Ecosystems and Biogeochemical Cycles Review

Flashcards covering key vocabulary from the Ecosystems and Biogeochemical Cycles lecture, including ecosystem basics, organism interactions, biomes, and the carbon, nitrogen, phosphorus, and hydrologic cycles.

Predator

An organism that eats another organism (the prey) in a predator-prey relationship.

Prey

An organism that is eaten by a predator in a predator-prey relationship.

Symbiosis

A close and long-term interaction between two species in an ecosystem.

Mutualism

A symbiotic relationship that benefits both organisms.

Commensalism

A symbiotic relationship that benefits one organism and doesn’t impact the other.

Parasitism

A symbiotic relationship where one organism (parasite) uses a host organism for energy, often without killing the host.

Competition

Occurs within or between species in an ecosystem where there are limited resources.

Resource Partitioning

Using resources in different ways, places, or at different times to reduce the negative impact of competition on survival.

Individual

One organism.

Population

A group of individuals of the same species.

Community

All living organisms in an area.

Ecosystem

All living and nonliving things in an area (plants, animals, rocks, soil, water, air).

Biome

The communities of plants and animals found in a given region, determined by climate (yearly temperature and precipitation averages).

Predation

One organism using another for an energy source (includes hunters, parasites, and herbivores).

True Predators

Carnivores that kill and eat prey for energy.

Herbivores

Organisms that eat plants for energy.

Parasites

Organisms that use a host organism for energy, often without killing the host and often living inside it.

Parasitoids

Organisms that lay eggs inside a host organism; eggs hatch and larvae eat the host for energy.

Temporal Partitioning

Using resources at different times to reduce competition.

Spatial Partitioning

Using different areas of a shared habitat to reduce competition.

Morphological Partitioning

Using different resources based on different evolved body features to reduce competition.

Latitude

Distance from the equator, which determines temperature and precipitation patterns, influencing biome distribution.

Nutrient Availability

The presence of essential chemicals in the soil or water that plants need to grow; a shortage can limit plant survival.

Freshwater Biomes

Include streams, rivers, ponds, and lakes, vital resources for drinking water.

Marine Biomes

Include oceans, coral reefs, marshland, and estuaries, important for Earth's oxygen production and CO2 absorption.

Salinity

The amount of salt in a body of water, determining which species can survive and its usability for drinking.

Depth

Influences how much sunlight can penetrate and reach plants below the surface for photosynthesis in aquatic biomes.

Turbidity

The clarity of water, influencing sunlight penetration.

Flow (Aquatic Biomes)

Determines which plants and organisms can survive and how much oxygen can dissolve into the water.

Littoral Zone

The shallow water zone in lakes with emergent plants.

Limnetic Zone

The open water zone in lakes where light can reach for photosynthesis, with no rooted plants, only phytoplankton.

Profundal Zone

The deep water zone in lakes where it is too deep for sunlight, so no photosynthesis occurs.

Benthic Zone

The murky bottom zone in lakes where invertebrates live and nutrient-rich sediments are found.

Wetland

An area with soil submerged or saturated in water for at least part of the year, but shallow enough for emergent plants.

Groundwater Recharge

The process where wetlands absorb rainfall and allow it to infiltrate into the soil, replenishing groundwater.

Estuaries

Areas where rivers empty into the ocean, characterized by a mix of fresh and salt water and high productivity due to rich sediments.

Salt Marsh

An estuary habitat found along coasts in temperate climates, serving as a breeding ground for many fish and shellfish species.

Mangrove Swamps

Estuary habitats along tropical coasts, characterized by mangrove trees with long, stilt roots that stabilize the shoreline and provide habitat.

Coral Reef

A warm, shallow water marine biome beyond the shoreline, known for being the most diverse and for the mutualistic relationship between coral and algae.

Intertidal Zone

The narrow band of coastline between high and low tide, where organisms must adapt to survive crashing waves and exposure to direct sunlight/heat.

Desiccation

The process of drying out, which intertidal organisms prevent with shells and tough outer skin.

Photic Zone

The area in the open ocean where sunlight can reach, allowing for photosynthesis.

Aphotic Zone (Abyssal)

The area in the open ocean too deep for sunlight to penetrate.

Carbon Cycle

The movement of atoms and molecules containing the element carbon between sources and sinks.

Carbon Sink

A reservoir that takes in more carbon than it releases (e.g., ocean, plants, soil).

Carbon Source

A reservoir that releases more carbon than it takes in (e.g., fossil fuel combustion, animal agriculture, deforestation).

Photosynthesis

The process by which plants, algae, and phytoplankton remove CO2 from the atmosphere and convert it into glucose (a biological form of carbon).

Cellular Respiration

The process by which plants and animals break down glucose using O2 to release stored energy, releasing CO2 into the atmosphere.

Ocean Acidification

The increase in ocean CO2 due to direct exchange with increasing atmospheric CO2, leading to higher acidity.

Sedimentation (Carbon Cycle)

The process where calcium carbonate precipitates out as sediment and settles on the ocean floor.

Burial (Carbon Cycle)

Over long periods, the compression of carbon-containing sediments on the ocean floor into sedimentary rock (e.g., limestone, sandstone), forming long-term carbon reservoirs.

Fossil Fuels (FF)

Coal, oil, and natural gas formed from the fossilized remains of organic matter over millions of years, acting as underground carbon sinks.

Extraction & Combustion

The process of digging up or mining fossil fuels and burning them as an energy source, which quickly releases stored carbon into the atmosphere as CO2.

Nitrogen Cycle

The movement of atoms and molecules containing the element nitrogen between sources and sinks, critical for plant and animal nutrients.

