Topic 7 - Alpine and tundra biomes
Essential elements from Topic 7:
1. Tundra and is dominated by perennial hemicryptophytes, chameophytes, and geophytes. Annuals (therophytes) and phanerophytes (shrubs) are uncommon.
2. Arctic tundra occurs between boreal and polar regions in the northern hemisphere and this biomes is undergoing the greatest increases in temperatures of all biomes on the planet. Winter temperatures are increasing, snowmelt is earlier, and growing season is expanding. As Arctic temperatures increase, permafrost distribution contracts (less abundant and deeper in the soil in summer). As Arctic tundra biomes warm, shrubs, such as willows, increase in abundance.
3. Alpine tundra is similar to Arctic tundra in many ways and occurs at high elevations in temperate and tropical latitudes; alpine tundra will occur at high elevations above treeline and permafrost is uncommon.
4. Climatically, the climate diagram of Arctic tundra biomes is similar to that of grasslands in temperate regions, but the wintertime temperatures are much colder.
5. Snow melt and frost heaving often results in a mosaic of polygons in Arctic tundra, with sharp changes in species composition along these abrupt moisture gradients. To a lesser degree, this phenomenon also occurs in the alpine tundra.
6. Precipitation in Arctic tundra biomes can often be less than 250 mm annually, but the region remains mesic because of the cool summer temperatures.
7. There is a convergence in arborescent forms in tropical high elevation site in both Africa (Senecio) and South America (Espeletia). A similar life form also occurs at high elevations in Hawaii (Argyroxiphium).
Terms to know from Topic 7
Essential elements from Topic 7:
1. Tundra and is dominated by perennial hemicryptophytes, chameophytes, and geophytes. Annuals (therophytes) and phanerophytes (shrubs) are uncommon.
2. Arctic tundra occurs between boreal and polar regions in the northern hemisphere and this biomes is undergoing the greatest increases in temperatures of all biomes on the planet. Winter temperatures are increasing, snowmelt is earlier, and growing season is expanding. As Arctic temperatures increase, permafrost distribution contracts (less abundant and deeper in the soil in summer). As Arctic tundra biomes warm, shrubs, such as willows, increase in abundance.
3. Alpine tundra is similar to Arctic tundra in many ways and occurs at high elevations in temperate and tropical latitudes; alpine tundra will occur at high elevations above treeline and permafrost is uncommon.
4. Climatically, the climate diagram of Arctic tundra biomes is similar to that of grasslands in temperate regions, but the wintertime temperatures are much colder.
5. Snow melt and frost heaving often results in a mosaic of polygons in Arctic tundra, with sharp changes in species composition along these abrupt moisture gradients. To a lesser degree, this phenomenon also occurs in the alpine tundra.
6. Precipitation in Arctic tundra biomes can often be less than 250 mm annually, but the region remains mesic because of the cool summer temperatures.
7. There is a convergence in arborescent forms in tropical high elevation site in both Africa (Senecio) and South America (Espeletia). A similar life form also occurs at high elevations in Hawaii (Argyroxiphium).
Terms to know from Topic 7