Energy in ecosystems starts with the sun and flows through producers and consumers across trophic levels, with only ~10% transferred at each step. ⚡🌿 While energy flows one-way and is lost as heat, matter cycles—including the carbon, nitrogen, and phosphorus cycles—are continuously recycled. This video also covers bottom-up vs. top-down effects and how human activities like industrial agriculture disrupt nutrient cycles, causing issues like eutrophication. Perfect for AP Biology Unit 8.2 review