How light intensity affects biodiversity
How Light Intensity Affects Biodiversity
Introduction : I chose to do a study into how light intensity affects biodiversity because I thought it would be an interesting and unusual topic to investigate. Also, one of the themes we do is on organisms and the environment, and part of that topic is water and light are important to living organisms. I carried out my investigation at the top of the slope at the side of the sports hall, and I took all of my results at the same level. The source of shade was two trees near the top of the slope. I am going to test the hypothesis that the higher the light intensity, the more species there will be. I believe this because plants need light to grow, so I would think that where it is lighter, more plants would be vying for it. I will be measuring the amount of species and the percentage of ground they cover, (and how much ground is bear,) inside the area I am using.
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Method : I used a quadrat, a light meter and a string with markings every 1 ½ m. I decided on a level that I would take all my results from which had a range of different intensity’s of light and decided on a point to start where I would get a decent number of results. From there I laid out the string to make it easier to keep the results equal distances apart, (½ m apart.) I put the quadrat down, using the string as a guideline of where to place it, and counted the number of squares containing each species to get a rough idea of how much of each species was covering how much ground and how much was bare. It was quite hard to not slip down when taking measurements, though that was quite easily overcome by finding good footholds. Measuring the percentage of ground each species covered was also a problem I encountered, because some of the taller plants would look as though they were taking up more ground than they actually were due to being flattened. I got around this difficulty by trying to only count where the roots of the plants were as ground covered by the plants. Another complication was that under the trees, the light kept on changing as the trees swayed in the wind, so I had to use the intensity it stayed at for longest.
Conclusion : My results show that there is no real difference in the different amount of species in low light intensity compared to the number in high light intensity, I noticed, when collecting my data, that the plants in the sun were larger and healthier looking. My results are not reliable because I used a tree to provide the shade, and that could have affected the species growing underneath it. Also, after the 21st result, the sports halls shadow affected the results. I think I did collect a wide enough range of data to show a very general view of what the real picture is. I don’t think my method was particularly accurate, but it was accurate enough for the purposes of my investigation. I would have preferred to have done another reading to make sure my results were accurate, but that wouldn’t have been practical for me as my experiment takes a long time to do.
Here's what a teacher thought of this essay
There has clearly been effort that has gone into collecting the results; however there are issues with this report: 1. There are lots of subheadings missing. 2. The report does not contain any researched information on the effects of light of the growth of plants. 3. The report is missing several sections including an evaluation. ***