Introduction to Ecology Overview

Introduction to Ecology

• Ecology was coined by German zoologist Ernst Haeckel in 1866.
• The word "ecology" comes from the Greek word "oikos" meaning "household," "home," or "place to live."
• "Ology" means "study of."
• Ecology refers to an organism and its environment.
• Ecology is the scientific study of the distribution, abundance, and dynamics of organisms, their interaction with other organisms, and their physical environment.

Components of the Environment

• The components of the environment include both natural and human-made elements.
• Natural components include atmosphere, hydrosphere, lithosphere, and biosphere.
• Human-made components include buildings, bridges, industries, and political situations.

Ecological Terms

• Species/organism: A group of organisms with shared genes, capable of sexual reproduction to produce fertile offspring. This includes native, alien, and invasive species.
• Native species naturally occur, e.g., Red-eye tree frog, Giant river otter, Harpy Eagle.
• Alien species are introduced by humans.
• Invasive species are alien species which tend to displace native species, e.g., Tilapia, Lionfish, Cane toad, Rock Pigeon.
• Population: A group of individuals of a given species that live in a specific geographic area. It's a quantitative measure. Colonies are related organisms living closely together. Territoriality is a subset of a population.
• Community: Populations of species living in a defined area (habitat/ecosystem) and interacting in various ways. Communities can be defined by taxon (like birds), habitat (like mudflats), or ecosystem (like marine).
• Ecosystem: A biological community interacting with the abiotic components of its habitat. The habitat sets the physical parameters of the ecosystem.
• Biome: A collection of interacting ecosystems defined on broad biophysical characteristics, including Tundra (coldest), Rainforest (rain all year round), Deserts (driest), and Grasslands.
• Biosphere: The collection of all biomes; the zone of life; Earth.
• Habitat: The area in an ecosystem defined by physical and chemical characteristics suitable for a species and its life, including micro-habitats, which are small areas. These may be large as forest or small as a burrow.
• Niche: The role species plays in its community, including the type of food it eats, where it lives, and its reproductive relationship with other species.
• Interactions: Relationships between organisms that can be categorized into mutualism, commensalism, parasitism, predation, or competition.

Levels of Organization

• Organisms are the fundamental building blocks.
• Populations are groups of the same species.
• Communities are groups of different species.
• Ecosystems include both biotic and abiotic factors.
• Biomes are large-scale ecosystems.
• The biosphere encompasses all living things and their environments.

Ecological Interactions

• Interactions can be categorized into:
  • Mutualism: Both organisms benefit (e.g., Acacia tree and ants, sea anemones and clownfish).
  • Commensalism: One organism benefits while the other is neither harmed nor helped (e.g., cattle egrets and cattle, tree frogs and plants).
  • Parasitism: One organism benefits while the other is harmed, but not usually killed (e.g., tapeworms, bacteria, ticks, fleas).
  • Predation: One organism kills and consumes the other.
  • Competition: Two or more organisms access the same limited resource. This can be intraspecific (among same species) or interspecific (among different species).

Ecology as a Systems Study

• Ecology studies ecosystems, which consist of components (tangible or physical) and the processes of interaction between those components. Systems are defined by boundaries.

Ecosystem Boundaries

• Ecosystem boundaries are based on biophysical limits, but are not solid or absolute.

Ecosystem Components

• Biotic components: Living organisms (e.g., Monera, Protista, Fungi, Plantae, Animalia).
• Abiotic components: Non-living components (e.g., air, water, soil, climate). Energy connects biotic and abiotic components.

Ecosystem Processes/Structure

• Ecosystem Structure: The network of interactions between biotic and abiotic components.
• Stratification: Vertical distribution of species. Example given is rainforest structure
• Organisms: Their morphology, physiology, and behavior shape due to interactions with each other and the physical environment.
• Population: Organisms present in a given environment.
• Community: A collection of niches, which organisms fit into.
• Tropic Levels: The feeding hierarchy in an ecosystem, including producers (e.g., plants), primary consumers (e.g., herbivores), secondary consumers (e.g., carnivores), and tertiary consumers (e.g., top carnivores).

Ecological Succession

• Ecological succession is the gradual process of change and replacement of species types in a community.
• This process takes hundreds or thousands of years.
• Each community that establishes itself makes it harder for the previous community to survive.
• Primary Succession: Succession starting on bare rock.
• Secondary Succession: Succession starting in disturbed areas where soil is present.

Ecosystem Function

• Ecosystem function is about supporting life and includes biodiversity (genes-species-ecosystems), and ecological stability (which depends on diversity). High diversity/low dominance often leads to higher stability but lower productivity, and low diversity/high dominance tends to have lower stability with high productivity.

Ecosystem Services

• Ecosystem services are benefits people obtain from ecosystems. These services include regulating (e.g., air quality), supporting (e.g., habitat), provisioning (e.g., resources), and cultural (e.g., recreation).

Explore the foundational concepts of ecology, from its origins to the components of the environment. This quiz covers essential ecological terms and the interplay between organisms and their surroundings, both natural and human-made.