Ecosystems: Components and Definition

Study Notes

An ecosystem is a community of living and non-living components that interact with each other in a specific environment.
It includes biotic factors (living organisms) and abiotic factors (non-living components).

Biotic factors:
- Producers (plants, algae, and some bacteria): convert sunlight into energy through photosynthesis.
- Consumers (herbivores, carnivores, omnivores): obtain energy by consuming other organisms.
- Decomposers (bacteria, fungi): break down dead organic matter into simple nutrients.
Abiotic factors:
- Light
- Temperature
- Water
- Soil
- Air
- Nutrients (e.g., nitrogen, phosphorus)

Energy flow:
- Energy from sunlight is converted into chemical energy through photosynthesis.
- Energy is transferred from one trophic level to the next through consumption.
Nutrient cycling:
- Nutrients are absorbed by producers from the soil.
- Nutrients are passed from one trophic level to the next through consumption.
- Decomposers release nutrients back into the soil.
Water cycling:
- Water is absorbed by producers from the soil.
- Water is lost through transpiration, evaporation, and runoff.
- Water is cycled back into the ecosystem through precipitation.

Symbiotic relationships:
- Mutualism (e.g., clownfish and sea anemone)
- Commensalism (e.g., remora fish and shark)
- Parasitism (e.g., tapeworm and host)
Predation:
- Predator-prey relationships
Competition:
- Resource competition (e.g., for light, water, nutrients)

Ecosystem comprises living (biotic) and non-living (abiotic) components interacting in a specific environment.

Biotic Factors:
- Producers (e.g., plants, algae): Utilize photosynthesis to convert sunlight into energy.
- Consumers: Obtain energy by consuming other organisms, categorized as herbivores, carnivores, or omnivores.
- Decomposers (e.g., bacteria, fungi): Break down dead organic matter, recycling nutrients back into the ecosystem.
Abiotic Factors:
- Include essential elements such as light, temperature, water, soil, air, and nutrients like nitrogen and phosphorus.

Energy Flow:
- Sunlight energy transforms into chemical energy via photosynthesis, forming the base for food chains.
- Energy is passed through trophic levels from producers to consumers.
Nutrient Cycling:
- Nutrients are absorbed by producers from the soil, facilitating growth.
- Through consumption, nutrients move through various trophic levels and are released back into the soil by decomposers.
Water Cycling:
- Producers extract water from the soil, with processes like transpiration releasing it back into the atmosphere.
- Water is reintroduced to the ecosystem through precipitation, maintaining the water cycle.

Terrestrial Ecosystems:
- Include forests, grasslands, and deserts, each with distinct flora and fauna.
Freshwater Ecosystems:
- Contain rivers, lakes, and wetlands, characterized by varying water levels and biodiversity.
Marine Ecosystems:
- Encompass coral reefs, estuaries, and the open ocean, hosting diverse aquatic life.
Arctic/Antarctic Ecosystems:
- Feature tundra and ice sheets, adapted to extreme cold and unique conditions.

Symbiotic Relationships:
- Mutualism: Both species gain benefits (e.g., clownfish and sea anemone).
- Commensalism: One species benefits without affecting the other (e.g., remora fish on shark).
- Parasitism: One species benefits at the cost of another (e.g., tapeworm in a host).
Predation:
- Reflects predator-prey dynamics, influencing population control and ecological balance.
Competition:
- Species compete for limited resources such as light, water, and nutrients, impacting survival and growth.