Friday, September 23, 2005
GEOG - CLIMATE & NATURAL VEGETATION
Equatorial climate: btwn 10oN &10oS
1.temperature: high, abt 27oC; small range of 3oC
-due to angle of incidence and thick cloud cover
2. humidity: high, thick cloud cover
3. rainfall: high, 2000mm/yr, no distinct dry season
Tropical rainforest
1. dense & luxuriant vegetation, multiple species: hot and wet climate encourages rapid plant growth
a. emergent layer >30m: struggle for light, buttress roots for supporting heavy weight of trees
b. canopy layer 20-30m: crowns form continuous canopy, prevents sunlight from reaching forest floor
c. understorey layer 5-15m: narrow crowns (oval)
d. shrub layer: shrubs, ferns and small young trees
e. undergrowth layer: sparse as little sunlight reaches the forest floor due to canopy; mostly small plants, ferns & saprophytes that live on dead organic matter à fast decomposition, little leaf litter
2. evergreen tress: climate allows continuous growth
3. smooth and waxy thick leathery leaves with pointing drip tips: allow rain to run off easily; withstand the heat (high rainfall & temperature)
4. thin barks: no need for protection frm cold
5. branches found on top one third of tree: to obtain maximum sunlight for photosynthesis
6. shallow roots: absorb water and nutrients quickly
-high rainfall and decomposition rate
Mangrove forest: near the tropics- peninsular m’sia
Climate: salty & brackish water; muddy, water logged soil with little oxygen
1. specialised roots to breathe in air during low tide
a. bruguiera zone (furthest frm sea): knee like roots
b. rhizophora zone: prop roots to anchor in mud
c. avicennia/sonneratia zone: pencil like roots
2. broad leathery leaves with drip tips: allow rain to flow off quickly; reduce excessive transpiration
3. special salt glands: excrete excess salt (eg. frm excessive transpiration) or store salt in old leaves
Tropical monsoon climate: 10oN-25oN, 10oS-25oS
temperature: larger annual range 5o-17o; 30oC or higher in hot season, <20o-24oC in cooler months
rainfall: distinct dry season; >2000mm/yr
Tropical monsoon forest
1. not as dense as & has fewer species than tropical rainforest: due to lower rainfall & harsher conditions
a. canopy layer 25-30m: no continuous canopy
b. understorey layer abt 15m
c. ground layer: dense with thick shrubs and herbs
-due to sunlight reaching forest floor
2. deciduous trees: shed leaves during a particular period annually to reduce loss of water through transpiration (seasonal rainfall)
3. waxy broad thick leaves with leathery texture: to withstand heat & remove water during rainy season
4. thick and coarse bark: adapt to dry conditions
5. branches not as high: less struggle for sunlight
6. deep roots: get water during dry season
Temperate deciduous forest: 40oN-60oN & south
Climate: rainfall: 600-1000mm; cool summers & mild winters; 6-8 growing months
1. less dense & fewer species than tropical rainforest
a. canopy layer~30m: oak, elm, ash, beech, chestnut
b. sub canopy: young saplings, shrubs, short trees
c. shrub layer: non woody plants that grow rapidly during warmer months when there is more sunlight
d. ground layer: mosses & lichens
2. deciduous: shed leaves in autumn to conserve energy and stop growth in winter
3. broad leaves: trap as much sunlight as possible
4. thick bark: protection in winter
5. deep roots: obtain nutrients & water when top surface of water is frozen
6. cell sap increase in winter: increased concentration gradient, can absorb more water through osmosis
Coniferous forest: 60oN-70oN ,also found on high mountains at lower latitudes
Climate: long cold winters (oct-apr), short & cool summers; brief growing season; temp can fall to -30oC or less; low annual precipitation (mostly snow)
1a. few species: larch, fir, pine, spruce (softwoods)
b. uniform height: 20-25m, large trees 40m
c. little undergrowth: mosses & lichens
-due to poor soil and insufficient sunlight
2. evergreen: photosynthesise as soon as conditions allow (>6oC), grow in spring when sun melts snow
3. needle like small leaves with thick cuticles: reduce transpiration in strong winds
4. thick barks: protection against extreme cold
5. long roots for anchorage; shallow roots as cold boulder soil does not allow deep root growth
6. cone shaped trees with downward sloping branches: allow snow to slide off w/o breaking
