• Dynamic system of organisms interactinginteracting with each other (biotic)(biotic) and the inanimate environment (abiotic).(abiotic).

Abiotic and Biotic

• Temperature• Water• Sunlight• Wind• Rocks & Soil• Periodic

disturbances

Global climate• Seasons • Precipitation & Winds

Food chain

• Sequence of organisms through which energy is transferred.

• Start with producer >>>>> end with consumer

Example :

Producer

1 Consumer st

2 Consumer nd

3 Consumer rd

4 Consumer th

1

2

3

Primaryconsumer

ProducerSecondaryconsumer

Tertiaryconsumer

From the organisms above, form three food chains.

Construct a food web from three food chains below

SnakeMice

Paddy

Grasshopper

Caterpillar Frog

Bird

Eagle

Identify the producer, primary consumer, secondary consumer, tertiary consumer and decomposer in a food web

Fungi

Dead

What is symbiosis• Interaction between 2 or more organisms

from different species which live closely together and interact with each other .

– Three types of symbiosis:• Commensalisms

– Epiphytes – Epizoites

• Parasitism– Endoparasite– Ectoparasite

• Mutualism– Two plants or– Plant and Animal or – Two animals

symbiosis

Sea anemones and hermit crab

Scallop with another sea snail?

symbiosis

Lichen

Mutualistic interaction between ants and an acacia species (a tree) in the tropics.

The ants protect the host tree, while the tree provides the ants with nutrient rich

food (the yellow bodies on the tip of leaflets).

Sea anemone and fish… what do each of them get?

fix nitrogen from the atmosphere in to a plant usable form. In return the plant feeds the bacteria with sugars, proteins, and oxygen.

Rafflesia

When in bloom,the Rafflesia emits a repulsive odor, similar to that of rotting meat. This odor attracts insectsthat pollinate the plant.

No visible leaves, roots, or stemIt attaches itself to a host plant to obtain water and nutrients

dodder

ectoparasites

A parasitic mold killing a locust

Various endoparasites of humans

The protozoan Tripanosoma gambiense causes the African sleeping sickness;

The roundworm Ascaris lumbricoides lives inthe intestinal cavities of humans and some other animals

The human liver fluke,a flatworm (Clonorchis sinensis).

Tapeworm

Saprophytes are the organisms that act as the decomposers,

• Predatory behavior is that which results in the killing of another animal for food.

• Predators usually possess excellent senses to find their prey and special abilities to capture the prey.

• Most species are potential prey for another animal at least sometime during their lives

Predator and preyrelationship

Regardless of body mass or numbers in a population, a given mass of prey will support a given mass of predator.  If the numbers of prey go down, the numbers of predators go down. On the other hand, if the numbers of predators go down, the numbers of prey will go up.

Colonization and succession

• Primary colonisers – organisms that are able to colonise a

disturbed habitat such as an area of bare soil or rock.

– They have adaptations that enable them to survive and reproduce in the harsh environment.

– Primary colonisers typically have effective methods of dispersal

succession

• A series of communities that develop in an area over time.

• If the succession develops from an area with no community, it is called a primary succession e.g. on exposed rock.

• If the succession develops from an area that has been prevented from changing e.g. by agriculture, it is called a secondary succession.

• Each community of plants and animals alters the environment making it less suitable for them and more suitable for other colonisers.

• the succession eventually reaches a stable community called the climatic climax.

Pioneer species:- adaptive character:

• Long root – water/stronghold of plant

• Small leaves / needlelike/thorn

– less transpiration

• Able to live in less nutrient soil

1st successor :

• Pioneer change the soil into more suitable condition.

• Not suitable for pioneer to live

• Soil moist and nutritious

• Shrubs and grass

2nd successor :

• Small trees and shrub

• Moist and fertilized soil

• Small animals able to live

>>>> forest gradually form and become climax comunity.

Colonisation and succession in a pond.

Example: unused mining pool

Pioneer plant:• Phytoplankton – micro algae

• Submerged plant – Hydrilla sp, Elodea sp.

- carry out photo – provide food

- died – decomposed at the bottom of the pond

- banks of pond are eroded and soil settle at the bottom of the pond

>> pond become shallow and not suitable for submerged plant.

1st successor :floating plant

• Duckweed(Lemna sp.) Pistia sp, Eichornia and lotus

• Prevent sunlight from penetrating into the pond

• Submerged plant unable to carry out photo

• Died and decomposed

• Pond become too shallow and fertile.

Duckweed/ Lemna sp

Lotus / Nelumbium sp

Eichornia sp

Pistia sp

2nd successor: amphibious plant

• Live with the root anchored to the pond bottom and banks soil

• Spread into the centre of the pond

• Plant died – decayed organic deposited at the bottom of the pond

• Pond dried up

Final successor: land plants

• Shrubs and woody plant

• Climax community formed

Mangrove swamp colonization and succession

Mangrove swamp

Unsuitable condition of muddy bank in mangrove swamp:

• Soft muddy soil

• Water logged soil which lacks of oxygen

• High salinity

• Strong sunlight

• Extreme heat

Pioneer species :

• Avicennia sp – grow facing the sea

• Sonneratia sp – at the mouth of river which is sheltered.

Adaptation of pioneer species:• Root system spread out widely to give support in

the soft muddy soil• Pneumotophores – grow vertically upwards –

spongy, able to taken in air for respiration• Having higher osmotic pressure of cell sap than

surrounding sea water• Excess salt secreted through hydathodes in

leaves.• Thick cuticle and succulent leaves • Sunken stoma – to reduce transpiration• Float seed.

Avicennia sp

Sonneratia sp:

1st successor – Rhizophora sp

• Root of avicennia and sonneratia trap mud and soil, bank raised and contain less water.

• More suitable for Rhizophora

• Slowly replace the pioneers

Rhizophora sp:

• Prop roots to support and anchor the trees

• Viviparity seeds to ensure seedling survival

• Prop roots traps a lot of soil and mud, died and decomposed adding humus to the soil

Prop root of Rhizopora

Viviparity fruit.

2nd successor : Bruguiera sp

• The banks are rised up higher and dried, the soil become compact, fertile and less saline.

• Not suitable for Rhizophora, slowly replaced by Bruguiera sp

Bruguiera sp :

• Buttress roots for support• Knee shape pneumatophores• More sedimentation of decayed

substances – dried land form• Replaced by other types of plants;

– Coconut, pandanus, palm trees and others

– Forest formed.

Buttress root

Knee root

3rd successor : Paya bakau forest

Plants :

Nypa sp.

Animals in mangrove swamps:

Ecological important of mangrove swamp:

• Food, nesting and nursery for animal e.g. fish, crabs, shrimp and birds.

• Protect coastline by acting as wave breakers and coastal erosion

• Natural barriers against storms and tsunamis

• Cleansing system, trap debris, excess nutrient and toxin brought down by the rivers

Economical value:• Poles: shaft of Rhizophora species • Fuel wood and charcoal: Rhizophora species wood

have a high calorific value (more heat)• Tannins and dyes: Bark of mangrove trees are

harvested as a source of tannin for the tanning industry

• Raw materials for industries: lignocellulose for the manufacture of chipboard, pulpwood (newspaper and cardboard) or synthetic materials (e.g., rayon).

Food product:• industrial ethanol from distillation of

the fermented plant sap – Nypa sp

• Seafood: Oysters, clams, mussels, cockles and other shellfish may be harvested directly or cultivated for consumption. Prawn and crab ponds converted from mangrove areas

Conduct a field study to estimatethe population size of animalssuch as garden snails and wood lice