Nitrogen Fixation

The process of converting N2 gas from the atmosphere into biologically available forms like ammonia (NH3) or nitrate (NO3-) that plants can use.

Synthetic Fixation

Conversion of N2 gas into ammonia (NH3) through fossil fuel combustion, or the industrial production of synthetic fertilizers.

Bacterial Fixation

Certain bacteria in the soil or in symbiotic relationships with plant root nodules convert N2 into ammonia (NH3).

Ammonia (NH3)

A biologically available form of nitrogen, often a product of nitrogen fixation.

Nitrate (NO3-)

A biologically available form of nitrogen, converted from ammonia or nitrite by soil bacteria.

Rhizobacteria

Bacteria that live in root nodules of legumes and fix nitrogen for them.

Nitrification

The conversion of ammonium (NH4+) into nitrite (NO2-) and then nitrate (NO3-) by soil bacteria.

Ammonification

Soil bacteria, microbes, and decomposers converting waste and dead biomass back into ammonia (NH3) and returning it to the soil.

Assimilation (Nitrogen Cycle)

Plants and animals taking in nitrogen and incorporating it into their body tissues (e.g., plant roots absorb NO3- or NH3; animals eat plants or other animals).

Denitrification

The conversion of soil nitrogen (NO3-) into nitrous oxide (N2O) gas, which then returns to the atmosphere.

Leaching

The process where nitrates (NO3-) are carried out of the soil by water, often due to synthetic fertilizer use.

Eutrophication

Excess inputs of nitrogen and phosphorus in aquatic ecosystems, fueling algae growth, leading to oxygen depletion and aquatic animal death.

Ammonia Volatilization

Excess fertilizer use leading to NH3 gas entering the atmosphere, causing respiratory irritation.

Nitrous Oxide (N2O)

A greenhouse gas produced by denitrification of nitrate in agricultural soils, which warms Earth's climate.

Phosphorus Cycle

The movement of phosphorus atoms and molecules between sources and sinks/reservoirs, a very slow cycle with no atmospheric component.

Limiting Nutrient

A nutrient (like phosphorus) that is naturally scarce and whose availability often limits plant growth in ecosystems.

Weathering (P cycle)

The process by which wind and rain break down rocks containing phosphorus minerals, releasing phosphate (PO4 -3) into water and soil.

Phosphate (PO4 -3)

A common form of phosphorus released by rock weathering, dissolved into water, and carried into soils.

Geological Uplift

Tectonic plate collision forcing up rock layers that form mountains, restarting the phosphorus cycle with new rock weathering.

Hydrologic Cycle

The movement of water in its various solid, liquid, and gaseous phases between sources and sinks, powered by the sun.

Evaporation

The process where liquid water absorbs heat energy and becomes water vapor (gas) in the atmosphere.

Transpiration

The process plants use to draw groundwater from roots up to their leaves, where water evaporates into the atmosphere through stomata.

Evapotranspiration

The combined amount of water that enters the atmosphere from both transpiration and evaporation.

Runoff

Precipitation that flows over Earth’s surface into a body of water, recharging surface waters.

Infiltration

Precipitation that trickles through soil down into groundwater aquifers, recharging groundwater.

Aquifers

Underground layers of permeable rock or unconsolidated materials (gravel, sand, or silt) from which groundwater can be extracted.

Permeable Ground

Ground that is able to let water pass through, allowing for infiltration and groundwater recharge.

Primary Productivity (PP)

The rate at which solar energy (sunlight) is converted into organic compounds via photosynthesis over a unit of time; essentially, the rate of plant growth.

Gross Primary Productivity (GPP)

The total amount of sun energy that plants capture and convert to chemical energy (glucose) through photosynthesis.

Respiration Loss (RL)

The energy plants use up for their own cellular respiration (movement, internal transportation) from the energy they generate via photosynthesis.

Net Primary Productivity (NPP)

The rate of energy storage by photosynthesizers in a given area, after subtracting the energy lost to respiration (NPP = GPP - RL); the biomass leftover for consumers.

Ecological Efficiency

The portion of incoming solar energy that is captured by plants and converted into biomass (NPP) available for consumers.

Conservation of Matter & Energy

The principle that matter and energy are never created or destroyed; they only change forms.

1st Law of Thermodynamics

States that energy is never created or destroyed.

2nd Law of Thermodynamics

States that each time energy is transferred, some of it is lost as heat, meaning the amount of usable energy decreases as you move up the food chain.

10% Rule

Approximates that in the transfer of energy from one trophic level to the next, only about 10% of the energy is passed on, with the other 90% being used or lost as heat.

Trophic Pyramid

A model used to represent how energy moves through an ecosystem, showing decreasing available energy at higher trophic levels.

Producers

Organisms (mainly plants) that convert the sun’s light energy into chemical energy (glucose) through photosynthesis, forming the base of the food web.

Primary Consumers

Herbivores; animals that eat plants for energy.

Secondary Consumers

Carnivores and omnivores; animals that eat primary consumers (herbivores).

Tertiary Consumers

Top/apex predators; animals that eat secondary consumers (carnivores and omnivores).

Biomass

The total mass of all living things at each trophic level; follows the 10% rule, decreasing at higher trophic levels.

Food Web

A model of an interlocking pattern of food chains that depicts the flow of energy and nutrients in two or more interconnected food chains within an ecosystem.

Food Chain

A linear path showing how energy and matter flow from one organism to another in an ecosystem.

Trophic Cascade

A ripple effect down through lower trophic levels caused by the removal or addition of a top predator in a food web.