Habitat conservation strategies (ESS HL)

Habitat conservation at Higher Level: Different places from SL: Chile's new parks, the Everglades, Maungatautari, Velondriake and the Great Barrier Reef. At HL, ask who pays for managing a habitat, which laws protect it, and whether it is fair to the people who live beside it.

Save the home, save the species: Habitat conservation protects species by protecting the place they live. It is in situ conservation: every species in that habitat is protected at once.

Remember it as: Save the home, save the family.

Example (HL): Chile. About 21% of Chile's land and 41% of its sea are protected. Since 2018 the government and private foundations have added five national parks in Patagonia, on land once used for sheep and cattle. One protected landscape shelters the huemul, pumas, condors and old forest together.

Better than captivity in the long run: Keeping a species in its habitat keeps its natural behaviour, its food web and a large gene pool; a zoo keeps only a few animals. This is the usual advantage asked of in situ over ex situ conservation.

Some habitats disappear even when they are protected by law. They survive only if people keep working on them. This is active management.

Remember it as: Graze, burn, weed, water, guard.

Example (HL): the Everglades, Florida. This shallow 'river of grass' needs water flowing south. Canals drained about half of it for sugar cane and Miami. The national park now depends on management outside it: canals removed, a road raised on bridges so water flows again, controlled burning, and teams catching invasive Burmese pythons.

Why removing invasive plants can be controversial: People may use the plants for timber, jobs, fuel or shade, or enjoy them; some species feed or nest in them; cutting them releases carbon and can leave soil to erode; it is costly, may harm native plants, and some say every species has a right to exist.

Say how, not just 'bigger': 'The habitat gets larger' or 'poaching is harder' is not enough. Give the mechanism: less fragmented, fewer road deaths, no vehicle access for poachers.

Fence the pests out: An ecosanctuary protects native species from the predators people brought in. Inside a pest-exclusion fence, every pest is removed, then native species are reintroduced.

Example (HL): Sanctuary Mountain Maungatautari. In 2006 a 47 km fence was finished round a forested mountain in the Waikato. Thirteen kinds of mammal pest were removed, and kiwi, takahē and hihi were returned. Local landowners and iwi run it together, and the land stays theirs.

Numbers in a sanctuary: percentage change: Percentage change = (new - old) ÷ old x 100. A count that rises from 40 birds to 110 birds is (110 - 40) ÷ 40 x 100 = +175%. A fall gives a minus sign: 29 800 to 24 850 is a 16.6% decrease.

Where a reserve is placed matters as much as what happens inside it. Look at its neighbours and how far it is from a town.

Example (HL): two different neighbours. Zealandia, 2 km from central Wellington, gets many visitors and volunteers, but city cats kill birds that leave it. Maungatautari, among dairy farms, has few visitors, and its long fence edge meets cattle and farm run-off. The Everglades' water passes sugar cane farms first, so it must be cleaned of phosphorus before it enters the park.

Asked why a park was put in a place?: Use the figures: high biodiversity or endemic species there, a threat such as fast deforestation, a link to another park, few villages to object, and a chance for ecotourism.

Some protected areas are run by the people who live beside them and use them. At sea these are called locally managed marine areas (LMMAs).

Remember it as: Our sea, our rules, our eyes.

Example (HL): Velondriake, Madagascar. In 2004 the fishing village of Andavadoaka closed one reef to octopus fishing for a few months. When it reopened, fishers landed more and bigger octopus. Other villages copied it, and in 2006 they formed Velondriake, an LMMA whose rules are set by the villages' own law and enforced by fishers.

The advantage of community management itself: When asked why community management works, do not list no-take zones, bigger fish, more jobs or tourism. Say what the community brings: ownership, local knowledge, fast and flexible decisions, policing.

When a country's protected areas grow, from a few small parks to a large network, species gain in several ways.

Example (HL): the Great Barrier Reef, Australia. In 2004 the marine park was rezoned: no-take zones grew from under 5% to about a third of the park. Within a few years coral trout, a fish caught for food, were more common and larger inside the no-take zones than in fished areas next to them.

Three separate ways, not one: In an Explain [3], give three different mechanisms from the list, each linked to species. Avoid vague phrases such as 'it reduces limiting factors'.

Climate change is the biggest test for habitat conservation, because a reserve cannot move but the climate its species need can.

Example (HL): the Great Barrier Reef again. Its zoning protects fish and coral from fishing, but marine heatwaves bleached large areas in 2016, 2017, 2020, 2022 and 2024. Managers cut other stresses, such as farm run-off and coral-eating starfish, to help reefs recover between heatwaves.

It can also slow climate change: Protecting sea otters in their kelp forests keeps sea urchins in check, so the kelp grows, photosynthesises more and takes in more carbon dioxide.