Climate & natural vegetation
Introduction:
Climate is the average weather conditions of a region over a considerable period of time (i.e. 30 years)
Various classifications of climates
Natural vegetation refers to all the types of plants which grow naturally.
Primary vegetation is those plants found at a location originally
Secondary vegetation is those plants that recolonise (i.e. naturally) an area after it is abandoned
CLIMOGRAPH:
graphical representation of a climate in terms of temperature & precipitation
mean mthly temp;
- absolute fig
- constant/variable
- seasonality
total mthly precipitn
- absolute fig
- constant/variable
- seasonality
CLIMOGRAPH:
arbitrary classification of figures:mean temp:
> 300C : very hot
20 - 300C : warm - hot
10 - 200C : moderately warm
0 - 100C : cold
< 00C : very coldTemp range: diurnal & mthly / ann. small : 0 - 30C / 0 - 30C moderate : 4 - 70C / 4 - 70C large
: 8 - 120C / 8 - 150C very large: >120C / >150C
CLIMOGRAPH:
arbitrary classification of figures:precipitation: annual / mthly
very high : >2000 / 120
high : 1000 - 2000 /100 - 120
moderate : 750 - 1000 / 75 - 100
low (arid) : 250 - 750 / 25 - 75
very low : 0 - 250 /(desert) 0 - 25
CLIMOGRAPH:
derive mean annual temperature & total annual precipitation if they are not given
EQUATORIAL CLIMATE
Distribution
EQUATORIAL CLIMATE
Distribution
close to the Equator (100N - 100S)
Amazon Basin, Northern Zaire Basin, & parts of Southeast Asia like Singapore, Malaysia & most parts of Indonesia
EQUATORIAL CLIMATE
Characteristics Spore
1. High mean annual temperature(26.90C)2. High mean mthly temperature (26-280C)3. Very small annual temp. range (20C)
4. Moderate diurnal temp. range ( 60C)5. High to very high annual rainfall (2344mm)6. High to very high mthly rainfall(>150mm)
EQUATORIAL CLIMATE
EQUATORIAL CLIMATE
EQUATORIAL CLIMATE
Reasons:
1. High & constant mthly temperature equatorial location
high angle of incidence;
not affected by tilt of Earth’s axis constant duration & intensity of
sunlight
2. Moderate diurnal temp. range moderating effect of thick clouds
EQUATORIAL CLIMATE
Reasons:
3. High to very high mthly & annual rainfall large body of water & frequent convectional rain; some places also have monsoon rain
TROPICAL RAINFOREST
Distribution:
TROPICAL RAINFOREST
Distribution:
TROPICAL RAINFOREST
Distribution:
~ Amazon Basin
~ Zaire Basin
~ much of Central America
~ much of Southeast Asia
TROPICAL RAINFOREST
Structure:
•some very tall trees (40 - 48 m) known as emergents form the emergent layer•canopy layer is formed from the interlocking crowns of most trees (25 - 40m); presence of lianas & epiphytes •understorey layer is formed by shorter trees (5 - 25 m); presence of lianas & epiphytes
TROPICAL RAINFOREST
Structure:
•shrub layer consists of shrubs, ferns & saplings (2 - 5m)
•ground layer is sparse; ferns, mosses, fungi & litter (0 - 2m)
TROPICAL RAINFOREST
Other Characteristics:•evergreen•hardwood•abundant species of flora & fauna; as many as 400 varieties of plants per hectare•broad leaves; thick, leathery, waxy or hairy leaves; drip tips
•shallow roots; buttress roots•colourful flowers & sweet-smelling fruits
TROPICAL RAINFOREST
TROPICAL RAINFOREST
TROPICAL RAINFOREST
TROPICAL RAINFOREST
TROPICAL RAINFOREST
TROPICAL RAINFOREST
Adaptations:} to climate
> evergreen> broad leaves
> thick leathery, waxy or waxy leaves> drip tips
Manufacture food from abundance sunlight & rain
To reduce transpiration from very high day time temp.
