Lecture 8 Waste and Reclaimed land Flashcards
(43 cards)
Primary vegetation
Secondary vegetation
Waste- and reclaimed land vegetation
Coastal vegetation
Species can be very different - in the boxed space. But coastal vegetation - the species dont really change
Primary, disturb alot can become waste land. But disturb abit will become secondary and might recover
Reclaimed Land
Definition In Singapore Land fill materials Other environmental conditions Adaptations to dry conditions Reclaimed land vegetation Spontaneous Cultivated Reclaimed land animals
Reclaimed Land
Reclaimed land in Singapore = Land that has been reclaimed from the sea by dumping subsoil from inland areas or marine sand dredged from seabeds in Singapore waters or purchased from neighbouring countries
Reclaimed Land in Singapore
Reclaimed land rather unique in the world 24.8% of current land area Original area of Singapore = 578.1 km2 Area at 2017 = 721.5 km2 Started in 1820 Major reclamations from 1961 onwards Mainland Offshore islands
Reclaimed Land Fill Materials
Subsoil
Marine sand
Alluvial sand or marine clay, (intermediate in characteristics between subsoil and sand)
Other Environmental Conditions
Like those of coastal habitats, since reclamation is at the coastline High light intensity High wind speeds High maximum temperatures Low relative humidity Salt spray Physiological dryness*
Physiological Dryness
Water moves from a more dilute solution to a more concentrated solution through a semi-permeable membrane
So cannot get water into body by drinking seawater because seawater is more concentrated that the body fluids and instead water from the body fluids will move into the seawater in the stomach
“Water, water, every where, Nor any drop to drink.” ― Samuel Taylor Coleridge in The Rime of the Ancient Mariner
Adaptations to Dry Conditions
Xerophyte
Xeromorphic
Xerophyte = Plant that grows in xeric (dry) conditions Xeromorphic = Having characteristics of a xerophyte
Main adaptations
For reduction of water loss
Tiny or modifed leaves Thick-walled cells at epidermis Thick cuticle Good stomatal control For water storage Water storage cells
Tiny or Modified Leaves
Casuarina
green stem
Cactus has spines which are modified leaves. Stems are green.
Thick-Walled Epidermal Cells and Thick Cuticle
cuticle is a multi layer structure but other most part is wax. waterproof the leaf with wax. Cuticle is produced by epidermis.
Good Stomatal Control
STOMATA - open, water loses. but co2 can enter
vice versa.
Plant controls stomato pore by guardcells. OPEN = guard cell is turgid (fully swollen)
if plant dw to lose water, then water is diffused out of the guard cells and this stomato pore closes
Water storage Cells
Aloe Vera
Vegetation of Reclaimed Land
A form of secondary vegetation
2 kinds
Spontaneous vegetation through wind, animal and water dispersal
Managed vegetation: Plants cultivated by National Parks Board (NParks), MINDEF, etc.
Reclaimed land near Tanah Merah Ferry Terminal
Pasir Ris Park
Spontaneous Vegetation
Pioneer species (bare ground specialists)
Exotic (non-native) species that are naturalised species
Native species that are widespread (occurring naturally in many countries)
Species composition depends on landfill used
Sand
Subsoil
Spontaneous Sandfill Plants
Coastal forest species, adapted to growing on sand Native species Casuarina Coconut Sea lettuce Seashore morning glory, etc. Exotic species Albizia Common acacia Leucaena, etc.
Casuarina =
rhu
Sea apple (Syzygium grande)
leaves are always opp
Trees that are used for fire breaks
leaves are glossy
Screw pine (Pandanus odorifer)
leaves are spiney and no smell - unlike pandan
Paku laut (Acrostichum aureum)
fern. one of 2 ferns that are found along the coast
Albizia (Falcataria moluccana)
fast growing tree
Hence wood doesnt have enough time to become very tough
strong wind = branches may break
same wood that is used to make matches
Spontaneous Subsoil-fill Plants
Adapted for growing on poorly drained soils Usually exotic species Albizia Common acacia Giant sensitive plant Leucaena
Leucaena
very similar to albiza
fix atmospheric nitrogen to nitrates
in the roots, for the plant to use
Cultivated Species on Reclaimed Land
Depends on what the land is used for Park Golf course Condominiums and HDB apartment blocks Office buildings Industrial parks Etc. Depends on fill material Sandfill sites use native or exotic coastal forest species Clayfill sites use same species found inland
Mostly exotic
