REN R 446 midterm 1

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REN R 446 midterm 1
2015-10-08 21:45:02
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  1. Net primary productivity eqn
  2. Total ecosystem respiration eqn
  3. NPP of most agricultural ecosystems?
    15 ha-1yr-1
  4. Yield/food production eqn
    = HI x NPP
  5. Amount of land needed to feed one person
    = consumption/yield
  6. Koppen Classification: A
    Tropical rainy climates
  7. Koppen Classification: B
    Dry climates
  8. Koppen Classification: C
    Temperate rainy climates
  9. Koppen Classification: D
    Cool snowy climates
  10. Koppen Classification: E
    Polar Climates
  11. Af
    • No dry season
    • little rainfall or temperature variation
    • evergreen rainforests
    • unrestricted cropping seasons->multiple croppings
    • perennials: rubber, oil palm, banana, lowland coffee, cocoa
    • annuals: root crops (yams, taro)
    • livestock limited by diseases, lack of natural grasslands
  12. Am
    • short dry season (monsoon)
    • little temperature variation
    • rainforest, some seasonal deciduous
    • two reliable cropping seasons
    • perennials: coffee, tea, bananas, cocoa, oil palms
    • annuals: yams, maize, rice, pulses, cotton
    • livestock: limited by lack of grasslands
  13. Aw
    • distinct dry season
    • two short or one long rainy season and one long dry season
    • one reliable cropping season
    • perennials: sisal, cashew
    • annuals: maize, sorghum, finger millet, ground nut, pulses, cotton
    • livestock: important bc of extensive natural grasslands, carrying capacity limited by dry season
  14. Problems with tropical rainy climates?
    • theoretical production > actual production
    • variable+high intensity rainfall causes runoff, erosion, leaching
    • high humidity causes plant disease, quality problems during storage
  15. Bs
    • Steppe
    • one short rainy season, one long dry season
    • cropping season variable, unreliable
    • drying winds from adjacent deserts -> wind erosion, rapid evapotranspiration
    • soils often have low water holding capacity, OM content, high salinity
    • perennials: unsuitable
    • annuals: short term and drought resistant-sorghum, bulrush millet
    • intense solar radiation makes irrigated agriculture highly productive
    • livestock: needs large area bc of low carrying capacity
  16. Bw
    • Desert
    • not really anything about this
  17. Cs
    • dry summer (mediterranean)
    • always near sea
    • Pa 25-90cm
    • modest, highly variable winter precip. hot dry summers
    • native vegetation: stunted trees, woody shrubs
    • perennials: olive, vines, irrigated citrus and avocado
    • annual crops: barley, wheat, pulses during winter
  18. Cfb
    • humid, warm summer
    • Pa ample for agriculture
    • soils acidic, soils leached with low pH, OM, fertility, highly erodible
    • conservation practices: surface residue, drainage, contour planting, cover crops
    • native vegetation: deciduous forest
    • crops: rice, maize, soybean, groundnuts
  19. Cfc, Dfc
    • cool summer
    • precipitation distributed throughout year, more in summer
    • Pa>Ea
    • low Ea makes drought uncommon unless soil has low WHC
    • most soils have high WHC, OM, fertility
    • Native vegetation: coniferous forest, heaths, moors
    • Pastures: well suited to permenant pasure, hay
    • Cfc crops: corn, soybean, potato, winter wheat, orchard
    • Dfc: sugarbeet, spring wheat, barley
  20. Ef
    ice cap
  21. Et
  22. shortwave radiation
    radiation in the ultraviolet, visible, and near infrared wavelengths (0.3-4u)
  23. longwave radiation
    radiation in the infrared wavelength (4-80u)
  24. photosynthetic radiation
    radiation in the visible wavelength (0.4-0.7u)
  25. ultraviolet radiation
    radiation at wavelength < visible (0.3-0.4u)
  26. net radiation
    difference between incoming and outgoing shortwave and longwave radiation
  27. radiant flux
    amount of radiant energy absorbed, transmitted, or emitted per unit time
  28. absorptivity
    fraction of shortwave or photosynthetic radiation absorbed by a material
  29. transmissivity
    fraction of a shortwave or photosynthetic radiation transmitted through a material
  30. emissivity
    ability of a surface to emit longwave radiation only compared to that of a blackbody surface
  31. albedo
    fraction of shortwave or photosynthetic radiation reflected by a surface, aka reflectivity
  32. GPP
    gross primary productivity, all CO2 fixation done by plants
  33. NEP
  34. Difference between potential NPP and actual NPP?
    potential NPP is the maximum hypothetical value, actual NPP may be reduced from potential by soil quality and management