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Ecology of leaves

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A Table Showing The Surface Area of Leaves From A Stinging Nettle In A Light Shaded Area And A Light Exposed Area Leaf Number Surface Area of Leaves In Light Exposed Area (cm�) Surface Area of Leaves In Light Shaded Area (cm�) 1 14 80* 2 18 98* 3 14 144 4 20* 104 5 10 174 6 4 134 7 6 144 8 12 138 9 10 84* 10 14 124 11 8 136 12 10 148 13 12 108 14 4 76* 15 10 68* 16 18 56* 17 24* 164 18 6 156 19 10 178 20 4 154 Mean 11.4 123.4 T-Test Result Anomalies or weird results are identified with an * and are in a bold font. Reasons for these anomalies will be evaluated further in the evaluation. Soil Statistics Table These readings are important as they could explain the differences in leave surface area at the different sites. Any problems found in this statistics tables readings, will be evaluated in the evaluation. Leaves In Light Exposed Area Leaves In Light Shaded Area Light F+ (High Intensity) A- (Low Intensity) Moisture 7 7 Temperature 4+/-1�C 8+/-1�C Nitrate Level 10 5 pH 6.5 6.5 Weight of Soil With Water 11.08g 13.16g Weight of Soil Without Water 9.02g 9.6g Weight of Water 2.06g 3.56g Conclusion and Analysis of Evidence My results show that there is a difference in surface area of leaves in a light exposed and light shaded area. ...read more.


Statistical T-Test & Hypothesis Testing To find the difference between the two readings, I will perform the T-Test then choose a null hypothesis or my original hypothesis. The T-Test will show me how big the difference is between my two readings. Light Exposed Area Light Shaded Area S x 228 2468 n 20 20 11.4 123.4 S x2 3184 330232 (S x)2 51984 6091024 2599.2 304551.2 Sd2 584.8 25680.8 s 2 30.8 1351.6 1.54 + 67.58 = 69.12 sd 8.31 112/8.31 = 13.48 Here is my working out for the T-Test:- The T-Test has given the figure 13.48; this figure is above all the probabilities below. Therefore I have come to the conclusion that my primary hypothesis was correct, that "There is a difference in surface area between leaves within a shaded area compared to a light exposed area". These results also prove my null hypothesis wrong. Any problems which I have faced in my investigation or any sort of limitations I may have face in my method, equipment or measurements will be evaluated in my evaluation. Degrees of Freedom Probability, p 0.1 0.05 0.01 0.001 40 1.68 2.02 2.70 3.55 Evaluation In my investigation I faced many problems and limitations due to my method, equipment and measurements. One problem which I faced was the anomalies in my results. These could of been to many reasons but I came to the conclusion that some of my leaves specifically the ones showing the anomalies had areas of the leaves taken away or had perforations. ...read more.


These would give an average light, nitrate, moisture, water weight and temperature reading. As on the day it had rained the night before and this may have affected my results, my new plan would counter this as there would be a mean moisture reading. Also to counter the light reading I could have a used a light probe with a large surface area, or recorded the light intensity in different places in each area, therefore giving me a better average light intensity reading. Overall I believe the equipment used was outdated and was not up to task at hand. Next time I may do a test run with new equipment and if I face any problems. I could counter them by changing my method for the actual investigation which would reduce any chance of error. I believe this to be a major factor which impacted my results. In conclusion I believe I have proven my hypothesis that "There is a difference in surface area between leaves within a shaded area compared to a light exposed area" even with my method and apparatus being seriously flawed. Even if my method and apparatus were to be flawless I believe my conclusion would still be the same. As there was obvious face validity and by just looking at the two sites you can tell that there was a difference. I believe the sample I collected was enough to prove my hypothesis correct as leaves were collected randomly from the area of choice. I could have further improved the validity of my results by repeating this investigation up to three times. ?? ?? ?? ?? ...read more.

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