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Geog - Coggle Diagram
Geog
spatial distribution of rainforests and mangroves
climate
tropical rainforests
in between tropic of
cancer
and
capricorn
has a
high
mean annual temperature of
27C
less than 10C
the average annual temperature is
low
at about
__
between 10-20C
the average annual temperature is
moderate
at about __
more than 20C
the average annual temperature is
high
at about __
has a
high
mean annual rainfall of about 2000mm
between 250-1000mm
the total annual percipitation is
moderate
at about __
more than 1000mm
the total annual percipation is
high
at about __
less than 250mm
the annual percipitation is
low
at about __
adaptations
roots
buttress roots
to keep the tree uprigth and prevent them from toppling over
due to the great height that the trees grow to to get maximum sunlight
shallow underground roots
nutrients are found mostly on the top layer of soil when dead leaves decompose
water is available throughout the years so theres no need for deep roots to search for underground water
leaves
drip tips
enable rain water to run off easily to prevent the growth of fungus and bacteria on the leaves
due to frequent rainfall
broader leaves in undergrowth
capture as much sunlight as possible for
photosynthesis
waxy leaves
reduces the amount of water vapour lost through transpiration
due to the high annual temperatures
environmental functions and uses
layers
canopy
20-30m
trees grow close together
crowns interlock to form a
continuous cover
prevents 97-98% of sunlight to pass through the forest floor
undergrowth
<20m
very little sunlight reach this layer, hence not many plants grow here
amount of vegetation growing near the ground surface is sparse except where there are gaps in the canopy, near riverbanks or where a canopy tree has fallen
emergent
50-80m
formed by the crowns of the trees
tall, striaght, smooth trunks with few branches
water can flow down easily towards the roots
rise through the canopy and towers above other trees
general characteristics
luxuriant
abundance, a lot of plant growth
evergreen
leaves will continuosly grow and will not shed at the same time
thick
spaced very close together
mangroves
horizontal zonations
middle zone
rhizophora
prop roots
grows from the trunk and lower branches towards the ground
helps the plant breathe and provides it with support as they form a
broader base
around it
further inland and are flooded for shorter periods of time
inland zone
further inland and are flooded for shorter periods of time
bruguiera
knee bend roots
bend upwards to emerge above the soil surface before bending downwards into soil at regular intervals
coastal zone
avicennia
pencil roots
grow vertically upwards from the main roots which are found just below the soils surface
grows up to 20cm tall
low lying parts of coast are flooded for longer periods of time
sonneratia
cone roots
thicker compared to pencil roots and has conical appearance
can grow up to 1.5m tall
conditions for mangrove growth
high air and water temperatures
at least 20C
calm water conditions
to ensure that seedlings won't be washed away by waves
encourage accumulation of fine sediments containing nutrients
high salinity
high concentration of salt in the water/soil
sheltered environments
along or very close to the coast
adaptations
leaves
salt secreting
remove salt from saline water that their roots have absorbed
when concentrated salt solution secreted by the leaves evaporates, salt crystals are left behind on the leaves and are then removed by rain or wind
eg. Avicennia
roots
salt excluding roots
trees take in H2O through their roots which prevent salt from entering
eg. Bruguiera
aerial roots
grows directly above the soil surface which allows them to take in O2 directly from the air when exposed to the low tide
helps them survive in
O2 poor soil
anchor the mangroves to
soft soil
which prevents them from getting uprooted by strong waves
characteristics
can tolerate higher salinity levels and longer periods of flooding by the tide
relatively uniform in height
lower density of trees compared to rainforests
horizontal zonation is determined by the high and low tides
evergreen
Green all year round and don't shed ther leaves