Pyramids Of Number & Biomass L.O: To understand pyramids of biomass

Which animal is not a polar bear's natural prey? a) Seal b) Walrus c) Penguin d) Reindeer

Which animal is not a rattlesnake's natural prey? a) Mouse b) Badger c) Rabbit d) Lizard

Which animal is not an adult sea turtle's natural predator? a) Manatee b) Shark c) Whale d) Crocodile

Which animal is not a beaver's natural predator? a) Wolf b) Moose c) Otter d) Owl

Which animal is the mongoose's natural prey? a) Hawk b) Meerkat c) Jackal d) Cobra

Which animal is not the porcupine's natural predator? a) Coyote b) Horned Owl c) Bear d) Bobcat

Which of these large animals is a wolverine's natural prey? a)Polar bear b) Whale c) Seal d) Caribou

9 Engage Which is predator and which is prey? Eupithecia caterpillarMedfly Habitat: tropical forests of Hawaii Population in each tree: 1000 Habitat: tropical forests of Hawaii Population in each tree: 10

10 Engage Which is predator and which is prey? The Eupithecia caterpillar is a predator of medflies. It is a carnivorous caterpillar.

11 Elicit There are always fewer predators than prey. discuss Why do you think this is ?

Food Chains & Webs A food chain shows what eats what in a particular habitat - the arrow points in the direction of the energy flow, e.g. Here the grass (producer) is eaten by the vole (primary consumer) which is eaten by the barn owl (secondary consumer) Energy is passed along the food chain, so the number of organisms decreases from one trophic level to the next (as energy is lost)

Food Chain Food chains are never very long (usually only 4/5 stages at most) – why is this? Remember the arrow shows the energy being transferred from one organism to the next - between each step energy is lost in a variety of ways, including: - Growth of the organism Reproductive costs Lost through waste products (poo) Lost through heat This is why food chains are never that long - as lots of energy is lost from one stage to the next

Food Chain

Food Web In most habitats organisms normally eat / are eaten by more than one other organism To represent this we use food webs (like food chains but they interlink with one another), e.g. a pond Here the producers are the pondweed and the microscopic algae Mayfly nymphs eat the pondweed and microscopic algae, and freshwater shrimp eat the microscopic algae Dragonfly nymphs and brown trout eat the mayfly nymphs and freshwater shrimp Brown trout also eat the dragonfly nymph!

Key Words Producers – green plants make food by photosynthesis Primary consumers – usually eat plant material (they are herbivores) Secondary consumers – usually eat animal material (they are carnivores) Predators – kill for food (they are either secondary or tertiary consumers) Prey – the animals that predators feed on Scavengers – feed on dead animals Decomposers – feed on dead and decaying organisms, and on the undigested parts of plant and animal matter in faeces

Balance Populations in a food chain are dependent upon one another – there is a balance between the producers and consumers in the food chain For example if there are lots of giraffes they will eat a large quantity of the trees and shrubs until there may be insufficient amounts to support them. If this is the case many will begin to starve and die Fewer giraffes means less food for lions, which will eventually see a population decrease Less giraffes will allow more shrubs and tress to survive, so the giraffe population recovers, leading to the lion population recovering, until the process repeats itself…

Population The population of each organism in a food chain can be shown in a sort of bar chart called a pyramid of numbers The more organisms there are, the wider the bar. The producer in the food chain always goes at the bottom of the pyramid of numbers E.g. clover  snail  thrush  hawk

Pyramid Of Number Pyramids of number show how many organisms there are in a habitat A pyramid of number for the food chain below might look like this: - If there were 200 grass plants; 25 voles; and 1 barn owl

Pyramid Of Number Pyramids of number show how many organisms there are in a habitat However they may not always look like classical pyramids: - Here there are much more caterpillars than there are oak trees which is why the pyramid is oddly shaped.

Pyramid Of Biomass Biomass means the amount of biological material The pyramid shows the amount of biological material at each level This means the oak tree has the most biological material whilst the sparrow hawk has the least

solar energy 22 Explore We can model the energy flow from producers to carnivores using water. SS1 The energy game Questions for discussion: What does the water represent? What does the transfer of water from cup to cup represent? Why does energy leak away from food chains? Why does the model animals have more holes in their cups than the model plants? How can the carnivores get more energy? What decides the total amount of energy flowing through the food chain?

Species at War Paradise 3 Pyramids The energy game – Write short answers to the following Questions for discussion: What does the water represent? What does the transfer of water from cup to cup represent? Why does energy leak away from food chains? Why do the model animals have more holes in their cups than the model plants? How can the carnivores get more energy? What decides the total amount of energy flowing through the food chain?

Explain Does the model show why there are so few carnivores? 24

The energy they use to stay alive, leaks away as waste heat so each organism passes less energy to the next one. Energy lost as waste heat 25 Explain Energy Energy trapped by photosynthesis

Less than 10% of the energy taken in gets passed to the next consumer... Energy lost to decomposers 100%10% 1% 0.1% Energy lost as waste heat 26 Explain

... so it takes many plants to support a few animals. 27 Explain Energy lost to decomposers 100%10% 1% 0.1% Energy lost as waste heat

Species at War Paradise 3 PyramidsSS2aSpecies at War Paradise 3 PyramidsSS2a How many? There are about 50,000 amaranth plants on the island. Each stores about 500 kJ in its seeds each year. That’s similar to the amount of energy in a chocolate bar. Use the data below to estimate how many curassow could survive on the island. Assume that all their energy comes from this food chain. A mouse needs 5,000 kJ per year: 4,500 kJ to keep it alive, and 500 kJ to make new tissues as it grows. A banana spider needs 5,000 kJ per year: 3,000 kJ to keep it alive, and 2,000 kJ to make new tissues as it grows. A curassow needs 40,000 kJ per year to live and grow. How many? There are about 50,000 amaranth plants on the island. Each stores about 500 kJ in its seeds each year. That’s similar to the amount of energy in a chocolate bar. Use the data below to estimate how many curassow could survive on the island. Assume that all their energy comes from this food chain. A mouse needs 5,000 kJ per year: 4,500 kJ to keep it alive, and 500 kJ to make new tissues as it grows. A banana spider needs 5,000 kJ per year: 3,000 kJ to keep it alive, and 2,000 kJ to make new tissues as it grows. A curassow needs 40,000 kJ per year to live and grow.

Species at War Paradise 3 PyramidsSS2bSpecies at War Paradise 3 PyramidsSS2b How many? There are about 50,000 amaranth plants growing on the island. Each mouse can get all the energy it needs from the seeds produced by 10 plants. Each spider has to eat 10 mice. Each curassow has to eat 20 spiders. How many? There are about 50,000 amaranth plants growing on the island. Each mouse can get all the energy it needs from the seeds produced by 10 plants. Each spider has to eat 10 mice. Each curassow has to eat 20 spiders. Use the data below to estimate how many curassow could survive on the island. Assume that all their energy comes from this food chain.