BIOL.1110 Principles of Biology II - Matter and Energy in Ecosystems Flashcards

Flashcards covering key vocabulary and concepts from the Matter and Energy in Ecosystems lecture.

Energy Flow vs. Chemical Cycling

There is a one-way flow of energy through an ecosystem, whereas chemicals cycle within the ecosystem.

Energy Flow in Ecosystems

Energy enters as sunlight, is converted to chemical energy by autotrophs, passed to heterotrophs as food, and lost as heat.

Ecosystem Dynamics

Ecosystem dynamics involve energy flow and chemical cycling.

Primary Producers

Autotrophs that build organic molecules using sunlight or inorganic compounds as energy sources; forms the energy foundation of ecosystems

Heterotrophs

Consumers that depend directly or indirectly on production by primary producers.

Primary Consumers

Herbivores that eat primary producers.

Secondary Consumers

Carnivores that eat herbivores.

Tertiary Consumers

Carnivores that eat other carnivores; apex predators.

Decomposers

Organisms that get their energy from detritus, non-living organic matter.

Primary Production (PP)

The amount of light energy converted to chemical energy by autotrophs during a given time period.

Net Primary Productivity (NPP)

Amount of new biomass added in a given time period (i.e., net biomass gain).

Biogeochemical Cycles

Nutrient cycles that involve both biotic and abiotic components.

Carbon Cycle - Photosynthesis

Photosynthetic organisms take chemicals (CO2) and incorporate them into organic compounds that make up biomass.

Carbon Reservoirs

Fossil fuels, atmospheric CO2, CO2 dissolved in oceans, on land (living organisms, rocks, soil).

Water Cycle

Water moves through evaporation, transpiration, condensation, precipitation, and movement through surface water and groundwater.

Nitrogen Reservoir

Atmosphere is 79% N2 (gas)

Nitrogen Cycle - Plant Absorption

N2 must be converted to nitrates (NO3–) before plants can absorb it

Nitrifying Bacteria

Convert N2 to nitrates.

Denitrifying Bacteria

Convert nitrates to N2.

Eutrophication

Excessive nutrients in water caused by runoff of nutrients (sewage, fertilizers) causing photosynthetic algae and cyanobacteria population explosion which depletes O2, causing mass die-off of marine/aquatic life