Chapter 1.10 Energy in Ecosystems

What energy is needed to survive on Planet Earth? Hint:

Photosynthesis Is the process by which green plants use sunlight energy to produce carbohydrates (sugars)

Albedo When solar energy strikes an object, some of the energy is absorbed and some is reflected Albedo is a measurement of the percentage of light which a material will reflect Polar Ice Cap – High or Low? Answer: High Black Roof – High or Low? Answer: Low Bare Soil – High or Low?

Albedo Effect The higher the albedo, the greater the objects’ ability to reflect light Can you suggest how the albedo effect is involved in speeding up the melting of the Polar Ice Caps (North & South Poles)????

ENERGY MOVEMENT IN ECOSYSTEMS Chapter 1.11 Chapter 1.11

FOOD WEB – a series of interlocking food chains Of the less than 1% (0.023%), how does the energy disperse throughout food chains and food webs. FOOD WEB – a series of interlocking food chains When talking about food webs and energy, new terms are used to describe producers and consumers/decomposers. When talking about food webs and energy, new terms are used to describe producers and consumers / decomposers

AUTOTROPHS Plants or algae which make their own food using the sun’s energy through photosynthesis Previously called producers

HETEROTROPHS Animals, fungi and bacteria that must eat or decompose plants or animals ( and their waste) to get their energy. Previously called consumers / decomposers

WHY NEW TERMS? Each of the feeding levels ( consumer, primary consumer, secondary consumer ) is called a trophic level. Every time something is consumed in a food chain, energy is passed along. However, less and less energy is passed on each time because some of the energy is used for life processes ( maintaining body temperature, digestion, growing, movement, etc)

ECOLOGICAL PYRAMID Number of Organisms Decreases Third Trophic level Secondary Consumers Available Energy Decreases Second Trophic Level Primary Consumers First Trophic Level Producers Energy from the Sun

With these new terms and previous old terms we can place labels on organisms within food chains and food webs. Lets look at Handout: Energy loss in a food chain

Energy Loss in Food Chains

ENERGY LOSS IN A FOOD CHAIN The higher the trophic level in the food chain, the more energy is lost. Consuming plants, which are the lowest trophic level, allows for the least amount of energy to be lost.

A SIMPLE FOOD WEB

More Complex Food Web

HOMEWORK Q. #1-3 p.33. Q: #1-6, 9,10 p.39.