Damian Bluff Essay, Research Paper

Introduction

The experiments that were carried out on Damian Bluff were to use plot method calculations, and quarter method calculations to find out what species of trees are in the area and how to characterize each tree. The plot method was used to produce an ecological importance value for each species. The quarter method is a type of plotless methods. The trees were observed to find out what kind they were. The experiments were carried out on both the north and the south sides of Damian Bluff to observe the differences and similarities each side has. The trees names were found using the book, A key to the Woody Plants of Minnesota by Brother Charles Severin. There are two different names for every tree. One name is the common name, which is like the Hackberry. The other is a scientific name in Latin combining two names of binomial nomenclature, that consists of the generic name of the tree first, then the species designation name second. Forestry is a science that seeks out to know what a forest has gone through in previous years, and how the forest is doing today.

There were no hypothesizes drawn for the first experiments because the experiments dealt with observations for the first time by the class. Before the second time of going up to observe the trees on the bluffs, there were some hypothesizes. The hypothesizes were that the trees that were found on the north side of the bluff needed less light to grow than the trees on the south side of the bluff. Therefore, the trees on the south side needed more light to grow than the trees on the north side.

Methods

The Damian Bluff experiments all started out by first understanding what was going to be done in the field and why it would be done. The instructions on what information was needed to be collected included that each group had to turn in sheets with the date, the group number, everyone s first and last name, what side was observed, then a list of every tree observed with its corresponding circumference. In the lab, the calculations of the basal are, total area sampled, the density (D), relative density (RD), dominance (Do), relative density (RDo), frequency (F), relative frequency (RF), and the importance value were explained to ensure complete knowledge on the calculations.

A lot of information can be learned from the aging of a tree. In the lab, how to age a tree was explained. To age a tree, one must count the growth rings, and one way to do that is with an increment borer. The use of this tool was explained to show other methods of observing forests. An increment borer is an auger like tool that is twisted into the trunk of a tree. The borer is hollow all the way through it, so a small stick of the core showing the growth bands is produced. The growth bands show how much growth was done in the previous years and can tell what type of environment was experienced in those previous years.

Measuring the forest was done by first staking off the area that was going to be observed. To do so, each group was given a side of the bluff to work on, then marking off a fifty-foot square section. The area observed was marked off by starting at a point and walking in a given direction a random number of pace4s. The random number of paces was found by taking a person s social security number, and breaking it up into increments of two numbers at a time. Like, taking the number 476-98-7816, and breaking it up to forty-seven, sixty-nine, eighty-seven, eighty-one, sixty-four (four comes from starting over with the beginning of the social security number, and continuing on), seventy-six, ninety-eight, seventy-eight, and sixteen. The number forty-seven was chosen because the number had to be greater than zero but less than fifty.

After the number of paces was walked off, a stake was placed in the ground. Orange ribbon was tied to the top of the stake, so it could be seen. Then fifty feet was marked off along the path (the path was the line that was to be followed to mark off the first stake) away from the starting point. Then a stake with an orange ribbon on it was placed in the ground and another fifty feet were marked off at a 90. angle from the path. There, another stake was placed, and another fifty feet were marked off at a 90. angle from that stake, completing a fifty foot square plot area. After the plot was established, the trees were then examined. The trees to be examined had to have a circumference equal or greater than 0.7ft.

The method of collecting the circumference was done by measuring with a field tape measure around the tree at breast height, or 4 + ft. (137cm). The tape measure had feet and tenths of feet marked on it. Once the circumference was collected, and then the type of tree had to be calculated using Severin s book (1976). The trees were calculated by observing the variations of the form and size of the leaves, the fruit (if available), the flowers (if available), the leaflets, branches, twigs, and bark of the tree, and following along through the key. The arrangement of the leaves and the twigs were also observed to find the name of the tree that correctly fit the tree that was being observed. In some cases, a pair of binoculars was used to see the leafs and branches that were higher than could be reached or seen by the naked eye. If a question about a tree came up, the instructor was asked to help clarify the tree to ensure that the correct species of tree was recorded.

The stakes were then all picked up, except for the stake that was placed second in the ground. From that point, and heading on the path that was originally followed, a new random number of paces was found and carried out to get the second plot area that had to be observed. The paces were walked out and a new plot was made using the same techniques as was used to make the first plotting area. The results were then brought back to the lab and collected to get the results from every group.

