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2013-06-20 07:07:03

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  1. Characteristics of the Tropical Rainforest
    • Within 10° of equator
    • Stable temperature across months
    • 2000-4000mm rain evenly distributed across months (leaches soil nutrients, Micorrhizae help to maintain)
    • Tall trees add a third dimension to this biome
    • Important staple foods (plants and animals) and medicines which are increasingly exploited
  2. Characteristics of Tropical Dry Forest
    • Between 10°-25°
    • More seasonal than Tropical Rainforest
    • Soils richer, but vulnerable to erosion.
    • Shares many animal and plant species with tropical rainforests.
    • Heavily settled by humans; extensive slash/burn.
  3. Characteristics of Tropical Savannah
    • North and south of tropical dry forests within 10°-20°
    • Wet  and dry seasons.
    • Drought can lead to lightning-caused wildfires.
    • Soils - low water permeability.
    • Saturated soils keeps trees out.
    • Landscape - more two-dimensional w/   increasing pressure to produce livestock
  4. Characteristics of the Desert
    • 30° from equator
    • ~20% of earth’s land surface.
    • Water loss > precipitation.
    • Soil low in organic matter.
    • Plant cover sparse / absent.
    • Animal abundance low, but biodiversity may
    • be high. (strong behavioral adaptations, endemics)
    • Human intrusion increasing
  5. Characteristics of Mediterranean Woodland and Shrubland
    • All continents except Antarctica.
    • Climate cool & moist fall, winter, spring; hot & dry in summer (fires).
    • Fragile soils, moderate   fertility.
    • Evergreen trees and shrubs.
    • Fire-resistant plants (due to fire regime).
    • Long history of human intrusion.
    • Cleared for agriculture.
  6. Characteristics of Temperature Grasslands
    • Extremely widespread distribution.
    • Annual rainfall 300 - 1,000 mm.
    • Periodic droughts.
    • Soils nutrient rich & deep.
    • Dominated by herbaceous (non-woody) vegetation.
    • Large roaming ungulates. (Bison vs. cattle)
  7. Characteristics of Temperate Forests (Old Growth)
    • Between 40°-50°
    • Rainfall 650 - 3,000 mm.
    • Fertile soils
    • Long growing seasons dominated by deciduous (not evergreen) plants.
    • Short growing seasons dominated by conifers.
    • Biomass production can be very high
    • Many major human population centers
  8. Characteristics of Boreal Forests (Taiga)
    • Northern Hemisphere (11% of earth's land area)
    • Thin, acidic soils low in fertility.
    • Dominated by evergreen conifers.
    • Relatively high animal density.
    • Historically, low levels of human intrusion
  9. Characteristics of Tundra
    • Covers most land north of Arctic Circle (60°-90º).
    • Cool & dry with short summers.
    • 200 - 600 mm precipitation.
    • Low decomposition rates (“permafrost”)
    • Supports substantial numbers of native mammals.
    • Human intrusion historically low, but increasing as resources become scarce.
  10. Characteristics of Mountains
    • Mountains in the Sky
    • Built by geological processes and thus concentrated in belts of geological
    • activity.
    • Climate changes with elevation and latitude.
    • Soils are well-drained and thin.
    • Flora and fauna change with elevation.
    • Historically used as a source of raw materials for human settlements.
  11. Characteristics of deep blue sea
    • Oceans most extensive biome on earth
    • Pacific basin > Atlantic basin > Indian basin
    • Average depth ~3900-4000m
    • Littoral zone: shallow shoreline
    • Neritic zone: coast to margin of continental shelf
    • Epipelagic zone < mesopelagic zone < bathypelagic zone < abyssal zone < hadal zone
    • Benthic: habitat ON BOTTOM
    • Pelagic: habitat NOT on bottom (regardless of depth)
    • ~80% of solar energy is absorbed in first 10m of ocean (photic zone)
    • Very little solar energy past 600m (aphotic zone) with bioluminescence as sole source of light
    • Thermocline: Layer of water through which temperature changes rapidly with depth.
    • Very low oxygen content in sea water
    • Oceans contribute 25% of total photosynthesis in the biosphere (limited to upper zone)
    • Chemosynthesis near underseas hotsprings
  12. Characteristics of Shallow marine waters
    • Reefs and kelp beds both grow in surface waters with sufficient light for photosynthesis (limited by temperature)
    • Currents deliver oxygen and remove wastes
    • Reefs/kelp beds among most productive and diverse ecosystems
    • intertidal zone: rocky and sandy shore
    • Organisms exhibit amphibious characteristics
  13. Characteristics of Rivers and Streams
    • Vertically divided: water surface, water column, benthic (bottom)
    • Nutrients from land erosion and suspended bottom sediments
    • Temperature closely tracks air temperature
    • Oxygen content is inversely correlated with temperature
    • River continuum concept: small headwater stream (cool, oxygenated water), medium headwater stream (moderate temp, lower oxygen), and large rivers (highest temp, lowest oxygen).
