The Rocky Mountains
A look into the alpine biome’s ecosystems and a potential stressor to them
The Rocky Mountains are located in the biome known as the alpine forest. The Rocky Mountains are a large mountain range that is located in western North America which runs more than 3,000 miles, from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States. Average January temperatures in the Rocky Mountains can range from -20 °F to 43 °F, with the average precipitation being between 10 to 60 inches per year. There are three main levels of vegetation in the Rocky Mountain vicinity, the montane, the subalpine, and the alpine levels. The type of vegetation that is able to grow in each surrounding area is based on the atmospheric conditions in the area, which are influenced by several factors including elevation, precipitation, and air pollution (Clow, & Mast 2003). Studies have shown that air pollution causes higher levels of nitrogen deposition in the Rocky Mountain region, which can be a challenge to the local plant community due to the already prevalent lack of variety in vegetation in this region (Burns, 2004). Based on this information, nitrogen deposition within the Rocky Mountains could be considered a stressor within the alpine biome. The Rocky Mountains, which are also known as the “Rockies”, form the Continental Divide of North America. The Continental Divide is the line that determines whether water will flow to the Pacific or the Atlantic Ocean. Twenty-five percent of the water supplied to North America comes from this mountain range. The Rocky Mountains are steep and rugged mountains. They were formed from 80 to 55 million years ago. The range’s highest point, Mount Elbert is located in Colorado and sits at 14,440 feet above sea level. The varying altitude of the range influences the climate. Certain areas experience what is called the rain shadow effect. This is when an area that has relatively little precipitation due to the effect of a barrier, such as a mountain range, causes winds to lose their moisture before reaching it. The rain shadow effect is a contributing factor the lack of diversity in vegetation located throughout the Rocky Mountain region. This factor combined with nitrogen fixation due to air pollution could be an even larger stressor to the plant life present in this area. Although there is a lack of variety in the vegetation located throughout the Rocky Mountain region, there is still a large number of plant species present. More than 5,000 plant species occur in the Rocky Mountains. This is a large number, but is still small in comparison with the amount of land the mountain region stretches across. Lichens are plant-like organisms made up of an alga and a fungus growing in symbiotic association on a solid surface (Merriam-Webster Online Dictionary, 2011). Lichens are a species that is native to the Rocky Mountain region and are a very important to the present ecosystems. At lower altitude levels, they may grow on trees and operate as a food source in the winter. Lichens have been used in the past as air pollution indicators. It is also believed that they may also be used to observe community diversity associated with habitat change (Rogers, & Ryel, 2008). Bristlecone pine (Pinus aristata) and limber pine (Pinus flexilis) are both native species to the alpine biome. They are found on exposed, cold, dry, rocky slopes and high mountain ridges up to the timberline at elevations between 9,200 to 11,800 feet. These vital species of trees are threatened due to the spread of white pine blister rust (Cronartium ribicola) in the Rocky Mountain region (Coop, & Schoettle, 2009). Due to the research of both species and their threatened nature, researchers were able to conclude that natural disturbances, such as fires could aid in the restoration of bristlecone and limber pine trees. However, it may take decades to see...
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