Abstract: This investigation was designed to compare the height of Pteridium aquilinum in a light area and a dark area of Rushy Plains, Epping Forest and to establish if light intensity does have an effect on the growth of Pteridium aquilinum, commonly known as Bracken. From my research it was clear that the height of Bracken is affected by abiotic factors, other than light intensity, such as: soil moisture, soil temperature, air temperature and soil pH so I had to control these factors. I carried out preliminary experiments to find a suitable site where all these factors where constant. For my actual investigation I measure …show more content…
At a higher temperature (in warmer conditions), the enzymes and substrates involved in photosynthetic reactions have more energy to collide and cause more successful collisions. As a result, the rate of photosynthesis increases. At lower temperatures (cooler conditions), the enzyme substrates have less energy to collide so less successful collisions. Therefore, the temperature affects the growth of plant as the more photosynthesis occurs, the more food produced for the plant which would result in an increased height of the plant. But it is also to be noted that photosynthesis increases with temperature only up to a certain point. This point is usually at which the enzymes become denatured. 
Temperature also affects respiration and transpiration. Respiration rapidly increases with temperature, this is because the gases can diffuse more easily through the stomata and give the mitochondria a greater supply of gases for respiration to occur. Transpiration also increases with temperature, this is because the stomata are usually open more at higher temperature which allows more water to evaporate through leaves.
The pH of the soil affects the height of the plant as most plant usually prefer slightly acidic soil and Bracken is one of them. Studies have shown that “Bracken litter reduced soil pH to 4 - 4.5.” This suggests that the preferred soil pH of a Bracken plant is between 4 –