Species Interactions I

  1. Distinguish between the five (7 if you split up consumptive interactions) types of interspecific interaction and describe the effect of each interaction on the fitness of participants

  2. Explain how species interaction outcome, and even type, can change with different environmental conditions.

Species Interaction Outcome in Different Environments:

Species interactions can vary based on environmental conditions. For example, competition may intensify in resource-limited environments, leading to shifts in dominance or even coexistence strategies. Predation rates may change with habitat structure, affecting prey populations. Mutualistic relationships may be disrupted by environmental stressors, altering the benefits exchanged. Overall, environmental conditions play a crucial role in shaping the type and outcome of species interactions.

  1. Explain how complete resource overlap leads to competitive exclusion while resource partitioning can allow two species to coexist.

  • Complete Resource Overlap: Leads to competitive exclusion as two species compete for the same resources, causing one species to outcompete the other, leading to extinction.

  • Resource Partitioning: Allows two species to coexist by dividing resources, reducing competition and enabling each species to thrive in their niche.

    1. Define a trophic cascade and give a specific example

Trophic Cascade:A trophic cascade is an ecological phenomenon where changes in the population of a species at one trophic level can influence populations at other trophic levels.Example:The reintroduction of wolves in Yellowstone National Park led to a trophic cascade where the increased wolf population resulted in a decrease in elk population, allowing vegetation to regenerate.

  • Define the following terms: competition, coexistence, intraspecific, interspecific, limiting resource, consumption, predation, herbivory, parasitism, mutualism, commensalism, amensalism, resource partitioning, competitive exclusion, species distribution, primary producer, autotroph, heterotroph, primary consumer, secondary consumer, tertiary consumer, decomposer, trophic levels, food webs, trophic cascade

  • Competition: Interaction where organisms compete for resources.

  • Coexistence: Multiple species living together in an ecosystem.

  • Intraspecific: Interaction between individuals of the same species.

  • Interspecific: Interaction between individuals of different species.

  • Limiting resource: Resource that limits population growth.

  • Consumption: Process of using resources for energy.

  • Predation: One organism consuming another.

  • Herbivory: Consumption of plants by animals.

  • Parasitism: One organism benefits at the expense of another.

  • Mutualism: Both organisms benefit from the interaction.

  • Commensalism: One organism benefits, the other is unaffected.

  • Amensalism: One organism is harmed, the other is unaffected.

  • Resource partitioning: Species divide resources to coexist.

  • Competitive exclusion: One species outcompetes another.

  • Species distribution: Geographic range of a species.

  • Primary producer: Organism that produces its own food.

  • Autotroph: Organism that produces its own food.

  • Heterotroph: Organism that consumes other organisms.

  • Primary consumer: Eats primary producers.

  • Secondary consumer: Eats primary consumers.

  • Tertiary consumer: Eats secondary consumers.

  • Decomposer: Breaks down dead organisms.

  • Trophic levels: Position in the food chain.

  • Food webs: Interconnected food chains.

  • Trophic cascade: Impact of changes in one trophic level on others.