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Examine the correlation between soil moisture at different heights up the slope and the length of the longest leaf of a Bracken Fern

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Introduction

Ketan Singh Research Question: What is the correlation between soil moisture at different heights up the slope and the length of the longest leaf of a Bracken Fern? Introduction: Slapton Wood, situated in the North-western corner of the reserve, is an Ancient Woodland (an area that has been wooded since 1600AD - Slapton Wood is mentioned in the Domesday Book), and as a result has very little active management. In practise what this means is that the only work that goes on in Slapton Wood is to maintain the network of footpaths and steps, which includes the clearing of dead, dying or dangerous trees when they pose a threat to public safety. The wood itself is a National Nature Reserve and is mostly composed of Sweet Chestnut and Oak, with a reasonable amount of Ash and Beech also present. An understory of Hazel and Holly can be found throughout most of the wood. Hypothesis: I think that there will be a correlation between the length of the longest leaf of a Bracken Fern and soil moisture at different heights up the slope. This is because soil moisture will decrease up the slope as the soil gets further and further away from the river, at the bottom of the slope. The importance of the river is that some of the water it contains is absorbed by the soil, thus meaning moisture levels in the soil closest to the river would be higher than soil anywhere else. Furthermore, when it rains, the rainfall would flow down the slope due to gravity and the slope angle. This results in the soil closer to the bottom of the slope being exposed to more water as the rainwater collects at the bottom of the slope, thus meaning that soil moisture would be higher here (at the bottom of the slope) than it would at the top of the slope as rainwater doesn?t collect here and the soil is therefore not in contact with the water for as long as the soil lower down the slope is. ...read more.

Middle

Furthermore, we are controlling the Soil PH to an extent as we?re recording the data in the same part of the wood, along the same section of the valley and therefore the conditions the soil is exposed to should be relatively constant throughout the area of measurement. Due to this we can therefore predict that Soil PH should be constant throughout our experiment and therefore shouldn?t affect our dependent variable. Wind Speed [controlled variable] With an Anemometer The Anemometer should be held at the same height as that of the leaf you are recording the longest length of, for 30 seconds (in order for the reading to stabilise). This recording should be made at the site of every Bracken Fern that is measured and should be repeated 3 times, in order to guarantee a reliable reading. Wind Speed is not the abiotic factor we are recording and we therefore want to keep it constant. However, because wind speed is constantly changing throughout the day, we therefore cannot fully control it. By measuring it we are therefore showing that we acknowledge its value and presence and the effects it can have on my final result as well as identifying any significant changes in wind speed values that may therefore affect our experiment. However, this should not be a problem because we?re controlling Wind speed to an extent, as we?re recording the data in the same part of the wood, along the same section of the valley and therefore the conditions the Ferns are exposed to should be relatively constant throughout the area of measurement. Due to this we can therefore predict that Soil PH should be constant throughout our experiment and therefore shouldn?t affect our dependent variable. Slope Angle [controlled variable] Measured with an inclinometer The slope angle should firstly be focused by looking into the inclinometer and focusing on one fixed point. After doing this the slope angle can then be measured at the site of every Bracken Fern that is being measured with the focus being kept on this one fixed point. ...read more.

Conclusion

at each of the 7 sites. 12) Using Spearman?s Rank, calculate if there is a correlation between the length of the longest leaf of a Bracken Fern and soil moisture at different heights up the slope and therefore if the hypothesis was correct. The Raw data can be displayed like this: Independent Variable: Location: 1st reading of Soil Moisture: 2nd reading of Soil Moisture: 3rd reading of Soil Moisture: Average soil Moisture: 0 metres from river 5 metre from river 10 metres from river 15 metres from river 20 metres from river 25 metres from river 30 metres from river Dependent Variable: Location: 1st reading of the Length of the longest leaf of a Bracken Fern: 2nd reading of the Length of the longest leaf of a Bracken Fern: 3rd reading of the Length of the longest leaf of a Bracken Fern: Average Length of the longest leaf of a Fern: 0 metres from river 5 metre from river 10 metres from river 15 metres from river 20 metres from river 25 metres from river 30 metres from river Risk Assessment Risk Assessment Precautions Ticks (Biting insects) Apply insect repellent to all exposed parts of the body and then check yourself thoroughly after the experiment for any bites, especially the more moist areas of the body (this is where Ticks normally reside). Hypothermia Ensure warm clothes are packed as well as a towel. Vicious Plants Take a skin healing cream (e.g. savlon) and suitable medication for anyone with allergies. Sun Burn Apply sun tan lotion before going out to carry out the experiment. Slip trip fall Be careful of where you?re walking and always be aware of your surroundings. Don?t run to minimize the chance of falling over and ensure that someone in your group has a first aid kit before setting out. Drowning in river Pair up to ensure that there is always someone to help if you do fall into the river. Also be careful of where you?re walking and always be aware of your surrounding and don?t run to minimize the chance of falling into the river. ...read more.

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