Chapter 1: The Living World: Ecosystems (copy)

Ecosystem

A community of living (biotic) organisms interacting with the non-living (abiotic) components of their environment as a system through various nutrients and energy cycles.

Biome

Major regional or global biotic communities characterized by dominant forms of plant life and the prevailing climates.

Ecological Niche

A particular area within a habitat occupied by an organism, as well as the function of that organism within its ecological community.

Generalists

Organisms able to survive on a wide variety of food resources and withstand a wide range of environmental conditions.

Specialists

Organisms with a specific or limited number of prey and narrow ecological niches.

Symbiosis

Any type of close and long-term biological interaction between two different biological organisms of the same or different species.

Mutualism

The interaction between two species whereby both species benefit.

Limiting Factor

Any abiotic factor that limits or prevents the growth of a population.

Predation

A biological interaction where predators hunt and kill their prey.

Trophic Level

The position an organism occupies in a food chain; the number of steps it is from the start of the chain.

Nitrogen Fixation

The process in which atmospheric nitrogen is converted into ammonia or nitrate ions, which are biologically usable forms of nitrogen.

Aquifer

A geologic formation that contains water in quantities sufficient to support a well or spring.

Photosynthesis

The process by which plants capture light energy to produce carbohydrates and other organic compounds.

Eutrophication

The process by which a body of water becomes overly enriched with nutrients, inducing excessive growth of algae.

Carbon Cycle

The cycle by which carbon is exchanged among the biosphere, geosphere, hydrosphere, and atmosphere.

Wetlands

Areas that are covered with water at some point in the year and that support aquatic plants.

Oligotrophic Lake

A deep, cold, nutrient-poor lake with clear waters.

Eutrophic Lake

A shallow, warm, nutrient-rich lake with abundant phytoplankton.

Biomass Pyramid

A graphical representation showing the amount of organic mass at each trophic level.

Energy Pyramid

A graphical representation showing the proportion of energy passed from one trophic level to the next.

Law of Tolerance

The principle stating that the existence, abundance, and distribution of species depend on their tolerance levels to physical and chemical factors.

Saprottrophism

The process where saprotrophs obtain nutrients from dead or decaying organic matter.

Alpine Tundra

A biome located on mountains at high altitudes where trees cannot grow.

Ecosystem Productivity

The rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances.

Thermohaline Currents

Currents driven by differences in water density, caused by temperature and salinity variations.

Nitrification

The process of converting ammonia into nitrites and nitrates, which are usable forms of nitrogen for plants.

Amensalism

The interaction between two species whereby one species suffers and the other is not affected.

Commensalism

The interaction between two species where one benefits and the other is unaffected.

Detritivores

Organisms that feed on detritus, decomposing organic material in the ecosystem.

Primary Productivity

The rate at which energy is converted to organic substances through photosynthesis in a given area and time.

Cellular Respiration

The process in which glucose is oxidized to produce energy, CO2, and water.

Decomposition

The process by which organic substances are broken down into simpler organic or inorganic matter.

Thermal Stratification

The separation of water layers in a lake due to temperature differences.

Carbon Sink

A natural environment that absorbs more carbon dioxide from the atmosphere than it releases.