Unit 1 - Ecosystems

Pandemic

When a new disease spreads worldwide

Environment

The conditions that surround us and influence life, seen collectively

Environmental Science

A discipline or field that looks at the interactions between natural and human systems

System

Interacting components that influence one another in some way

Ecosystem

A specified location on earth that has abiotic and biotic components that interact

Biotic

Living

Abiotic

Nonliving

Environmentalism

A social movement to protect the environment

Environmental studies

A field of study including environmental science, environmental policy, economics, ethics, literature

Sustainability

Being able to do something in the present that won’t hurt the ability of future generations to do similar things

Scientific method

An objective way to explore the natural world, draw inferences from the natural world, and then predict the outcome of certain events or changes

Hypothesis

A testable conjecture about how something works

Variable

Categories, conditions, factors, or traits that differ in the natural world or experimental situations

Independent variable

Variable not dependent on other factors being studied. The variable that is changed and has an impact on the dependent variable

Dependent variable

The variable dependent on the other factors that the experiment is changing

Null hypothesis

A prediction that there is no difference between compared groups and conditions

Control group

A group that has the exact same conditions as the experimental group except for a single variable that is being studied. This helps determine sources of error

Natural experiment

A natural event occurs that acts as an experimental treatment in an ecosystem

Replication

The data collection procedure of taking repeated measurements

Sample size

The number of times an experiment is replicated in data collection

Accuracy

How close a measured variable is to the actual or true value

Precision

How close the repeated measurements of a sample are to one another

Uncertainty

An estimate of how much a measured or calculated value differs from a true value

Inductive reasoning

The process of making general statements from specific facts or examples

Deductive reasoning

The process of applying a general statement to specific facts or situations

Theory

A hypothesis that has been repeatedly tested and confirmed by many groups of researchers and is widely accepted

1st Law of Thermodynamics

Energy cannot be created or destroyed but just changes form

2nd Law of Thermodynamics

Energy is transformed, but as that happens, the amount of energy is the same but it cannot do as much work (some is released to heat, etc.)

Community ecology

The study of interactions among species

Symbiosis

Two species living in a close and long-term association with one another in an ecosystem

Biosphere

The region of Earth where life lives

Competition

The struggle of individuals, either within or between species, to obtain a shared limited resource

Competitive exclusion principle

The principle stating that two species competing for the same limiting resource cannot coexist

Predation

An interaction in which one animals typically kills and consumes another animal

Parasitoid

A specialized type of predator that lays eggs inside other organisms, eventually killing them (those organisms are called the host)

Parasitism

An interaction in which one organism lives on or in another organism, referred to as the host

Pathogen

A parasite that causes disease in its host

Herbivory

An interaction in which an animal consumes plants or algae

Mutualism

An interaction between two species that increases the chances of survival or reproduction for both species

Photosynthesis

The process by which plants and algae use solar energy to convert carbon dioxide and water into glucose and oxygen

Commensalism

An interaction between two species in which one species benefits and the other species is neither harmed nor helped

Native species

A species that lives in its historical range, typically where it has lived for thousands or millions of years

Exotic species

A species living outside its historical range. Also called an alien species

Invasive species

A species that spreads rapidly across large areas and causes harm

Climate

The average weather in a certain area over many many years (often decades)

Weather

A short-term concept that talks about the atmospheric conditions in an area. Weather includes things such as temperature, humidity, clouds, precipitation, and wind speed

Ecosystem boundary

A transition zone between two distinct ecosystems, characterized by a noticeable change in environmental conditions and the composition of plant and animal communities, or can be based on topographic or administrative criteria

Resource partitioning

A natural process that allows species to coexist by dividing up resources and avoiding competition (temporal/time, spatial/where, morphological/physical evolution to use a different variant of the resource)

Freshwater biomes

Categorized as streams and rivers, lakes and ponds, or freshwater wetlands

Littoral zone

The shallow zone of soil and water in lakes and ponds near the shore where most algae and emergent plants grow

Limnetic zone

A zone of open water in lakes and ponds as deep as the sunlight can penetrate

Phytoplankton

Floating algae

Profundal zone

A region of water where sunlight does not reach, below the limnetic zone in very deep lakes

