Carbon cycle

Definition

The carbon cycle is the process through which carbon atoms move between the Earth's atmosphere, land, water bodies, and living organisms. This cycle is crucial for maintaining the balance of ecosystems and supports biodiversity by regulating carbon dioxide levels, which are essential for photosynthesis and respiration in living organisms.

5 Must Know Facts For Your Next Test

1. The carbon cycle consists of several key processes including photosynthesis, respiration, decomposition, and combustion that collectively regulate carbon flow through different spheres of the Earth.
2. Carbon is stored in various forms such as fossil fuels, plant biomass, ocean waters, and atmospheric carbon dioxide, highlighting its dynamic movement within the cycle.
3. Human activities, particularly fossil fuel combustion and deforestation, have significantly disrupted the carbon cycle by increasing atmospheric carbon dioxide levels, contributing to climate change.
4. Ecosystems with high biodiversity tend to have more efficient carbon cycling due to a variety of species performing different roles in processes like decomposition and nutrient cycling.
5. Climate change impacts the carbon cycle by altering patterns of vegetation growth and decay, affecting both carbon sources and sinks.

Review Questions

• How do processes like photosynthesis and respiration contribute to the carbon cycle's functioning?
  • Photosynthesis allows plants to absorb carbon dioxide from the atmosphere and convert it into glucose while releasing oxygen. Respiration occurs when organisms consume this glucose for energy, resulting in the release of carbon dioxide back into the atmosphere. This interplay between photosynthesis and respiration forms a critical loop in the carbon cycle that maintains atmospheric balance and supports life.
• Discuss how human activities are influencing the natural processes of the carbon cycle.
  • Human activities such as burning fossil fuels for energy and deforestation are significantly impacting the natural processes of the carbon cycle. The combustion of fossil fuels releases large amounts of carbon dioxide into the atmosphere, which enhances the greenhouse effect and drives climate change. Deforestation reduces the number of trees available for photosynthesis, further decreasing the ability of ecosystems to sequester carbon. These actions disrupt the delicate balance of carbon storage and release within natural systems.
• Evaluate the implications of altered carbon cycling on biodiversity within ecosystems.
  • Altered carbon cycling has serious implications for biodiversity within ecosystems. Changes in atmospheric CO2 levels can shift climate patterns, leading to habitat loss for many species. Ecosystems with reduced biodiversity often face diminished resilience to these changes, making them more vulnerable to disturbances such as extreme weather events or disease outbreaks. Additionally, disruptions in nutrient cycling may impair plant growth, further reducing habitat availability for various organisms and threatening overall ecosystem stability.

Related terms

photosynthesis: The process by which green plants and some other organisms convert light energy into chemical energy in the form of glucose, using carbon dioxide and water.

respiration: The biochemical process in which living organisms convert glucose and oxygen into energy, releasing carbon dioxide and water as byproducts.

carbon sink: Natural or artificial reservoirs that absorb and store carbon dioxide from the atmosphere, such as forests, oceans, and soil.