Biodiversity

1. Period 1: Presentation slides 1-9 (the kākāpō phenomenon, targets, what biodiversity means, the named-species bar graph, richness and evenness, natural levels, the tundra-rainforest comparison, first check). W1 phenomenon worksheet as the opener.
2. Period 2: Lab 1 session 1, Count the Kinds: groups mark out quadrats by dice roll in a mowed lawn and a less-managed patch, build a kind key and record 25 point-intercept hits per quadrat.
3. Period 3: Lab 1 session 2: pool class data, calculate richness and Simpson's index, graph the species-accumulation curve and answer the analysis questions. W7 misconception (fixing a field report) pairs with the calculations. Slides 10-11 (fragile tundra and the sea-ice chain). W2 vocabulary for homework.
4. Period 4: Slides 12-18 (the sea otter keystone, its causal chain, vocabulary, the extirpation-or-extinction check, rainforest niches, the 'is more always healthier?' discussion, people depend on biodiversity). W3 reading on the three levels of biodiversity, habitat loss and invasive species.
5. Period 5: Lab 2, Case File: Two Kelp Coves: groups compare two coves' survey data, test five suspects against clue cards and draw the causal chain. W6 CER (an invasive species and native ants) can follow as homework.
6. Period 6: Slides 19-21 (California condors, otters and abalone; judging a plan; the gecko-and-mussel adhesive). W4 diagram (habitat loss and fragmentation) and W5 data (richness, evenness and a diversity index), in class or as homework.
7. Period 7: Slides 22-24 (the otter return discussion, the kākāpō habitat task, combining plans check). Lab 3 session 1, Bring Back the Forest: score the single plans and design a hybrid.
8. Period 8: Lab 3 session 2: read the hybrid results card, decide and justify. Slides 25-27 (misconception, synthesis, exit). W8 collaborative (the island fox jigsaw: twelve evidence cards, a cause-and-effect chain and five real solutions scored against shared criteria) and W9 transfer (the salt-pond design challenge: check three San Francisco Bay shoreline designs against cost, upkeep, waterbird and marsh limits, then build and justify a pond-by-pond plan) each need about 55 minutes; run them in an added period after Lab 3, or use W9 as pair work in place of one presentation period. W10 mastery (12 items, 30 points, ending in a synthesis paragraph that judges two solutions to one threat) is the individual quiz in the next class. Preview Lesson 28, where ecosystem services are given a price.

Materials overview: Lab 1 needs quadrat frames (cardboard or PVC, 50 cm square), string for a 5 by 5 grid, a blunt skewer or pencil for point readings, dice, clipboards, hand lenses and a site the teacher has checked for hazards. Labs 2 and 3 are paper only: printed case files, clue cards, data tables, a calculator and colored pencils. The presentation needs only the slides; a photo of a kākāpō and of an urchin barren help.

• Multilingual learners: Pre-teach richness, evenness, keystone, extirpation and extinction with picture cards (an arch with its keystone, an empty map region versus an empty world). Give sentence frames: 'This plan meets ___ because ___, but it misses ___ by ___.' and 'Without ___, the ___ population ___, so ___.' Let students keep their Lab 1 kind key in their home language.
• Students who need more support: In Lab 1, supply a kind key with the three most common lawn plants already drawn and a Simpson's table with p and p² columns set up. In Lab 2, release clue cards two at a time with a 'supports / rules out / no effect' prompt on each. In Lab 3, give the single-plan scorecard with plan A already completed as a model.
• Students ready for extension: Have them compare Simpson's index with species richness for the class data and explain when the two rank patches differently; read about why sunflower sea stars are being raised in captivity and list what would need testing before release; or redesign the Lab 3 hybrid to treat only part of the cove and estimate the savings.
• Students who need movement or alternative output: Lab 1 is outdoors; give these students the Site setter role (pacing out the dice-roll positions). Act out the tundra chain as a human web in which the 'sea ice' student steps away. Accept an annotated photo of a quadrat as the kind key and a recorded spoken justification for the Lab 3 decision.
• Students with mobility, allergy or sensory needs: Choose quadrat sites on flat ground next to a path; let students who cannot kneel do the point readings from a stool or record while a partner reads. Students with grass or pollen allergies can do the kind key from photos and the calculations indoors. Offer large-print case files in Lab 2.

