24.9 Environmetntally sensitive ecosystems
Some regions are less resistant to changes than others, referred to as environmentally sensitive ecosystems. Management techniques used for these regions include
limiting the areas tourists can visit
controlling the movement of livestock
introducing anti-poaching measures
replanting of forests and native plants
limiting hunting through quotas and seasonal bands
The Galapagos Islands, Pacific Oceans
This is an achipelago of volcanic islands that rise up from the bed of teh ocean 1000km west of Ecudor. They are of special interest because they have never been connected to the mainalnd. The original flora and fauna had to survive a crossing of many kilometers, Darwin used evience he gained to develop his theory of natural selection.
Animals Present
majority are reptiles - there is only one species of land mammal, the Galapagos rice rat. These arrived by being washed away from mainland river banks.
The Galapagos giant tortoise - grows over 150cm
Flightless cormorant, reduced wings were better for fishing underwater, when flight was not needed to escape mainland problems.
Marine iguana, contains the advantageous mutation, over a land iguana of the ability to swim effectively. Unless they are trying to attract a mate, the iguana appears black or dark grey, allowing these exotherms to bask in the sun and raise their body temperature to 36 before swimming in the cold where they forage for food.. The higher the temperature the longer they can forage.
Plants present
3 distinct regions that supports particular plants
the coastal zone - contains salt-tolerant species like mangrove and saltbush
the arid zone - contains drought-tolerant species such as cacti and carob tree
the humid zone - contains dense cloud-forest, these trees support populations of mosses and liverworts.
Control of human activities
Until 19th century, it was hardly visited by humans, now because of whaling trade, this changed.
They allowed domestic animals to roam loose, chopping forests for fires to render down whale fat, tortoises meat would keep them alive. The goats introduced then outcompeted them.
The Galapagos National Park was established in 1959.
introduction of park rangers across the islands
limiting human access to particular islands or specific parts
controlling migrations to and from the islands
strict control over movement of introduced animals
Antarctica - coldest, highest, driest, windiest and emptiest.
Covered by an ice sheet, about 2km thick, around 70% of the world’s fresh water.
The average temperature in winter is below -30, it only has 2 seasons, in summer they may experience 24 hours of sunlight but in winter darkness.
Animals present
All endothermic animals living rely on their thick layers of blubber to insulate them, whales, seals and penguins.
Emperor penguin is the only warm-blooded animal that remains on the Antarctic during the winter months. Females lay one egg in June and leave to spend winter at sea, the amles stay on land and survive the most extreme winter conditions for up to 9 weeks keeping their egg warm by balancing it on their feet and covering with a flap of abdominal skin.
Few invertebrates live on the continent all year, largest belgica antarctica, body size of 5mm.
Plants present
Plants can only grow in ice free conditions (2%). Lichens and moss grow in any favourable niche such as sand, soil, weathered bones and feathers of dead animals. Algae are also able to grow in many sheltered areas.
Control for human activities
Effects
global warming, leading to ice to break upm and ozone depletion
hunting of whales and seals and fishing of some species
soil contamination especially in research stations
discharging waste into the sea
Antarctic Treaty established - 1961 to protect
scientific cooperations between nations
protection of the Antarctic environment
conservation of plants and animals
designation and management of protected areas
management of tourism.
Snowdonia National Park, Wales
Covers 2000 square kilometres of countryside in north-west Wales, it contians the highest mountain range in England and Wales