Biology chapter 8 colonisation and succession in a pond
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Transcript of Biology chapter 8 colonisation and succession in a pond
Colonisation and Succession in a Pond
1. Four groups of plants play important roles in the colonisation and the succession of a newly formed pond.
2. These 4 groups are:
(a)Submerged plants(b)Floating plants(c)Amphibious plants(d)Land plants
(a) Submerged plants
1. Submerged plants are plants that grow and live below the surface of water.
2. They are the pioneer species in a pond.
3. They have adaptive features such as long fibrous roots that penetrate deep into the soil to absorb nutrients and hold the sand together.
4. These submerged plants also possess fine leaves which enable the plants to flow with the current of the water
Examples of submerged plants:
Elodea sp.Hydrilla sp. Cabomba sp. Vallisneria sp.
(b) Floating plants
1. Floating plants are plants that float on the surface of the pond/water.
2. They succeed the submerged plants after the pioneer stage.
3. The multiplication of floating plants on the surface of the pond prevents less sunlight from entering the pond.
4. This results in the death of submerged plants as they cannot photosynthesise due to the lack of sufficient sunlight.
Examples of floating plants:
Nelumbium sp. (lotus)
Eichornia sp.(water hyacinth)
Lemna sp.(Duck weed)
(c) Amphibious plants1. Amphibious plants are also called emergent
plants.
2. These type of plants can live both on land and in water.
3. These plants succeed the floating plants when the eroded soil in the pond gradually rises and causes the water level in the pond to be too shallow for the growth of floating plants.
4. The rhizomes of amphibious plants grows rapidly from the edge of the pond to the middle of the pond. This is to allow the soil to bind together, the plants to absorb nutrients and change the habitat.
Examples of amphibious plants:
Scirpus grossus
Cyperus sp. Scirpus mucronatus
(d) Land plants
1. Land plants are basically the plants that grow on dry ground after the pond dries up.
2. Land plants are the successors of amphibious plants.
3. Examples of land plants:
(a) Grass(b) Creepers(c) Ferns(d) Herbaceous plants and woody plants (shrubs)
4. These plants are also known as terrestrial plants.
Stages of colonisation and succession in a
pond
There are five stages in the colonisation and the succession in a pond:
They are:
(a) The pioneer stage(b) Succession by aquatic floating plants(c) Succession by amphibious plants(d) Succession by land plants(e) Climax community
1. Photoplankton, zooplankton, and submerged plants are the first colonisers.
2. These submerged plants have long fibrous roots to penetrate the soil and absorb nutrients.
3. The plankton also supports other organisms such as water bugs and its larvae, mosquito larvae and others.
4. When the pioneer plants die and decompose, the organic matter settles to the bottom of the pond. This organic matter, together with the eroded soil from the bank of the pond, gradually settles to the pond, making it shallower and more suitable for floating plants.
(a) Pioneer stage
(b) Succession by aquatic
floating plants
1. Floating plants such as Pistia sp., Eichornia sp., and Lemna sp. gradually multiply and cover the surface of the pond and prevent light from entering it.
2. This causes the submerged plants to die as they cannot carry out photosynthesis.
3. These dead plants decompose and add on to the layer of organic matter at the bottom of the pond.
(c) Succession by amphibious plants
1. The layer of organic matter raises the floor of the pond, making it too shallow for the floating plants to float.
2. Amphibious plants such as Scirpus sp. and Cyperus sp. succeed the floating plants. These plants are types to cattails and sedges.
3. The amphibious plants multiply and their rhizomes grow from the edge of the pond towards the middle, and their extensive roots penetrate deep, binding the soil together and changing the habitat.
4. When the amphibious plants die, their decomposed remains add on to the sediment.
5. The pond becomes even shallower.
(d) Succession by land
plants
1. The death and decay of the amphibious plants caused by the continued deposition of organic matter and evaporation of pond water will make the pond very shallow and eventually dry it up.
2. Finally, land plants such as grass, creepers, herbaceous and other woody plants will replace the amphibious plants and gradually form a jungle.
(e) Clim
ax stage
1. The process of succession will stop when a level of balance is achieved
2. The tropical rainforest is a climax community.
3. The climax community takes a few hundred years to form.
Questionnaire:
1. Phytoplankton, zooplankton and algae are often among the first species to establish themselves in a mining pond. As time passes, submerged and floating plants will grow, followed by amphibious plants, grasses, small shrubs, bushes and eventually trees.
This is an example of A. colonisation B. competition C. evolution D. succession
Answer: D
2. Over many years a forest can be found on an initially barren piece of land left behind by a volcanic eruption. What is the correct sequence of ecological processes that have taken place?
A. Colonisation, succession, climax community
B. Colonisation, climax community, succession
C. Succession, colonisation, climax communiity
D. Succession, climax community, colonisation
Answer: A
3. Which gives the correct sequence of plants involved in the process of succession in a disused pond?
A. Emergent plants, floating plants, land plants, submerged plants B. Floating plants, submerged plants, land plants, emergent plants C. Submerged plants, floating plants, emergent plants, land plants
D. Land plants, emergent plants, floating plants, submerged plants
Answer: C
Thank YouPresentation by: Group 3a)Joel Ivan Lingb)Samuel Liewc)Michael Yeod)Adrain Taye)Chai Zhi Renf)Andy Heng