SSS1207 Lecture 10 Coastal Vegetation 2015 IVLE Version1

Coastal

Vegetation

Lecture 10 Dr Amy Choong

SSS 1207 — The Natural Heritage of Singapore Lecture Topics

• References

• Coastal vegetation

– Mangrove forest

– Beach vegetation

• The future

• Summary

References

• Chapter 5 of main textbook

• Sivasothi, S. and P.K.L. Ng (editors), 1999. A Guide to the Mangroves of Singapore, Vols. 1 and 2. Singapore Science Centre, Singapore. QH541.5 Man.Gu 1 and QH541.5 Man.Gu 2

Singapore s Coastal Vegetation

• Coastal vegetation

• Types of coastal vegetation

• Animals of coastal vegetation

• Economic value

Coastal Vegetation • Coastal vegetation = Vegetation that grows on land at the edge of the sea

Sandy beach vegetation and mangrove forest

at Chek Jawa, Pulau Ubin, at high tide

Types of Coastal Vegetation

in Singapore

• Mangrove forest

• Sandy beach vegetation

• Rocky shore or cliff vegetation

Mangrove Forest • Mangrove forest is one of the most dangerous of habitats!

Mangrove Forest

• Mangrove forest = mangal = Tropical or subtropical, intertidal

saltwater community dominated by tree and shrub species, especially

such as bakau (Rhizophora species)

• Community = The interacting populations of species (single-species

groupings) of all the animal and plant species at a specific area

Tropic of

Cancer

Tropic of

Capricorn

Mangrove Forest Areas of the World

Mangrove Forest at Chek Jawa Mangrove Forest at Pulau Tekong

Mangrove Forest at Lim Chu Kang Mangrove Forest at Sungei Khatib Bongsu

Sungei Khatib Bongsu

Status of Singapore s Mangrove Forests 1 • Coasts in primeval Singapore

– Mostly fringed by mangrove forest (13% of Singapore Island; 7,500 ha)

– Beaches with beach vegetation

– Cliffs and rocky headlands and their vegetation

– Mouths of sluggish streams and rivers

Status of Singapore s Mangrove Forests 2

• Present-day mangrove forest

– Only about 659 ha presently (see: Yee, A.T.K., W.F. Ang, S. Teo, S.C. Liew and H.T.W. Tan., 2010. The present extent of mangrove forests in Singapore. Nature in Singapore, 3: 139–145. http://rmbr.nus.edu.sg/nis/bulletin2010/2010nis139-145.pdf)

– Isolated patches and narrow strips

Status of Singapore s Mangrove Forests 3

• Room for optimism

– Sungei Buloh Wetland Reserve set up in 1989 (131.4

ha) = Nature Reserve (new extension totals 202 ha)

– Mangrove patch in Pasir Ris Park (20 ha of mangrove

forest) = Park

Pasir Ris

Park

Mangrove

Patch

Status of Singapore s Mangrove Forests 4 • Room for optimism (continued)

– Malaysians not building crooked bridge to replace causeway so no water currents to wash away sediments of mangrove forest patches protruding into Straits of Johore

– Public awareness of value of mangrove forest

Kranji

mangrove

forest

Sungei Buloh mangrove forest

International Coastal Cleanup, Singapore

celebrated its 20th year on 17 Sep 2011!

http://coastalcleanup.nus.edu.sg/

Mangrove Forest Environment 1

• Intertidal zone = Between the high-tide to low-tide levels of the

shore

• Mangrove forest zone = Between the high-tide to the mid-tide

levels on sheltered, muddy shores or rivermouths where there is

fine sediment deposits What do you think will happen to

mangrove forest with sea level

rise through climate change?

high tide level

mid-tide level

low tide level

intertidal zone

mangrove

forest zone

Mangrove Forest Environment 2 • Salinity varies with time of day, depending on

the tides (from 35‰ to less) ― seawater is physiologically dry

• Substrate is anaerobic, unstable

• Wave action and strong winds during storms

• Rainfall, humidity, insolation, temperatures, etc., like other tropical forest types

unstable substrate low tide

high tide

Mangrove Plant Adaptations • To cope with high salinity

• To cope with unstable substrate

• To cope with anaerobic substrate

NUS undergraduates stuck in

mangrove mud!

