Population Interactions and Dynamics
This page delves deeper into population interactions and dynamics, exploring how different species interact and the factors that influence population growth over time.
Population interactions can take various forms:
- Parasitism (+/-): The parasite benefits while the host is harmed.
- Competition (-/-): Both species suffer as they compete for resources.
- Mutualism (+/+): Both partners benefit from the interaction.
Example: Lichens are a classic example of mutualism, where fungi and green algae form a symbiotic relationship that benefits both partners.
Predator-prey interactions are a crucial aspect of population dynamics. These interactions typically show cyclical patterns, with predator populations lagging behind prey populations.
Highlight: The number of predators is usually significantly lower than the number of prey in a predator-prey system.
Population growth can be expressed by the equation:
Population growth = (births - deaths) + (immigration - emigration)
In closed systems without migration, population dynamics are primarily influenced by births, deaths, and seasonal effects.
Species can be classified based on their life history strategies as either r-selected or K-selected:
- r-selected species: Small body size, short life cycle, rapid reproduction, high dispersal ability
- K-selected species: Large body size, long life cycle, few offspring, low dispersal ability
Vocabulary: A community is the sum total of all populations in a particular area, including interactions between autotrophic and heterotrophic populations.
Definition: Succession refers to changes over time in ecosystems, reflecting the dynamic nature of ecological communities.