• Kākāpō numbers: the textbook's phenomenon says only 18 kākāpō were alive in the 1970s and about 160 now. In the 1970s searchers found 18 birds in Fiordland, all of them males; in 1977 a larger group, estimated at roughly 100 to 200 birds, was found on Rakiura/Stewart Island, where females were confirmed in 1980 and feral cats were killing many birds. Between 1980 and 1997 all known birds were moved to offshore island sanctuaries, from which cats and rats were then removed. The lowest count was 51 birds in 1995. DOC reported 242 birds on 30 June 2025 and an official count of 325 on 1 September 2026, after a record 90 chicks from the 2026 season. Teach the 1995 low and the 2026 count, and say the textbook's numbers are out of date.
• Biodiversity has three levels: the textbook defines it as the variety of organisms (pp. 359-360). The usual scientific definition, used in the Convention on Biological Diversity, includes variety within species (genetic), between species and among ecosystems. This chapter says which level is being compared, usually species.
• Health is judged against the natural set: the lesson's standard box says the completeness or integrity of biodiversity indicates health (p. 359). This means having the species that belong there, not simply the most species. A higher count can come from invasive species, so the chapter never treats richness alone as a health score.
• Species counts are dated: about 1.9 million identified species (p. 361) reflects older catalogs; the Catalogue of Life now lists well over 2 million. Figure 1 labels insects 50 percent while the text says 52 percent; with 52 the wedges sum to 100, so slide 5 uses 52 percent and calls all the shares approximate.
• Polar bears do not hibernate: Section 2 (p. 362) lists them with hibernating animals. Only pregnant females den; other polar bears hunt seals on the sea ice through the winter.
• Scavengers and seals: the textbook says the foxes and gulls that eat polar bear leftovers cannot hunt seals themselves and that no other species fills the polar bear's niche (p. 363). Arctic foxes do tunnel into ringed seal birth lairs and kill pups. The chapter calls polar bears the chief hunters of grown seals on the sea ice.
• Fragility is a tendency, not a law: low biodiversity tends to make an ecosystem easier to disrupt (p. 363), but high biodiversity is no guarantee. Coral reefs, among the richest ecosystems, are badly damaged by marine heat waves that cause bleaching.
• Sea otters live in more than kelp forests: Section 3 (p. 364) calls the sea otter a species found only in kelp forests. Sea otters also live in estuaries such as Elkhorn Slough, seagrass beds and soft-bottomed coastal waters.
• California's otters were not fully extirpated: the fur trade wiped sea otters out along most of the Pacific coast, and the textbook says many kelp forests lost all their otters (p. 365). In California a remnant colony of about 50 survived on the Big Sur coast, and today's southern sea otters descend from it. Washington's otters come from 59 animals moved from Alaska in 1969 and 1970.
• Kelp recovery is not automatic: the textbook says the forest will die without otters (p. 364) and that kelp recovered where otters returned (p. 365). Other predators, especially sunflower sea stars, also eat urchins, and how strongly otters affect kelp depends on how many there are, how long they stay and local conditions. North of San Francisco, where there are no otters, a sea star wasting disease from 2013 and a marine heat wave from 2014 to 2016 were followed by an urchin explosion and the loss of more than 90 percent of bull kelp canopy along more than 350 km of coast (Rogers-Bennett and Catton 2019).
• Keystone species definition: the textbook defines a keystone species simply by its effect on a whole ecosystem's diversity (pp. 359, 365). The defining feature is an effect far larger than the species' abundance would suggest; the chapter teaches that version and uses the arch only as an analogy.
• Medicines: Section 5 (p. 370) says the chemical in willow bark is what makes aspirin work and that foxglove prevents heart failure. Willow bark contains salicin, which led chemists to aspirin (acetylsalicylic acid), a lab-made compound. Purple foxglove is the source of digitoxin and its relative woolly foxglove of digoxin; these drugs treat some heart rhythm problems and ease heart-failure symptoms rather than prevent heart failure. Madagascar periwinkle comes from eastern and southern Madagascar, mainly seasonally dry habitats rather than rainforest; its alkaloids vinblastine and vincristine are used against several cancers, including childhood leukemia.
• Gastric brooding frogs: the textbook dates the discovery to the 1970s (p. 371). The southern gastric brooding frog was found in Queensland in the early 1970s and had vanished from the wild by the early 1980s; a second, northern species found in 1984 disappeared within about a year. The cause is uncertain. The chapter says only that they disappeared within about a decade of being discovered.
• The bandage was a lab prototype: Section 6 (pp. 372-373) presents the gecko-and-mussel bandage as a finished design that meets all criteria. The research it describes (Lee, Lee and Messersmith, 2007) produced a lab adhesive, an array of tiny pillars coated with a mussel-like polymer, that held and released reliably in wet and dry tests. Using it on patients would need further testing.
• Rainforest numbers are not used: Section 4 (p. 366) gives figures such as nearly 1,000 beetle species on one tree and 650 kinds of trees in a small patch. These are rounded or hard to verify, so the chapter says only that a small patch can hold hundreds of tree species.
• Coral reefs and nutrients: the Key Science Concept (p. 369) credits high marine biodiversity to abundant nutrients and light, naming coral reefs. Reef-building corals grow best in clear, nutrient-poor water; their richness comes from warm, sunlit shallows. The chapter credits reefs to warmth and light only.
• California facts used in the chapter: condors fell to 22 birds in 1982, and the last wild bird was captured in 1987, leaving 27 in captivity; releases began in 1992 and the U.S. Fish and Wildlife Service counted 607 condors at the end of 2025, 392 of them flying free. The last published range-wide southern sea otter index (2019) was 2,962; the species has been listed as threatened since 1977. White abalone have declined about 99 percent since the 1970s, became in 2001 the first marine invertebrate listed as endangered under the federal Endangered Species Act, and have been released from captive breeding since 2019. The north coast recreational red abalone fishery closed in 2018 after the kelp collapse, and in December 2025 the Fish and Game Commission extended the closure to 1 April 2036.