To drain off excess water from heavy rain to prevent fungus growth
TROPICAL RAINFOREST
Adaptations:} to soil> shallow
roots
} to competition> aerial location
> buttress root> colourful flowers & sweet-smelling fruits
To obtain nutrients from decaying litter since soil is generally infertile from leaching
To compete for sunlight given dense vegetation
To attract animals to help propagate since the air is still within dense forest
(TROPICAL) MANGROVE FOREST
Distribution:~ muddy & waterlogged; e.g. low-energy low- lying coast & river banks
Structure:
3 � horizontal zones
Nearest to the sea are trees most �tolerant of salt & flooding like avicennia & sonneratiaNext zone are trees less tolerant of salt and flooding like rhizophoraFurthest zone consists of trees least �tolerant of salt and flooding like bruguiera
(TROPICAL) MANGROVE FOREST
Characteristics: • evergreen hardwood
• specialised roots to survive water-logged condition ~ pencil-like breathing root (avicennia) ~ prop root (rhizophora) tree-like root (bruguiera)• special salt glands in leaves • thick leathery leaves with drip tips• specialised fruits
~ elongated tube-like fruit~ buoyant fruit
(TROPICAL) MANGROVE FOREST
(TROPICAL) MANGROVE FOREST
(TROPICAL) MANGROVE FOREST
(TROPICAL) MANGROVE FOREST
TROPICAL MONSOON CLIMATE
DISTRIBUTION:
TROPICAL MONSOON CLIMATE
DISTRIBUTION:~ western Africa (e.g. Liberia, Ivory Coast & Ghana)
~ west coast of India
~ west coast of Thailand & Myanmar
these places have rainfall characteristics heavily influenced by monsoon winds (i.e. a distinct wet & dry season according to the specific monsoon season)
TROPICAL MONSOON CLIMATE
CHARACTERISTICS: Bombay ~ high mean ann. temp.
26.40C ~ high - very high mean mthly temp. 24 -
280C~ low - moderate
ann. temp. range 40C
~ high - very high ann. r/f 1855mm~ distinct wet & dry season wet season > 150 mm dry season < 100 mm
TROPICAL MONSOON CLIMATE
REASONS:~ High - very high ann. temp
tropical latitudes high angle of incidence direct & concentrated rays
~ low - moderate ann. temp. range those towards the subtropical
location will be affected by the ‘movement’ of Sun between Tropic of Cancer & Tropic of Capricorn higher temp. during summer mths & lower temp. during winter mths; although no true seasons experienced
TROPICAL MONSOON CLIMATE
REASONS:~ High - very high total ann. r/f
seasonal moisture laden winds came from sea high temp. of wind huge amt of water vapour stored
~ dry season wind blows offshore in response to
seasonal regional pressure systems dry wind ~ wet season
wind blows onshore in response to seasonal regional pressure systems wet wind
TROPICAL MONSOON CLIMATE
REASONS FOR WEST COAST OF INDIA:~ during the winter months (around Dec), the lower intensity & shorter duration of insolation in the temperate northern region due to the overhead Sun being at the Tropic of Capricorn very cold temp at interior Asia very high pressure system air moves out (for west coast of India) as the wind moves southward, deflection to the right due to the rotation of the Earth (Coriolis effect) NE Monsoon dry offshore wind
TROPICAL MONSOON CLIMATE
REASONS FOR WEST COAST OF INDIA:~ during the summer months (around July), the higher intensity & longer duration of insolation in the temperate northern region due to the overhead Sun being at the Tropic of Cancer very high temp at interior northern India very low pressure system air moves in (for west coast of India) as the wind moves northward, deflection to the right due to the rotation of the Earth (Coriolis effect) SW Monsoon wet onshore wind
TROPICAL MONSOON CLIMATE
REASONS FOR WEST COAST OF INDIA:
TROPICAL MONSOON FOREST
Distribution:
TROPICAL MONSOON FOREST
Distribution:
~ West coast of India
~ west coast of Myanmar
~ West coast of Central America
~ East coast of Vietnam
TROPICAL MONSOON FOREST
Structure:
~ 3 layers
~ canopy layer formed by crowns of trees; 25-30m; + epiphytes & lianas
~ ground layer consists of thick shrubs & thickets/herbs/grasses especially the start of dry season
~ understorey layer formed by shorter trees about 15m + bamboos
