Iceland

When the island was first settled, it was extensively forested. In the late 12th century, Ari the Wise described it in the Íslendingabók as "forested from mountain to sea shore". Permanent human settlement greatly disturbed the isolated ecosystem of thin, volcanic soils and limited species diversity. The forests were heavily exploited over the centuries for firewood and timber. Deforestation, climatic deterioration during the Little Ice Age and overgrazing by sheep imported by settlers caused a loss of critical topsoil due to erosion. Today, many farms have been abandoned. Three quarters of Iceland's 100,000 square kilometres are affected by soil erosion, 18,000 km2 (6,900 sq mi) so seriously as to be useless. Only a few small birch stands now exist in isolated reserves. The planting of new forests has increased the number of trees, but the result does not compare to the original forests. Some of the planted forests include introduced species. The tallest tree in Iceland is a sitka spruce planted in 1949 in Kirkjubæjarklaustur; it was measured at 25.2 metres (83 ft) in 2013.
The animals of Iceland include the Icelandic sheep, cattle, chickens, goats, the sturdy Icelandic horse, and the Icelandic Sheepdog, all descendants of animals imported by Europeans. Wild mammals include the Arctic fox, mink, mice, rats, rabbits and reindeer. Polar bears occasionally visit the island, travelling on icebergs from Greenland. In June 2008, two polar bears arrived in the same month. Marine mammals include the grey seal (Halichoerus grypus) and harbor seal (Phoca vitulina). Many species of fish live in the ocean waters surrounding Iceland, and the fishing industry is a major part of Iceland's economy, accounting for approximately half of the country's total exports. Birds, especially seabirds, are an important part of Iceland's animal life. Puffins, skuas, and kittiwakes nest on its sea cliffs.
Commercial whaling is practised intermittently along with scientific whale hunts. Whale watching has become an important part of Iceland's economy since 1997.