Untitled Flashcard Set

Primary productivity – Rate at which producers convert solar energy into organic compounds over time (photosynthesis rate per area).

Gross primary productivity (GPP) – Total solar energy captured by producers and fixed as chemical energy (glucose).

Respiration loss (RL) – Energy producers use for cellular respiration and maintenance that is not stored as biomass.

Net primary productivity (NPP) – Energy/biomass available to consumers; NPP = GPP − RL.

Ecological efficiency (producer level) – Small fraction of incoming sunlight captured; ~1% becomes GPP and ~0.4% becomes NPP.

10% rule (energy) – About 10% of energy transfers to the next trophic level; ~90% is used or lost as heat.

10% rule (biomass) – Only ~10% of biomass at one trophic level can be supported at the next level.

Trophic level – Position in a food chain (producer, primary consumer, secondary consumer, tertiary consumer).

Primary consumer – Herbivore that eats producers.

Secondary consumer – Carnivore/omnivore that eats herbivores.

Tertiary consumer – Predator feeding on secondary consumers (often apex).

First law of thermodynamics – Energy is conserved; it changes form but is neither created nor destroyed.

Second law of thermodynamics – Every energy transfer loses usable energy as heat; less usable energy at higher trophic levels.

Factors increasing NPP – High water availability, warm temperatures, and nutrient availability.

Trophic cascade – Top-down effect where predators indirectly benefit lower trophic levels by controlling herbivores.

Ecosystem – All living and nonliving components interacting in an area.

Community – All living organisms in an area.

Population – Individuals of the same species in an area.

Biome – Regional community of plants/animals defined by long-term temperature and precipitation.

Weather – Short-term atmospheric conditions.

Climate – Long-term average weather in a location.

Mutualism – Symbiosis where both species benefit (e.g., coral and algae).

Commensalism – One species benefits, the other is unaffected.

Parasitism – One species benefits at the other’s expense without immediate killing (parasites).

Parasitoid – Lays eggs in/on host; larvae consume and usually kill host.

Predation – One organism consumes another for energy.

Competition – Organisms vie for limited resources, reducing population sizes.

Resource partitioning – Species reduce competition by using the same resource in different ways/times/places.

Temporal partitioning – Using resources at different times (e.g., day vs. night).

Spatial partitioning – Using different areas or depths of a habitat.

Morphological partitioning – Using resources differently due to body differences.

Shifting biomes – Biomes shift geographically as climate changes (e.g., boreal forest moves poleward)
Depth (light penetration) – Controls photosynthesis below surface; defines photic vs. aphotic zones.

Temperature (aquatic) – Warmer water holds less dissolved oxygen, supporting fewer organisms.

Salinity – Salt concentration determines species tolerance and water use (fresh vs. estuary vs. ocean).

Flow – Water movement shapes habitat, oxygenation, and species survival.

Dissolved oxygen (DO) – Oxygen in water; generally higher in fast-flowing rivers due to mixing.

River – Flowing freshwater with high DO and sediment transport; forms fertile deltas/floodplains.

Lake – Standing freshwater; key drinking source with distinct light/plant zones.

Littoral zone – Shallow, near-shore area with rooted emergent plants.

Limnetic zone – Open-water, well-lit zone where phytoplankton photosynthesize; few rooted plants.

Profundal zone – Deep, dark lake zone with no photosynthesis.

Benthic zone – Bottom sediments; nutrient-rich, supports invertebrates.

Wetland – Ground is submerged/saturated part of the year; supports emergent plants and provides flood control, groundwater recharge, and pollutant filtration.

Swamp – Forested wetland (woody plants).

Marsh – Non-woody wetland dominated by reeds/cattails.

Bog – Wetland with highly acidic soils, often sphagnum-rich.

Estuary – Where rivers meet the ocean; brackish water, high productivity from nutrient-rich sediments.

Salt marsh – Temperate estuary habitat, crucial nursery for fish/shellfish.

Mangrove swamp – Tropical estuary habitat with stilt-rooted trees that stabilize shorelines and offer nursery habitat.

Coral reef – Warm, shallow, most diverse marine biome; coral–algae mutualism and calcium carbonate reef building.

