Q.Write important features of a sedimentary cycle in an ecosystem.

Step 1. Reservoir. In a sedimentary cycle, unlike a gaseous cycle, the main reservoir of the nutrient is the Earth's crust — rock — rather than the atmosphere. Step 2. Release. The nutrient becomes available only when rocks are weathered, releasing small amounts that dissolve into the soil solution. Step 3. Biological uptake and transfer. Plant roots absorb the dissolved nutrient from the soil; herbivores and other animals then obtain it by consuming plants, and it passes further along the food chain. Step 4. Return to soil. Waste products and dead organisms are broken down by decomposers (e.g., phosphate-solubilizing bacteria for phosphorus), releasing the nutrient back into the soil for re-uptake by plants. Step 5. Slow, largely non-atmospheric exchange. Because there is no significant gaseous phase, atmospheric inputs (such as through rainfall) are much smaller than in a gaseous cycle, and exchange between organisms and the environment is comparatively limited. Step 6. Long-term sedimentation. A portion of the nutrient is lost from active circulation each cycle — through leaching, runoff and settling of detritus at the bottom of water bodies — and over geological time this sediment is converted back into new rock via sedimentation and geological uplifting, only re-entering the cycle over ver …

• Confusing sedimentary cycles with gaseous cycles by including an atmospheric respiratory-release step. …