Ekologi: Uholo Nsɛm a wɔda ho adi

Ekologi

• Ekologi is the study of the relationships between living things and their environment.
• The word "ecology" comes from the Latin words "oikos" (home or habitat) and "logos" (study).
• It was introduced by Ernest Haeckel (1834-1914).
• The environment of living things is made up of two kinds of components:
  • Biotic environment ( producers, consumers, decomposers)
  • Abiotic environment ( physical and chemical components)

Interactions of Living Organisms with their Environment

• Interactions between individuals: Competition between individuals in the same species (intraspecific competition).
• Interactions between populations:
  • Competition: Competition between populations (interspecific competition) occurs when populations need the same resources, but those resources are limited.
  • Symbiosis: A close relationship between organisms living together. This includes mutualism, commensalism, parasitism, amensalism, and protocooperation.
  • Predation: The interaction between a predator and its prey.

Interactions between biotic and abiotic components

• Niche (role): The unique position and function of an organism in an ecosystem
• Four categories of organisms according to their role:
  • Producers (autotrophs)
  • Consumers (heterotrophs)
  • Decomposers (decomposers)
  • Detritivores
• Decomposers (breakdown of organic matter to inorganic matter)
  • Examples include bacteria and fungi.
• Detritivores (consume organic matter)
  • Examples include earthworms, snails, and millipedes.

Ecosystems

• Ecosystems: Relationships between living things and their environments
• Three types of ecosystems:
  • Aquatic ecosystems:
    • Freshwater ecosystems:
      • Lotic (flowing): rivers and streams
      • Lentic (still): lakes and ponds
    • Marine ecosystems:
      • Coastal (e.g., estuaries, beaches)
      • Shallow-water reefs
      • Open ocean
  • Terrestrial ecosystems
    • The structure of these are dominated by plants.
    • Seven categories of biome are classified based on dominant vegetation and climate types:
      • tropical rainforests, savannas, grasslands, deserts, temperate deciduous forests, taigas, and tundra.
  • Artificial ecosystems: Ecosystems created or significantly modified by humans (e.g., farms, urban areas).

Food Chains and Food Webs

• Food chain: A linear sequence of organisms where each organism eats the one before it.
  • Example: Grass => grasshopper => frog => snake => hawk
• Food web: A network of interconnected food chains in an ecosystem with many interactions.

Types of Food Chains

• Grazing food chain: Start with producers (plants) and include herbivores and carnivores
• Detritus food chain: Starts with dead organic matter (detritivores)

Ecological Pyramids

• Energy pyramids: Show the flow of energy through trophic levels; energy decreases as it moves from one trophic level to the next.
• Biomass pyramids: Indicate the dry weight of the organisms at different trophic levels.
• Number pyramids: Show the number of organisms at each trophic level.

Biogeochemical Cycles

• Biogeochemical cycles are the movement and transformation of nutrients and mineral elements within ecosystems.
• Four cycles specifically discussed in this material:
  • Water cycle
  • Carbon cycle
  • Nitrogen cycle
  • Phosphorus cycle
  • Sulfur cycle

Ecological Succession

• Ecological succession: The gradual change in the species composition of a community over time.
• Two types of succession are:
  • Primary succession: Occurs on newly exposed land, devoid of previous life. (e.g., volcanic islands, glaciers).
  • Secondary Succession: Occurs on land that has been cleared of life or habitat. (e.g., forests cleared for farming)

Climax Community

• Climax community is the stable, final community that is established during ecological succession.