Intertidal zone – Shoreline between high/low tide; organisms adapt to wave action and desiccation.

Open ocean – Low productivity per area; photic zone allows photosynthesis, aphotic is too deep for light; ocean biota act as a major CO₂ sink.

Carbon sink – Reservoir taking in more carbon than it releases (ocean, plants, soils).

Carbon source – Reservoir releasing more carbon than it absorbs (FF combustion, deforestation, animal agriculture CH₄).

Photosynthesis – CO₂ + H₂O → C₆H₁₂O₆ + O₂; pulls CO₂ from air/water into biomass.

Cellular respiration – C₆H₁₂O₆ + O₂ → CO₂ + H₂O + energy; returns CO₂ to atmosphere.

Direct exchange (air–sea) – Rapid two-way CO₂ exchange between atmosphere and ocean surface waters.

Ocean acidification – Rising oceanic CO₂ lowers pH.

Marine calcification – Coral and shell-formers use dissolved C to build CaCO₃ skeletons/shells.

Sedimentation – Carbonate and organic particles settle to the seafloor, forming sediments.

Burial – Long-term geological storage of carbon in sedimentary rocks and fossil fuels.

Extraction and combustion – Mining/drilling fossil fuels and burning them; adds CO₂ to atmosphere.

Main reservoir (N) – Atmosphere (N₂ gas), biologically unavailable without conversion.

Nitrogen fixation (biotic) – Soil or symbiotic bacteria convert N₂ to NH₃/NH₄⁺; legumes host rhizobacteria in root nodules.

Nitrogen fixation (abiotic/synthetic) – Human processes (e.g., fertilizer production; FF combustion producing reactive N) yield NH₃/NOₓ for ecosystems.

Nitrification – Soil bacteria convert NH₄⁺ → NO₂⁻ → NO₃⁻.

Assimilation (N) – Plants take up NH₃/NH₄⁺/NO₃⁻; animals obtain N by eating.

Ammonification – Decomposers convert organic N in waste/dead biomass to NH₃/NH₄⁺.

Denitrification – Anaerobic bacteria convert NO₃⁻ to gaseous forms (N₂O, N₂), returning N to atmosphere.

Leaching (nitrate) – NO₃⁻ is water-soluble and can be carried from soils into groundwater/surface waters.

Ammonia volatilization – Excess NH₃ from fertilizers enters the atmosphere.

Nitrous oxide (N₂O) – Greenhouse gas produced during denitrification; warms climate.

Main reservoirs (P) – Rocks and sediments containing phosphate minerals; no significant atmospheric gas phase.

Weathering (P) – Wind/rain break down rocks, releasing phosphate (PO₄³⁻) to soils and waters.

Limiting nutrient (P) – Slow cycling and low solubility make P limiting for plant growth in many ecosystems.

Assimilation (P) – Plants absorb phosphate; animals obtain P by feeding.

Excretion/decomposition (P) – Returns phosphate to soils; low solubility leads to sedimentation.

Sedimentation (P) – Insoluble phosphates settle as sediments, forming long-term reservoirs.

Geological uplift – Tectonics raise sedimentary rocks, exposing P to weathering again.

Anthropogenic P sources – Mining phosphates for fertilizers/detergents adds P to waters via runoff and wastewater.

Eutrophication – Excess N and P fuel algal blooms that block light; decomposition consumes dissolved oxygen, causing fish kills and a positive feedback of further O₂ loss.

Largest water reservoir – The ocean.

Freshwater reservoirs – Ice caps/glaciers and groundwater aquifers (key usable freshwater).

Evaporation – Liquid water becomes vapor due to solar energy.

Transpiration – Plants pull water from roots to leaves; water exits stomata as vapor.

Evapotranspiration – Combined water vapor flux from evaporation and transpiration.

Runoff – Precipitation flowing over land into surface waters.

Infiltration – Water percolating into soil to recharge groundwater; depends on soil permeability.

Aquifer – Underground water-bearing rock/sediment storing groundwater.

Clean Water Act (CWA) – U.S. law (1972) to restore/maintain water integrity by regulating pollutant discharges, setting water-quality standards, funding treatment facilities, covering waters with continuous surface connection to navigable waters, and enforcing via EPA/states.