Environmental Science Exam 1 Study Guide

Vocabulary practice flashcards covering key concepts from Environmental Science Chapters 1 through 4 and the Chasing Coral documentary.

Environmental science

The interdisciplinary study of the natural world, human interactions with it, and solutions to environmental problems.

Ecology

The scientific study of relationships among organisms and their environment.

Environmentalism

Social and political advocacy for environmental protection.

Renewable resource

A resource that replenishes on a human timescale if its rate of consumption does not exceed its renewal rate.

Nonrenewable resource

A resource that forms too slowly in nature to replace current rates of human use.

Ecosystem services

Benefits provided by ecosystems, including pollination, water purification, climate regulation, soil formation, flood control, and recreation.

Tragedy of the commons

A scenario in which individuals pursuing short-term self-interest collectively deplete or degrade a shared, open-access resource.

IPAT model

A conceptual model representing environmental impact as $Impact = Population \times Affluence \times Technology$.

Ecological footprint

The amount of biologically productive land and water needed to supply resources and absorb wastes for a given population.

Biocapacity

The capacity of a given ecosystem to regenerate renewable resources and absorb generated waste.

Ecological overshoot

The condition that occurs when human ecological footprint exceeds the available biocapacity of the ecosystem.

Sustainability

Meeting current needs without undermining the ability of future generations to meet their environmental and resource needs.

Sustainable development

Development that integrates environmental protection, economic viability, and social equity.

Pragmatic resource conservation

A conservation view advocating managed, wise resource use for the greatest good over time, associated with Gifford Pinchot.

Biocentric preservation

A philosophy asserting that nature has intrinsic value and should be protected from human development, associated with John Muir.

Anthropocentrism

An ethical perspective holding that human interests are primary and that nature is valued mainly for human benefit.

Biocentrism

An ethical perspective according intrinsic value to all living organisms.

Ecocentrism

An ethical perspective placing primary intrinsic value on whole ecological systems, species, communities, and natural processes.

Stewardship

The ethical duty of humans to manage and care for nature responsibly.

Environmental justice

The fair treatment and meaningful involvement of all people in environmental decisions regardless of background or income.

Environmental racism

Policies or practices that disproportionately expose racial or ethnic minority communities to environmental hazards or deny equal protection.

Toxic colonialism

The practice of transferring hazardous industries or waste materials from powerful or wealthy nations to poorer or less powerful communities.

Hypothesis

A specific, testable, and falsifiable proposed explanation or prediction for an observation.

Theory

A broad, highly supported explanation of natural phenomena sustained by extensive scientific evidence.

Inductive reasoning

Reasoning that proceeds from specific observations to a broad, general explanation.

Deductive reasoning

Reasoning that proceeds from a general principle to a specific testable prediction.

Independent variable

The factor intentionally manipulated or altered by an investigator in an experiment.

Dependent variable

The measured response factor that changes in response to the independent variable.

Confounder

An uncontrolled factor in an experiment that could account for the observed experimental pattern.

Dynamic equilibrium

A state in a system where inputs and outputs continue, but average stock levels remain relatively constant over time.

Homeostasis

System regulation that maintains conditions within a functional range, often maintained through negative feedback.

Negative feedback loop

A feedback mechanism that counteracts or opposes an initial change, helping to stabilize a system.

Positive feedback loop

A feedback mechanism that amplifies or reinforces an initial change within a system.

Resistance

The capacity of a system to remain largely unchanged when subjected to a disturbance.

Resilience

The capacity of a system to recover back to its original state following a disturbance.

Tipping point (Threshold)

A critical point in a system where a small additional change triggers a major, rapid shift in system state.

Alternative stable state

A distinct, self-sustaining set of ecological conditions that replaces a prior state following a threshold breach.

First law of thermodynamics

The physical law stating that energy can change forms but cannot be created or destroyed.

Second law of thermodynamics

The physical law stating that every energy transfer increases total entropy, reducing usable energy as heat disperses.

Photosynthesis

The chemical process represented by $6 CO_2 + 6 H_2O + \text{light} \rightarrow C_6H_{12}O_6 + 6 O_2$, storing solar energy in glucose.

Cellular respiration

The biological process represented by $C_6H_{12}O_6 + 6 O_2 \rightarrow 6 CO_2 + 6 H_2O + ATP + \text{heat}$, releasing stored energy for cellular work.

