1992

Tundra

Depending on how different organizations of biologists and ecologists classify them, the world can be divided into between one and two dozen distinct ecological regions, or biomes. One type of biome that is common to all classification schemes because it occurs in many places around the world is tundra—regions of relatively low temperatures and short growing seasons where tree growth is limited and vegetation consists mostly of shrubs, grasses, mosses, and lichens. Tundra occurs in three main regions of our planet: in the Arctic, in the Antarctic, and in high-elevation alpine terrains. In mountainous regions, tundra is the ecological zone just above the tree line.

Vegetation dominates the biodiversity of the tundra; only a small number of land mammals and fish species dwell permanently in the tundra (for example, Arctic reindeer, rabbits, foxes, and polar bears), though millions of birds migrate there each year. In Arctic and Antarctic tundra regions (and some alpine tundra), the shallow subsurface is characterized by permafrost, or permanently frozen soil. These soils can hold enormous amounts of freshwater, and when frozen they trap large quantities of CO₂ and methane (from decaying plants and animals), which are also potent greenhouse gases. Tundra thus plays an important potential role in the world’s climate, because melting of its permafrosted soils could significantly enhance global warming.

Partly because of their remote locations and enormous global extent, scientists don’t really know how much water, CO₂, or methane is stored in the world’s tundra soils, nor is there yet a full accounting of the biologic diversity of tundra regions. Understanding the detailed nature and inventory of this particular biome, as well as the others, was thus a major driver for a global Biodiversity Action Plan (BAP) developed by the United Nations as part of the landmark 1992 Convention on Biologic Diversity. The major goal of this international treaty is to guide national strategies for the conservation and sustainable use of biological diversity. Major fractions of tundra in Canada and Russia, for example, are protected by BAP stipulations. All UN member states have signed the treaty, but only one has not yet ratified it: the United States.

Beautiful trails through the high-altitude tundra environment in the Rocky Mountains, Colorado.