Issues in the Tundra

 

Arctic, Antarctic, and alpine tundra covers almost 20% of the earth’s surface. Summers are generally warm (37 to 60◦F) in the tundra. In the summer, melt water pools form on top of the permafrost creating streams, marshes, lakes, and bogs. The winter season is characterized by extreme cold (-34◦F), dryness (< 5 inches of precipitation), and 6-10 months of darkness. Overall, the tundra is important in the global weather cycle through the cooling of tropical air masses.

 

Nutritional paucity and a short growing and reproductive season (50-60 days) contribute to low biotic diversity and morphologically simple vegetation in the tundra. Even though the tundra has low diversity, almost 1700 kinds of plants and 400 types of flowers have been reported.

 

Arctic and subarctic tundra is comprised of low shrubs, sedges, liverworts, grasses, crustose and foliose lichen, and reindeer mosses. In many cases, extreme winds sculpt the plant-life, keeping it low to the ground and stunted. Trees grow only sporadically where the permafrost is less developed or near forest ecotones.

The tundra nutrient pool is composed of dead organic matter perched on top of frozen permafrost. Under the right conditions, accumulated tundra organic matter can ignite, and wildfire-event return intervals varying from 150 to 200 years.

 

Mosquitoes, flies, moths, black-flies, bumblebees, and grasshoppers proliferate in the summer months. Migratory birds including snow buntings, ravens, falcons, gulls, loons, sandpipers, and terns migrate to the tundra in the spring and summer to nest. These migratory birds are a major part of the global food chain. Loss of tundra breeding areas for these species would have major effects on the global food web. Mammals such as lemmings, voles, arctic hares, squirrels, caribou, musk ox, arctic foxes, wolves, and polar bears inhabit the tundra year round. Cod, flatfish, salmon, and trout fill the streams, lakes, and surrounding oceans year-round.

 

Eight different neartic tundra habitats are in the United States (https://www.worldwildlife.org/biomes/tundra). These include the Pacific coastal mountain ice fields and tundra, Brooks British range tundra, Beringia upland tundra, Beringia lowland tundra, arctic foothills tundra, arctic coastal tundra, Aleutian islands, and the Alaska-St. Elias range.

 

The tundra has four issues that affect its biotic diversity and integrity: