quest 2 ecology: D4.3 Climate Change

Ecosystem Open System

A system where both matter (air, water, organisms) and energy (sunlight) can enter and exit.

Sunlight

The principal source of initial energy that sustains most ecosystems.

Food Chain

A linear sequence of organisms through which nutrients and energy pass as one organism eats another.

Trophic Level

The position an organism occupies in a food chain (e.g., Producer, Primary Consumer).

Autotroph

An organism that uses external energy to synthesize carbon compounds from simple inorganic substances.

Photoautotroph

An autotroph that uses light energy to convert inorganic substances into organic compounds.

Chemoautotroph

An autotroph that uses energy from oxidation reactions (e.g., iron-oxidizing bacteria) instead of sunlight.

Heterotroph

An organism that uses carbon compounds obtained from other organisms to synthesize required molecules.

Saprotroph

A decomposer that obtains nutrients from dead organisms via external digestion (secreting enzymes).

Detritivore

A decomposer that obtains organic nutrients from dead organisms via internal digestion (ingestion).

Cell Respiration

Process in both autotrophs and heterotrophs that releases energy by the oxidation of carbon compounds.

Energy Loss

Reduction in available energy at each trophic level (approx. 90% lost) due to heat, waste, and incomplete consumption.

10% Rule

The trend where only about 10% of energy is transferred to the next trophic level.

Energy Pyramid Unit

Standard measurement for energy transfer: kJ m−2 yr−1.

Heat Waste

Heat produced during ATP production/use that is lost to the environment and cannot be recycled.

Biomass

The total mass of a group of organisms consisting of all carbon compounds in their cells and tissues.

Primary Production

The accumulation of carbon compounds in biomass by autotrophs (producers).

Secondary Production

The accumulation of carbon compounds in biomass by heterotrophs; always lower than primary production.

Carbon Sink

A reservoir that stores more carbon than it releases, such as a standing forest.

Carbon Source

An ecosystem or process that releases more carbon than it stores, such as combustion.

Keeling Curve

Data from Mauna Loa showing an upward trend in atmospheric CO2 with annual fluctuations.

Annual CO2 Fluctuation

The seasonal "zigzag" in CO2 levels caused by higher photosynthesis rates in northern hemisphere summers.

Greenhouse Effect

Natural process where gases trap long-wave radiation (heat) to maintain Earth's temperature.

Most Influential GHGs

Carbon dioxide (CO2) and water vapor (H2O).

Secondary GHGs

Methane (CH4) and nitrous oxides (N2O).

Short-wave Radiation

Solar radiation (UV and visible light) that passes through the atmosphere to Earth.

Long-wave Radiation

Infrared radiation (heat) emitted by Earth that is absorbed by greenhouse gases.

Ocean Acidification

The reduction in pH of the ocean caused by the absorption of increased atmospheric CO2.

Coral Bleaching

Stress response in corals caused by rising ocean temperatures, often leading to death.

Precautionary Principle

The ethical guideline stating that if an action has a risk of harm, proponents must prove it is not harmful before proceeding.