Leaf Structure And Light Microenvironments

By Author: ANTHONY BILLS
Total Articles: 158
Comment this article

Plants have several organs which play crucial roles for them to survival. These include roots, stems and leaves. Though each of the various organs is interconnected in their in one way or another so as to perfectly perform their functions, leave are of significance importance in the plant photosynthetic processes. Generally, plant organs’ structures have been paradox in many ways, and in most cases the structure of the various organs has been portrayed as mosaic of contradictory in regard to the plants requirements and productivity. Plants require light for them to photosynthesis. The photosynthetic rate depends on the inputs and the outputs of the materials need to carry out the process. Leaves of the plants are dualistic in that they are the system through which the necessary elements for photosynthesis are channeled into the plant body, and the same elements such as water and CO2 can be lost. This compromises the plants life (Martin, 3).
Like in the macro-environments of the plants, plants may exhibit certain adaptations of the various organs. This adaptation includes both morphological and anatomical features. Different ...
... plants exhibit leaves variations ranging from leave size, leaf shapes as well as the internal contents number such as the number of chlorophyll. In addition, plants also may show different leave arrangements depending on the ecological conditions in which the plants grows. Some of the leaves are thickened while others are thin; these disparities perhaps are brought about by the number of layers or the size of the inner structures of the leaf organs such as microphylls and chloroplasts (Mantovani 2).
The surfaces for light absorption and transpirations are vital for maximum photosynthesis of the plants. In most case, leaf variation have been reveal to exist for different taxa, there is also some evidence that variations occur within a plant in response to local changes in the environment. Different plant species thus show considerable leaf variations on shape, weight and surface area due to local light variations (Coker and Kent 1).
Materials and method
Materials
The following materials were used in this experiment: 50 sun oak leaves and 50, shade oak leaves, graph paper, pencil, top-loading balance, ruler and thread string,
Methodology
50 sun leaves and 50 shade leaves were placed labeled on the benchmark ready for different analysis. Each of the leaves was analyzed to establish its characteristics. A thread string was stretched lengthwise from one end of the leaf through the centre to the other end, and then tracing the thread string on the ruler to establish the leaf length. Similarly, the thread was traced across the leaf and then the measurements were taken by tracing it on the ruler. Afterwards, the thread was wound around the leaf and then tracing the length of the wound thread on the ruler to get the perimeter of the leaf. The area of each leaf was determined by careful tracing it shape on square graphical paper and the using the least square method calculating the surface area of the leaf as well as the leaf sinus area. Finally, each of the leaves was placed on a top loading balance and the reading was taken for each leaf and recorded. The data was tabulated as shown in table 3 and analyzed using the descriptive data analysis.
Results
The data of the two groups had the property of precision with just very few leaves whose values were greatly varied from the others. The leave that were drawn from the exterior parts of the plant had an average surface areas of 72.5, while that of the leaves that were labeled as shade leave had a mean surface area 81. 5cm2. The average surface area for the sun leaves was considerably less as compared to that of the shade leaves. Hence, the overall means surface areas of the sun and shade leaves were estimated to lies between the extremes. Certainly, the mean surface area of the shade leave was skewed to the right side of the central tendency, while the mean surface area of the sun leaves tended to lie to the left side of the overall mean area.
Moreover, the leaves from the different plant parts showed variations the weight. Similar to the average surface areas, the shade leaves had more weight than the sun leaves. The average weight of the sun leaves was indicated as 1. 2g while that of the shade leaves was higher by 0.3, hence showing an average weight of 1.5g. The average weights of the leaves from the two classes were thus not widely varied as it was with the average surface areas.
Despite the fact the sun leaves and shade leaves had different mean averages of area and weight; they had one thing in common concerning the distribution of their perimeters. On the extremes side of the perimeter of 0.5cm and 2.5cm, there were very few leaves at these extremes. However, most of the leaves’ perimeter fell on the range 60.cm and 90.cm with very few of them measuring above this and below 48.cm. Most of the sun leaves were clustered on the weight range of 1 and 1.5g. On the other hand the shade leaves were clustered between 1.5g to 2. g but they were widely spread from one another as in relation to their perimeters. A large proportion of the shade leaves had a maximum perimeter of about 80.cm but very few of them fell above 80.cm. The results also showed that some of the leaves had a perimeter of below 40.cm. Generally, shade leaves were clustered between 45.cm and 70.cm