Biotic Factors in Ecosystems

Biotic Factors Affecting Distribution and Abundance of Organisms

• Definition of Biotic Factors: Living components of an ecosystem that influence the distribution, abundance, and survival of organisms.

• Types of Biotic Factors:

  1. Predation:

     • Top-down control on prey populations.
     • Influences prey distribution and behavior.

  2. Competition:

     • Interspecific (between different species) and intraspecific (within the same species).
     • Competing for resources like food, light, and space can limit abundance and distribution.

  3. Mutualism:

     • Interactions that benefit both species (e.g., pollinators and flowering plants).
     • Can enhance the abundance of both species involved.

  4. Parasitism:

     • Relationships where one organism benefits at the expense of another.
     • Reduces host population and can influence their distribution.

  5. Disease:

     • Pathogens can greatly affect population sizes and distribution.
     • Disease outbreaks can lead to local extinction or reduced abundance.

  6. Symbiosis:

     • Close interaction between species, which may be beneficial, neutral, or harmful.
     • Alters community structure and species distribution.

• Influence of Biotic Factors:

  • Habitat Selection:

    • Species may avoid habitats with high competition or predation risks, affecting their distribution.

  • Niche Differentiation:

    • Species evolve to occupy different niches to reduce competition, impacting their abundance.

  • Community Interactions:

    • Dynamics between species (e.g., keystone species) can shape community structure and species abundance.

• Adaptive Strategies:

  • Organisms may develop adaptations (e.g., protective structures, behaviors) in response to biotic factors, affecting survival and reproduction.

• Human Impact:

  • Habitat destruction, introduction of invasive species, and pollution can alter biotic interactions, affecting natural distribution and abundance patterns.

Biotic Factors

• Definition: Living things that influence the distribution, abundance and survival of other organisms within an ecosystem.
• Types of Biotic Factors:

  Predation

  • Predation can control the size of prey populations.
  • Prey distribution and behavior can be influenced by the presence of predators.

  Competition

  • Interspecific competition: Competition between different species.
  • Intraspecific competition: Competition within the same species.
  • Competition for resources like food, space, and light can limit the abundance and distribution of organisms.

  Mutualism

  • Both species benefit from the interaction (e.g., pollinators and flowers).
  • Can lead to an increase in the abundance of both interacting species.

  Parasitism

  • One organism benefits at the expense of another.
  • Affects host populations by reducing their abundance and influencing their distribution.

  Disease

  • Pathogens can drastically affect population size and distribution.
  • Disease outbreaks can cause local extinction or reduced abundance.

  Symbiosis

  • Close interactions between different species.
  • Can be beneficial, neutral, or harmful.
  • Influences community structure and species distribution.

Influence of Biotic Factors

• Habitat Selection: Organisms may avoid habitats with high competition or predation risks, affecting their distribution.
• Niche Differentiation: Species evolve to occupy different niches to reduce competition, influencing their abundance.
• Community Interactions: Dynamics between species can shape community structure and species abundance.
• Adaptive Strategies: Organisms develop adaptations to survive biotic factors, affecting survival and reproduction.
• Human Impact: Habitat destruction, invasive species and pollution alter biotic interactions, influencing natural distribution and abundance patterns.

Explore the various biotic factors that influence the distribution and abundance of organisms within ecosystems. This quiz covers concepts like predation, competition, mutualism, parasitism, and disease, providing insights into how these interactions shape living communities.