All organisms function by using and processing energy. Energy enters the web of life via photosyndicsis, is stored in biomass, and is released by cellular respiration (see Laboratory Topic 5). As a living being, you arc dependent on a continual inflow of energy. Since humans arc not capablc of photosynthesis, we must get all our energy from the food we eat. Where did the energy in our food come from? Ultimately it came from the sun.
The objective of this excrcisc is for you to get a sense for "your piece of the sun." In other words, we will calculate the amount of energy needed to support you as an organism, in particular, a normal consumer of the early tw enty-first century. By keeping track of your f<xxl consumption, you will estimate how much energy you consume in an average year. Then, based on what you typically cat, we will build your personal food web (fig. 10.1). You will be able to account for the energy as it flows from the sun, through other organisms, and finally to you. You will sec the connections between you and the other plants and animals needed to provide your food. If you lived like other animals, this food web would be adequate to describe all die energy inputs needed to meet your metabolic needs. However, modern humans are different from other organisms. We use additional sources of energy for cooking, processing, transporting, refrigerating, fertilizing, and cultivating our food. You will estimate some of these additional subsidies and add them to your total energy consumption. Sincc most of this added energy comes from fossil fuels, it can be considered "your piecc of the past."
It is so easy to go to the grocery store or visit your favorite fast-food restaurant diat many of us have lost touch with the agricultural system that helps provide our food. In this exercise, you will connect the food you eat with the bigger picture.
Total Solar Energy
(nooded to support you)
Solar onoKjy reflocted or remdintQ<i
(23) ioa kcal yr1
10* kcal yr
Plant crops: Gross production
Your consumplion of plants
Crops led to livestock Gross production
_ 106 kcal yr1
Livestock: Gross energy Intake
Your consumption o( meat nn<l dairy products (6) 10r' kcal yr1
Phytoplnnkton: Gross production
Your consumption ol fish & shollflsh
106 kcal yr1
Your gross onorgy intako (1) 10° kcal yr'
Rosplration and other losses (21) to"kcal yr1
Energy activity onorgy
Digestion and wasto
Was this article helpful?
You Might Just End Up Spending More Time In Planning Your Greenhouse Than Your Home Don’t Blame Us If Your Wife Gets Mad. Don't Be A Conventional Greenhouse Dreamer! Come Out Of The Mould, Build Your Own And Let Your Greenhouse Give A Better Yield Than Any Other In Town! Discover How You Can Start Your Own Greenhouse With Healthier Plants… Anytime Of The Year!