Nutrient Cycles and Carbon Cycle

Nutrient Cycles

• Nutrient cycles have three stages: input, throughput, and output
• Input: nutrients enter an organism through various means, such as breathing or eating
• Throughput: nutrients are used by the organism for growth and function
• Output: waste matter is eliminated and unneeded nutrients are returned to the environment

Carbon Cycle

• The carbon cycle involves the movement of carbon between the atmosphere, plants, animals, and the ground
• Carbon flows from the atmosphere to plants and oceans, then to animals, and finally to the ground and fossil fuels
• Carbon sequestration is the process by which carbon sinks remove CO2 from the atmosphere

Nitrogen Cycle

• The nitrogen cycle involves the movement of nitrogen between the atmosphere, soil, water, plants, and animals
• Nitrogen flows from the atmosphere to soil and water, then to plants and animals, and finally back to soil and water

Energy and Matter

• Energy flows through an ecosystem, while matter cycles
• Energy and matter constantly circulate through ecosystems

Carbon Stores

• Short-term carbon stores include living things, rotting tissues, the atmosphere, and plants
• Long-term carbon stores include underground oil, natural gas, coal, sedimentary rock limestone, and the ocean floor

Human Impact on Carbon Cycle

• Human activities, such as burning fossil fuels and deforestation, affect the carbon cycle
• Burning fossil fuels releases CO2 into the atmosphere, increasing the concentration of CO2 by 30% in the past 160 years
• Deforestation releases CO2 into the atmosphere, as trees absorb CO2 during their growth

Human Impact on Nitrogen Cycle

• Human activities, such as industrial fertilizers and automobile emissions, disrupt the nitrogen cycle balance
• Industrial fertilizers harm soil and trees, while nitrogen gases from industries and automobiles cause acid precipitation
• Excess nitrogen ends up in ecosystem water

Water Cycle

• The water cycle involves the movement of water between the atmosphere, land, and oceans
• The process includes evaporation, condensation, precipitation, and infiltration
• Only 3% of the Earth's water is freshwater, and most of it is found in glaciers and ice caps

Human Impact on Water Cycle

• Human activities affect the water cycle, reducing the availability of freshwater

Phosphorus Cycle

• Phosphorus helps form important molecules like DNA and RNA
• Phosphorus exists in the form of inorganic phosphate, which is released into the soil and water as sedimentary rock is eroded
• Human activities, such as mining phosphate rock for fertilizers and detergents, impact the phosphorus cycle
• Phosphorus is not found as a gas and takes millions of years to replenish
• Cultural eutrophication, caused by livestock waste and municipal sewage, leads to eutrophication

Greenhouse Effect

• The greenhouse effect involves the trapping of heat by greenhouse gases, such as CO2 and methane
• The increased concentration of greenhouse gases due to human activities, such as burning fossil fuels, accelerates climate change

Photosynthesis and Cellular Respiration

• Photosynthesis: converting solar energy into usable chemical energy
• Cellular respiration: releasing energy in sugar to be used by the organism
• Photosynthesis: CO2 + H2O + Solar Energy → C6H12O6 + O2
• Cellular respiration: C6H12O6 + O2 → CO2 + H2O + Energy

Eutrophication

• Eutrophication: excess nutrients in a lake, leading to increased plant growth and decomposition
• Nitrogen runoffs in lakes and ponds increase plant growth, hindering deeper photosynthesis, leading to decomposers feeding on decaying matter, causing further oxygen decline and animal death

Food Web

• A simple food web consists of four stages: producers, primary consumers, secondary consumers, and tertiary consumers
• Producers: plants and algae that convert sunlight into energy
• Primary consumers: herbivores that feed on producers
• Secondary consumers: carnivores that feed on primary consumers
• Tertiary consumers: apex predators that feed on secondary consumers