ATMOSPHERIC HABITAT
Regions in Atmosphere
Trophosphere
nearest to Earth
most highly populated area
location of the bad ozone
stratosphere
location of good enzyme
increasing temperature with height
extreme low temperatures
Mesosphere
temperature decreasing with height
Thermosphere
Temperature increases with altitude
Exosphere
extending into outer space
Helium and H2 predominant
Lonosphere
extreme low temperature
extreme UV and ionizing radiation levels
Physical features of aerial environment
air movement in troposhere
main agent of dipersal
principle
temperature decreases with altitude
sun heats up the ground, create gradient
displacement of air occur
radiation
from the sun
mostly absorbed or reflected back
precipitation
water vapour--- continually recycled
9 days average of water vapour in air
other extreme environment
Hot springs
at volcanic areas
grow of m/os limited by
high temperature
high acidity/alkalinity
low concentration of organic matter
low concentration of dissolved oxygen
Salt lakes
high concentration of sodium chloride
dehydration
precipitation of intracellular proteins
Antartica
Environmental conditions
low temperature
low humidity
high velocity of desiccating winds
high radiation
Atmospheric habitat
Dispersal vs. growth
lower atmosphere can theoritically support growth cause
clouds---sufficient water
light intensity within appropriate limits
spores (better adapted)
low metabolic rates
produced in high numbers
small size & low density
xenosphores
primarily adapted to reproduction vs. resistance to environment
fungi
algae
protozoans
bacteria
adaptation for survival & fecundity
endospores
primarily adapted to resistance other than reproduction
limited to gram +ve bacteria
Dispersal of airborne particles
Liberation & take off into the air
requires energy to overcome adhesive forces
features
virus&bacteria are poorly adapted
fungi have many adaptation
Dispersion
depend on physical characteristics of particles
spores
size
shape
degree of surface roughness
density
environment
wind movement
turbulence
air humidity
convection
Deposition
methods
sedimation due to gravity
impaction with surfaces
Brownian movement
Electrostatic deposition
Rainwashing