Biodiversity
Define "biodiversity" at the three commonly cited levels and give one example for each level.
Biodiversity levels: ecosystem diversity (variety of habitats/communities — e.g., coral reef vs. kelp forest), species diversity (number of species — e.g., number of bird species in a forest), genetic diversity (variation of genes within species — e.g., different potato cultivars).
What is "topsoil," and why is it critical for agriculture?
Name one agricultural practice that threatens topsoil.
Topsoil = nutrient-rich surface layer; critical for plant growth.
Threatening practice: intensive monoculture / leaving soil bare.
What organism commonly blooms with excess nutrients?
Algae
List four common forms of air pollution
Smog, acid rain, greenhouse gases, particulates.
Acronym for the program of architecture emphasizing sustainability and environmental innovation
LEED Architecture
Explain how habitat fragmentation can reduce species diversity.
Fragmentation reduces migration, isolates populations, reduces gene flow; smaller "islands" support fewer species per island biogeography, raising extinction risk.
Describe two soil-conserving farming techniques mentioned in this chapter and explain how each reduces erosion or nutrient loss.
Crop rotation (restores nutrients, breaks pest cycles); contour plowing/terracing (reduces runoff and erosion).
Differentiate point source and non-point source water pollution and give one local example of each.
Point-source: factory effluent pipe; nonpoint-source: agricultural runoff from many fields.
Explain how burning fossil fuels contributes to both smog (ground-level ozone) and acid rain.
Fossil fuel combustion emits NOx (nitrogen) and SOx (sulfur); NOx + VOCs under sunlight form ozone (smog); NOx/SOx oxidize to acids that form acid rain.
Define "sustainable development"
Sustainable development: meeting human needs while preserving ecosystem capacity to provide resources in the future.
Describe biological magnification (biomagnification). Explain why top predators are most affected and give a real-world pollutant example from the provided text.
Biomagnification: pollutant concentration increases up trophic levels; top predators accumulate highest concentrations; example: DDT.
Explain the Dust Bowl's connection to soil management and describe two policy or practice changes that would reduce the risk of similar events today.
Poor tilling + lack of cover crops left soil exposed, wind erosion removed fertile topsoil. Policies/practices: conservation tillage, cover crops, crop rotation, windbreaks, subsidized sustainable practices.
Explain how residential sewage can create "dead zones." Include the role of nutrients and the resulting effects on aquatic life.
Sewage supplies N and P → algal blooms → decomposition consumes oxygen → hypoxic “dead zones” → fish kills.
Define greenhouse gases and describe how increased concentrations affect Earth's energy balance. Name two major greenhouse gases
Greenhouse gases trap outgoing infrared radiation, warming the planet. Ex. CO2, H2O, methane CH4.
Explain the "Tragedy of the Commons" with an environmental example (from the text or related) and a policy or community solution to prevent it.
Tragedy: common-pool resource overuse (e.g., overfishing).
Solutions: regulation, quotas, community management, privatization or rights-based fishing.
Compare and contrast introduced (non-native) species and invasive species. Explain two ecological effects invasive species can have on native communities.
Introduced = non-native; invasive = introduced that cause harm.
Effects: outcompete natives, alter food webs, introduce disease, change habitat structure.
Distinguish between renewable and nonrenewable ecosystem resources. Provide two examples of each and explain why each fits its category.
Renewable: wind, forests (if properly managed); Nonrenewable: fossil fuels, old-growth forests in practical terms when they don't regrow in human timescales. Explanation: renewables replenish on human timescales, nonrenewables do not.
Describe the concept of LD50 and explain why it is important when assessing chemical risk to ecosystems and humans.
LD50 = dose causing 50% mortality in test population; used to compare acute toxicity; helps set safe exposure limits but has ethical/interpretation limits.
Compare ozone at ground level versus stratospheric ozone. Explain the ecological and health consequences of a depletion in stratospheric ozone.
Ground-level ozone is a pollutant harming lungs/vegetation; stratospheric ozone absorbs UV and protects life. Depletion increases surface UV, raising skin cancer risk and harming ecosystems.
Interpret "ecological footprint." Explain why the average American footprint being over four times the global average is significant for global sustainability.
Ecological footprint = land/water area needed to support consumption and waste absorption.
If American footprint is 4× global average, global equity and carrying capacity issues arise; disproportionate resource use and higher environmental burden.
Evaluate the roles of genetic diversity and ecosystem diversity in species' long-term adaptability to climate change. Include at least two conservation strategies that protect biodiversity.
Genetic diversity enables adaptation to new stresses; ecosystem diversity provides multiple niches and resilience.
Conservation strategies: protected area networks, seed/gene banks, habitat corridors, captive breeding programs.
Critically analyze monoculture farming: list two benefits and three environmental drawbacks, then propose a mixed strategy that maintains productivity while reducing ecological harm.
Benefits of monoculture: mechanization efficiency, high yields, simplified management.
Drawbacks: soil depletion, pest/disease vulnerability, loss of biodiversity, increased chemical use.
Mixed strategy: polyculture / crop rotation + integrated pest management + agroforestry.
Discuss how industrial chemicals like PCBs and pesticides accumulate in organisms. Explain how this process can affect food webs and human health.
Persistent organic pollutants resist degradation, accumulate in fatty tissues, biomagnify; affect reproduction, endocrine systems; humans exposed via food consumption.
Summarize the history and science connecting CFCs to stratospheric ozone depletion, and evaluate the international response and its effectiveness.
CFCs release chlorine radicals in stratosphere that catalyze ozone destruction; Policies were implemented (Montreal Protocol) that phased out CFCs; ozone holes have shown signs of recovery due to reduced CFC emissions.
Describe three ecosystem goods and services that healthy ecosystems provide and explain the economic implications when these services are lost.
Examples: clean water (provisioning/regulating), pollination (supporting/service), flood control and water purification (regulating).
Economic implications: replacing services costs money (water treatment plants, artificial pollination).