Describing a Population: Method B

Describing a Population - Method B

Introduction

Characteristics of life vary among populations from one individual to another. Within each population variety occurs on a grand scale. An ecologist's goal is to understand life on that grand scale and do this by using measurements and calculations. These measurements and calculations are the primary reasoning for describing the differences from individual to individual. An example of this system of describing populations can be observed in the determining of pine needle length differences among trees of the same population. By determining the differences in pine needle lengths it may ultimately be productive in determining the overall health of the entire tree (McDonald et al. 1991). Pine needles perform the crucial job of photosynthesis which ultimately produces chemical energy for the tree (Ledig et al.) . The lengths of the pine needles are important and can ultimately determine how well it functions in the photosynthetic process (Myers et al.). It can be said that a correlation exists between a pine needle being too short and it lacking the proper amount of photosynthetic tissue. The same can be said with the correlation that exists between a pine needle being too large and ultimately not being able to transport enough water to its tip. Since the length of pine needles play a part in the overall health of the tree it can be said that in the sample of pine needles acquired the overall length of each needle will be relatively similar (Pardos et al. 2009).

Methods

To prepare this procedure, a local pine tree was selected and samples of eighty pine needles were collected in standard zip lock bags (as seen in figure 1). The eighty pine needles were collected randomly and free from any bias; the length of each pine needle was measured using the millimeter side of a standard ruler and recorded. Once the pine needles length was recorded, a set of calculations were then able to be performed which helped determine the similarity of length between each pine needle.

Figure 1 - Collected sample of pine needles

Results

Figure 1 - shows the distribution of pine needle length among each frequency class.

Table 2 - The table below shows the calculations that were made from the set of collected data.

Mean 94.5375

Sum of Square Deviation 33133.18

Variance 419.4073

Standard Deviation 20.4794

Standard Error 2.29

Confidence Interval ±4.49

90.05