Environmental Science Lecture Review Flashcards

Vocabulary practice flashcards generated from the environmental science lecture notes covering foundational concepts, ecosystems, demographic metrics, thermodynamics, and population ecology.

Environmental Science

An interdisciplinary field incorporating the natural world (biology, chemistry, geology) along with technological, social, political, and cultural aspects of human interactions with the environment.

Components of the Environment

The four main environmental components: the natural world (ecosystems, physical processes), technological systems (built environment, infrastructure), social structures (human societies, policy), and cultural beliefs.

Provisioning Ecosystem Services

Ecosystem services that yield physical goods directly consumed by humans, such as food and water.

Regulating Ecosystem Services

Ecosystem services that mediate environmental processes and climate, such as climate regulation and flood control.

Cultural Ecosystem Services

Non-material ecosystem services that provide human enjoyment and spiritual value, such as recreation.

Ecosystem Services Valuation Issue

Problems arising when unpriced services (e.g., air purification) are undervalued or depleted because only monetized services are prioritized.

Sustainable Development

Development that meets current needs without compromising future generations.

Sustainability for Impoverished Populations

An approach requiring that immediate basic needs—such as food, clean water, and shelter—be met before long-term conservation can be addressed.

UN Sustainable Development Goal 1

No Poverty.

UN Sustainable Development Goal 2

Zero Hunger.

UN Sustainable Development Goal 3

Good Health and Well-being.

Science

A systematic process of producing knowledge about the natural world through empirical observation, hypothesis testing, and rigorous evaluation.

Scientific Method

A systematic process involving observation, hypothesis formulation, controlled experimentation, data collection, analysis, and conclusion drawing to test explanations of natural phenomena.

Experimental Control

An unmanipulated baseline comparison that ensures observed changes in the experimental group are caused solely by the variable being tested.

Hypothesis Falsification

The principle that a hypothesis can never be proven absolute truth because future evidence may refute it; however, it can be proven false (falsified) if empirical data contradicts its predictions.

Repeatability in Science

The requirement that experimental results must be reproducible by independent researchers to verify findings are reliable and not artifacts of chance, error, or bias.

Scientific Theory

A well-tested, broadly accepted explanation supported by extensive empirical evidence, contrasting with the everyday use of 'theory' as a hunch or guess.

Scientific Consensus

The collective agreement among experts in a field based on rigorous evaluation of evidence, serving as the most reliable basis for decision-making.

Sound Science Evaluation

Checking for peer-reviewed publication, controlled and repeatable experimental design, clear conflict of interest disclosures, and alignment with established evidence.

State Variables

Measurable components of a system that store matter or energy.

Open System

A system that exchanges both energy and matter with its surroundings, such as a wetland receiving rainfall and discharging runoff.

Positive Feedback Loop

A feedback loop that amplifies changes and pushes systems away from equilibrium, such as ice-albedo melt.

Negative Feedback Loop

A feedback loop that counteracts changes and stabilizes a system, such as predator-prey population regulation.

System Disturbances

Events (e.g., fires, storms) that disrupt existing system structure and nutrient pathways, forcing systems to recover via feedback mechanisms or shift into new equilibrium states.

Law of Conservation of Matter

The principle stating that matter cannot be created or destroyed, only transformed, requiring biological nutrients to be continuously recycled through biosphere processes.

Environmental Ions

Charged atoms like $\text{Ca}^{2+}$, $\text{NO}_3^-$, and $\text{H}^+$ essential for cellular processes, soil nutrient availability, aquatic chemistry, and driving chemical reactions.

Acids

Chemical substances that release $\text{H}^+$ ions and have a $\text{pH} < 7$ (e.g., lemon juice, acid rain).

Bases

Chemical substances that absorb $\text{H}^+$ ions or release $\text{OH}^-$ ions and have a $\text{pH} > 7$ (e.g., bleach).

Neutral pH

A $\text{pH}$ value of $7$.

Organic Compounds

Carbon-based molecules held together by covalent bonds that form the basis of life, including carbohydrates, lipids, proteins, and nucleic acids.

High Specific Heat of Water

A property of water that stabilizes global and regional climate.

Water Expansion Upon Freezing

A unique physical property where ice expands and floats, insulating aquatic life underneath.

Universal Solvent Property of Water

A property of water enabling it to dissolve and transport nutrients throughout ecosystems.

Water Cohesion and Surface Tension

High attractive forces between water molecules driving capillary action in plants.

Kinetic Energy

The energy of motion, such as flowing water.

Potential Energy

Stored energy, such as chemical bonds in food.

Radiant Energy

Solar radiation that drives global climate and photosynthesis.

First Law of Thermodynamics

The thermodynamic law stating energy is conserved and can only change form.

Second Law of Thermodynamics

The thermodynamic law stating energy transformations increase entropy, releasing low-quality heat.

Role of the Sun in Earth Systems

Drives global climate patterns, powers ocean and hydrologic cycles, and provides radiant solar energy captured by autotrophs to sustain biosphere food webs.

