APES Unit 1.1 Ecosystems (refined)

Individual

One single organism (e.g., an elk)

Population

A group of individuals of the same species living in an area

Community

All living organisms in a given area

Ecosystem

All living (biotic) and nonliving (abiotic) things in an area

Biome

The plants and animals found in a given region, determined by climate (annual temperature and precipitation)

Mutualism

A symbiotic relationship that benefits both organisms (+/+)

Commensalism

A symbiotic relationship that benefits one organism and doesn't impact the other (+/0)

Parasitism

A relationship where one organism uses a host for energy, often without killing the host (+/-)

Competition

Organisms fighting over a shared, limited resource like food or shelter

Resource Partitioning

Different species using the same resource in different ways, places, or times to reduce competition

Temporal Partitioning

Using a shared resource at different times (e.g., hunting at night vs. day)

Spatial Partitioning

Using different areas of a shared habitat to reduce competition (e.g., plant roots of different lengths)

Morphological Partitioning

Using different resources based on different evolved body features

Herbivores

Plant eaters that consume plants for energy

True Predators

Carnivores that kill and eat prey for energy

Parasitoids

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

Littoral Zone

Shallow water area of a lake with emergent plants

Limnetic Zone

Open water area of a lake where light can reach for photosynthesis; contains no rooted plants, only phytoplankton

Profundal Zone

Deep water area of a lake where sunlight cannot reach (no photosynthesis)

Benthic Zone

The murky bottom of a lake where invertebrates live in nutrient-rich sediments

Wetland

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

Estuary

An area where rivers empty into the ocean, creating a highly productive mix of fresh and salt water

Photic Zone

The upper layer of the open ocean where sunlight can reach for photosynthesis

Aphotic Zone

The deep layer of the ocean (abyssal zone) that is too deep for sunlight

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, deforestation)

Photosynthesis

Process by which plants and algae remove CO2 from the atmosphere and convert it to glucose

Cellular Respiration

Process done by living organisms that uses O2 to break down glucose and release energy, emitting CO2

Ocean Acidification

Increased acidity of ocean water caused by increasing atmospheric CO2 directly dissolving into the ocean

Burial (Carbon Cycle)

A slow, geological process that stores carbon in underground sinks like sedimentary rock or fossil fuels

Nitrogen Fixation

The process of N2 gas being converted into biologically available forms (useable by plants) like ammonia (NH3) or nitrate (NO3-)

Assimilation

Plants and animals taking in nutrients (like nitrogen or phosphorus) and incorporating them into their body tissues

Ammonification

Soil bacteria and decomposers converting waste and dead biomass back into NH3 and returning it to soil

Nitrification

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

Denitrification

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

Leaching

Nutrients (like nitrates from synthetic fertilizers) being washed or carried out of the soil by water

Eutrophication

A process where excess nutrients (nitrogen and phosphorus) in aquatic ecosystems fuel algae blooms that block sunlight and deplete oxygen

Weathering

The breakdown of rock by wind and rain; the major natural source of phosphorus in the environment

Geological Uplift

Tectonic plate collisions forcing up rock layers to form mountains, restarting the phosphorus cycle

Transpiration

The process plants use to draw groundwater from roots up to their leaves, where it evaporates into the atmosphere

Evapotranspiration

The total amount of water that enters the atmosphere from plant transpiration and surface evaporation combined

Infiltration

Precipitation trickling through permeable soil down into groundwater aquifers

Primary Productivity

The rate at which solar energy is converted into organic compounds via photosynthesis over a unit of time

Gross Primary Productivity (GPP)

The total amount of sun energy that plants capture and convert to glucose through photosynthesis

Net Primary Productivity (NPP)

The amount of energy (biomass) leftover for consumers after plants have used some for their own respiration (NPP = GPP - Respiration Loss)

Respiration Loss (RL)

The energy plants use up from their own photosynthesis by doing cellular respiration

1st Law of Thermodynamics

Energy is never created or destroyed; it only changes forms

2nd Law of Thermodynamics

Each time energy is transferred, some of it is lost as heat, decreasing the amount of useable energy

10% Rule

In trophic pyramids, only about 10% of the energy or biomass from one level makes it to the next level (the rest is used or lost as heat)

Producers

Organisms (plants) that convert the sun's light energy into chemical energy

Primary Consumers

Animals that eat plants (herbivores)

Secondary Consumers

Animals that eat primary consumers (carnivores and omnivores)

Tertiary Consumers

Animals that eat secondary consumers (top/apex predators)

Food Web

A model showing at least 2 different, interconnected food chains that depicts how matter and energy flow through an ecosystem

Trophic Cascade

The ripple effect down through lower trophic levels that occurs when a top predator is removed from or added to an ecosystem