<P> Prairie in North America is usually split into three groups: wet, mesic, and dry . They are generally characterized by tallgrass prairie, mixed, or shortgrass prairie, depending on the quality of soil and rainfall . </P> <P> In wet prairies the soil is usually very moist, including during most of the growing season, because of poor water drainage . The resulting stagnant water is conducive to the formation of bogs and fens . Wet prairies have excellent farming soil . The average precipitation amount is 10 - 30 inches a year . </P> <P> Mesic prairie has good drainage, but good soil during the growing season . This type of prairie is the most often converted for agricultural usage, consequently it is one of the more endangered types of prairies . </P> <P> Dry prairie has somewhat wet to very dry soil during the growing season because of good drainage in the soil . Often, this prairie can be found on uplands or slopes . Dry soil usually doesn't get much vegetation due to lack of rain . This is the dominant biome in the Southern Canadian agricultural and climatic region known as Palliser's Triangle . Once thought to be completely unarable, the Triangle is now one of the most important agricultural regions in Canada thanks to advances in irrigation technology . In addition to its very high local importance to Canada, Palliser's Triangle is now also one of the most important sources of wheat in the world as a result of these improved methods of watering wheat fields (along with the rest of the Southern prairie provinces which also grow wheat, canola and many other grains). Despite these advances in farming technology, the area is still very prone to extended periods of drought which can be disastrous for the industry if it is significantly prolonged . An infamous example of this is the Dust Bowl of the 1930s, which also hit much of the United States great plains ecoregion - contributing greatly to the Great Depression . </P>

Describe the flora and fauna of the prairies