P6 Interactions — Environmental Interactions (Concept Map)
Primary 6 Science — Concept Map
Created by Miss Clarissa Ng · www.clartutors.com
Environmental Interactions
a stable ecosystem is delicately balanced
energy through the ecosystem
Food chainenergy transferred · begins with a food producer · producer → primary → secondary → tertiary consumer
Energy loss98% of the Sun's energy lost · 2% trapped by producers · ~90% lost at each position
Food weblinked food chains · shows all the relationships in an ecosystem
pyramids & relationships
Ecological pyramidmore producers than consumers · more prey than predators · pyramid of numbers can be inverted
three relationships
Predator–preyone benefits and the other is harmed — the predator eats the prey
Competitionboth are harmed — they compete for the same food, water, light or space
Mutualismboth benefit — each gives the other something it needs
recyclers at work
Decomposersthey break waste and dead matter into simpler substances so nutrients return to the soil
Matter is finitethe same matter has to be recycled again and again through the ecosystem
Detritivorestermites, woodlice, millipedes and earthworms break dead matter into smaller pieces
pyramids in more detail
Pyramid of numbersshows how many organisms are at each level — easily obtained, but it does not account for size, or biomass
Inverted pyramida pyramid of numbers can be inverted when few producers support many consumers
Apex predatorthe consumer at the very top of the pyramid
a change ripples out
One change, many effectsa change in one population changes the other populations linked to it
Poisoninga poison that cannot be flushed out of the body stays in it
keeping food fresh
Take away what they needdecomposers need moisture, oxygen and warmth — vacuum-sealing, freezing and drying each remove one of them
A change in one population changes the others linked to it · predators lag behind their prey
Food preservation: remove oxygen (vacuum-sealed), reduce warmth (freezer), remove moisture (dried)