At over 665,000 square miles, Alaska is the largest US state. It was purchased in 1867 from the Russian Empire to the tune of $7.2 million dollars ($129 million in today's dollars). Its immense size, small population, and relative isolation may cause one to wonder, what, exactly, is in Alaska?
The answer is a number of coastal settlements, few interior settlements, and a diverse array of unpopulated forests, tundra, mountains and bog. Our October 2024 map of the month, Major Ecosystems of Alaska (1973), depicts these environments from Utqiagvik (here labeled “Barrow”) in the north to Amatignak Island in the south.
The ecosystems of Alaska are typical of a location so far north, with widespread spruce and birch forest, tundra, bogs and alpine tundra. The southern portions of the state, along the coast line, are forested by thick humid temperate forests dominated by spruce and western hemlock. Inland, various forms of boreal (northern) forest predominate. These consist of spruce forests with significant populations of poplars and birches within.
The height and density of the trees within these forests is determined primarily by latitude and altitude, until the point at which few trees grow at all: tundra. This occurs high in the mountains, creating high alpine tundra throughout the state. Wet tundra form in the northern and western portions of the state as well, and bogs form periodically throughout the entirety of the state, often in proximity to rivers.
As seen in this section of the map, physiographic factors determine the character of each ecosystem. Bottomland spruce-poplar forest forms directly on the banks of rivers; bogs nearby to that. Alpine tundra exists on the mountain peaks, with its accompanying upland spruce-hardwood forest found at lower elevations. The lowland spruce-hardwood forest is found at even lower elevations, but not along rivers.
Tundra tends to form on the coastlines in the north, with high brush forming around the rivers in this area. The northern coast is further distinguished by its significant amount of underlying permafrost, that is ground which has remained frozen for at least two consecutive years, which is one reason for the scarcity of trees in this region as they are unable to grow in such soil.
The south of the state is dominated by thick coastal forest, inhabited largely by Sitka spruce and hemlock. It is here that the climate is similar to that of northern Europe.
On the back of the map, one can see a climate classification map of the state showing the four varieties. These are each defined by annual average rainfall and temperature ranges. The arctic climate is the coolest and driest on average, this region is inhospitable to tree growth and is almost exclusively tundra. Continental climate tends to be the second coolest, albeit with the highest maximum temperature and lowest minimum temperature and little rainfall. The transitional area lies between continental and maritime both in temperature and rainfall. The maritime climate is the wettest and warmest of the climate zones. It is comparable to the climate of northern Scotland or portions of southern Norway.
Additionally, the map shows the extent of Alaska’s permafrost. Permafrost is an important feature of far northern environments as it lies beneath a significant portion of North America and Eurasia. The oldest permafrost can be tens of thousands of years old. As the climate warms due to anthropogenic climate change, this important ecological feature is threatened and the greenhouse gasses it stores risks being released into the atmosphere.
We hope you enjoyed our October 2024 Map of the Month.
- Title: Major Ecosystems of Alaska
- Date: 1973
- Publisher: Joint Federal State Land Use Planning Commission for Alaska
As with all of our Map of the Month features, if you’d like to get a scanned copy of this map, please submit a Map and Geo Service Request and we’ll be sure to get back to you within two business days, but typically sooner.
- Grace Behan, Map and GIS Assistant