Cycling of Matter in Ecosystems
20 likes9,326 views
The document discusses several biogeochemical cycles, including the water, carbon, and nitrogen cycles. These cycles describe the continuous movement and exchange of substances between living organisms and their inorganic environment. Specifically, it notes that the water cycle involves the processes that move water through the environment, the carbon cycle involves the exchange of carbon between the atmosphere, organisms, and carbon deposits, and the nitrogen cycle describes how nitrogen is converted between different forms and moves between organisms and the atmosphere.
Cycling of Matter in Ecosystems
- 1. Cycling of Matter in ecosystems
- 2. Biogeochemical Cycles Recall: The particles that make up matter cannot be created or destroyed . This means that all water and nutrients must be produced or obtained from chemicals that already exist in the environment.
- 3. This happens in a series of cycles in which chemicals are continuously consumed , rearranged , stored and used. Because these cycles involve living (bio) organisms and occur on Earth (geo), they are called biogeochemical cycles . Biogeochemical Cycles
- 4. Every particle in every organism is part of a biogeochemical cycle! Biogeochemical Cycles
- 5. Water cycle = the series of processes that cycles water through the environment Most of the water that is present in the water cycle is found in the abiotic environment. The Water Cycle
- 7. Carbon moves between the abiotic and biotic parts of an ecosystem in the carbon cycle. Most of this exchange occurs between carbon dioxide (either in the atmosphere or dissolved in water) and photosynthesizing plants and micro organisms. The Carbon Cycle
- 9. While large quantities of carbon cycle through photosynthesis and cellular respiration , most of Earth’s carbon is not cycled. Carbon Deposits
- 10. Carbon Deposits Instead, it is stored in carbon-rich deposits such as fossil fuels (coal, oil, natural gas etc.) that form when decomposed organisms are compressed over millions of years.
- 11. Carbon is also stored for millions of years as limestone formed from dead marine organisms.
- 12. Large quantities of carbon are also contained in plant tissue and as dissolved carbon dioxide in the world’s oceans . Carbon Deposits
- 13. These locations are referred to as carbon sinks because carbon can enter or leave them over relatively short periods of time. Carbon Deposits
- 14. Human activities have a dramatic impact on the carbon cycle. By burning fossil fuels , humans release the stored carbon into the atmosphere, which is contributing to global climate change . Human Impact
- 15. Deforestation also increases the concentration of carbon dioxide in the atmosphere.
- 16. Nitrogen is extremely abundant in the atmosphere , however it is not easy to acquire directly from the abiotic environment. Nitrogen Cycle
- 17. Nitrogen enters and leaves the atmosphere through a complex biochemical pathway called the nitrogen cycle . Nitrogen Cycle
- 18. Most of the nitrogen used by living things is taken from the atmosphere by certain bacteria in a process called nitrogen fixation . Nitrogen Cycle
- 19. These micro-organisms convert nitrogen gas into a variety of nitrogen-containing compounds, including nitrates , nitrites and ammonia . Nitrogen Cycle
- 20. Lightning and UV light also fix small amounts of nitrogen.
- 21. In addition, humans add nitrogen to the soil as fertilizer . Nitrogen Cycle
- 22. Once in the soil ecosystem, the nitrogen-rich compounds are available to producers . After the nitrogen is absorbed, it is passed from producer to consumer and moves up the food chain. Nitrogen Cycle
- 23. Many animals consume more nitrogen than they can use, and excrete the excess in the form of urea or ammonia . Nitrogen Cycle
- 24. A dead organism’s nitrogen-rich compounds are taken in by decomposers , or are released back into the environment.
- 25. These compounds are either recycled again by soil micro-organisms, or they are converted by denitrifying bacteria back into nitrogen gas which then re-enters the atmosphere . Nitrogen Cycle