Principles of Ecology

Bell Ringer How do these organisms interact with one another and with the non-living aspects of the environment?

Organisms and Their Environment Ecology is the study of interactions that take place between organisms and their environment. Most ecologists use both descriptive and quantitative research. They obtain descriptive information by observing organisms. They obtain quantitative information based on measurements and conducting experiments.

The Biosphere The biosphere is the portion of the Earth that supports life. Abiotic factors (non-living) include air currents, temperature, moisture, light and soil. Biotic factors (living) includes plants, animals and bacteria.

Levels of Organization We can think about the interactions and types of living things by organizing them into groups, smallest to largest. A species includes only one type of organism. Example: hawks A population includes all members of one species that live in the same area. Example: all the hawks in Santa Fe

An ecosystem includes both the community and the abiotic factors. A community includes all of the different species that live in the same area. Example: all the pigeons, ants, maple trees, dogs, etc. that live in Santa Fe An ecosystem includes both the community and the abiotic factors. Example: the Santa Fe community plus the cars, buildings, rocks, air…

Levels of Organization species community population ecosystem

Organisms in an Ecosystem Habitat: a place where an organism lives out its life. Example: trout in a stream, birds in a forest. Niche: role or position a species has in its environment, includes all biotic and abiotic interactions as an animal meets its needs for survival and reproduction. Example: birds need to specialize in what they eat, hummingbird drink nectar, sparrows eat bugs and seeds.

Species interactions Mutualism (+/+) Commensalism (+/0) Parasitism (+/-) Competition (-/-) + benefit, - detriment, 0 no effect

Mutualism (+/+) Both participants benefits from the interaction. Here the clownfish finds protection in the sea anemone. The sea anemone receives food from the clownfish.

Commensalism (+/0) Cattle egrets forage for insects near large mammals. The movement of the large animal flush out insects, which the birds eat. The mammal does not gain or lose anything from this interaction.

Parasitism or Predator/ Prey (+/-) Predator benefits from the death of their prey. Parasites benefit from entering another organism. They gain shelter and food. The host organism may or may not suffer from this interaction.

Competition (-/-) Two similar organisms living in the same niche are in competition for food, water and shelter. The stronger of the two will survive, or one organism will have to learn to adapt.

The Roles of Organisms 1. Producer (autotroph) Here are some important terms that will help you describe interactions in a food web. 1. Producer (autotroph) can make its own food forms the base of the food web Plants, trees, grass… etc.

2. Consumer (heterotroph) cannot make its own food There are several words that describe consumers… Prey: the hunted Predator: the hunter Herbivore: eats plants Carnivore: eats animals Omnivore: eats both plants and animals Scavenger: eats the remains of dead organisms

3. Decomposer Breaks down dead organisms Examples: bacteria, maggots, fungi, worms Complete the circle of life by returning nutrients to the soil

Flow of Matter and Energy Trophic levels: organisms that represents a feeding step in the movement of energy and materials through an ecosystem. Producer herbivore carnivore Energy is always lost from one trophic level to the next.

Food Chain A food chain is a simple model of how matter and energy moves through an ecosystem.

Food Web Food webs show all the possible feeding relationships at each trophic level.