  14. Characteristics of Lakes
    • Most freshwater in just a few lakes
    • Littoral zone: shallows
    • Limnetic zone: open waters (epiliminion [warm surface], metalimnion [temp changes with depth], hypolimnion [cold and dark]
    • Lake color dependent on light absorption and biological activity
    • Seasonal temperature changes (freezing at top, mixing)
    • Local conditions mask the tides
    • Oligotrophic: low biological production, may be well oxygenated (blue and lovely)
    • Eutrophic: high biological production, possibly oxygen deficient (green) 
    • Humans have led to eutrophication and exotic invasive species
  15. What is the equation for photosynthesis?
    6CO2 + 12H2O -> 6O2 + C6H12O6 + 6H2O
  16. Various body temperature regulation
    • Poikilotherms: body temperature varies directly with environmental temperature
    • Homeotherms: body temperature remains constant, regardless of environmental temperature
    • Ectotherms: use an external energy source
    • Endotherm: rely on internal metabolic energy
  17. Temperature and microbial activity
    • Psychrophyllic: extreme cold loving (marine, around antarctica)
    • Thermophillic: hot temperatures (hot springs)
  18. Total heat storage equation
    • Hs = Hm ± Hcd ± Hcv ± Hr - He
    • Hm: heat gained via metabolism
    • Hcd: heat gained/lost via conduction (2 solids)
    • Hcv: heat gained/lost via convection (solid/liquid)
    • Hr: heat gained/lost via radiation
    • He: heat lost via evaporation
  19. Temperature regulation of thermogenic plants
    • Eastern skunk cabbage uses metabolic energy to heat flowers (attracts pollinators, prevents freezing)
    • Starch storage in in root is translocated to flower and metabolized at high rates
  20. Temperature regulation of Plants (arctic and tropic alpines)
    • Arctic: increase radiative heating and decrease convective cooling (growing close to ground, increase SA/V ratio, darker color)
    • Tropic Alpine plants: drastic temperature difference between night and day
    • Retain dead leaves for insulation, thick pubescence
  21. Temperature regulation of lizards/grasshoppers
    • Ectotherms
    • Lizards: use environment (burrows, dark pigment, sun basking, press body to ground) to maintain optimal temperature
    • Grasshoppers: become pigmented during cold times, and lose pigment during hot times
    • Elevated internal temperature to prevent fungal growth
  22. Temperature regulation of Aquatic endotherms (penguin, seal whale)
    • Water is a heat sink (fairly even)
    • Many are air breathers and insulated (fur or fat)
    • Countercurrent heat exchange: cool arterial blood from gills flows to swim muscle, warms in muscle, and leaves warmed
    • Swimming muscles allow large fish to keep temperature elevated from surroundings
  23. Temperature regulaton of moths/bees
    • Insects use flight activity to regulate/maintain body temperature.
    • Bees maintain temperatures regardless of air temperatures
    • Moths thorax has a maximum temperature, but the flow of blood acts as coolant moving hot blood from thorax to abdomen
  24. Temperature regulation for extreme temperatures
    • Inactivity (seek shelter during extreme periods)
    • Reduce metabolic rate
    • Hummingbirds: enter state of torpor (decreased metabolic activity)
    • Bears: hibernation (winter/cold)
    • Lizards/frogs: estivation (summer/dry)
    • Arctic species tend to have a larger range of temperatures they can easily adapt to than tropical species
  25. Discuss humidity
    • Relative humidity = water vapor density / saturation water vapor density x 100
    • Vapor pressure defecit: different between actual water vapor pressure and saturation water vapor pressure
    • Measure of the potential of air to take up moisture (high VPD = steeper gradient, low VPD = air near saturation)
    • High VPD increases evaporative loss from organism
  26. What happens to organisms in different osmolarities?
    • Isosmotic: salts/water diffuse evenly (marine invertebrate)
    • Hyperosmotic: salts diffuse out, osmosis in (freshwater fish)
    • Hyposmotic: salt diffuse in, osmosis out (marine fish)
  27. Information about Water potential
    • Ability to move/do work
    • Flows from higher Ψ to lower Ψ
    • Solute potential (alters the flow/rate of osmosis)
    • Pressure potential (+/- pressure must be taken into account)
    • Pure water Ψ = 0
    • Ψplant = Ψsolute + Ψmatric + Ψpressure
  28. Describe water regulation on land (w/ equation)
    • Two major challenges: evaporative loss to environment and reduced access to replacement water
    • Internal water equation for animals: 
    • Wia = Wd + Wf + Wa - We - Ws
    • Wd: drinking
    • Wf: food
    • Wa: absorption
    • We: evaporation
    • Ws: secretions
    • Wip = Wr + Wa - Wt - Ws
    • Wr: roots
    • Wa: absorption
    • Wt: transiration
    • Ws: secretions