Habitat conservation strategies

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 (SL): Kaziranga National Park, India. About 12 greater one-horned rhinos were left there in 1905. Protecting the whole floodplain grassland, with armed rangers against poaching, raised the number to about 2600, roughly two thirds of all that are left. Tigers, elephants and wild water buffalo share the same protected habitat.

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 (SL): the Dorset heaths, England. Heather heath is home to the sand lizard and the Dartford warbler. Left alone, birch and pine grow up and the heath becomes woodland by succession. So cattle and ponies graze it, volunteers pull scrub, small patches are burnt in winter, and bare sand is scraped for lizards to lay eggs.

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 (SL): Zealandia, Wellington, New Zealand. New Zealand's birds evolved with no land mammals to hunt them, so rats and stoats wiped many out. In 1999 an 8.6 km fence closed off a city valley. Little spotted kiwi, tuatara and kākā were returned, and kākā now nest in Wellington's gardens.

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 (SL): the Dorset heaths again. Poole and Bournemouth press right up against the heaths: summer fires started by people, pet cats and heavy trampling. So the councils allow no new homes within 400 m of the protected heaths, and developers further out pay for new green spaces that draw dog walkers away.

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 (SL): Fiji. In 1997 the village of Ucunivanua closed part of its own reef flat to collecting clams. The villagers chose the area, counted the clams themselves and watched for outsiders. Clams inside the closed area soon became far more common, and over 400 villages across the Pacific have since set up their own LMMAs.

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 (SL): Costa Rica. Its first national parks came in the 1970s; today about a quarter of the country is protected. Forest cover roughly doubled, from about a fifth of the land in the 1980s to over half. The country holds about 5% of the world's species, and ecotourism in its parks is now a major source of income.

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 (SL): the golden toad, Costa Rica. It lived only in the protected Monteverde cloud forest. After very dry, warm years in the late 1980s it was never seen again, and it was declared extinct in 2004: a reserve cannot protect a species from a climate that changes around it.

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.

How this comes up: Paper 1 gives a fact file on a threatened species and asks how an in situ strategy could improve its IUCN category [3]; Paper 2 Section B asks how effective habitat conservation is [9].