The Impact of Lake Bonneville and Lake Lahontan on the Halophytes of the Great Basin

Abstract

The rivers in the Great Basin in the Western United States do not drain into the Pacific Ocean. Some 30,000 years ago a lot of water was present in the Great Basin and two huge lakes (Bonneville and Lahontan) were formed. These lakes were very large and very deep. Over the next 17,000 years, the weather became very dry and the lakes began to evaporate leaving lots of salts on the land and in the few remaining smaller lakes. Great salt lake is the largest remaining lake in the Great Basin and is very salty. Because the dissolved salts were deposited mainly on the valley floors, only salt tolerate plants (halophytes) can grow in the high salt areas. Because of the mountains in the Great Basin area there is considerable diversity in the plant population. The area is ranked 4th out of 116 Eco regions in North America. The number of halophytic species is the highest in the Great Basin in North America. In addition a number of non-native salt tolerant plants have been introduced.