Ecosystems
Ecosystems
An ecosystem is a community of living organisms interacting with their non-living environment. Learn the components: biotic (producers, consumers, decomposers) and abiotic (climate, soil, water, light, temperature). Understand food chains, food webs, trophic levels, energy flow and nutrient cycling; energy is lost at each level (roughly 90%), limiting food-chain length. Learn biodiversity, adaptation, succession and the difference between ecosystems and biomes (large-scale climate-defined zones such as tropical rainforest, savanna, desert, tundra).
Study tropical rainforests (high biodiversity, nutrient-poor soils, rapid nutrient cycling, layered structure) and coral reefs and mangroves as Caribbean examples. Understand human impacts: deforestation, pollution, overfishing, climate change, and conservation through protected areas, sustainable management and restoration.
Traps: saying rainforest soils are fertile (they are often nutrient-poor because nutrients are locked in vegetation); confusing a food chain with a food web; muddling a biome with a habitat; and forgetting decomposers recycle nutrients rather than create energy.
Rule of thumb: energy flows one way (sun to producers to consumers) and is lost; nutrients cycle repeatedly.
Worked example: Clearing rainforest for farming reduces biodiversity because habitats and food webs are destroyed; exposed soils are leached by heavy rain, so fertility falls quickly, and the loss of roots increases erosion and runoff.