The Transpiration Rate of Two Different Branchlets under Different Environment - Lab Report Example

TITLE: THE TRANSPIRATION RATE OF TWO DIFFERENT BRANCHLETS UNDER DIFFERENT ENVINRONMENT. NAME: DATE: INTRODUCTION: The experiment was designed to measure the transpiration rate of two different plants using the same method under different condition. The experiment is performed on two specimens, a branchlet of lilly-pilly (Syzygium smithii) and water lily, how the rate of transpiration in these two plants varies in three different environment; arid /semi-arid, wet and terrestrial environment. The experiment was set to determine the factors that affect the rate of transpiration, in the contrasting environment. The factors which the experiment was testing through include; humidity, temperature, light and wind. We expect the two plants to have two different measures when read through the potometer. Firstly, we expect the plants to lose more water in some environment such as, arid. This differs due to the environmental conditions like light, temperature, humidity and wind. We expect the lilly-pilly to lose less water than the water lily when they are exposed to the factors of the environmental conditions. Procedures: We required the branchlets of the two plant samples, a potometer, a beaker, a stopwatch and a capillary tube. We filled the beaker with water from the tap. We then placed the branchlets of the lilly-pilly and water lily in the stem holder at the top of the potometer, which, we had placed in the water with its bottom. We emerged the bottom of the potometer out of the water and observed the capillary tube. We returned the tip of the potometer in the water. We used the stopwatch to observe the capillary tube keenly so as to measure the transpiration rate. RESULTS: After 7 minutes we stopped the stopwatch and record the distance that the bubble had travelled through the capillary tube. In the lilly-pilly branchlet, the distance according to our reading was that the air bubble travelled 0.16 inches in 300 seconds, while in the water lily the bubble travelled 1 inch in 300 seconds. To get the rate of the transpiration rate in both branchlets we divided the distance covered by the predetermined time limit. For the lilly-pilly the rate was 0.000533 inches per second, while for water lily was 0.00333 inches per second. These results changed in the three different environments, as shown in the table and the graph below. The results obtain here were from the calculation from the potometer readings. Taking the distance from where the bubble in the capillary tube had travelled, we timed it in 300 seconds and then divide the variables. This was repeated in the three environments, that is, the arid, the wet land and the terrestrial environment. From the table, we used the figures to plot a suitable and simple graph to present the experiment figuratively. The graph below shows clearly the range by which the two branchlets transpire in different rates. Environment Arid(hot) Wet Terrestrial(normal) Lilly-pilly(ml/300sec) 0.000166 0.000533 0.000333 water lily(ml/300sec) 0.00667 0.003333 0.002867 The graph represents the results in our experiment through the three environments. the graph clearly shows that the water lily experience high transpiration rate in both environments due to its features that it adapts. DISCUSSION: The lilly-pilly is a xerophyte, which means that it is used to hostile and dry environment. The lilly-pilly has rough woody bark and green smooth waxy leaves and produces berries. It’s specially has these feature which enables it to adapt to its hush environment. The rough woody bark protects the stem inner tissue from the dangerous ultra-violet rays from the sun. Its leaves also adapt to the environment, it’s waxy so as to reflect some light from the sun and increase the distance through which the water would travelled due to transpiration and its evergreen so as to perform photosynthesis. With high temperature, strong wind and much light the rate of transpiration of the lilly-pilly is high, thus, it tends to develop features that enables it to lose less water. This forces the plant to develop unique features like travelling roots so as to find water to replace the lost one. The water lily on the other hand, is a mesophyte. It only survive in mass water environment, its features enable it to survive in these environment. The water lily has broad green and thin leaves to perform continuous and rapid transpiration. For water lily to survive in this environment it has to lose more water and be exposed to much light. Since it’s fond of growing on water surface, it has develop broad roots. This also means that the water lily has large stomata pores so as to increase transpiration. Water lily cannot survive in hostile and dry environment as it will develop plant stress and eventually die. (Clum, 1926: 30) In our experiment, we obtain