The Biosphere and Ecosystems

These flashcards cover the key concepts of the biosphere and ecosystems, focusing on definitions, processes, and current environmental issues.

Ecosystem

All organisms (biotic) plus the environment (abiotic) in a given area.

Energy flow

The movement of energy through an ecosystem, typically from sunlight to producers, consumers, and decomposers.

Nutrient cycling

The process through which nutrients like carbon, nitrogen, phosphorus, and sulfur cycle through the ecosystem.

Decomposers

Organisms such as fungi, mold, and bacteria that break down dead organic matter and recycle nutrients.

Food web

A graphical representation of the interconnected feeding relationships among organisms in an ecosystem.

Trophic levels

The hierarchical levels in an ecosystem, defined by how organisms obtain energy.

Nitrogen fixation

The process by which nitrogen in the atmosphere is converted into ammonia or related compounds in soil.

Carbon cycle

The series of processes in which carbon compounds are interconverted in the environment.

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem.

Mass extinction

A widespread and rapid decrease in the biodiversity on Earth, often attributed to human activities.

Dead zones

Areas in aquatic ecosystems where the oxygen level is so low that most marine life cannot survive.