Basic Concepts of Ecology

Table of Contents

Ecology is the study of how organisms interact with each other and their environment.
The term ecology is derived from the Greek words oikos (household) and logos (study).
The environment refers to the surrounding conditions and factors that affect the life and development of living organisms.

The interactions between organisms and their environment.
The transfer of energy and nutrients within ecosystems.
The mechanisms that maintain ecosystem stability and resilience.
The importance of biodiversity and sustainable practices to conserve ecosystems.

Ecology examines organisms and their environment across various levels:

Organism: A single living individual (e.g., a lion).
Population: A group of individuals of the same species living in a specific area (e.g., a pride of lions).
Community: All populations of different species in an area, interacting with each other (e.g., lions, zebras, and grasses in a savanna).
Ecosystem: The community of living organisms (biotic) interacting with non-living components (abiotic) like water, soil, and air (e.g., the savanna ecosystem).
Biome: Large areas with similar climate, flora, and fauna (e.g., tropical rainforest, desert).
Biosphere: The global ecological system, encompassing all ecosystems on Earth.

Abiotic Components: Non-living factors such as sunlight, temperature, water, soil, and air that influence living organisms.
Biotic Components: Living organisms, including producers (plants), consumers (animals), and decomposers (fungi and bacteria).

Energy enters ecosystems primarily through sunlight, which is captured by producers (plants) via photosynthesis.
Energy flows through the ecosystem in a food chain or food web, from producers to consumers to decomposers.
At each trophic level, energy is lost as heat due to metabolic activities, following the 10% energy rule.

Essential elements like carbon, nitrogen, phosphorus, and water cycle through the biotic and abiotic components of the ecosystem.
Biogeochemical Cycles ensure that nutrients are reused and made available to organisms over time.

Habitat: The physical location or environment where an organism lives (e.g., a pond, forest, or desert).
Niche: The specific role or function of an organism in its ecosystem, including its feeding habits, behavior, and interactions (e.g., bees pollinating flowers).

Organisms develop specific traits to survive in their environment (e.g., camels storing water to survive in deserts).

Homeostasis: Ecosystems maintain a balance through feedback mechanisms (e.g., predator-prey relationships).
Succession: Ecosystems evolve over time, transitioning from simpler communities to more complex ones.

Refers to the variety of life within an ecosystem, including genetic, species, and ecosystem diversity.
High biodiversity increases the stability and resilience of ecosystems.

Organisms depend on one another and their environment for survival. For example:
- Producers provide energy for consumers.
- Decomposers recycle nutrients for producers.

The maximum number of individuals an environment can support without degrading its resources.

Intraspecific Interaction: Occurs between members of the same species (e.g., competition for mates).
Interspecific Interaction: Occurs between members of different species, including:
- Predation: One organism preys on another.
- Competition: Organisms compete for resources like food and space.
- Symbiosis: Close interactions between species, such as:
  - Mutualism: Both species benefit (e.g., bees and flowers).
  - Commensalism: One benefits, the other is unaffected (e.g., barnacles on whales).
  - Parasitism: One benefits, the other is harmed (e.g., ticks on dogs).

Represent the structure of ecosystems in terms of energy, biomass, or numbers:
- Energy Pyramid: Shows energy flow across trophic levels.
- Biomass Pyramid: Depicts the total mass of organisms at each level.
- Numbers Pyramid: Displays the number of organisms at each trophic level.