on Like threads in a spider’s web food chains interconnect and support one another Strands in a Web All life needs sunlight water air and food Green plants change light from the Sun into food energy through photosynthesis Plants use the food to live and grow When an animal eats the plant the energy passes to the animal and passes again when the animal is eaten This energy pathway from one living thing to another is a food chain Since organisms are part of many food chains all the food connections in an area compose a food web CHEW THIS Plants use water carbon dioxide and chlorophyll to change sunlight into a simple sugar 4
Food chains begin with sunlight and end with an animal 5
Natural Forest Networks An area’s plants and animals and the ways they interact with each other and the land define an ecosystem Climate and the availability of resources like food and water determine the kinds and numbers of species Forests grow in many climates Tropical forests are warm and moist all year Leafy or deciduous trees handle seasonal temperature changes in temperate forests Temperate forests grow between equatorial rainforests and northern boreal forests Boreal forests are without frost only 50 to 100 days each year General distribution of boreal forests 6