different results in different environment due to the above mentioned adaptations of the branchlets. When the branchlets were dipped in water according to the procedure, we acquired different results. First, for the lilly-pilly the results in the water environment were lower than the water lily, this is because the lilly-pilly has developed features which try to minimize the water loss by transpiration. This is due to the conditions of the environment which it’s used to, that is, the dry and hostile environment. For the water lily, the results were higher than the lilly-pilly. This is because the water lily is used to lose more water because of the environment it develops in. The results in the dry environment differ from the ones in the wet environment. For the lilly-pilly, the results were lower than the water lily, very minimal than the one in the wet land. This is where the lilly-pilly adjust so well through its features; it minimizes the stomatal pores which reduces the transpiration rate. For the water lily, the rate was too high than when it was in the wet land. Water lily do not have the features to survive in dry area, they have large stomatal pore and thus end up loosing water to large extent (Pandey and Sinha, 2009:40). Their leaves also are largely exposed to sunlight, this also increase the rate of evaporation of water thus leading to plant stress. The thinness of the leaves of the water lily decrease the distance through which the water is lost through evaporation, and thus, increase rate of the transpiration. In the terrestrial environment, for lilly-pilly the rate of transpiration was lower than water lily. This is because in terrestrial the temperature varies, this creates an environment similar to the one in the dry area, and thus, the rate of transpiration tends to be close to the one in the dry area. The water lilies in this condition transpire more than the lilly-pilly because the water is not much like the one in the wet area. Transpiration does not occur in saturated humidity and it occurs most in high temperatures. Strong winds also affect transpiration. All these factors are situated in terrestrial environment, which makes all plants to experience varied climatic changes. This makes some plants to survive while others suffer from stress and thus, dying. Leaves of these plants have developed some physical barriers that tend to prevent water loss through transpiration. For instance, the thick waxy cuticle in the lilly-pilly is very essential in preventing the water loss from the plant through the leaf’s epidermis. This causes the gases like the oxygen and the carbon dioxide plus water to be forced out through the stomata by the process of diffusion (Rastogi, 1997: 52). CONCLUSION: From this experiment it’s clearly that some plants do well on specific environment. Considering the factors that affect the rate of transpiration, that is, humidity, light, temperature and wind, the rate of transpiration depends totally on the environment. The experiment is important because it help us to witness the adaptations of these plants under different environment. Although, this experiment tests only plants under the wet land experiment and sometimes it’s hard to know how other plants from other environment adapt; for instance, when we test the terrestrial plants with this experiment it’s hard to know how they adapt because it terrestrial the climate factors keep changing. In the other hand, the experiment clearly shows the adaptation of xerophytes and mesophyte because in these environments the conditions are constant. References (1968). Biology Experiments for High School Students G. Congdon Wood. The American Biology Teacher, 30(4), 341-342. Clum, H. H. (1926). The effect of transpiration and environmental factors on leaf temperatures. London : Routledge . Fanger, G. (1997). On-farm estimates of stomatal conductance, leaf area development and transpiration in pearl millet cultivation in the Sahel (Niger). Uppsala: Swedish University of Agricultural Sciences, International Office. Lab 9 Transpiration  by Merissa Ludwig. (n.d.). Lab 9 Transpiration  by Merissa Ludwig. Retrieved April 13, 2014, from http://www.biologyjunction.com/lab_9_transpiration.htm Macmillan, (1997) Biology in Laboratory: With BioBytes 3.1 CD-ROM, London: Macmillan. Pandey, S.N. & Sinha, B. K. (2009) Plant Physiology, 4E, Bengaluru: Vikas Publishing House Pvt Ltd Rastogi, V. B (1997) Modern Biology, Mumbai: Pitambar Publishing. The Lilly Pilly — versatile, tough and native beauty (Part One). (n.d.).Evergreen Growers Blog. Retrieved April 13, 2014, from http://www.evergreengrowers.com.au/wordpress/?p=129 Transpiration. (n.d.). Transpiration. Retrieved April 12, 2014, from http://users.rcn.com/jkimball.ma.ultranet/ United States Office of the Experiment Stations (1922), Experiment Station Record, Pennsylvania State University: PSU University Press. Read More