The second sets of experiments were then carried out by using the quarter method, which is a plotless method, instead of using the plot method again. This was done so everyone would have an understanding about how to do plot methods and plotless methods. The groups were assigned to do experiments on the opposite sides of the bluffs than they did the last time. A beginning point was chosen by walking in a given direction, from the given starting point, a random number of steps. The social security number used this time was 392-93-1452, so it was broken up as thirty-nine, twenty-nine, thirty-one, forty-five, twenty-three (starting over again), ninety-two, ninety-three, fourteen, and fifty-two. The number fourteen was picked as our random number, and was paced off. At the first beginning point, four imaginary sections were thought up by taking the path to the beginning point and continuing past the point to divided the area in halves. Then two imaginary lines at 90. angles from the point in two directions, cutting the area into quarters, giving this method its name, the quarter method. From the beginning point, the closest tree to the point was to be observed in all four quarters. The distance to each tree being observed was then measured. The circumference of that tree was calculated in feet and tenths of feet. Then back at the beginning point, the Bitterlich number was calculated.

A new technique in timber cruising (research) was introduced into the United States from Germany by Dr. L. R. Grosenbaugh, of the Forest Service in 1952, and is called the Bitterlich method of direct basal area determination. Variable plot cruising, as it is also called, is a timesaver, since plot boundaries are not laid out. It requires that the cruiser (observer) stand on a spot in the forest and, while rotating, count all the trees whose diameters appear greater than the width of a small vertical object, called an angle gauge, held outstretched at eye level (Allen, 1976: 277).

After the Bitterlich method was found, it was time to move onto the next plotting point. To do so, the same path as used before, was randomly paced out a new random number. Then the new point was set and broken into quarters again to be observed. This was done five times by every group, so there was a total of twenty trees being observed, and their circumferences calculated for each group. The Bitterlich method was used again at every point, too. The amount of trees counted during the Bitterlich method was not a set number of trees, and could differ from each new point.

On the south side of the bluff, there was also a path that went through the areas being observed. So if a group s random number of paces or a tree being observed went across the path, the paces or measurement went up to the edge of the path, then started again on the other side of the path. This was done because the path inflicted bare spots in the observed area, so it was not included in the measurements.

After all of the data was collected and put together for each group in both classes, the calculations had to be done. For the plot method, the circumferences of each tree was converted to basal area using the formula A=C^2/4p. The total area sampled was calculated. The density for each species was calculated by counting the number of trees of that species in all plots, dividing that number by the conversion factor, 43,560 ft^2/acre, to get the number of trees per acre. The relative density was calculated by first adding the densities for all species, and dividing this number into the individual species density. The sum of the relative densities should add up to one, however, there was a little difference for rounding errors. The dominance and relative dominance were determined the same way as density was except the basal area measurements are summed instead of tree counts. Frequency was found by taking the number of plots in which the species occurred, divided by the number of plots. The relative frequency was calculated by summing all frequencies and dividing this number into the individual frequency. The importance value of each species was then calculated by adding its relative density, relative dominance, and relative frequency.

The quarter method calculations included finding the density, relative density, etc. The calculations were a little different due to the different methods of observing the trees. Both methods were calculated for both the north and south sides, and the total calculations were found.

Results

The plot method results for the north side (Table 1), the south side (Table 2), the plotless methods for the north side (Table 3), the south side (Table 4), and the total results (Table 5) show the results for all of the participating groups on Damian Bluff. The Bitterlich method works by counting the trees with a special instrument. The trees are only counted if the trunk is larger than the slot on the Bitterlich chain (Figure 1).

Table 1. North plot method data for density (trees/acre), relative density, dominance (ft^2 basal area/acre), relative frequency, and importance value.

