Biosphere

Biosphere: Consists of all life on Earth and all parts of the Earth in which life exists.

The biosphere contains every organism, from bacteria living underground to giant trees in rain forests, whales in polar seas, mold spores drifting through the air and of course humans. The biosphere extends from about 8 kilometers above Earth’s surface to as far as 11 kilometers below the surface of the ocean.

Species: Is a group of similar organisms that can breed and produce fertile offspring.

Population: Is a group of individuals that belong to the same species and live in the same area.

Community: An assemblage of different populations that live together in a defined area.

Ecosystem: All the organisms that live in a place, together with their physical environment.

Biome: Is a group of ecosystems that share similar climates and typical organisms.

Biosphere: Our entire planet, with all its organisms and physical environments.

Ecology: Is the scientific study of interactions among organisms and between organisms and their physical environment.

Biotic Factor: Is any living part of the environment with which an organism might interact, including animals, plants, mushrooms, and bacteria.

Abiotic Factor: Is any nonliving part of the environment, such as sunlight, heat, precipitation, humidity, wind or water currents, soil type, and so on.

Regardless of their tools, modern ecologists use three methods in their work: observation, experimentation, and modeling. Each of these approaches relies on scientific methodology to guide inquiry.

Observation: Is often the first step in asking ecological questions. Some observations are simple: Which species live here? How many individuals of each species are there? Other observations are more complex: How does an animal protect its young from predators?

Experimentation: Can be used to test the hypotheses. An ecologist may, for example, set up an artificial environment in a laboratory or greenhouse to see how growing plants react to different conditions of temperature, lighting, or carbon dioxide concentration. Other experiments carefully alter conditions in selected parts of the natural ecosystems.

Modeling: Many ecological events, such as effects of global warming on ecosystems, occur over such long periods of time or over such large distances that they are difficult to study directly. Ecologists make models to help them understand these phenomena. Many ecological models consist of mathematical formulas based on data collected through observation and experimentation. Further observations by ecologists can be used to test predictions based on those models.

Autotrophs: Use solar or chemical energy to produce “food” by assembling inorganic compounds into complex

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