Benthic zone

The muddy bottom of a lake, pond, or ocean beneath the limnetic and profundal zones

Oligotrophic

Describes a lake with a low level of phytoplankton due to low amounts of nutrients in the water

Mesotrophic

Describes a lake with a moderate level of fertility

Eutrophic

Describes a lake with a high level of fertility

Freshwater wetland

An aquatic biome that is submerged or saturated by water for at least part of the year, but shallow enough to support emergent vegetation

Estuary

An area along the coast where the fresh water of rivers mixes with salt water from the ocean

Salt marsh

Found along the coast in temperate climates, a marsh containing non-woody emergent vegetation

Mangrove swamp

A swamp that occurs along tropical and subtropical coasts, and contains salt-tolerant trees with roots submerged in water

Intertidal zone

The narrow band of coastline that exists between high and low tide

Coral reef

Earth’s most diverse marine biome, found in warm, shallow waters beyond shoreline in tropical regions

Coral bleaching

A phenomenon in which algae inside corals dies, causing corals to turn white

Open ocean

Deep-ocean water, located away from the shoreline where sunlight can no longer reach the ocean bottom

Photic zone

The upper layer of ocean water in the ocean that receives enough sunlight for photosynthesis

Aphotic zone

The deeper layer of ocean water that lacks sufficient sunlight for photosynthesis

Chemosynthesis

A process used by some bacteria to generate energy with methane and hydrogen sulfide

Biogeochemical cycles

The movements of matter within and between ecosystems involving cycles of biological, geological, and chemical processes

Reservoirs

The components of the biogeochemical cycle that contain the matter, including air, water, and organisms

Carbon Cycle

The movement of carbon around the biosphere among reservoir sources and sinks

Aerobic respiration

The process by which cells convert glucose and oxygen into energy, carbon dioxide, and water

Steady state

When a system’s inputs equal outputs, so that the system is not changing over time

Limiting nutrient

A nutrient required for the growth of an organism but available in a lower quantity than other nutrients

Nitrogen cycle

The movement of nitrogen around the biosphere among reservoir sources and sinks

Nitrogen fixation

The process that converts nitrogen gas in the atmosphere (N2) into forms of nitrogen that plants and algae can use

Nitrification

The conversion of ammonia (NH₄⁺) into nitrite (NO₂^-) and then into nitrate (NO₃⁺)

Assimilation

A process by which plants and algae incorporate nitrogen into their tissues

Mineralization/ammonification

The process by which fungal and bacterial decomposers break down the organic matter found in dead bodies and waste products and convert these organic compounds back into inorganic compounds, such as inorganic ammonium

Denitrification

The conversion of nitrate in a series of steps into the gases nitrous oxide and eventually nitrogen gas N2 which is emitted back into the atmosphere

Anaerobic

An environment that lacks oxygen

Aerobic

An environment with abundant oxygen

Leaching

A process in which dissolved molecules are transported through the soil via groundwater

FNAAD and ANPAN

Fixation, nitrification, assimilation, ammonification, denitrification —> ammonia, nitrate/nitrite, plant tissues/proteins, ammonium, nitrogen gas

Hypoxic

Low in oxygen

Dead zone

When oxygen concentrations become so low that it kills fish and other aquatic animals

Transpiration

The release of water from leaves into the atmosphere during photosynthesis

Evapotranspiration

The combined amount of evaporation and transpiration

Runoff

Water that moves across land surface and into streams and rivers

Producers/autotrophs

Plants, algae, and some bacteria that use the Sun’s energy to produce usable forms of energy, such as sugars. Also known as autotrophs

Cellular respiration

The process by which cells unlock the energy of chemical compounds

Anaerobic respiration

The process by which cells convert glucose into energy in the absence of oxygen

Primary productivity

The rate of converting solar energy into organic compounds over a period of time

Gross Primary Productivity (GPP)

The total amount of solar energy that producers in an ecosystem capture via photosynthesis over given amount of time

Net Primary Productivity (NPP)

The energy captured by producers in an ecosystem minus the energy producers respire

Biomass

The total mass of all living matter present in a specific area

Standing crop

The amount of biomass present in an ecosystem at a particular time

Formula for NPP

GPP-R=NPP