What is an Ecosystem?

An ecosystem is a community of living organisms (plants, animals, and microbes) interacting with each other and their non-living environment (air, water, soil) in a specific area. Ecosystems can be as small as a puddle or as large as a forest or ocean.

Components of an Ecosystem

  • Biotic Factors: Living things (plants, animals, bacteria, fungi)
  • Abiotic Factors: Non-living things (sunlight, water, minerals, temperature)

Ecosystems rely on the flow of energy and the cycling of nutrients to sustain life.

Food Chains and Food Webs

Food Chain

A food chain shows how energy and nutrients flow from one organism to another in a linear sequence.

  • Producer: Usually a green plant or algae; makes its own food using sunlight.
  • Primary Consumer: Herbivore; eats producers.
  • Secondary Consumer: Carnivore; eats primary consumers.
  • Tertiary Consumer: Top predator; eats secondary consumers.
  • Decomposer: Breaks down dead organisms; recycles nutrients.

Food Web

A food web is a complex network of interconnected food chains within an ecosystem. It shows how different organisms are linked by what they eat.

Food Web Diagram

Mind Map: Ecosystems and Food Webs

Mind Map

Case Studies

1. Coral Reef Ecosystem

  • Location: Tropical oceans
  • Key Species: Coral polyps, fish, sea turtles, algae
  • Food Web: Algae are producers; small fish eat algae; larger fish eat small fish; sharks eat larger fish; decomposers recycle nutrients.
  • Threats: Overfishing, climate change, pollution (including plastic).

2. Deep Ocean Ecosystem

  • Location: Mariana Trench, Pacific Ocean
  • Key Species: Deep-sea fish, tube worms, bacteria
  • Food Web: Bacteria use chemicals from hydrothermal vents; tube worms eat bacteria; fish eat tube worms.
  • Surprising Fact: Plastic pollution has been found even in the deepest parts of the ocean, affecting food webs at extreme depths (Jamieson et al., 2020).

3. Urban Ecosystem

  • Location: Cities and towns
  • Key Species: Pigeons, rats, insects, humans, trees
  • Food Web: Trees produce food; insects eat plants; birds eat insects; decomposers break down waste.
  • Impact: Human activities (waste, pollution) can disrupt food webs.

Surprising Facts

  1. Plastic pollution has reached the deepest ocean trenches. Microplastics were found in organisms living at 10,000+ meters below sea level (Nature, 2020).
  2. Some plants are carnivorous. For example, Venus flytraps and pitcher plants eat insects, adding a twist to traditional food webs.
  3. Decomposers are essential but often invisible. Without bacteria and fungi, dead matter would pile up and nutrients would not return to the ecosystem.

How Does This Topic Impact Daily Life?

  • Food Choices: The health of ecosystems affects the availability and quality of food (fish, fruits, vegetables).
  • Pollution: Plastic and chemical pollution disrupts food webs, which can lead to fewer fish in the ocean or unhealthy crops.
  • Biodiversity: Healthy ecosystems provide clean air, water, and fertile soil. Losing species from food webs can make ecosystems less resilient.
  • Climate: Plants and trees in ecosystems absorb carbon dioxide, helping to regulate climate.

Recent Research

A 2020 study published in Nature Scientific Reports found microplastics in amphipods collected from the Mariana Trench, the world’s deepest ocean point. This discovery shows that human pollution has reached even the most remote and extreme ecosystems, impacting food webs at all levels (Jamieson et al., 2020).

Summary Table: Key Terms

Term Definition
Ecosystem Community of living and non-living things interacting together
Food Chain Linear sequence showing who eats whom
Food Web Complex network of interconnected food chains
Producer Organism that makes its own food (usually plants)
Consumer Organism that eats other organisms
Decomposer Organism that breaks down dead material
Biodiversity Variety of living things in an ecosystem

Diagram: Food Chain Example

Food Chain Example

Review Questions

  1. What is the difference between a food chain and a food web?
  2. Name two abiotic factors in an ecosystem.
  3. How does plastic pollution affect deep ocean food webs?
  4. Why are decomposers important in ecosystems?
  5. How do ecosystems impact your daily life?

References

  • Jamieson, A.J., et al. (2020). Microplastics and synthetic particles ingested by deep-sea amphipods in the Mariana Trench. Nature Scientific Reports, 10, 6630. Read Article

End of Study Notes