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Biology Assignment Transpiration rates between Exotic vs.. Native plants In this investigation we will be looking at transpiration. The topic we will be focusing on is transpiration rates between native plants as well as exotic plants. We will be experimenting with 2 native plants as well as 2 exotic plants. The reason we are experimenting on this topic is because of Australia’s dry weather, we are wanting to find out which plants will be able to hold more water during Australia’s peaking temperatures, to do this we need to test their transpiration rates.
Transpiration Transpiration is the evaporation of water from the plants in the form of water vapor; water exits the plants through the leaves. Water vapor exits the leave through a pore, which is known as the stoma or stomata. The stoma is a pore, which is usually located in large amounts on the underside of the leave. The stoma is used to control gas exchange of CO, which is also known as carbon dioxide and H2O, which we all know as water. Carbon dioxide is gained while Water is loss.
CO is present in the atmosphere at around 390 pump (parts per million). It is required for the plants stoma o be open during the daytime. Transpiration works because there are air spaces in the leaf where saturated water vapor is present, so whenever the plant stoma is open for it to gain carbon dioxide, which is needs for photosynthesis, it simultaneously looses water vapor. The transpiration rate is dependent on the diffusion provided by the stomata pores and also humidity’s gradient between the leafs air spaces, and outside air.
Different plants have different rates of transpiration because of the different environments their in, with this said we can assume native Australian plants have slower rates of remonstration then exotic plants because of the environment they are in (Australia’s dry weather) and the can adapt to their environment. The factors that affect transpiration rate are sunlight, temperature of air and humidity of air, wind or air movement and the availability of water in the soil.
Another factor that affects the rate of transpiration is the capacity for the root to move the water from the soil and up to the leaf. Some plants are much better then others at doing this, even though there may be plenty of available water. Native Plants vs.. Exotic Plants The plants we will be looking at are Red bottlers plants which are endemic to Australia (native) Birds of paradise (south African, exotic) Eucalyptus melancholia(native to Queensland) and the Mock orange which is an exotic plant.
The red bottle brush plant is endemic to Australia, which meaner it is common in Australia and can be found basically anywhere in Australia, it has been chosen because it is quite native amongst majority of plants in Australia and because it is grown nearly everywhere in Australia it must have slow transpiration rates to with stand Australia’s climate. The bird of paradise is an exotic plant, which is native to South Africa it is also known as the Sterilizer Regina.
It has been chosen because of its features, it is easy to grow and grows best warm and sunny temperatures, It is found all over the world, but they are sensitive to cold weather and need to be sheltered from frost. They are also low maintenance. The mock orange is a plant, which is native to North America, Central America, Asia and in southeast Europe. Let was chosen because it is known to grow in quite average conditions, which could mean faster rates.
These plants will most likely have faster remonstration rates because they only survive in temperatures such as 10-ICC, and Queensland temperatures are normally much higher The eucalyptus is native plant, there are more than 700 species of Eucalyptus which are native to Australia. The family of eucalyptus we will be looking at is the marketplace family which are quite common in Australia, this meaner they can with stand the heat of Australian climate meaning they will have slower transpiration rates.
I Investigation AIM: The aim of this investigation is find out the different rates of transpiration between Native plants and Exotic plants. Hypothesis: it is hypothesized that the native plants will have slower rates of transpiration compare to the exotic plants, meaning that the native plants will loose less water whereas the exotic plants will loose more water. This is because in Australia temperatures can reach up to ICC meaning that native plants will have to adapt to their environment (Australia’s climate) in order to survive and reproduce.
Since the native plants can adapt to their environment and survive, they can with stand high temperatures and sustain their water for longer periods of time (slower rates of transpiration). However the exotic plants we have chosen to use come from country where the climate is cooler then Australia’s such as America, Asia and South Africa. Which meaner they are not adapted to Australia’s environment as much as the native plants. If they are use to colder temperatures they will have faster rates of transpiration (they will loose more water) because they cannot with stand Australia’s heat.
They need to cool themselves down by giving off water(transpiration). Materials: * 4 plants (2 native, 2 exotic) * 4 pedometers * Water * Beaker * Syringe * Blue-tack * 4 stands with clamps Closed environment for controlled tests * Scissors or scalpel * Food coloring (optional) * Stop timer * Paper towel Method: 1 Use shoots from a shrub or tree with leaves that have thin waxy cuticles,. Leaves with thicker waxy cuticles do not work as well. 2 You must cut the shoots under water and you must assemble the photometer under water. This requires a large sink.
