Chapter 12 ECOLOGY Hour3 Edited

7/30/2019 Chapter 12 ECOLOGY Hour3 Edited

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Powerpoint@lecture Slides Are Prepared By Biology Lecturer, KMPk
mailto:point@lecturemailto:point@lecture


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12.1 : Introduction to ecology

12.2 : Ecosystem concept

12.3 : Energy Flow through ecosystem

12.4 : Biogeochemical cycles

12.5 : Biodiversity:

Conservation & management


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Strata Type of tree Animal of community

Emergent Tualang tree Eagle

Canopy Nephelium sp. Beetle

Shrub Hibiscus rosa-sinensis Honey bee

Herb Dryopteris(Fern) Reptile

Taloid Bryophyta Ant

Table of Forest Stratification


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12.3 : Energy Flow through

ecosystem


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At the end of this topic, studentsshould be able to;

a) Describe ecological pyramid in relation

to trophic levels and energy transfer


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FOOD CHAIN

In a food chain, energy

and nutrients are

passed from one

organism to another.

It represents one path

of energy flow through

an ecosystem.

FOOD WEB

Most food chains are

interconnected.

Most animals will utilize several

food sources.

shows the flow of biomass and

energy from one trophic level to

the next


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The position that an organism

occupies in a food chain.

Many animals feed at severaldifferent tropic levels.

Example: green plants which

obtain their energy directly fromsunlight are the producer that is

tropic level 1.


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Secondary consumer

Carnivore

Primary consumer

Herbivore

Producer

Tertiary consumer

Top carnivoreTrophic level 4

Trophic level 3

Trophic level 2

Trophic level 1


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Ecological pyramid

A diagram representation of the relative

energy value at each trophic level / the flow

of energy through the food chain


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Three types of pyramid have been used.

These are :

a) pyramids of numbers, based on counting

numbers of organisms at each trophic level.

b) pyramids of biomass, which note weight (usually

dry weight) of organisms at each trophic level.

c) pyramids of energy, which monitor energy

content of organisms at each trophic level.

Types of Pyramid


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a) Pyramid of numbers

Based on counting the

numbers of organisms at

each trophic level. The number of

organisms less than

produces because small

proportion of energytaken in by an organism.


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Note the weight (usually

dry mass) of organisms at

each trophic level

Biomass decreases at each

ascending level of the food

chain because of decreaseof the number organisms.

b) Pyramid of biomass


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Energy pyramid indicates total amount

of energy present in each trophic level.

Also shows loss of energy from one

trophic level to the next.

Shows clearly that energy transfer fromone trophic level to next accompanied

by decrease due to waste, respiration

and death.

c) Pyramid of energy


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Calculation on energy

Gross Primary Production (GPP) is the rate at which an ecosystem's producers

capture and store a given amount of chemical energy as biomass.

Some fraction of this fixed energy is used by primary producers for cellular

respiration and maintenance of existing tissues

(i.e., "growth respiration" and "maintenance respiration").

Net Primary Production (NPP). referred to the remaining fixed energy

(i.e., mass of photosynthate)

Ra = autotrophic respiration (respiration by plant)

NPP = GPP - Ra

Both gross and net primary production are in units of mass / area / time. In

terrestrial ecosystems, mass of carbon per unit area per year (g C/m2/yr) is most

often used as the unit of measurement.


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Discuss why food chain does not consists

more than five trophic level.

When energy flows from one trophic level toanother, energy lost through respiration, excretionand heat to surroundings.

Each trophic level receives less energy than the levelbelow it.

After the fifth trophic level, only small amount ofenergy left which may be insufficient to supportother trophic levels, thus limiting length of foodchain.


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12.4 Biogeochemical

cycles

12.5 Biodiversity:Conservation and

management

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Chapter 12 ECOLOGY Hour3 Edited