The effect of sunlight exposure and crowdedness on plant height in Solidago canadensis, Cirsium vulgare and Aster prenanthoides.

Plant heights were gathered using transects in the grasslands south of Stong College at the York University Keele campus on October 14th and 21st 2014 at approximately 3:00 pm. The three plant species studies were Solidago canadensis (Golden Rod), Cirsium vulgare (Spear Thistle), and Aster prenanthoides (Purple Aster). Transects were set out twice; once deep into the grassland and the other time on the edge of the field. Every five meters, one of each plant species was randomly selected within 1ft and the height was measured using a second transect. 60 replicates were gathered in total and each time a measurement was taken for each of the three species. The shadiness was estimated on a nominal basis so that the plant being measured was in lots of shade (L), some shade (S) or no shade (S). In addition, the crowdedness of the area the plants were in was observed and recorded on a scale from 0 to 3, where 0 is not crowded at all and 3 is very crowded.