NUS professor looking cool

in mangrove forest

Adaptations for High Salinity • Salt secretion

– Uptake salt

– Pump out

through glands

– api api, sea

holly

• Salt

ultrafiltration – Exclude salt at

point of uptake

– bakau,

Bruguiera,

Lumnitzera,

perepat

salt

crystals

Adaptations for Unstable Substrate 1

• Modified

roots – Prop or

stilt roots • bakau

– Plank root • nyireh,

dungun

plank root of nyireh

prop roots stilt roots

Adaptations for Unstable Substrate 2

• Vivipary – Ordinary

• bakau family

members

– Cryptovivipary • api api,

kacang-

kacang, nipah

palm

Nyireh (Xylocarpus)

Adaptations for Anaerobic Substrate

• Breathing roots – Pencil/cone roots

• api api, perepat

– Kneed roots • Bruguiera

species, tengar

– Plank roots • nyireh, dungun

– Prop or stilt

roots • bakau

wavy plank

root of nyireh

straight plank

root of non-

mangrove

plant

Singapore Mangrove Plant Types

Major component

species

Minor component

species

Mangrove

associates

Occur only in mangrove forest May occur outside mangrove

forest in other habitats

Occur outside mangrove forest

in other habitats

Play a major role in the

mangrove ecosystem

Play a more minor role in the

mangrove ecosystem

Play a minor role in the

mangrove ecosystem

Often form pure stands* in

mangrove forest

Rarely form pure stands* in

mangrove forest

Rarely form pure stands* in

mangrove forest

Possess morphological and

physiological adaptations for

the mangrove environment

May not possess

morphological and



May not possess

morphological and



Taxonomically isolated from

their closest relatives

Less taxonomically isolated Not taxonomically isolated

21 species 9 species Several species

* Pure stand = Group of trees at a site consisting of only one species

Seashore

Pandanus

Singapore Mangrove Plant Types

bakau (major

component) sea hibiscus

(mangrove associate)

piai raya (minor

component)

• Bruguiera hainesii

• rare in Singapore, with only a few known

specimens; one at Pasir Ris, one at Kranji

Nature Trail and two at Pulau Ubin.

• Bruguiera sexangula

• two on Pulau Tekong, and two at Sungei

Buloh and it is being replanted at Chek Jawa,

Pulau Ubin and at Pasir Ris Park.

Sandy Beach 1 • Sandy beach ― the world s most enjoyable holiday habitat!

Ipanema Beach, Rio de Janeiro, Brazil

Sandy Beach 1 • Sandy beach = Coast which consists of sands (such as quartz grains),

usually between two rocky headlands

rocky headlands

sandy beach

headland headland

beach

sea

sea sea current current

Sandy Beach 2 • Sandy beaches undergo

– Erosion

– Accretion

– Continual cycle of erosion-accretion, depending on prevailing sea currents

Sep 1994

Sep 1995

Key concepts

• Know the different forest types, their

characteristics,

• Key flora and fauna, often repeated during

lectures

• Videos

Sandy Beaches in Singapore

present day sandy beach

• Sandy beaches in primeval Singapore

– Longest from Tanjong Ru to Changi Point

– Southern side of Sentosa

• Present day natural beaches

– Few left, mostly reclaimed

– Pulau Ubin, Pulau Tekong, Changi Beach, etc.

• Present day artificial beaches

– East Coast Park, Pasir Ris, etc.

– Pulau Seletar, Pulau Serangoon, etc. primeval sandy beach

sandy beach of past and present

Sandy Beaches of Singapore’s Past

Pasir Panjang, 1911 (now reclaimed)

Pasir Ris Beach, 1940

Tanjong Rhu, 1900

Changi Beach, 1962

Present Day Natural Sandy Beaches

Kampong Wak Hassan Beach,

Sembawang Park

Changi Beach

Kampong Noordin Beach, Pulau

Ubin

Present Day Natural Sandy Beaches

Sandy Beach Environmental Conditions • Like reclaimed

land s conditions,

since reclamation

is at the coastline • High light

intensity

• High wind speeds

• High maximum

temperatures

• Low relative

humidity

• Salt spray ―

physiological

dryness

Flag trees

Beach Vegetation Succession

• Ecological succession = Process of

continuous, uni-directional change in the

vegetation (Revision)

• 2 stages – Pes-caprae association (after the seashore

morning glory, Ipomoea pes-caprae) • Starts on bare ground (on accreting beaches)

• Non-woody (herbaceous) plants (herbs, trailers)

– Barringtonia association (after the sea putat,

Barringtonia asiatica) • Succeeds pes-caprae association

• Woody plants (shrubs, trees, epiphytes)

Seashore Morning Glory • Ipomoea pes-caprae; pes-caprae = goat s foot

water-

dispersed

seeds

explosive fruit

Sea Putat

fruit

water-dispersed

fruit

bat-pollinated flower

Singapore’s Rocky Shore or Cliff Vegetation

• Cliffs and rocky shores were rare in primeval Singapore

• Even rarer today through reclamation or development

• More extreme than

those for the sandy

beach – Hot rocks day and

night

– Little or no soil

– Strong wave action

– Landslides

• High light intensity

• High wind speeds

• High maximum

temperatures

• Low relative humidity

• Salt spray ―

Physiological dryness

Cliff or Rocky Shore Environmental Conditions

Cliffs and rocky shore at

Pulau Tekukor

Cliffs and Rocky Shores of Singapore

St. John s Island

Below Fort

Siloso, Sentosa Pulau Biola

Lazarus Island

Cliffs and Rocky Shore at Pulau Tekukor

Cliffs and Rocky Shores at Pulau Salu Cliff or Rocky Shore Plants • Have to be species that can tolerate these harsh conditions

