Card Set Information
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
Characteristics of Tropical Dry Forest
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.
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
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
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.
Characteristics of Temperature Grasslands
Extremely widespread distribution.
Annual rainfall 300 - 1,000 mm.
Soils nutrient rich & deep.
Dominated by herbaceous (non-woody) vegetation.
Large roaming ungulates. (Bison vs. cattle)
Characteristics of Temperate Forests (Old Growth)
Rainfall 650 - 3,000 mm.
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
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
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.
Characteristics of Mountains
Mountains in the Sky
Built by geological processes and thus concentrated in belts of geological
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.
Characteristics of deep blue sea
Oceans most extensive biome on earth
Pacific basin > Atlantic basin > Indian basin
Average depth ~3900-4000m
: shallow shoreline
: coast to margin of continental shelf
Epipelagic zone < mesopelagic zone < bathypelagic zone < abyssal zone < hadal zone
: habitat ON BOTTOM
: 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
: 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
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
: rocky and sandy shore
Organisms exhibit amphibious characteristics
Characteristics of Rivers and Streams
: 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).
Characteristics of Lakes
Most freshwater in just a few lakes
: 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
: low biological production, may be well oxygenated (blue and lovely)
: high biological production, possibly oxygen deficient (green)
Humans have led to eutrophication and exotic invasive species
What is the equation for photosynthesis?
6CO2 + 12H2O -> 6O2 + C6H12O6 + 6H2O
Various body temperature regulation
: body temperature varies directly with environmental temperature
: body temperature remains constant, regardless of environmental temperature
: use an external energy source
: rely on internal metabolic energy
Temperature and microbial activity
: extreme cold loving (marine, around antarctica)
: hot temperatures (hot springs)
Total heat storage equation
Hs = Hm ± Hcd ± Hcv ± Hr - He
: heat gained via metabolism
: heat gained/lost via conduction (2 solids)
: heat gained/lost via convection (solid/liquid)
: heat gained/lost via radiation
: heat lost via evaporation
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
Temperature regulation of Plants (arctic and tropic alpines)
: 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
Temperature regulation of lizards/grasshoppers
: use environment (burrows, dark pigment, sun basking, press body to ground) to maintain optimal temperature
: become pigmented during cold times, and lose pigment during hot times
Elevated internal temperature to prevent fungal growth
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
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
Temperature regulation for extreme temperatures
Inactivity (seek shelter during extreme periods)
Reduce metabolic rate
: enter state of torpor (decreased metabolic activity)
: hibernation (winter/cold)
: estivation (summer/dry)
Arctic species tend to have a larger range of temperatures they can easily adapt to than tropical species
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
What happens to organisms in different osmolarities?
: salts/water diffuse evenly (marine invertebrate)
: salts diffuse out, osmosis in (freshwater fish)
: salt diffuse in, osmosis out (marine fish)
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
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
Wip = Wr + Wa - Wt - Ws