Community Ecology Flashcards

Community and Community Ecology

• A community consists of multiple species within a specific area, interacting and influencing one another.
• Community ecology examines the interactions among species in a community, focusing on how these relationships create functional ecosystems.

Tolerance Range

• Tolerance range determines where a species can distribute itself, influenced by its specific environmental limits.
• Factors dictating tolerance range include life cycle traits, interspecies interactions, and the individual species' survival capabilities in varying abiotic conditions.
• A species' tolerance range helps define the community's species composition.

Community Distinctions

• Sharp boundaries between communities often arise from significant biotic or abiotic environmental changes.
• However, communities are typically not sharply defined due to gradual environmental gradients, leading to intermingling.

Ecological Niche

• An ecological niche describes the specific role of a species within its community, considering both biotic and abiotic factors.
• Examples of ecological niches include habitat, food sources, and predator-prey relationships.

Niche Types

• Fundamental niche: Theoretical niche an organism could occupy without any restrictions from other species, based exclusively on abiotic conditions.
• Realized niche: The actual niche a species occupies, accounting for competition and predation within a community.

Interactions in Ecology

• Various interactions define relationships among species:
  • Competition: Negative impact on both parties.
  • Mutualism: Benefits both species involved.
  • Predation/Parasitism: Harms one organism while benefiting another.
  • Commensalism: One organism benefits, and the other remains unaffected.
  • Amensalism: One species is harmed while the other is unaffected.

Competition Dynamics

• Competition occurs when multiple organisms vie for resources such as food and space.
• It's categorized into:
  • Interspecific competition: Between different populations.
  • Intraspecific competition: Within a single population.
• Consumptive competition involves organisms competing for identical nutrients.

Competitive Exclusion Principle

• Two species cannot coexist indefinitely if they share the same niche; one species will dominate, forcing the other to adapt or perish.

Prey Defenses

• Ongoing threats from predators stimulate the evolution of prey defenses.
• Types of prey defenses include:
  • Mechanical defenses: Physical traits that deter predators.
  • Safety in numbers: Group protection against predation.
  • Colouration: Cryptic or warning colors that can confuse or deter predators.
  • Mimicry: Adaptations where one species resembles another to avoid predation.

Mimicry Types

• Mullerian mimicry: Harmful prey species resemble one another, reinforcing avoidance by predators.
• Batesian mimicry: Harmless prey mimics the appearance of harmful prey, deterring predators due to mistaken identity.

Symbiosis

• Symbiosis refers to the close association and co-evolution of different species, resulting in varying levels of interaction and impact between them.