The goal of this research is to understand the impact vicuna grazing has on the growth of vegetation by fencing areas to prevent grazing.
Research question one established that vicunas in risky areas spend more time vigilant than they do feeding. The question now is what happens to vegetation when grazing pressure by vicunas decreases. The number of vicunas grazing in a given area cannot be manipulated; however, researchers can stop the vicuna from grazing by putting a fence around certain areas.Since vicunas spend a lot of time vigilant in risky areas (tall grass habitats), they have little effect on the plants. Fencing a plot in a safe area (short grass habitat) would show how vegetation responds to decreasing vicuna grazing pressure.
How will vegetation be different in habitats where vicuna spend more time vigilant than in habitats where they spend more time feeding?
How much more vegetation will there be in areas where vicuna are prevented from grazing?
Make a hypothesis based on the research question and record it in your notes.
Based your hypothesis, make a prediction and record them in your notes.
Step 1. Design an experiment.To test their hypothesis and predictions Emiliano and his team evaluated how vicuna grazing affected vegetation by measuring plant height (in inches) in sites with and without grazing.
Plots were fenced to prevent vicuna from grazing. After several months the plant height inside the fenced area was measured and compared to the plant height outside the fenced area where vicunas were allowed to graze.
This is an experimental approach because Emiliano manipulated the main factor, vicuna grazing, that he thinks is responsible for plant height. The unfenced area, or exclosure, is the control. The fenced area, or enclosure, represents the experiment.
As Emiliano and his team identified the sites they would fence, they took care to be sure that the only factor affecting vegetation is vicuna grazing. This can very difficult in the field.
Step 2. Define how plant height is measured.
Because Emiliano’s team did not have time to measure every plant inside and outside the fenced areas, they randomly chose five plants inside the fence and five plants outside the fence to measured.