Environment and Ecosystem Overview

Environment and Ecosystem

• Environment encompasses all living and non-living things surrounding us.
• An ecosystem is a community where living and non-living components interact and depend on each other.
• Examples of ecosystems are forests, lakes, and oceans.
• Ecosystems are categorized as:
  • Natural ecosystems: Naturally occurring, like forests, lakes, and oceans.
  • Artificial ecosystems: Created by humans, examples include gardens and aquariums.
• Natural ecosystems are further divided into:
  • Aquatic ecosystems: Water-based, such as marine and freshwater ecosystems.
  • Terrestrial ecosystems: Land-based, including forests, deserts, and grasslands

Components of an Ecosystem

• Biotic components: Living parts of an ecosystem, encompassing plants and animals.
• Abiotic components: Non-living parts of an ecosystem, involving air, water, soil, sunlight, and minerals.
• Biotic components are categorized as follows:
  • Producers: Organisms that create their food, like plants.
  • Consumers: Organisms that rely on other organisms for food. Consumers are classified as:
    • Primary consumers (herbivores): Consume producers, for example, rats.
    • Secondary consumers (carnivores): Consume primary consumers, like cats.
    • Tertiary consumers (carnivores): Consume secondary consumers, such as tigers.
  • Decomposers: Bacteria and fungi that break down dead plants and animals, returning nutrients to the ecosystem.

Food Chain and Food Web

• Food Chain: A linear sequence describing feeding relationships, showing who eats whom.
• Food Web: A complex network of interconnected food chains, illustrating diverse feeding relationships.
• Trophic levels: An organism's position in a food chain, representing its feeding level:
  • Trophic level 1: Producers (plants)
  • Trophic level 2: Primary consumers (herbivores)
  • Trophic level 3: Secondary consumers (carnivores)
  • Trophic level 4: Tertiary consumers (top carnivores).

10% Law of Energy

• Only 10% of energy transfers from one trophic level to the next. The remaining 90% is lost as heat or used in life processes.
• This limits food chains to typically three or four trophic levels due to dwindling energy.

Biomagnification and Bioaccumulation

• Biomagnification: Toxic chemicals concentrate in higher trophic levels as organisms consume others with accumulated toxins.
• Examples: Mercury builds up in fish, potentially impacting humans.

Garbage Disposal and Management

• Garbage types:
  • Biodegradable waste: Breaks down through microorganisms, like vegetable scraps.
  • Non-biodegradable waste: Doesn't break down by microorganisms, such as plastic.
• Waste management methods include:
  • Biogas plants: Convert biodegradable waste into biogas.
  • Sewage treatment: Cleans wastewater.
  • Landfilling: Buries non-biodegradable waste.
  • Composting: Decomposes biodegradable waste into fertilizer.
  • Recycling and reuse: Reprocesses or reuses materials.
  • Incineration: Burns waste at high temperatures to reduce volume and sterilize hazardous materials.

Ozone Layer Depletion

• Ozone (O3): Atmospheric layer absorbing harmful UV radiation.
• Ozone depletion: Thinning of the ozone layer due to harmful chemical releases, mainly CFCs.
• CFCs: Released from refrigerants, air conditioners, and industrial processes.
• CFC breakdown in the stratosphere releases chlorine atoms, reacting with and destroying ozone molecules.
• Consequences of depletion: Increased UV radiation, increasing health concerns such as skin cancer and cataracts.
• UNEP: Works on international agreements, like the Montreal Protocol, to phase out ozone-depleting substances.