• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The effect of wind speed on the rate of transpiration.

Extracts from this document...


The effect of wind speed on the rate of transpiration. I was asked to design an experiment to investigate the effect wind or air movement on leaves on the rate of transpiration. Most of the water entering a plant does so via the root hairs. It travels across the root cortex to the xylem, ascends in the xylem to the leaves and is lost by evaporation from the surface of the mesophyll cells before diffusing out through the stomata. This process is called transpiration, and the flow of water from the roots to the transpiring surfaces forms the transpiration stream. Apparatus 1 plant pot with plant 1 electronic scale 1 anemometer 1 thermometer 1 hydrometer 1 Stopwatch 1 meter stick 1 fan 1 plastic bag I will start the experiment by first wrapping the plant pot/plant roots in the plastic bag. This is to prevent water loss via evaporation, I don't want this to happen because I am trying to measure transpiration and it will interfere with my experiment dramatically. Then I will weigh the plant pot/ plant using an electronic scale, which should be very accurate. I will record this in my table of results. I will then use a hydrometer to measure the humidity of the room and use a thermometer to measure the temperature of the room. ...read more.


My independent variable will be the distance from the fan, which in reality is wind speed, which I will change, each time. The wind will come from a fan and will measured using an anemometer. WIND- Air movements carry away water vapour from leaves and this prevents air around them from becoming saturated with water vapour. Consequently, depending upon temperature and humidity, transpiration is faster on a windy day than in still air. Wind moves the air and water vapour away from the leaf, this increases the water potential gradient from the plant to the air. The best conditions for a higher rate of transpiration are the same as those needed for drying washing on a line: a warm, dry, sunny, windy day. Variables that I will keep the same are: Weber LIGHT- effects transpiration because stomata usually open in light and close in darkness. At night therefore, and only small amounts of water are lost through the waxy cuticle: As stomata open in the morning, transpiration rates increase. TEMPERATURE- the higher the temperature, the greater the rate of evaporation of water from mesophyll cells. It increases the capacity of air to absorb water from leaves and it warms the water inside leaves making it evaporate more quickly. Direct sunlight has the same effect since it warms leaves to a higher temperature than the atmosphere. ...read more.


This pulls up water from the roots. Water molecules stick together to form a column. The mechanism which provides the force that pulls water up the plant is called the cohesion-tension hypothesis. Some plants such as the cactus are adapted to prevent water loss these are called xerophytes. These plants have special features that prevent them from loosing too much water. They have special features like a leaf that is rolled inwards this traps humid air around the leaf surface. Some have hairs that reduce air movement around the surface of the plant. Others have a swollen stem, which gives it a low surface to volume ratio and acts as a reservoir for water. I will try and make it fair by sticking to the plan. I will use a stopwatch to measure the time and will stand equal distance from the leaf. There is nothing in this experiment that I feel is of any danger to others or me. I will hang my coat up and have my bag under the table. I will use the same fan each time because different fans have different wind speeds and different diameters. I will use a meter stick to measure the distance accurately and precisely. Once I have obtained my results I will plot them on a graph. This will enable me to see the results more accurately and I will be able to see the rate of transpiration better. The graph will look something like this. Water loss (%) ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Green Plants as Organisms section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Green Plants as Organisms essays

  1. Marked by a teacher

    Investigate which surface of a leaf loses more water by transpiration.

    3 star(s)

    I then covered the topside of one of them in Vaseline, the underside of the second and both of the surfaces on the third. I left the fourth one with no Vaseline on it. I then weighed the leaves again to obtain a weight for the Vaseline on that particular leaf, and hung them up on a line using paperclips.

  2. The investigation is aiming to look at transpiration.

    It is this, which makes the inner walls less able to stretch and thus result in the typical kidney shape of guard cells. Guard cells are different from normal epidermal cells because they possess chloroplasts. An increase in the volume of guard cells, owing, for example to the osmotic uptake,

  1. Experiment to Compare Stomata Density in Different Dicotyledonous

    will be present. Camellia: A species of evergreen shrubs or trees of the tea family. They are native in tropical and subtropical Asia. Camellias are grown in warm, damp regions in various parts of the world. Camellias have quite thick leaves with a very thick waxy cuticle on the upper epidermis.

  2. Three separate experiments which are to be carried out to investigate a plant's unique ...

    divisible by 4), evaporating dish, water, Vaseline, scalpel (to remove the leaves). Diagram: A - Thistle funnel B - Laurel cut-off holder C - Laurel cut-off D - Evaporating dish full of water E - Capillary tube F - Ruler to measure distance bubble travels We will be very vigilant when inserting the Laurel leaf into the cut-off holder.

  1. Conducting an experiment to find out what effect the surface area has on the ...

    intensity will not change as no lights will be switched on or off during the experiment. 2) Temperature: when the temperature increases the plant gets warmer and it loses more water too cool down so transpiration increases. Increase in temperature also increases the capacity of the air so it absorbs more water from the leaves thus increasing transpiration.

  2. Factors affecting the rate of transpiration

    Pale-coloured leaves reflect more of this radiation than normal leaves and therefore do not heat up as rapidly. The pale colour is usually due to a thick coat of epidermal hairs, waxy deposits or scales, and is a xeromorphic feature.

  1. Design and Carry out an investigation to see what effect light intensity has on ...

    External factors will be minimised using the following precautions. * Humidity- this I assume will be constant in the lab and will not drastically alter, in the time frame of the experiment. * Temperature - will be constant in the room, but will vary as the intensity is increased, due

  2. Investigation Into The Rate of Water Uptake By Transpiration.

    with water vapour so that no more can escape from the leaf. In these conditions, transpiration will slow down. In moving air, the water vapour will be swept away from the leaf as fast as it diffuses out. This will increase the rate of transpiration.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work