User: | Open Learning Faculty Member:
The organism that I have chosen to study is the perennial plant Canada goldenrod (Solidago canadensis). As mentioned in a previous post, I observed that the height and density of this plant varied depending on its location. In some areas the plants were completely in the shade, while in other areas they were exposed to direct sunlight. Therefore, the environmental gradient I have chosen is the degree of sunlight exposure. The three locations along the environmental gradient I have identified are areas where the goldenrod has access to direct sunlight, has only partial sunlight exposure, and is completely in the shade. I have labelled these areas as high, moderate, and low levels of sunlight exposure, respectively. In the areas of low sun exposure, the plants had the lowest density, appeared to be the shortest, had minimal flowering buds, and were sparsely distributed. In the areas of moderate sun exposure, the plants appeared to be slightly taller than the plants in the low sun exposure area and had greater plant density. In the areas of high sun exposure, the plants were the tallest, appeared to have the greatest density, and a majority of the goldenrod plants exhibited flowering buds.
Hypothesis: Level of sunlight exposure affects the growth of Canada goldenrod (Solidago canadensis).
Prediction: If this hypothesis is true, then it is predicted that the height of Canada goldenrod will increase with the level of sunlight exposure.
Response variable: Plant height. This is a continuous variable as it is measured on a numerical scale in inches.
Prediction (explanatory) variable: Level of sunlight exposure. This is a categorical variable as we are observing, not measuring, the categories low, moderate, and high sunlight exposure.
