Cycling of Nutrients (Biogeochemical Cycles) – S5 Biology Notes

These Senior Five Biology notes explain how essential elements move between living things and their surroundings. They cover the nitrogen cycle, including lightning, nitrogen fixation, nitrification and denitrification, along with the importance of nitrogen and the effects of its deficiency. The notes also describe the carbon cycle and the water cycle, and they explain how human activities such as deforestation, pollution and dam construction affect these cycles and energy flow. Later sections introduce ecological succession, covering primary and secondary succession on land and in water, seral stages and climax communities. A sample exam question on succession after a forest fire is included with a marking-style answer.