Biogeochemical Cycles, Food Webs & Ecosystem Energy

Biogeochemical Cycle

Movement of matter through living organisms and the environment.

Reservoir

A place where matter is stored.

Source

A location or process that releases more of a substance than it absorbs.

Sink

A location or process that absorbs more of a substance than it releases.

Carbon Cycle

Movement of carbon through the atmosphere, oceans, soil, and organisms.

Photosynthesis

Plants use sunlight, CO2, and water to make glucose.

Cellular Respiration

Organisms break down glucose to release energy and CO2.

Combustion

Burning fossil fuels, releasing CO2 into the atmosphere.

Nitrogen Fixation

Converts atmospheric nitrogen into usable nitrogen compounds.

Nitrification

Bacteria convert ammonium into nitrites and nitrates.

Assimilation

Plants absorb nitrogen compounds through their roots.

Ammonification

Decomposers convert organic nitrogen into ammonium.

Denitrification

Bacteria convert nitrates into nitrogen gas.

Phosphorus Cycle

Movement of phosphorus through rocks, soil, water, and organisms.

Weathering

Breaking down rocks and releasing phosphorus.

Water Cycle

Continuous movement of water through Earth's atmosphere, land, and oceans.

Evaporation

Liquid water changes into water vapor.

Condensation

Water vapor cools and becomes liquid droplets.

Precipitation

Water falls from clouds as rain, snow, sleet, or hail.

Transpiration

Plants release water vapor into the atmosphere.

Food Chain

A single pathway showing how energy moves between organisms.

Food Web

Multiple interconnected food chains in an ecosystem.

Food Web Arrows

Show the direction energy travels, from food to consumer.

Producer / Autotroph

Organism that makes its own food.

Heterotroph

Organism that gets energy by consuming other organisms.

Primary Consumer

Organism that eats producers.

Secondary Consumer

Organism that eats primary consumers.

Tertiary Consumer

Organism that eats secondary consumers.

Quaternary Consumer

Organism that eats tertiary consumers.

Herbivore

Organism that eats plants.

Carnivore

Organism that eats animals.

Omnivore

Organism that eats both plants and animals.

Decomposer

Organism that breaks down dead organisms and waste.

Trophic Level

An organism's feeding position in a food chain.

10% Rule

Only about 10% of energy transfers to the next trophic level.

Energy Pyramid

Shows available energy at each trophic level.

GPP

Total energy captured by producers through photosynthesis.

NPP

Energy remaining for growth after producer respiration.

NPP Formula

NPP = GPP - Respiration.

Resistance

Ability of an ecosystem to withstand disturbance.

Resilience

Ability of an ecosystem to recover after disturbance.

Intermediate Disturbance Hypothesis

Species diversity is highest at moderate disturbance.