Carrying Capacity and Population Dynamics
The carrying capacity is a fundamental concept in ecology, defined as the maximum population size that a particular habitat can sustain indefinitely. This page explores the factors affecting carrying capacity and the phases of population growth.
Factors influencing carrying capacity include physical and chemical aspects of the environment such as pH, mineral nutrients, light intensity, temperature, water availability, aspect, topography, and oxygen and carbon dioxide concentrations. These elements collectively determine the resources available to a population.
Definition: Carrying capacity is the maximum population size for a species that can be sustained in a particular habitat.
The standard growth curve of a population consists of four distinct phases:
- Lag phase: Characterized by a small population and acclimatization to the environment.
- Log phase: Rapid growth with abundant resources and minimal competition.
- Stationary phase: Population reaches carrying capacity, with some limiting factors emerging.
- Death phase: Resources are depleted, and waste products become toxic, leading to population decline.
Highlight: Understanding the phases of population growth is crucial for managing ecosystems and predicting population dynamics.
Human activities can significantly impact carrying capacity. For instance, culling may be used to control invasive species or manage populations that have grown beyond sustainable levels.
Example: Culling programs might be implemented to replace a lost predator when prey populations grow out of control.
The page also introduces the concepts of r-selected and K-selected species, which represent different evolutionary strategies:
• r-selected species: Fast reproduction, early maturity, little parental care, shorter lifespans (e.g., insects, some fish)
• K-selected species: Slow reproduction, late maturity, extended parental care, longer lifespans (e.g., elephants, humans)
Vocabulary: r-selected species are typically pioneer species that can quickly colonize new environments, while K-selected species are often found in more stable, established ecosystems.
Lastly, the page discusses density-dependent and density-independent factors affecting population dynamics. Density-dependent factors, such as food supply and intraspecific competition, become more significant as population density increases. Density-independent factors, like catastrophic environmental events, affect populations regardless of their density.