7. cones protect seeds during very cold winters
:))) - lala
1.temperature: high, abt 27oC; small range of 3oC
-due to angle of incidence and thick cloud cover
2. humidity: high, thick cloud cover
3. rainfall: high, 2000mm/yr, no distinct dry season
Tropical rainforest
1. dense & luxuriant vegetation, multiple species: hot and wet climate encourages rapid plant growth
a. emergent layer >30m: struggle for light, buttress roots for supporting heavy weight of trees
b. canopy layer 20-30m: crowns form continuous canopy, prevents sunlight from reaching forest floor
c. understorey layer 5-15m: narrow crowns (oval)
d. shrub layer: shrubs, ferns and small young trees
e. undergrowth layer: sparse as little sunlight reaches the forest floor due to canopy; mostly small plants, ferns & saprophytes that live on dead organic matter à fast decomposition, little leaf litter
2. evergreen tress: climate allows continuous growth
3. smooth and waxy thick leathery leaves with pointing drip tips: allow rain to run off easily; withstand the heat (high rainfall & temperature)
4. thin barks: no need for protection frm cold
5. branches found on top one third of tree: to obtain maximum sunlight for photosynthesis
6. shallow roots: absorb water and nutrients quickly
-high rainfall and decomposition rate
Mangrove forest: near the tropics- peninsular m’sia
Climate: salty & brackish water; muddy, water logged soil with little oxygen
1. specialised roots to breathe in air during low tide
a. bruguiera zone (furthest frm sea): knee like roots
b. rhizophora zone: prop roots to anchor in mud
c. avicennia/sonneratia zone: pencil like roots
2. broad leathery leaves with drip tips: allow rain to flow off quickly; reduce excessive transpiration
3. special salt glands: excrete excess salt (eg. frm excessive transpiration) or store salt in old leaves
Tropical monsoon climate: 10oN-25oN, 10oS-25oS
temperature: larger annual range 5o-17o; 30oC or higher in hot season, <20o-24oC in cooler months
rainfall: distinct dry season; >2000mm/yr
Tropical monsoon forest
1. not as dense as & has fewer species than tropical rainforest: due to lower rainfall & harsher conditions
a. canopy layer 25-30m: no continuous canopy
b. understorey layer abt 15m
c. ground layer: dense with thick shrubs and herbs
-due to sunlight reaching forest floor
2. deciduous trees: shed leaves during a particular period annually to reduce loss of water through transpiration (seasonal rainfall)
3. waxy broad thick leaves with leathery texture: to withstand heat & remove water during rainy season
4. thick and coarse bark: adapt to dry conditions
5. branches not as high: less struggle for sunlight
6. deep roots: get water during dry season
Temperate deciduous forest: 40oN-60oN & south
Climate: rainfall: 600-1000mm; cool summers & mild winters; 6-8 growing months
1. less dense & fewer species than tropical rainforest
a. canopy layer~30m: oak, elm, ash, beech, chestnut
b. sub canopy: young saplings, shrubs, short trees
c. shrub layer: non woody plants that grow rapidly during warmer months when there is more sunlight
d. ground layer: mosses & lichens
2. deciduous: shed leaves in autumn to conserve energy and stop growth in winter
3. broad leaves: trap as much sunlight as possible
4. thick bark: protection in winter
5. deep roots: obtain nutrients & water when top surface of water is frozen
6. cell sap increase in winter: increased concentration gradient, can absorb more water through osmosis
Coniferous forest: 60oN-70oN ,also found on high mountains at lower latitudes
Climate: long cold winters (oct-apr), short & cool summers; brief growing season; temp can fall to -30oC or less; low annual precipitation (mostly snow)
1a. few species: larch, fir, pine, spruce (softwoods)
b. uniform height: 20-25m, large trees 40m
c. little undergrowth: mosses & lichens
-due to poor soil and insufficient sunlight
2. evergreen: photosynthesise as soon as conditions allow (>6oC), grow in spring when sun melts snow
3. needle like small leaves with thick cuticles: reduce transpiration in strong winds
4. thick barks: protection against extreme cold
5. long roots for anchorage; shallow roots as cold boulder soil does not allow deep root growth
6. cone shaped trees with downward sloping branches: allow snow to slide off w/o breaking
7. cones protect seeds during very cold winters
:))) - lala
# we mugged! @ 9:35 PM 
