Lesson 1, Topic 4
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September 8, 2020
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Plants growing on stream banks are critical to holding soil in place and reducing the movement of sediment, nutrients and other pollutants into the stream channel. A healthy vegetation cover takes up excess nutrients that could lead to excess algal growth, provides shading to reduce water temperatures, controls stream bank erosion and reduces impacts from grazing and recreational activities. Native vegetation species are considered healthier than exotic species, although this is not accounted for in this evaluation. Vegetation cover on the bank, expressed as a percent, is estimated by randomly choosing a transect direction to walk and noting at every other step whether there is vegetation cover or bare soil. Ninety-five percent vegetation cover is considered an adequate cover for erosion control, while less than 40% is considered poor. Scores from both banks are averaged.

percentage coverTo measure this parameter, stand in the middle of the upper bank area and toss a pencil randomly. Determine the direction where the point of the pencil is aimed. Walk a line in that direction and observe if the ground is covered with live vegetation at each place where the tip of your foot lands on the ground. When the tip of your foot lands on dirt and the square inch nearest your big toes is mostly dirt, count that point as dirt. If the tip of your foot lands on vegetation, count that point as vegetation. Measure the cover in at least 10 steps. Divide the number steps in which the ground was covered by the total number of steps you measured to calculate a percentage that the soil is covered with vegetation. Compare the percentage to the form for a rating.