Luokat: Kaikki - flowers - salt - leaves - roots

jonka yuhui ng 15 vuotta sitten

478

Natural Vegetation - Egeog, Yuhui

Mangrove forests are unique ecosystems found primarily in tropical climates within 23.5 degrees north and south of the Equator. These forests thrive in sheltered coastal regions and areas where rivers frequently deposit sediments.

Natural Vegetation - Egeog, Yuhui

Natural Vegetation

Plants that grow naturally in a place with little or no human interference

CONIFEROUS Forests

MANGROVE Forest

Kneed roots

provide firms suppost on the soft soil

bruguiera

Prop roots

anchors tree firmly into muddy soil

rhizhopora

Aerial roots

takes in oxygen

Flowers & fruits

Colourful

attract insects

bright red lantern-shaped flowers

Germinates while attached to parent tree

Sharp tips helps fruit anchor in soft muddy soil

drops directly into ground and grows

Elongated structure

Bouyant

waves & currents carry to new coastal area to take roots

Adapted to regulate amt of salt on tree

Ultrafiltrators

Rhizophora & sonneratia

Absorb salt, store xs salt in old leaves which then fall off

Salt secreters

Avicennia

Secrete xs salt on leaves, removed by wind/rain

Thick & leathery

Reduce water loss thru transpiration (due to high temp)

Drip tips

salt-tolerant (halophytes)

sea hibiscus, Nipah plam

Structure

Horizontal zones, not vertical

Inland ~

Knee-like roots

Bruguiera

Least tolereant of salt water

Middle ~

Prop/stilt roots (air ventricles)

Rhizophora

Coastal zone

Nearest to the coast

flooded w/ salt water

Breathing/ aerial roots

adapted to growing in brackish water

Avicennia & sonneratia

Location
23.5N & S of the Equator
Along sheltered coastal regions & places whr rivers constanly deposit clay & silt
mainly tropical climate

Tropical MOONSOON forest

3 Layers

6m

Bamboo thickts, grass

Dry season -> less dense

wet season-> dense

Abt 15m (6-15m)

25-30m

Tropical Moonsoon Climate

Due to moonsoon winds

btween 10 & 25 N & S of the Equator
S.Asia, SEA, S. China, N. Aus
Distinct wet & dry seasons
High temp(abt 26C)
Trees

mostly hardwoods

Commercially valuable ones incl, sandalwood, teak, sal

Many bear fruits duning dry season when they're leafless

Bark and Branches

Branches located arnd the middle of trunks

Grows less dense than TRF =>sunlight reach lower parts of forest

Thick & coarse

Withstand extreme heat frm natural forest fires(occassionally)

Protects trunk frm heat & dryness during dry season

Deep roots

tap water sources deep underground as rf is not regular thruout the year

Narrow

Bamboo

minimise loss of water thru transpiration

Waxy with drip tips

Deciduous

Leaves grow agn quickly during rainy season

Shed leaves during dry season

minimise water loss thru transpiration

Tropical RAINFOREST

IMPORTANCE
maintain water supply

enable water to be collested & stores within a water catchment

Central Catchment Nature Reserve in SG

Water Quantity

plays impt role in water cycle

DEFORSTATION in Kalimantan

permanant clearing & destruction of forests

Policies

Problems

Causes

forests fires

growth of industries

improved transport networks

growth of settlements

^^ in dd for agri landuse

indon govt popn resettlement prog to ease overcrowding in islands such as java and sumatra => many indons resettled in K

growing world's popn

crowded places, esp cities

forests cleared to create more land for settlements, agri and industry

more & more pple depend on the forest as a resource

dd for land ^^^

Features
Fruits and Flowers

Produce fruits thruout the yr

Brightly coloured

still air below canopy=>pollination can't be wind

Roots

Shallow and spread widely

do not need to reach deep into soil for water and nutrients

Buttress Roots

Supposrts great wt of the tree

Branch and Bark

Branches only @ top 1/3 of trunk

Spread out like umbrella=> get as much sunlight as they can

Smooth and Thin

No need for protection against cold/dry

Leaves

Waxy w/ drip tips

Rainwater drain off easily

prevent harmful bacteria frm growing on them

prevents plants from diseases

Evergreen

Leaves remains green all yr round

don't shed their leaves at the same time in the year.

Broad

Max surface area for photosynthesis

5 distinct layers
Undergrowth

Leaf litter

decompose-> humus->supports abundant vegetation growth

v. little sunlight reaches this layer

Sparse

Grasses, Ferns, Mosses & fungi

<5m

Shrub

Tree saplings and woody plants

<6m

Understory

Grow whr gaps in the canopy allows sunlight to pass thru

Narrower, oval-shaped crowns

6-15m

Canopy

Plants

Parasitic plants

Strangling fig

Wrap itself arnd trunk of host -> compete w/ the host for space, sunlight & nutrients

Cause harm/death to host trees

Lianas

Thick woody vines that wind arnd tree trunks to reach for sunlight.

90m

Epiphytes

Plants that have adapted to low light condition by growing on tree branches to get more sunlight.

Grows on & use trees as physical support.

Rainwater & decaying leaves collected @ the joints of branched = water & food

Bird nest ferns, orchids

wide,shallow,umbrella shaped crown

Forms con't leaf cover

AKA Canopy

Prevents sunlight frm penetrating

15-30m

Emergent

Tall, Straight, thick Trunks

Crowns abv canopy

30-50m

Tropical Equatorail Climate
High r/f (>1500mm)
High temp (abt 27C)
Amazon Basin, Congo Basin, parts of SEA
10N & S of the Equator