Module 5: The Biosphere: Nutrient Pollution and Biogeochemical Cycles

ecosystem

an ecological unit comprising the resident organisms and the environment

photosynthesis

the metabolic process by which plants use chlorophyll and solar energy to convert water and carbon dioxide to larger organic molecules

photosynthesis equation

6CO₂ + 6H₂O + solar energy → C₆H₁₂O₆ + 6O₂

carbon + water + solar energy → glucose + oxygen dioxide

respiration

the conversion of organic molecules in the presence of oxygen into carbon dioxide, water, and energy, which are used by organisms to carry out metabolic processes

respiration equation

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6 H₂O + Energy

glucose + oxygen → carbon dioxide + water + energy

limiting nutrients

inorganic substances that, when present in small quantities, limit biological growth; phosphorus and nitrogen are he most common

biogeochemical cycle

the movement of an element (commonly a nutrient element such as phosphorus, carbon or nitrogen) through Earth’s different systems via biological, chemical, and physical processes

food chains

a collection of organisms related to one another through food consumption

autotrophs/primary producers

organisms (commonly plants) capable of producing their own food from inorganic substances through the absorption of energy from sunlight (photosynthesis) or chemic reactions (chemosynthesis)

heterotrophs/consumers

animals that must eat plants or other animals to acquire the energy they need to maintain themselves, grow, and reproduce

detrivores

animals that consume dead organic matter such as fallen leaves and twigs

ecological succession

replacement of one community of organisms with another over time due to changes in light levels and microclimate brought about by the organisms themselves

intraspecific competition

competition among individuals of the same species

interspecific competition

competition among individuals of different species

mutualists

species that benefit from interactions

commensalism

interaction where one group benefits and the other is unaffected

amensalism

interaction where one species is harmed while the other benefits

carrying capacity

the population of a series that can be supported with food, water, and other necessities by a given area of land

predator-prey cycles

oscillations in the populations sizes of predators and their prey based upon food availability

resilience

the ability to recover from ecological disturbances such as fire, hurricanes, volcanic eruptions, or disease

biomes

major biological communities determined by climate, geology, and topography; primary terrestrial biomes include forests, grasslands, desserts, and tundra

habitats

the place where a particular organism lives, as determined by its food, water, and shelter requirements

ecological niche

the way an organism lives in its environment, including its response to climatic conditions, the type of food it eats and how it acquires that food, its reproductive behavior, and its interactions with other organisms

hypoxic

having a dissolved oxygen concentration in water below 2 mg/L

anoxia

a complete lack of oxygen in water

eutrophication

the process that begins when an extreme influx of nutrients into a body of water encourages unusually large algae blooms, which prevent light from penetrating the water and thereby inhibit subsurface photosynthesis and deplete the water of oxygen

dead zones

a part of the ocean with hypoxic or anoxic conditions, resulting in the death of sessile organisms and out-migration of mobile organisms; usually the result of eutrophication

bioremediation

the use of microbes to clean up oil spills and contaminated soils and aquifers