• Thus a very small subset of Singapore s flora

• Some examples – mentigi

– superb fig

– sea purselane

– pelir musang

– sea teak

Animals of Coastal Vegetation

• Have to be able to cope with the

harsh conditions, salinity

• Similar animals in mangrove forest,

sandy beaches and rocky shores or

cliffs

• Dependant on plants for food and

shelter

• Types – Molluscs

– Crabs

– Mud lobster

– Fishes

– Reptiles

Molluscs

• telescope shell

• red berry snail

• mangrove slug

• mangrove periwinkle

• common nerite

Crabs

• face-banded sesarmine

• tree-climbing crab

• fiddler crab

Mud Lobster

• Makes mud lobster mounds in mangrove forest that changes

the habitat significantly ― a keystone species

• Animals which live in or forage in and round the mud

lobster mounds – ant

– mound crab

– mud shrimp

– file snake

Fishes • Adapted to changing salinity of the

habitat

• Examples – Archer fish

– Mudskipper

Reptiles

• Versatile, terrestrial

and aquatic habits

• Examples – water monitor

– dog-faced water

snake

– estuarine crocodile

Dugong

Carcass found in June 2006,

Pulau Tekong

Economic Values of Coastal Vegetation 1 • Direct values (products which are consumed by their use;

Singapore s earlier days) – Timber – Fuelwood and charcoal (especially from bakau) – Wood for chipboard – Tannins and dyes

Charcoal kiln

Bakau piles

Economic Values of Coastal Vegetation 2

• Direct values (products

which are consumed by

their use; Singapore s

earlier days) – Nipah palm products

(attap chee, gula Melaka,

roofing thatch, salt, etc.)


• Direct values

(products which are

consumed by their

use; Singapore s

earlier days) – Seafood (cockles,

oysters, mussels,

crabs, prawns, fish)

– Commercial honey

– Seaweed

– Live pet food (crab-

eating frog for

arrowanas)

– Land


• Indirect values (services which are not consumed by their utilization; present day Singapore) – Food for marine organisms from

the detritus food chain starting with the fallen mangrove tree leaves (food webs more realistic)

– Nurseries for juvenile fish, prawns, crabs, etc.

shark

snapper

crab

fallen leaves


• Indirect values (services which

are not consumed by their

utilization; present day

Singapore)

– Natural sewage treatment

– Protection and stabilization of

the coastline (within limits;

tsunamis can wipe out

mangrove forests!)

– Carbon sequestration

– Deforestation also release

Carbon into atmosphere

Toilet in mangrove

Mangrove forest can protect

inshore areas even in hurricanes

as here in Honduras

Economic Values of Coastal Vegetation 5a

Acheh, 13 Dec 2004 (before tsunami) Acheh, 29 Dec 2004 (after tsunami)


• Indirect values (services

which are not consumed

by their utilization;

present day Singapore) – Ecotourism (mangrove

forests are interesting;

beaches for swimming or

recreation; cliffs and

rocky shores for their

rugged and wild beauty)

– Education


• Indirect values (services which are not consumed by their utilization; present day Singapore) – Potential sources for

industrial chemicals, pharmaceuticals and other products and their corresponding genes for producing such

– Ornamental plants for use on roadsides, parks and gardens

Factor C extracted from the blood of the

horseshoe crab which binds to bacterial

endotoxins; gene isolated to

manufacture this at DBS, NUS

Yellow flame Pong pong

Sea almond

The Future • Natural coastal habitats

are now very rare in Singapore so must be well protected

• Propagation and replanting of coastal plant species

• Setting up Labrador Nature Reserve in 1 Jan 2002 – Good move by government – Developments (restaurant

inside; spa and hotel just outside) nearby should be monitored

• Threat of oil or chemical spills from shipping traffic by accidents or terrorist attack

restaurant

Development is just across the Straits

Coastal debris

Summary • Coastal vegetation occurred on all coastlines in primeval

Singapore and covered about 13% of Singapore Island

• Natural coastal vegetation is now extremely rare

• Coastal vegetation is quite complex and diverse with

almost no exotic species, so conservation value is the

second highest of all habitats after primary forest (ties for

second with secondary vegetation)

• Coastal vegetation provides numerous economic products

and services to Singapore and the rest of the world

• If undisturbed, coastal vegetation should persist but

development, pollution and global warming are real

threats

SSS1207 Lecture 10 Coastal Vegetation 2015 IVLE Version1

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