Introduction to Ecology
Definition of Ecology
- Study of interactions among organisms and between organisms and their physical environment.
Key Vocabulary
- Habitat: The place where an organism lives.
- Population: All individuals of a particular species.
- Community: Multiple species interacting in a given area.
- Ecosystem: Includes both the community of species and abiotic factors like water, light, and soil.
- Biosphere: All communities on Earth, encompassing terrestrial, aquatic, and atmospheric environments.
Ecological Levels
- Single organism (e.g., a fish)
- Population of a species
- Community interactions
- Ecosystem including abiotic factors
Demography
- Statistical study of populations.
- Focuses on population density, distribution, and growth rates.
- Factors influencing growth include birth and death rates.
Biotic Potential
- Maximum rate of natural increase when resources are unlimited.
- Influenced by factors like offspring number, survival rate, reproductive frequency, and age at reproduction.
Mortality Patterns
- Cohort: Group of organisms born at the same time.
- Survivorship curves: Types showing different mortality rates (e.g., grasses, reptiles, insects).
Age Distribution
- Three major groups: pre-reproductive, reproductive, post-reproductive.
- Age distribution helps predict future population changes.
Population Growth
- Logistic Growth: Growth that is controlled by environmental resistance.
- Carrying Capacity: Max number of individuals an environment can support sustainably.
- Density Independent Factors: Natural disasters that affect populations regardless of density.
- Density Dependent Factors: Factors like competition and predation that increase with population density.
Life History Patterns
- R-strategists: Opportunistic species with high fecundity, early maturity, short lifespan, and little parental care.
- K-strategists: Equilibrium species with low fecundity, late maturity, long lifespan, and extensive parental care.
Human Population Growth
- Expected to double every 52 years.
- Predicted to reach 12 billion by 2050.
- Important to consider resources and potential consequences of unchecked growth.
Developed vs. Less Developed Countries
- More Developed Countries: Slow population growth, high standard of living, controlled birth rates.
- Less Developed Countries: Rapid population growth, lower standard of living, strategies needed to reduce growth (e.g., family planning).
Environmental Impact
- Population size, resource consumption, and pollution.
- More developed countries have higher resource consumption and waste production.
These notes summarize the key points from the introductory lecture on ecology, focusing on terminology, population dynamics, and environmental implications.