Essential Concepts of Population Ecology and Species Interaction

Biology13 May 20262.7 KB

Core Concepts of Population Ecology

Population: A group of individuals of the same species inhabiting a given area at a given time.
Birth: The number of births in a proportional population within a given time.
Mortality: The number of dead individuals in a population during a given period.
Habitat: The environment where an individual or group typically develops.
Density: The number of individuals per unit of area or volume, depending on the ecosystem.

These interactions define how species coexist within a community:

Symbiotic Relationships: Interactions where one or both species are closely associated.
Antagonistic Relationships: Interactions where one or both species are harmed.

Mutualism: Occurs when two different species are interrelated and become mutually dependent.
Commensalism: A relationship where one of the two species involved receives a benefit.
Renters: A form of commensalism where an individual lives in the nest, burrow, or shelter of another species.

Competition: Occurs when species living in the same area compete for resources necessary for survival.
Parasitism: A relationship where a parasite feeds on a host, which may lead to the host's death.
- Endoparasites: Parasites that live inside the host (e.g., tapeworms).
- Ectoparasites: Parasites that live on the outside of the host (e.g., ticks).
Predation: A relationship where one species consumes another.
Antibiosis: A relationship where one species excretes a substance that is toxic to other species.

The Population Growth Rate is the numerical relationship between population change and the existing base, expressed as a percentage.

TC = TN - TM + (TI - TE)

TN (Birth Rate): (Number of births / Total number of individuals) × 100 or 1000.
TM (Mortality Rate): (Number of deaths / Total number of individuals) × 100 or 1000.
IT (Immigration Rate): (Number of immigrants / Total number of individuals) × 100 or 1000.
TE (Emigration Rate): (Number of emigrants / Total number of individuals) × 100 or 1000.