Nature
During the last Ice Age almost all of Iceland was covered by permanent snow and glacier ice. The short time since the last ice age, only about 10,000 years, has provided very little time for plants and animals to immigrate from elsewhere or evolve locally. Approximately three-quarters of the island is barren of vegetation, and plant life consists mainly of grassland, which is regularly grazed by livestock. The only native tree in Iceland is the northern birch Betula pubescens.
Fauna
The animals of Iceland are mainly agricultural and include Icelandic sheep, cattle, and the sturdy Icelandic horse. Many varieties of fish live in the ocean waters surrounding Iceland, and the fishing industry is a main contributor to Iceland's economy, accounting for more than half of Iceland's total exports. Wild mammals include the arctic fox, mink, mice, rats, rabbits and reindeer. Before and around the 1900's, polar bears would sometimes visit the island, travelling with sea ice from Greenland. Birds are also a very important part of Iceland's animal life. Most of these are sea birds. Puffins, skuas, and kittiwakes all nest on Iceland's sea cliffs.
The only native land mammal when humans arrived was the arctic fox. It came to the island at the end of the ice age, walking over the frozen sea. There are no native reptiles or amphibians on the island. There are around 1,300 known species of insects in Iceland, which is rather low compared with other countries (there are about 925,000 known species in the world).
Flora
When humans arrived, birch forest and woodland probably covered 25-40% of Iceland's land area. However, the initiation of permanent human settlement caused great disturbance to an isolated ecosystem with thin, volcanic soils and limited species diversity. The forests were heavily exploited over the centuries for firewood and timber. Deforestation resulted in a loss of critical top soil due to erosion, greatly reducing the ability of the birches to regrow. Today, only a few small birch stands can be found in isolated drainages.
National Parks
Iceland has four national parks:
- Jokulsargljufur National Park
- Skaftafell National Park
- Snaefellsjokull National Park
- Thingvellir National Park