Photosynthesis Word Equation

$$\text{Carbon Dioxide} + \text{Water} + \text{Light Energy} \rightarrow \text{Glucose} + \text{Oxygen}$$

Cellular Respiration Word Equation

$$\text{Glucose} + \text{Oxygen} \rightarrow \text{Carbon Dioxide} + \text{Water} + \text{Energy (ATP)}$$

Relationship Between Photosynthesis and Respiration

A complementary cycle where products of photosynthesis (glucose, oxygen) serve as reactants for respiration, and products of respiration (carbon dioxide, water) feed photosynthesis.

Species Level of Organization

Individuals that can interbreed and produce fertile offspring.

Population Level of Organization

Members of the same species residing in a given area.

Community Level of Organization

Interacting populations of different species within a specific area.

Ecosystem Level of Organization

A biological community integrated with its abiotic physical environment.

Primary Producers

Autotrophs that manufacture organic food molecules from solar or inorganic energy.

Primary Consumers

Herbivores that feed directly on primary producers.

Secondary Consumers

Carnivores that feed on primary consumers.

Tertiary Consumers

Top predators that feed on secondary consumers.

Food Chain vs. Food Web

A food chain is a linear sequence showing energy transfer from producer to consumers; a food web is a complex network of interconnected food chains reflecting ecosystem feeding relationships.

Herbivore

An organism that eats plants.

Carnivore

An organism that eats animals.

Omnivore

An organism that eats both plants and animals.

Scavenger

An organism that eats dead carcasses.

Detritivore

An organism that consumes organic debris.

Decomposer

An organism that breaks down dead matter into inorganic nutrients.

Energy Pyramids & Trophic Efficiency

Only about $10BA2$ (specifically 10\text{\textpercent}) of energy transfers to the next trophic level due to metabolic heat loss (2nd Law of Thermodynamics), causing higher trophic levels to support far fewer individuals and less biomass.

Biogeochemical Cycles

Processes circulating essential nutrients through biotic and abiotic reservoirs.

Hydrologic Cycle Movements

Water enters the atmosphere via evaporation and transpiration, falls as precipitation, and flows via runoff, groundwater percolation, and river discharge back to oceans.

Carbon Cycle Dynamics & Fossil Fuel Impact

Sources (respiration, combustion) release carbon; sinks (oceans, forests) store carbon. Fossil fuels locked carbon underground for millions of years; burning them bypasses natural balancing sinks and increases atmospheric $\text{CO}_2$.

Acclimation

A temporary, non-heritable physiological adjustment.

Adaptation

An inherited trait evolved over generations via natural selection, where favorable random genetic mutations increase reproductive success.

Human Influence on Natural Selection

Humans drive natural selection through selective breeding (artificial selection), habitat fragmentation, climate change, and heavy pesticide or antibiotic application leading to resistant strains.

Determinants of Species Distribution

Physiological tolerance limits (temperature, moisture, $\text{pH}$), resource availability, biological interactions (competition, predation), and physical dispersal barriers.

Tolerance Limits

The minimum and maximum environmental bounds required for an organism's survival.

Indicator Species

Species with narrow tolerance limits whose health directly reflects specific environmental conditions.

Habitat vs. Ecological Niche

Habitat is the physical address where an organism lives. Ecological niche is its full role, functional position, and resource use.

Competitive Exclusion Principle

The rule stating that no two species can occupy the exact same niche indefinitely.

Resource Partitioning

The dividing of space, time, or diet by coexisting species to minimize niche overlap.

Speciation Mechanisms

The evolutionary process forming new species, occurring via allopatric speciation (geographic isolation) or sympatric speciation (reproductive isolation in the same location).

Predator-Prey Coevolution

Predators select for prey adaptations (camouflage, toxins, mimicry), which in turn selects for enhanced predator hunting mechanisms, driving reciprocal evolutionary adaptations.

Symbiotic Interactions

Mutualism (both species benefit), Commensalism (one benefits, one unaffected), and Parasitism (one benefits at the expense of host harm).

Biotic Potential

The maximum reproductive rate of a population achievable only under ideal conditions with unlimited resources, zero predation, no disease, and absent environmental resistance.

Carrying Capacity ($K$)

The maximum sustainable population size determined by limiting factors such as food, water, space, shelter, waste accumulation, and disease.

Exponential vs. Logistic Growth

Exponential growth ($J$-shaped) occurs with unlimited resources, leading to overshoot and dieback. Logistic growth ($S$-shaped) slows as population approaches carrying capacity ($K$) due to environmental resistance.

r-Selected vs. K-Selected Traits

$r$-selected species prioritize rapid reproduction (high growth rate $r$, small size, many offspring, low parental care). $K$-selected species prioritize survival near carrying capacity ($K$) (large size, few offspring, high parental care).

Ecological Diversity vs. Abundance

Diversity is the total number of different species in a community (high in tropical rainforests). Abundance is the total number of individuals of a single species (high in arctic tundra).

Demographic Transition Stages

Stage 1: High birth/death rates; Stage 2: Death rates drop, population booms; Stage 3: Birth rates drop; Stage 4: Low birth/death rates (stable). US is in Stage 4; underdeveloped countries are in Stage 2 or early Stage 3.