If air gets into the xylem vessels of the plant, it can form air locks, which will prevent the plant taking up water, and so prevent steady transpiration. 3 The pedometers should be left for the leaves to dry. Alternatively dry the leaves gently with a paper towel. The photometer will not work properly until any excess water on the leaves has evaporated or been removed. 4 Assemble the pedometers before the lesson, since there is a real art in setting them up. This will give the leaves time to dry, and give technicians a chance to check they are working before the students begin to take measurements. Adding food coloring to the water makes it easier to see the air bubble in the capillary tube. Preparation A) Set up the apparatus as in the diagram. (on the paper given) B) Leave undisturbed o that the shoot equilibrates to the conditions. C) Starting about 2 CM from the free end of the capillary tubing, mark the tubing at 1 CM intervals using the ruler and marker pen. Make as many marks as possible (at least Investigation D) Introduce a bubble into the capillary tubing by lifting the whole photometer upwards.
To do this, loosen the screw on the boss and slide the boss up the clamp stand so that the capillary tube comes out of the water in the beaker. Rewritten the screw on the boss. E) Gently blot the end of the capillary tube with a piece of paper towel; an air bubble should appear in the capillary tube. F) Loosen the screw on the boss and lower the photometer, so that the capillary tube Just goes back into the water in the beaker. Rewritten the screw on the boss. G) Taking measurements:Start the stop clock when the bubble of air touches the first marked line.
Stop the clock when the bubble has traveled a fixed distance (2 or 3 CM) Transpiration rates Native vs. Exotic plant Transpiration rates Native vs. Exotic plant Results Plants I Test I(water loss in CM) I Test 2 (water loss in CM) I Red bottlers (native) 1 1. CM 1 1. CM I Birds of paradise (exotic) I No results I No results I Eucalyptus (native) 1 1. CM 1 1. CM I Mock orange (exotic) 1 2. CM 1 2. CM I Discussion In this experiment we have been looking at Transpiration rates between native and exotic plants. Our aim was investigate and find out different transpiration rates of native and exotic plants.
We can clearly see the results recorded support my thesis, Stating that the native plants would have a slower rate of transpiration compare to exotic plants. In the results we see the native plants such as the red bottle brush and the eucalyptus have a rate of transpiration of around 1. CM of water loss in 4 days of direct sunlight. However the exotic plants such as the mock orange had a rate of 2. CM of water loss in 4 days of direct sunlight. The reason to the native plants having a slower rate of transpiration is because in country where the climate is cooler then Australia’s.
For example the mock orange, it is native to America and Asia and can only survive in temperatures of 10-13 degrees, Which meaner they are not adapted to Australia’s dry environment as much as the heat. Since the native plants had slower transpiration rates it could mean there stoma cells ere not as opened as those of the exotic plants. The stoma cells of the native plant such as the eucalyptus has adapted to its environment and only opening a large amount when there is excess water. However the mock orange (exotic plant) is not use to Australia’s hot climate it prefers its colder weather.
We can say that the stoma cells were probably open more wide because in order to cool itself from Australia’s heat(which it is not use to) it needs to loose water. Although we have results that show us that the native plants have slower rates of transpiration. It cannot be fully supported with my thesis because it is not an accurate or fair investigation. During our investigation we were unsuccessful with our exotic plants, when we chose our exotic plants we did not realism that the thickness of the stem of the plant mattered.
The birds of paradise plant had a pretty thick stem, which could not fit in the photometer. This meant we only had 1 exotic plant to get results off. To improve this error, in future we should choose plants, which would be suitable for this investigation and to find out prior to us choosing our plants find the size of the photometer. Some other errors experienced in this investigation would be the timing. We gave both native and exotic plants a 4 day period of sunlight to see the amount of water absorbed by the plant.
Our problem was that we did not let them out in the sun at the same time which could of affected the results. For example on the 4 days given for the native plants the weather could have been colder which meant that the plants did not have to absorb much water, whereas for the 4 days given for the exotic plants the weather could have been much hotter meaning the plants would have to absorb ore water. To improve this investigation in future and give it a more accurate go, we could place both the native and exotic plants out at the exact same time.
Another error, which could have affected the results, could be the size of the plants, although most of the plants were similar size we did not take in, that it was possible that the plant could transpire faster if there were more leaves on the plant because of a larger surface area we did not have the exact same amount of leaves on each plant. In future to improve this investigation and make it more accurate we could use he same size and number of leaves for each plant, this will give us a more accurate result.
Other ways of furthering this investigation could be by using more plants, for example we could of used 4 native plants and 4 exotic plants, we could of also furthered this investigation by doing repeated trials, we could of tested each plant 3 times, instead of Just once. By doing so we could extend the variety and have much more accurate and persistent results. In conclusion it can be said that during this experiment of investigating transpiration rates between native and exotic plants. That the rates of transpiration in native lands to Australia are slower than the exotic plants, The native plants had an average rate of 1. CM water loss in 4 days. The exotic plant had a water loss of 2. CM. Because plants adapt to their environment, the native Australian plants have the ability to adapt to Australia’s climate of hot weather and can sustain on to their water for a longer period of time, whereas the exotic plants are not use to Australia’s hot climate and they are not able to sustain their water for a long period of time. They are use to their colder temperatures and cannot easily adapt to Australia’s hot climate.