TROPICAL MONSOON FOREST
Other Characteristics:
~ deciduous, shed leaves at start of dry season~ dense & luxuriant vegetation during wet season, though less compared to tropical rainforest
~ many varieties of plants; about 200 varieties per hectare
~ hardwoods; like teak & rosewood
~ dense undergrowth during dry season when sunlight is able to reach the ground
TROPICAL MONSOON FOREST
Adaptations:~ deciduous reduce transpiration during dry season
~ thick leathery, waxy or hairy leaves withstand very high daytime temperature
~ deep roots tap deep groundwater, especially when water is scarce in dry season
~ drip tips prevent fungal growth & photosynthesise effectively
~ thick rough barks protection against fires in dry season
COLD/COOL TEMPERATE CLIMATE
DISTRIBUTION:
~ between 400 & 700 North only~ e.g. interior of eastern Europe (e.g. east Poland & Romania); Byelorussia; Ukraine; central Russia; much of Scandinavia (Norway; Sweden & Finland)
COLD/COOL TEMPERATE CLIMATE
CHARACTERISTICS:
~ low-very low mean annual temperature < 100C~ true seasons; spring, summer, autumn & winter~ very cold winter, with coldest mean mthly temp. <-50C~ cool summer, with warmest mean mthly temp. < 200C~ moderate to low annual precipitation; if moderate with inland location Humid Continental Cold/Cool Temperate Climate
COLD TEMPERATE CLIMATE
CHARACTERISTICS for WINNIPEG, CANADA:~ mean ann. temp 1.40C~ true seasons~ coldest mean mthly temp. (Dec) -190C~ warmest mean mthly temp. (Jul) 200C~ moderate total ann. precipitation of 555 mm; with slightly more in summer months; considered humid given continental (inland) location
COLD TEMPERATE CLIMATEEXPLANATION:
~ low mean ann. temp + true seasons high temperate latitudes (in
the 50s) small angle of incidence slanted & diffused rays low temp temperate latitudes affected by tilt of Earth’s axis variation in intensity & duration of insolation with ‘movement’ of Sun between Tropic of Cancer & Capricorn true seasons~ moderate to low precipitation
low temperature results in air having lower ability to store water vapour
low temperature causes water droplets to freeze (snow, hail & sleet)
COLD TEMPERATE CLIMATEEXPLANATION:
~ higher precipitation in summer higher temperature leads to
convectional rain
TEMPERATE CONIFEROUS FOREST
DISTRIBUTION:
~ much of Eastern Europe & Russia
~ much of Sweden & Finland
~ much of Canada & Alaska
TEMPERATE CONIFEROUS FOREST
STRUCTURE:~ single layer of conifers which grow close together to a height of about 20 metres
TEMPERATE CONIFEROUS FOREST
CHARACTERISTICS:~ evergreen conifers (straight-trunked, cone-shaped trees)
~ softwoods; e.g. fir, pine, spruce & cedar
~ needle-like leaves
~ thick barks~ very few varieties of plants; 1-2 varieties per hectare
TEMPERATE CONIFEROUS FOREST
ADAPTATIONS:
~ shedding leaves to conserve heat loss & prevent possible leaf cells damage from frost ~ thick barks to protect from low temperatures at night during winter
~ deep roots to tap deep groundwater; as surface soil moisture may freeze during winter & evaporate during summer
FOREST:
Importance:- protect against soil erosion; fertile topsoil- reduce leaching- protection of catchment area- absorption of carbon dioxide- production of oxygen- natural habitat of animals- diversity of plants/fauna- biodiversity- tribal/traditional cultures
FOREST:
Reasons for Loss of Forest:- rapid population growth; around 2%
- outflow of overcrowded cities; Rio de Janerio & Sao Paulo
- mean of subsistence living
- for commercial farming; cattle ranching, plantation cultivation of bananas, sugar cane & coffee- for mining; timber, iron ore, gold, bauxite & oil- improvement of transport; Transamazonia Highway
- for (quick easy) development
FOREST:
Measures to Save the Forest:
- control population growth
- improvement of cities’ infrastructure to cater for the growing population
- practise selective logging
- cost-benefit analysis of any econ. activities- setting aside protected areas
- setting aside tribal land reserves
- ensure sustainable development
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