1. Cycles of Matter 3.3

2. Biogeochemical Cycle Process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another.

3. Evaporation Process by which water changes from a liquid into an atmospheric gas.

4. Transpiration Loss of water from a plant through its leaves.

5. Nutrient Chemical substances that an organism requires to live.

6. Nitrogen Fixation Process of converting nitrogen gas into ammonia.

7. Denitrification Conversion of nitrates into nitrogen gas.

8. Primary Productivity Rate at which organic matter is created by producers in an ecosystem.

9. Limiting Nutrient Single nutrient that either is scarce or cycles very slowly, limiting the growth of organisms in an ecosystem.

10. Algal Bloom An immediate increase in the amount of algae and other producers that from a large input of a limiting nutrient.

11. Key Concept How does matter move among the living and nonliving parts of an ecosystem? Unlike the one-way flow of energy, matter is recycled within and between ecosystems.

12. Key Concept How are nutrients important in living systems? Every living organism needs nutrients to build tissues and carry out essential life functions. Like water, nutrients are passed between organisms and the environment through biogeochemical cycles.