Genre Nonfiction Comprehension Skill Text Features Main Idea and Details • Captions Labels Text Boxes Glossary Science Content Ecosystems Scott Foresman Science 3.3 ISBN 0-328-13815-0 ì<(sk$m)=bdibfj< +^-Ä-U-Ä-U Vocabulary community desert ecosystem environment grassland population tundra wetland What did you learn? 1. What happens when one part of an ecosystem changes? 2. Why can’t trees grow in some grasslands? 3. Lemmings are able to live on the tundra. Why? by Barbara Fierman Picture Credits Every effort has been made to secure permission and provide appropriate credit for photographic material. The publisher deeply regrets any omission and pledges to correct errors called to its attention in subsequent editions. Photo locators denoted as follows: Top (T), Center (C), Bottom (B), Left (L), Right (R), Background (Bkgd). Opener: Digital Vision; 1 Getty Images; 3 (T) Getty Images; 5 Getty Images; 7 ©Jerry Young/DK Images; 8 Tom Bean/Corbis; 11 Digital Vision; 12 Francois Gohier/Ardea; 14 Getty Images; 15 Digital Vision; 16 (BC) ©Jerry Young/DK Images; 18 (Bkgd) Getty Images; 22 (CR) Tom Bean/Corbis, (BC) Digital Vision; 23 (CR) Francois Gohier/Ardea, (BC) Getty Images. Scott Foresman/Dorling Kindersley would also like to thank: 10 (BC) Jerry Young/DK Images. Unless otherwise acknowledged, all photographs are the copyright © of Dorling Kindersley, a division of Pearson. ISBN: 0-328-13815-0 Copyright © Pearson Education, Inc. All Rights Reserved. Printed in the United States of America. This publication is protected by Copyright, and permission should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form by any means, electronic, mechanical, photocopying, recording, or likewise. For information regarding permission(s), write to Permissions Department, Scott Foresman, 1900 East Lake Avenue, Glenview, Illinois 60025. 3 4 5 6 7 8 9 10 V010 13 12 11 10 09 08 07 06 05 4. You ha