Introduction to Ecology and Environmental Interactions

Ecology

The study of the interactions among organisms with each other and their surrounding environments.

Biotic interactions

All of the interactions among the organisms (i.e. living factors) such as humans, animals, plants, and insects.

Abiotic interactions

All of the interactions among the organisms and their non-living environment, such as light, temperature, water, nutrients, and periodic disturbances (fires, avalanches, tornadoes, etc.).

Atoms

The smallest unit of an element; all matter is composed of atoms.

Molecules

A group of two or more atoms chemically bonded together.

Organelles

Structures or 'organs' of the cell.

Cells

The simplest unit of life.

Tissues

Many cells of the same type that perform a specific function.

Organs

Two or more types of tissues performing a specific function.

Organisms

Individual living 'things' made up of a collection of different organs.

Population

A group of organisms of the same species occupying the same environment.

Community

All organisms (i.e. different species) that interact with one another in a particular environment.

Ecosystem

Interactions of a community of organisms with their physical environment.

Biosphere

The worldwide ecosystem (i.e. Earth) including in the air, in bodies of water, on the land, and in the soil.

Organismal ecology

Individual organism's behavior, physiology, morphology, etc. in response to interactions within their abiotic environment.

Physiological ecology

How organisms are physiologically adapted to their environment and how the environment impacts the distribution of species.

Behavioral ecology

How the behavior of individual organisms contributes to their survival and reproductive success, which, in turn, can affect the population density of the species.

Distribution of organisms

Both the distribution and abundance of organisms are limited by their surrounding abiotic environment.

Temperature

A factor that limits the distribution and abundance of organisms.

Wind

A factor that limits the distribution and abundance of organisms.

Water

A factor that limits the distribution and abundance of organisms.

Light

A factor that limits the distribution and abundance of organisms.

Salt concentration and pH

Factors in soil and water that limit the distribution and abundance of organisms.

Periodic disturbances

Events such as fires, avalanches, and tornadoes that limit the distribution and abundance of organisms.

Temperature

Most important factor in the distribution of organisms because of its effect on biological processes.

Ideal Temperature

Most organisms have an ideal temperature where maximum populations will flourish.

Acceptable Temperature Range

There is also an acceptable temperature range; outside of the acceptable range, the organism will not survive.

Low Temperatures

Low temperatures freeze organisms.

High Temperatures

High temperatures denature molecules.

Wind

Wind is air in motion.

Wind Effects

Amplifies the effects of temperature by increasing heat loss by convection and water loss by evaporation.

Wind Movement

Wind movement effects wave motion of bodies of water (lakes and oceans), which in turn will have a direct effect on the organisms living in those environments.

Water

Water is essential for life and all organisms depend on it for survival.

Water Importance

Water is critical for chemical reactions, plant cell structure, osmosis, photosynthesis, etc.

Water Levels

At an organismal level, too much and too little water can be detrimental.

pH and Water Concentration

The pH and concentration of water will effect what organisms can live in which particular location (i.e. freshwater versus saltwater).

Light

Provides the energy necessary to drive photosynthesis and thus the primary source of energy in nearly all ecosystems.

Light Intensity and Duration

Intensity and daily duration (seasons) affects living things.

Competition for Light

Competition for light can be an important factor.

Under Foliage and Underwater Habitats

Under foliage and underwater habitats get varying levels of light due to intensity, amount, and competition.

Salt Concentrations

Salt concentrations in aquatic environments will effect the osmotic balance in animals.

Freshwater and Saltwater Fishes

Freshwater fishes cannot live in salt water and saltwater fishes cannot live in fresh water, due to different mechanisms to maintain osmotic balance with their environment.

pH of Soil or Water

pH of soil or water will vary greatly; can be acidic, basic, or neutral.

pH Limitation

Will limit distribution of plants and hence animals that feed on those plants.

Rain Water pH

Rain water has a pH of approx. 5.6; will effect organisms directly when rained upon, as well as the pH of the soil.

Acid Rain

Acid rain has a pH of less than 5.6.