Physical environment Flashcards
air cycles globe
warm air rises at equator -> then to pole -> cool down -> surface -> at surface back to equator
currents & gyres
current: patterns of water movement
- affected by global wind patterns
- warm water to pole -> cools down gets back (golfstream)
gyres: dominate water movements in oceans
- clockwise in north
- counterclockwise in south
percipitation distribution
where biggest?
north south?
latitudinal pattern
highest where trade winds come together (intertropical zone):
equator
then around 50deg
southern hemisphere more rain -> more ocean area
maritime influence on climate
locations close to large water bodies (big lakes, oceans) have more stable climate
large water bodies store thermal energy
mountain influence on climate
altitude (up) -> temp (down)
mountainridge creates rainshadow on leeward side (arid) when between water and land
luvwards is moist
wolken regnen sich an den bergen aus
microclimate influences
can affected by local soil, temperature, wind, moisture,….
can be warmer further up the mountain when grassland above forest
water cycle changes
if big stream breaks (golfstreams) -> global changes…
much cold water gets in stream
water properties
-bipolar
-hydrogen bonding possible
-ice lower density than water
-good heat capacity -> buffer for changes -> beneficial
to live close to water
-bouyancy beneficial for gravity -> less structural stability
needed in water
-plankton can float in water
water mixing
most dense at 4 degrees epilimnion warm low density surface thermocline zone of rapid water changes hypolimnion cold, high density, deep waters
plankton
float in water forest of water bodies major compenent of food web 1/4 of oxygen we breathe primary producers
light intensity water
decreases exponentially with depth
longwave penetrates deeper -> water is blue
the darker the less colorfull
water movements
upweling at equator and coasts (coriolis effect?)
upwelling zones are enriched with nutrients
upweeling causes mixing of material energy & genetic information
increases biodiv
water habitats consequences for life
vertebrates have torpedo shape
primary production only in photic zone
absorbance spektra (photosynthesis)
different organisms different pigments to absorb light (chlorophyll, carotine, ect, …)
-> different niches
photosynthesis absorption spektrum
~400 - 700 nm
light reflection on water
the lower the angle, the less penetration
the more waves, the less penetration
forest vs meadow absorbance
forest (80% by canopy, 10% reflected)
meadow (35% in higher plants, 35 % in lower plants, 20% reflection)
LAI (leaf area index)
total leaf area/ projected ground area
most part of leaf area in upper third of the tree
available light down canopy
exponential decrease (groundlevel only ~10%)
what can tree do?
change angle of leaf (60deg -> 50%)
high altitude -> low sun angle -> leaf maximal area
hot and dry -> reduce area to sun -> not dry out
light, photosynthesis and water balance are related
forest change in seasons
spring lightest (not many leafes, high radiation) -> forest floor is blooming summer darkest (most leafs)
geosphere vs biosphere
geo -> abiotic , bio -> biotic
unweathered rock
FACHBEGRIFF
regolith (ground): hard, crumbled rock:
medium for plant growth
recycling system
mechanical weathering
water
temperature -> freezing expands water -> breaks rocks
wind -> scours surface with dust and sand
organisms -> roots split rocks
cheamical weathering
breaks down stones and minerals
organisms -> produce water oxygen and acid
organis material from dead organisms or shed tissues
factors for soil formation
interrelated factors:
- parent material
- biotic factors
- climate
- topography
- time
parent material (soil formation) \+ origin
physical and chemical character determines soil properties
origins:
underlying bedrock
glacial deposits (till)
windborne sand (eolian)
gravitiy moving down slope(colluvium)
sediments caried by water bodies(fluvial)
biotic factors (soil formation)
plants -> transfer organic carbon to soil (from CO2)
roots -> break up stones
animal -> burrow and dig the soil
fungi & bacteria -> decompose organics
climate (soil formation)
abiotic!!
temperature -> rate of chemical reactions
water -> chemical weathering and leaching (maximal at high temperatures and with much water)
irrelevant und cold and dry condis
time (soil formation)
how long?
it takes long time for proper soil to form
reformation 2000 to 20000 years!!!
erosion
when soil is dry -> easily eroded by wind
-> dust storms -> “dust bowl”
effect of dust storms
killes lifestock buried infrastructure health risk useless farmland mass migration (homeless)
danger of erosion
50% of land surface is farmland
farmland higher risk of erosion
bc soil plowed and vegetation removed -> destabilization of soil
crop land often without vegetation -> bare soil
80% of cropland moderate or servere soil erosion
soil texture
which 3?
importance?
different sizes of particles (soil forming process) sand 0-2mm silt 0.002 to 0.05mm clay < 0.002mm (most stable) movement of air and water through air root penetration
coarse soils
large pores
rapid water drainige
medium fine soil
medium pore size
more surface for water -> more chemical activity
very fine soils
compacted (caddle)
poor aeration
difficult root penetration
soil depth
depends on slope
grasslands deep soils -> grasses deep roots -> adds OM to soil
forest shallow soils -> falling leaves major source of OM
soil layers
organic layer (leafs, uncomposed)
topsoil (mineral soil, dark color from OM)
subsoil (mineral and slat particles)
onconsolidated material (thick stones ect)
how moisture loss?
capillary water
evaporation and plants
water fills all pores held by capillary forces
FACHBEGRIFF
field capacity
point where plants can no longer extract water (FACHBEGRIFF)
wilting point
available water
FACHBEGRIFF
AWC (available water content)
field capacity - wilting point
Cation Exchange Capacity (CEC)
is important for soil fertility
if not many in soil -> anions(nutrients) get washed away
soil pH
from 3 to 9
if to acidic - toxic A3+ can be leached
differences aquatic and terrestial
water mixes -> faster exchagen of energy, dna and matter
water structure influence on physical structure of organisms
thermal capacity of water