Gross Primary Productivity (GPP)

The total solar energy captured and converted into organic matter by primary producers per unit time.

Net Primary Productivity (NPP)

The organic energy remaining after producer respiration, calculated using the formula $NPP = GPP - R$.

Aquifer

An underground layer of permeable rock, sand, or gravel that stores accessible groundwater.

Water table

The top surface boundary of the saturated subterranean zone within an aquifer.

Carbon sink

A biological or physical reservoir that absorbs and stores more carbon than it releases into the environment.

Nitrogen fixation

The transformation of inert atmospheric nitrogen gas ($N_2$) into bioavailable ammonia or ammonium by bacteria, lightning, or industrial manufacturing.

Nitrification

The biological conversion of soil ammonium into nitrite and subsequently into nitrate.

Assimilation (Nitrogen cycle)

The absorption of inorganic nitrogen compounds by plants to synthesize organic biological compounds.

Ammonification

The decomposition process that converts organic nitrogen compounds from dead organisms back into ammonium.

Denitrification

The bacterial conversion of soil nitrate into nitrogen gas ($N_2$) or nitrous oxide ($N_2O$) returned to the atmosphere.

Eutrophication

Ecosystem degradation initiated by excess nitrogen and phosphorus, leading to algal blooms, high decomposition, and aquatic hypoxia.

Evolution

A change in the allele frequencies within a population over successive generations.

Mutation

A random change in DNA sequence that acts as the ultimate source of new genetic alleles.

Natural selection

The mechanism where individuals possessing advantageous heritable traits reproduce more successfully, increasing those traits' frequency in a population.

Genetic drift

Random fluctuations in population allele frequencies, exerting its most significant effect in small populations.

Gene flow

The exchange of genetic alleles between distinct populations through migration and interbreeding.

Allopatric speciation

The formation of new species resulting from geographic isolation and subsequent genetic divergence.

Sympatric speciation

The formation of new species occurring within populations sharing the same geographical region.

Habitat

The physical environment and location where an organism resides.

Ecological niche

The complete functional role, resource usage, and environmental tolerance spectrum of a species.

Fundamental niche

The full potential ecological range an organism could occupy in the absence of biotic constraints like competition or predation.

Realized niche

The actual range of resources and conditions an organism occupies in the presence of biotic interactions.

Specialist species

A species characterized by a narrow diet, strict habitat requirements, and limited environmental tolerance limits.

Generalist species

A species characterized by a broad diet, flexible habitat requirements, and wide environmental tolerance limits.

Species richness

The total count of distinct species living within a given ecological community.

Species evenness

The relative abundance and numerical equality of individual organisms across species in a community.

Keystone species

A species that exerts an exceptionally large, critical influence on community structure relative to its biomass.

Foundation species

A species that creates, structurally modifies, or defines an entire habitat, such as reef-building corals.

Indicator species

A species whose health or presence serves as an early signal of specific environmental conditions or ecosystem health.

Primary succession

Ecological succession initiating on exposed, bare substrate lacking original soil, such as volcanic rock.

Secondary succession

Ecological succession occurring after a disturbance alters an existing community but leaves the soil intact.

Competitive exclusion principle

The principle stating that two species competing for identical limited resources cannot stably coexist if their niches overlap completely.

Resource partitioning

The division of limited environmental resources by space, time, or behavior, permitting competing species to coexist.

Character displacement

The evolutionary divergence of morphological or behavioral traits in competing species where their geographic ranges overlap.

Batesian mimicry

An evolutionary strategy where a harmless species mimics the appearance or warning signals of a harmful species.

Mullerian mimicry

An evolutionary strategy where multiple harmful or noxious species share a common warning appearance.

Mutualism

A symbiotic relationship between species where both participating organisms benefit ($+ / +$).

Commensalism

A symbiotic relationship where one organism benefits while the other remains unaffected ($+ / 0$).

Parasitism

A symbiotic relationship where one organism benefits at the physical expense of the host ($+ / -$).

Coral bleaching

The stress response where thermal stress causes corals to expel their photosynthetic algae symbionts, exposing their white calcium carbonate skeleton.

Ocean acidification

The decrease in seawater pH caused by ocean uptake of atmospheric carbon dioxide ($CO_2$), which reduces marine carbonate availability.