NI

Untitled Flashcard Set

🌱 Primary Productivity & Energy Flow

  • Primary productivity: Rate producers convert solar energy → organic compounds (photosynthesis per area).

  • GPP: Total solar energy captured and fixed as glucose.

  • Respiration loss (RL): Energy used for cellular respiration.

  • NPP: Energy available to consumers. Formula → NPP = GPP − RL.

  • Ecological efficiency: ~1% of sunlight captured as GPP, ~0.4% becomes NPP.

  • 10% rule (energy): Only ~10% of energy transfers to next trophic level.

  • 10% rule (biomass): Only ~10% of biomass can be supported at next level.

  • Trophic levels: Producers → Primary → Secondary → Tertiary.

  • Consumers: Primary (herbivores), Secondary (omnivores/carnivores), Tertiary (apex predators).

  • 1st Law Thermodynamics: Energy conserved, only changes form.

  • 2nd Law Thermodynamics: Energy transfers lose usable energy as heat.

  • High NPP conditions: Warm, wet, nutrient-rich ecosystems.

  • Trophic cascade: Predators indirectly benefit plants by controlling herbivores.

🌍 Ecosystems & Species Interactions

  • Ecosystem: All living + nonliving in an area.

  • Community: All living organisms in an area.

  • Population: Individuals of same species.

  • Biome: Regional community, climate-driven.

  • Weather vs. Climate: Short-term vs. long-term atmospheric conditions.

Interactions

  • Mutualism: Both benefit (coral + algae).

  • Commensalism: One benefits, other unaffected.

  • Parasitism: One benefits at host’s expense.

  • Parasitoid: Lays eggs inside host → kills it.

  • Predation: One organism eats another.

  • Competition: Species compete for resources.

  • Resource partitioning: Different resource use to reduce competition.

    • Temporal (different times)

    • Spatial (different areas)

    • Morphological (different structures).

  • Shifting biomes: Climate change moves biome boundaries.

🌳 Terrestrial Biomes

  • Tropical rainforest: Warm, wet, poor soils.

  • Temperate rainforest: Cool/mild, rainy, nutrient-rich soils.

  • Deciduous forest: Seasonal, fertile loamy soils.

  • Shrubland (chaparral): Hot/dry, nutrient-poor soils.

  • Temperate grassland (prairie): Semiarid, fertile deep soils.

  • Savanna: Warm, wet/dry seasons, scattered trees.

  • Desert: Dry, poor soils, sparse vegetation.

  • Tundra: Cold, low nutrients, permafrost.

  • Taiga (boreal): Cold, conifers, nutrient-poor soils.

  • Latitude pattern: Tundra at poles, temperate mid-latitude, tropics near equator.

🌊 Aquatic Systems

Key Factors

  • Depth: Light penetration = photosynthesis.

  • Temperature: Warmer water = less dissolved oxygen.

  • Salinity: Controls tolerance + water use.

  • Flow: Shapes oxygenation and habitats.

  • Dissolved oxygen (DO): Higher in fast rivers.

Freshwater

  • Rivers = high DO, sediment transport.

  • Lakes = zones: Littoral (shallow plants), Limnetic (phytoplankton), Profundal (dark, no photosynthesis), Benthic (bottom sediments).

  • Wetlands = flood control, filtration, recharge.

    • Swamp (trees), Marsh (reeds), Bog (acidic, moss).

Estuaries & Marine

  • Estuaries = where rivers meet ocean, brackish water, very productive.

  • Salt marshes = temperate, nursery habitat.

  • Mangroves = tropical coastlines, stabilize shores.

  • Coral reefs = most biodiverse, algae–coral symbiosis.

  • Intertidal zones = adapted to tides/waves.

  • Open ocean = huge CO₂ sink, photic vs. aphotic zones.

♻ Carbon Cycle

  • Sinks = oceans, plants, soils.

  • Sources = fossil fuel burning, deforestation, livestock CH₄.

  • Photosynthesis = CO₂ + H₂O → glucose + O₂.

  • Respiration = glucose + O₂ → CO₂ + water + energy.

  • Direct exchange: Atmosphere ↔ ocean.

  • Ocean acidification: CO₂ dissolves → lower pH.

  • Marine calcification: Corals/shells use carbonate.

  • Sedimentation: Organic material settles → sediments.

  • Burial: Long-term storage (fossil fuels).

  • Extraction/combustion: Releases CO₂.

🌾 Nitrogen Cycle

  • Main reservoir = atmosphere (N₂).

  • Fixation (biotic) = bacteria convert N₂ → NH₃/NH₄⁺.

  • Fixation (abiotic) = lightning, fertilizer, combustion.

  • Nitrification = NH₄⁺ → NO₂⁻ → NO₃⁻.

  • Assimilation = plants/animals absorb N.

  • Ammonification = waste/dead → NH₃/NH₄⁺.

  • Denitrification = NO₃⁻ → N₂ gas (back to atmosphere).

  • Leaching = nitrates wash into groundwater.

  • Ammonia volatilization = NH₃ loss to air.

  • N₂O = potent greenhouse gas.

rock emoji Phosphorus Cycle

  • Reservoirs = rocks, sediments (no gas phase).

  • Weathering = rocks release phosphate.

  • Limiting nutrient = P often limits plant growth.

  • Assimilation = plants/animals take up phosphate.

  • Decomposition = returns P to soils.

  • Sedimentation = phosphate → sediments.

  • Geological uplift = tectonics expose rocks.

  • Anthropogenic sources = fertilizer, detergents.

  • Eutrophication = excess N + P → algal blooms → O₂ depletion.

💧 Hydrologic Cycle

  • Largest reservoir = ocean.

  • Freshwater = glaciers, groundwater aquifers.

  • Evaporation = water → vapor.

  • Transpiration = plants release vapor.

  • Evapotranspiration = combined total.

  • Runoff = flows over land → surface water.

  • Infiltration = percolates → groundwater.

  • Aquifer = underground water storage.

⚖ Policy

  • Clean Water Act (1972): Protects U.S. waters, regulates pollutants, EPA enforcement.