1. Biomass

2. Competition – Who will finish first?
Herbivore
Consumer
Carnivore
Producer
Omnivore
Mass
Weight

3. The sun's radiant energy is the energy source for all life on earth
The sun's radiant energy is the energy source for all life on earth. Green plants trap the sunlight and use chlorophyll to make food. We call green plants producers

4. This food is in the form of starch, which is a carbohydrate
This food is in the form of starch, which is a carbohydrate. The green plants can also convert this into fats and proteins. They use this to provide enough building materials for their own bodies.

5. By adding more to their bodies they are adding more mass to themselves
By adding more to their bodies they are adding more mass to themselves. Because it’s alive we say that it’s adding more Biomass to itself.

6. Definition: the total mass of living matter in a given unit area
The total amount of living material in a given habitat, population, or sample
Specific measures of biomass are expressed in dry weight (after removal of all water from the sample)
It’s measured in kilograms (kg)

7. Food Chains Examples of food chains include: Grass Rose bush Squirrel
Food chains commonly have four links but seldom more than six.
In food chains the arrows go from food to feeder.
In other words the arrows mean ‘eaten by’
Examples of food chains include:
Top carnivore
Carnivore
Herbivore
Producer
Animals eat the green plants in other words they eat the biomass! They use the energy locked up in the chemicals such as starch, protein and fat to enable their own bodies to respire and make new cells and so their own biomass increases. These are called consumers. A food chain can be used to show how this energy is passed from one organism to another.
Grass
Rose bush
Squirrel
Beetles
Racoon
Shrew
Cougar
Wolf

8. Complete - Aquarium ecosystem

9. Animals respire, keep warm, excrete and move = MRS NERG
Animals respire, keep warm, excrete and move = MRS NERG. All the time, energy is being used up by each organism in the food chain link!

10. In a food chain there is energy lost between each link
 In a food chain there is energy lost between each link. This means that the number of organisms at each level gets less.

11. Complete – Energy Transfer

12. Pyramids of Numbers Energy is passed along food chains
The number of organisms decreases as you go from one trophic level to the next.
This is because most of the energy is lost as you go from one level to the next in a food chain.
The number of organisms in each level can be represented using a pyramid of numbers.
It is obvious that food chains can only sustain a few top carnivores because there is so much energy lost between each level.

13. Pyramids of Numbers
Just staying alive uses up most of the food energy that’s ‘acquired’ by a consumer.
Its needed for moving, growing and keeping warm.
Not all of the material from each level is eaten.
The food energy only passes along the food chain when its eaten by a consumer from the next level up.

14. Pyramids of Numbers Pyramids of numbers can look weird.
This is because an oak tree is very large compared to the caterpillar.
There is only 1 oak tree but 1000’s of leaves for the caterpillars to feed on.

15. Pyramids of Biomass
Pyramid of numbers looks weird because it doesn’t take into account the mass of the oak tree.
If the pyramid represented the total mass of the organisms at each level it would look more like a pyramid.
It would then be a pyramid of biomass.
Some organisms are far bigger and heavier than others, so a pyramid of numbers is not the most accurate way of representing the movement of energy through a food chain. The most accurate method would be to calculate the amount of energy at each level. This would require killing all the organisms to determine their energy content. Instead of this, the amount of biological matter, or biomass, is calculated. This is measured in Kg.
Robins (10 kg)
Caterpillars (20 kg)
Oak Tree (10,000kg)

16. Complete:
Produce a pyramid of numbers and then a pyramid of biomass using this data.
Use graph paper, colour pencils and a ruler.
What do you notice about the pyramids?
10 cabbages
250 caterpillars
5 thrushes
1 sparrow hawk

17. Energy Flow
So: in a food chain, usually only 1% to 10% of the biomass (energy)
in one feeding level is passed on to the next feeding level
Assuming only 10% of the biomass is passed on at each stage of the following food chain, calculate the biomass at each successive feeding level
Top carnivore
Carnivores 66
Herbivores
Producers ,600
Figures show dry mass in grammes per square metre
Thus at each stage of a food chain, less material and less energy are contained in the biomass of the organisms. This means that the efficiency of food production can be improved by reducing the number of stages in the food chains involved, so that less biomass is lost

18. Food chains involved in feeding humans:
Cereals human
Grass sheep human
Algae mayfly larvae pond skater (insect) trout human
Which of the above food chains is most efficient at getting biomass to humans?
‘Cereals to humans’ is most efficient, because it has least stages (one) to lose biomass
‘Algae to humans’ is least efficient, because it has most stages (four) to lose biomass

19. To sum up: the amounts of the material and energy contained in the biomass of organisms is reduced at each successive stage in a food chain because:
Some materials and energy are lost in the organism’s waste materials (excretion) or via undigested or indigestible (defaecation);
The heat losses are especially large in mammals and birds whose bodies must be kept at a a constant temperature which is usually higher than that of their surroundings

20. Energy Flow
So the efficiency of food production in food animals, (for example, chickens, turkeys, sheep, pigs, cattle), can be improved by:
Restricting energy loss from food animals by limiting their movement;
By controlling the temperature of their surroundings so that they do not lose biomass trying to keep warm