Alaska is the largest of the 50 states, spanning 656,425 square miles. The state's ecosystems include coastlands, mountainous regions, arctic tundra, plains and a variety of forests. Attempts to classify Alaska's ecosystems are numerous and range from simply dividing the state into tundra and boreal forest regions to extensive subdivisions within those two large regions.
The Alaska Department of Fish and Game divides Alaska into two ecosystems: the tundra and the boreal forest region. The tundra encompasses the north, west and southwest edges of the state. The boreal forest region, which ultimately stretches into Siberia, Northern Asia and Northern Europe, makes up the large interior landscape of Alaska. The tundra is defined by its cooler summers which barely reach above 50 degrees F, creating ideal conditions for permafrost to form. The boreal forest region, on the other hand, includes several forest types, mountain regions, valleys and plains.
The Arctic Coastal Plain is the northernmost geographic region in Alaska. It would be included in the tundra region. The Arctic Coastal Plain is defined by permafrost, a permanent layer of frozen soil. No trees grow in this region, though scattered small shrubs and wildflowers may grow in the spring. This area stretches from north of the Rocky Mountain system and then slopes to the Arctic Ocean.
Alaska's Rocky Mountain System (separate from the Rocky Mountains in the western United States and Canada) spans from the Brooks Range to the Brooks Range foothills. The Rocky Mountain System is composed primarily of mountains and glaciers. Some mountains in this region stand at 9,000 feet above sea level.
The Central Uplands and Lowlands ecosystem is located within the broader boreal forest region of Alaska. It makes up the largest land area in Alaska and lies between the Alaska Range in the south of the state and the Brooks Range of the Rocky Mountain System in the north. This ecosystem includes numerous river valleys and marshlands.
Running from the Aleutian Islands through the south central areas of Alaska is the Pacific Mountain System. This system actually continues through Alaska into Washington, Oregon and California. It includes the lowlands Copper River Basin and the Susitna-Cook Inlet as well as Mt. McKinley in the Alaska Range.
