Nutrient Cycling and Biogeochemical Processes

These flashcards cover key terms and concepts related to nutrient cycling and biogeochemical processes crucial for understanding ecosystems.

NPP (Net Primary Productivity)

The rate at which plants and other photosynthetic organisms produce organic compounds in an ecosystem, after accounting for the energy used by respiration.

C uptake - Closs

Macronutrients

Nutrients required in large amounts for organisms to grow and function, including carbohydrates, lipids, proteins, and inorganic compounds.

Phosphorus cycle

The biogeochemical cycle that describes the movement of phosphorus through the biosphere, lithosphere, and hydrosphere.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll, converting carbon dioxide and water into glucose and oxygen.

common things in a nutrient cycle

1. reservoirs

2. fast pace and slow phase

3. soluble and insoluble

nitrogen fixation

is a crucial process in nutrient cycling that enables plants to access nitrogen by converting N2 gas from the atmosphere into organic compounds.

nitrification

Ammonium nh4→ Nitrite (NO₂⁻) → Nitrate (NO₃⁻)

denitrification

no3 back into n2

phosphorus cycle

no gaseous phase no fast cycle only slow cycle

pacific guano from the islands

important source of phosphorus fertilizer

liberation of carbon

1. respiration

2. fossil fuel and firewood burning

3. volcanic eruptions

flow of energy

sunlight → producers → consumers → decomposers

natural selection

1. heritable selection

2. struggle for existence

3. varation matters in the struggle

directional selection

A mode of natural selection in which a single phenotype is favored, causing the allele frequency to shift in one direction.

stabilizing selection

an intermediate phenotype favored over extreme ones (medium baby better than small)

it favors intermediate phenotypes, eliminates extremes, and reduces variance

disruptive selection

penalizes intermediates and favors both extreme phenotypes

adaptation

a trait shaped by natural selection that increases fitness in a given environment

fitness

relative reproductive success (per capita growth rate)

high and low bpp

• High NPP = tropical forests (~1600 g/m²/yr)

• Lower NPP = boreal forests (~800 g/m²/yr)

Ammonification

Decomposers convert organic N → NH₃/NH₄⁺.

The Carbon Cycle

• Fast phase (biological):

  • CO₂ ↔ biosphere via photosynthesis & respiration.

  • Carbon moves between atmosphere, ocean, and living organisms within years.

• Slow phase (geological):

  • Carbon stored in rocks (limestone, kerogen, fossil fuels) for millions of years.

  • Volcanic activity & weathering return C to atmosphere.