+

NR 501 FINAL EXAM ALL QUESTIONS AND ANSWERS

QUESTION

How do soils impact climate change?

ANSWER

Soil Impact:
- impact concentration of greenhouse gases (e.g. CO2, CH4, and NO2)
- waterlogged soils produce methane (anaerobic environments, methanogens)
- soil microbes release CO2
- soils store carbon



QUESTION

How are soils impacted by climate change?

ANSWER

- Temperature increase
- impact microbial activity and plant growth
- respiration, CO2, and emissions increase
- Altered precipitation affects soil moisture
- Drought limits soil respiration and decreases plant growth and carbon inputs
- Increased precip stimulates respiration, plant productivity, and carbon inputs.
- Soil freezing and thawing
- less snowpack --> increased susceptibility of soils to freezing (and freeze-thaw cycles)
- Severe freezing and thawing tend to increase soil respiration
- can increase soil carbon



QUESTION

What factors influence greenhouse gas fluxes from soils?-

ANSWER

, - Moisture
•Temperature
• Vegetation type
• Organic matter content
• Soil texture
• Soil structure
• pH
• Microbial community composition
• Land use



QUESTION

How is climate expected to change in the Northeastern U.S?

ANSWER

- expected to increase by 2.3-8°C (4-14°F) by 2100
- Boston could experience 30-60 days of temps over 90°F each summer
- more precip as rain and less as snow
- increased frequency of summer/fall droughts
- increased frequency of extreme weather events



QUESTION

Describe the process by which soil organisms release CO2 and other trace gases to the
atmosphere (or in some cases, take up greenhouse gases from the atmosphere

ANSWER

- plant respiration- microbial respiration and decomposition carbon and use it for cell growth,
producing CO2 as a byproduct
- Methanogens produce methane in oxygen-poor environments
uptake:
- plants take up CO2 through photosynthesis
- Methanotrophs consume methane
ADD MORE?



QUESTION