Ecosystems: Essential Cycles and Interactions
An ecosystem is defined by the interaction of organisms (biotic factors) with their environment (abiotic factors).
A sustainable ecosystem maintains a balance of resources, environment, and biodiversity over time.
Water’s Role: Water is essential for survival, photosynthesis, nutrient transport, temperature regulation, and habitat.
Components of an Ecosystem
- Biotic Components: Organisms like plants and animals.
- Abiotic Components: Non-living things like water, nutrients (nitrogen, phosphorus), and climate.
Nutrient Cycling
Nutrient cycling is essential for resource sustainability. It occurs in the lithosphere, hydrosphere, atmosphere, and biosphere.
Main Cycles
- Water Cycle: Includes processes like transpiration, percolation, and runoff.
- Carbon Cycle: Involves photosynthesis, respiration, decomposition, and the extraction of fossil fuels.
- Nitrogen Cycle: Involves nitrogen fixation, nitrification, denitrification, and human impacts like fertilizer use, leading to eutrophication.
Photosynthesis vs. Cellular Respiration
These are complementary processes; one produces what the other uses.
Human Impact: Burning fossil fuels and deforestation affect the carbon cycle, increasing atmospheric CO2.
Photosynthesis/Respiration Importance: These processes convert light to chemical energy, release energy for life functions, and cycle oxygen and carbon dioxide.
Energy Flow vs. Nutrient Cycling
- Energy Flow: Energy flows one way (sun to producers to consumers).
- Nutrient Cycling: Nutrients recycle within the ecosystem.
Food Web Energy
Most energy is found in green plants, and then it decreases through trophic levels (e.g., grasshoppers, frogs, birds, snakes, falcons).
Energy Usage: Only about 10% of consumed energy is incorporated into the consumer’s tissues; the rest is used or lost as heat.
Memory Aid for Science
- Photosynthesis
- Cellular Respiration
- Biosphere
- Lithosphere
- Hydrosphere
Photosynthesis: Carbon dioxide + water + light energy → glucose + oxygen
Cellular Respiration: Glucose + oxygen → carbon dioxide + water vapor + usable energy
Biosphere: Earth’s only sphere where there are living organisms.
Lithosphere: Earth’s land.
Hydrosphere: Where water is located.
Atmosphere: Air and gases above Earth’s surface.
Water Cycle Processes
Evaporation: When water is heated and changes from liquid to gas/vapor/steam.
Condensation: When water condenses from vapor to form clouds.
Precipitation: When the condensation in the clouds becomes too heavy and is released as rain, snow, or hail.
Runoff: Water not absorbed by the land that flows to nearby water bodies like lakes, ponds, rivers, or oceans.
Carbon Cycle Steps
- Photosynthesis
- Cellular Respiration
- Cellular Respiration
- Eaten
- Eaten
- Death
- Death
- Death
- Decomposition
- Burning Fossil Fuels
- Burning Plants
- Burning Fossil Fuels
- Decomposition
Nitrogen Cycle Steps
A – Nitrogen Gas in Atmosphere
B – Nitrogen Fixation
D – Nitrogen Fixing Bacteria
E – Decomposition
F – Nitrification
G – Nitrifying Bacteria
J – Eaten
K – Denitrification
Chlorophyll helps with photosynthesis.
Cellular respiration is when living organisms use glucose for energy by breaking it down.