Bray Jacobson 
Cadenas y redes alimentarias (Food Chains and Webs) [PDF ebook] 

All organisms in an ecosystem are connected. Some are predator, some are prey, and others are just there to help decomposition. What»s more, food chains and food webs are a crucial part of the Earth and life science curricula. Written for struggling upper elementary readers, the main content highlights the most important points, as well as the essential vocabulary relating to food chains and webs. Full-color diagrams aid readers» comprehension.