Ecosystem - p. 375 + 399
Producers - p. 92 + 108
Consumers - p. 92 + 432
Primary consumers - p. 92 + 434
Secondary consumers - p. 432 + 434
Tertiary consumers - p. 432 + 434
Omnivores - p. 434 + 476
Decomposers - p. 433 + 302
Energy flow through an ecosystem - p. 6 + 437 + 451
Food chain - GRASS -> MOUSE -> SNAKE -> HAWK - p. 432
Trophic Level - p. 434
Food web - p. 434
Primary Productivity - p. 438 + 439
Biogeochemical cycles - p. 440
Carbon cycle - p. 441 + 394 + 395
Hydrologic cycle - p. 391
Evaporation - p. 391
Nitrogen Cycle - p. 442