Ecology Basics

Ecology

Definition

• Study of the interactions between organisms and their environment
• Examines the relationships between biotic (living) and abiotic (non-living) factors in an ecosystem

Levels of Organization

• Ecosystem: community of organisms and their physical environment
• Community: group of different species living in a specific area
• Population: group of individuals of the same species living in a specific area
• Organism: individual living thing
• Ecosystem Services: benefits humans derive from functioning ecosystems (e.g., clean air, water, food)

Ecological Relationships

• Predation: one organism captures and consumes another
• Competition: organisms compete for limited resources
• Symbiosis: close, long-term relationships between different species
  • Mutualism: both species benefit
  • Commensalism: one species benefits, the other unaffected
  • Parasitism: one species benefits, the other harmed

Ecosystem Components

• Producers: organisms that make their own food (e.g., plants, algae)
• Consumers: organisms that obtain energy by consuming other organisms
  • Herbivores: consume plants
  • Carnivores: consume animals
  • Omnivores: consume both plants and animals
• Decomposers: organisms that break down dead organic matter (e.g., bacteria, fungi)

Energy Flow

• Energy Pyramid: represents the flow of energy through an ecosystem
• Trophic Levels: each level represents a step in the energy flow
  • Producers (1st trophic level)
  • Primary consumers (2nd trophic level)
  • Secondary consumers (3rd trophic level)
  • Tertiary consumers (4th trophic level)

Ecological Succession

• Primary Succession: development of a new ecosystem in a previously uninhabited area
• Secondary Succession: recovery of an ecosystem after a disturbance
• Climax Community: stable, mature ecosystem reached after succession

Ecology

Definition and Scope

• Ecology is the study of interactions between organisms and their environment, examining relationships between biotic and abiotic factors.
• It encompasses the study of ecosystem structure, function, and interactions within ecosystems.

Levels of Organization

• An ecosystem consists of a community of organisms and their physical environment.
• A community comprises different species living in a specific area.
• A population is a group of individuals of the same species living in a specific area.
• An organism is an individual living thing.
• Ecosystem services are benefits humans derive from functioning ecosystems, including clean air, water, and food.

Ecological Relationships

• Predation involves one organism capturing and consuming another.
• Competition occurs when organisms vie for limited resources.
• Symbiosis refers to close, long-term relationships between different species, which can be mutualistic, commensalistic, or parasitic.

Ecosystem Components

• Producers, such as plants and algae, make their own food through photosynthesis.
• Consumers obtain energy by consuming other organisms, including herbivores, carnivores, and omnivores.
• Decomposers, such as bacteria and fungi, break down dead organic matter.

Energy Flow

• Energy pyramids represent the flow of energy through an ecosystem, with each trophic level representing a step in energy transfer.
• Trophic levels include producers (1st), primary consumers (2nd), secondary consumers (3rd), and tertiary consumers (4th).

Ecological Succession

• Primary succession involves the development of a new ecosystem in a previously uninhabited area.
• Secondary succession is the recovery of an ecosystem after a disturbance.
• The climax community is the stable, mature ecosystem reached after succession.