Hobbies And Interests
Extreme Conditions
The tundra is the northernmost biome of the world, which subjects it to harsh extremes of all sorts. In terms of precipitation levels, the tundra most closely resembles a desert. Yearly precipitation levels average only 6 to 10 inches, including snow that melts during warmer seasons. Winds in tundra regions can reach 30 to 60 miles per hour on top of the already bitter temperatures; the yearly average is minus 18 degrees Fahrenheit, and lows may drop to nearly minus 100 degrees in the winter while the sun makes only the briefest monthly appearances. In the summer, however, temperatures may climb to 60 degrees Fahrenheit with nearly 24 hours of continuous sun.
Flora and Fauna
The drastic extremes of the tundra limit the potential for wildlife diversity. Roughly 1,700 plant species and few animals, including only 48 land mammals, are apt for tundra survival. Among plants, this includes reindeer mosses, low shrubs, lichens and grasses: low-growing plants, which grow in bunches to resist heavy winds and cold temperatures. Mammals in this biome are similarly modified to handle their surroundings. The brown bear, for example, stores fat for sustenance during hibernation. Other mammals include caribou, polar bears and arctic hares and foxes; birds, insects and fish are also found here. Many animals hibernate or migrate during the cruel winters and breed quickly during the short summers, causing a constantly fluctuating population. As these species are very specifically adapted to the conditions of the tundra, they are very vulnerable to its continuous changes.
Short Growing Season
Only two distinct seasons exist in the tundra, with spring and fall existing as brief periods between them. The growing season in the coldest regions of the tundra is only approximately 50 to 60 days in length; even in the less harsh tundra, the growing season is only as long as 180 days. Tundra soil is low in nutrients, so plant growth is stimulated by animal droppings, frequently rooting in the melted snow that forms bogs and pond in the summer.
Permafrost
Beneath the top layer of soil in the tundra is completely frozen ground known as permafrost. This occurs anywhere between 10 inches to 3 feet below the ground and continues as deep as 1,500 feet, preventing deep-rooting trees from growing in this biome. Seasonally, in warmer parts of the tundra, the uppermost parts of the permafrost melt to form shallow pools for plant growth while the rest remains frozen year-round. Unfortunately, global warming is bringing changes to this fragile ecosystem, beginning with the permafrost. Once known as a carbon sink, capturing carbon dioxide from plant matter as it froze, the permafrost is now melting too rapidly as the earth warms, releasing carbon dioxide into the atmosphere. Permafrost, currently being lost at a rate of several feet per year from tundra worldwide, is expected to contain about 14 percent of the Earth's carbon.