Reduce rate of transpiration to retain
more water in response to the lack of
rainfall
Stems
Increased in girth
To become swollen and
succulent to store water
Thick
Skin
Lock water within
Tightly closed stomata
Lock water within
Roots
Grows 15m deep into the ground
To tap ground water
Behavioural
Desert Ephemeral plant
Plants with short life cycles
Adapted to take advantage of short
wet periods in arid tropics
environment
Resurection Plant
Absorbs water and grows rapidly when
the soil is moist (hardly)
When there is no water, it folds up into a tight ball as it becomes dry to retain
whatever water is left and all metabolic functions are minimised to the
minimum until the soil becomes wet
Rocks
Weathering and Erosion
Weathering
Breaking down or disintegrating of rocks
and minerals on Earth's surface
Agents
Water
Ice
Acids
Salts
Plants
Animals
Winds
Changes in
temperature
Types
Physical
Freeze Thaw
Water enters rock through hole. when water freezes in cold
temperature, it expands by 9 percent before being melted back to
water Repeating this cycle, it will eventually break the rock into 2
Cold area like mountains
Exfoliotian
When the rock is heated, it expands, and when it is cooled, it contracts. After
repeating this cycle multiple times, the surface layer eventually breaks off and parts
get peeled off
Occurs in places with high temp like desert
Pressure release
A big rock underground experiences pressure from all sides, so it escapes to the
side which has the least pressure towards the surface breaking the surface and
weathering it
Occurs in desert and mountains
Growth the salt crystals in rock
Crystal grows in rock and expands, weathering it
Occurs in hot deserts
Biological
Sprouting of tree seed in rock
Growing of tree roots in rock
Lichens growing on rocks
Tunneling action of
animals
Hot and humid climates like forest
Chemical
Hydrolosis
Break down of rocks by acidic water to produce clay and soluble salt
Example: Feldspar + acidic water= clay
Oxidation
Breakdown of rock by oxygen and water, giving iron- rich rocks a rusty coloured surface
Occurs in rocks with iron
Solution
Removal of rock in solution by acidic rainwater
Erosion
Broken down and disintegrated Soil and Rock
particles are moved elsewhere
Agents: Moving water,
winds
Humid Tropic
Spatial distribution
Generally between The Tropic of Cancer(23.5 degrees N)
and Tropic of Capricon(23.5 degrees S)
Where?
Brazil, Amazon rainforest
Congo
Southeast asia
Characteristic
Hot, average temperature of over 27 degrees celsius, min 25, max 33
Wet, Total annual rainfall of over 1000 mm of rain, up to 2400 mm of rain
Hot and Wet climate makes it favourable for plants growth
Causing a wide variety of plants to thrive here
Must take note of when see temperature on climatograph
Mean annual temperature (high/low)
Annual temp range (Max temp minus Min temp)
Fluctuation
If every month has constant high temperatures:
high uniform temperature
If every month has constant low temperatures:
Low uniform temperature
Sun rays heat up the ground, which in turn heats the air. The hot air containing water vapour will rise. Water
vapour will then cool down and condense into water droplets to form clouds. Rainfall will then take place when
the cloud is too heavy to hold itself
Relief
Rain
Requires a high mountain to work
Hot Wind from the ocean will flow towards the mountain and move up the slope. It will increase in height
and will soon cool down and condense. The rain will fall onto the windward side of the mountain, which is
where the air flowed up, and the dry cold air will go down the leeward side
Wind
Simple flow of huge amount of air, from high pressure to low pressure
Warm air rises, cold air sinks
Local
winds
Sea Breeze
Formation
Land gets heated faster than sun
Air gains heat and
rises
As air moves from a high pressure to a low pressure, the air from the sea will go towards the land
The air will then heat up and rise, creating a cycle
Structure
Emergant Layer
40-50m
high
Receives highest sunlight, hottest temperatures, wind and rain
Eg: Seraya tree
Canopy
layer
25-30 m high
Shelters the fauna and flora below from extreme heats, wind and
rain
Little wind below canopy
Home to thousands of animal species
Eg Kapur
Climbing plants like liana
Creeping plants like bird nest fern
Understorey
Between canopy and forest floor
15m in height
Little sunlight little rainfall
leaf litter
Forest
floor
High humidity of 95 percent
less than 10 percent of light reaches the ground
Adaptation
Crown of tree
Emergent, small crown with small leaves to reduce water loss to
combat high sunlight received
Canopy, large crown with bigger leaves
Plenty of sunlight but many trees competing for it
Leaves
Emergent, small leaves
Exposed to sunlight which
causes leaf to gain heat and
lose water. no need for
competition
Undergrowth, Big leaves
reach out and Absorb maximum sunlight to combat
low sunlight levels for photosynthesis
Arid tropics
Location
Between 30 degrees north and 30 degrees south
Characteristics
Hot dry climate
Temperature
Mean annual temperature range
20-25 degrees celsius
Extreme maximum ranges=43.5-49
min temp drop to -18
Rainfall
total annual rainfall= 30 mm ( below 100 mm)
Sun earth relationship
earth n sun
Sun strikes near the poles at an angle, spreading the heat over an area
and not concentrated at an area like the equator