Species D RD Do RDo F RF Iv

Green ash 67.518 0.284 23.631 0.211 1.000 0.174 0.67

N. red oak 21.780 0.092 31.842 0.285 0.750 0.130 0.51

Hackberry 60.984 0.257 11.347 0.102 0.750 0.130 0.49

S. Hickory 30.492 0.128 3.7897 0.034 0.750 0.130 0.29

Cottonwood 4.356 0.0183 23.086 0.206 0.250 0.044 0.27

W.b. cherry 21.780 0.092 2.3522 0.021 0.750 0.130 0.24

b. walnut 6.534 0.028 9.8446 0.088 0.375 0.650 0.18

Sm.t. aspen 6.534 0.028 3.7026 0.033 0.375 0.065 0.12

Hard maple 6.534 0.028 1.2197 0.011 0.250 0.044 0.08

E. buckthorn 6.534 0.028 0.5227 0.005 0.250 0.044 0.08

American elm 4.356 0.018 0.4791 0.004 0.250 0.044 0.07

Total 237.402 1 111.8185 1 5.750 1 3

N = Northern

S = Shagbark

W = Wild

B = black

Sm = Small

t = toothed

E. = European

Table 2. South side plot method data for density (trees/acre), relative density, dominance (ft^2 basal area/acre), relative dominance, frequency (# plots tree is present/total plots), relative frequency, and importance value.

Species D RD Do RDo F RF Iv

B. walnut 102.366 0.602 57.848 0.70 1.000 0.363 1.66

Red cedar32.670 0.192 20.103 0.24 0.875 0.318 0.75

Hackberry 10.890 0.064 2.8749 0.04 0.375 0.136 0.24

Tar. maple*17.424 0.103 1.0672 0.01 0.125 0.045 0.16

Hard maple 2.1780 0.013 0.4356 0.01 0.125 0.045 0.07

Bur oak* 2.1780 0.013 0.0871 0.00 0.125 0.045 0.06

Nannyberry 2.1780 0.013 0.1742 0.00 0.125 0.045 0.06

Total 169.884 1 82.5897 1 2.750 1 3

* incorrect identification

B = Black

Tar = Tartarian

Table 3. North side quarter method data for density (trees/acre), relative density, dominance(ft^2 basal area/acre), relative dominance, frequency (# plots tree is present/total plots), relative frequency, and importance value.

Species D RD Do RDo F RF Iv

N. red oak 45.734 0.126 91.103 0.400 0.45 0.15 0.6766

Hackberry 86.898 0.240 13.208 0.058 0.55 0.18 0.4785

Green ash 64.031 0.177 23.871 0.105 0.45 0.15 0.4322

S. hickory 50.308 0.139 5.3981 0.024 0.50 0.17 0.3332

Cottonwood 9.1484 0.025 52.054 0.228 0.10 0.03 0.2833

B. walnut 18.293 0.050 27.074 0.119 0.20 0.07 0.2396

W.B. cherry 36.586 0.101 4.7567 0.021 0.30 0.10 0.2223

Hard maple 32.015 0.088 7.1363 0.031 0.25 0.08 0.1996

American elm 13.718 0.038 2.8810 0.013 0.15 0.05 0.1010

E. buckthorn 4.574 0.012 0.2289 0.001 0.05 0.02 0.0336

Total 361.31 1 227.712 1 3 1 3

N = Northern

S = Shagbark

B = Black

W = Wild

E = European

Table 4. South side quarter method data for Density (trees/acre), relative density, dominance (ft^2 basal area/acre), relative dominance, frequency (# plots tree is present/total plots), relative frequency, and importance value.

Species D RD Do RDo F RF Iv

B. walnut 91.403 0.650 58.50 0.73 1.00 0.47 1.8500

Red cedar 31.639 0.225 17.72 0.22 0.65 0.30 0.7450

S. hickory 3.5155 0.025 0.91 0.01 0.10 0.05 0.0850

Green ash 3.5155 0.025 0.81 0.01 0.10 0.05 0.0850

W. mulberry 3.5155 0.025 0.56 0.01 0.10 0.05 0.0850

Hackberry 1.7578 0.0125 0.62 0.01 0.05 0.02 0.0425

P. dogwood* 1.7578 0.0125 0.51 0.01 0.05 0.02 0.0425

Honeysuckle 1.7578 0.0125 0.09 0.00 0.05 0.02 0.0325

A. basswood 1.7578 0.0125 0.09 0.00 0.05 0.02 0.0325

Total 140.62 1 79.81 1 2.15 1 3

* incorrect identification

B = Black

S = Shagbark

W = White

P = Pagoda

A = American

Table 5. North and south side dominance according to the Bitterlich method (ft^2 basal area/acre)

Side of Damian Bluff Total dominance

North 188

South 80

Discussion

The results of the observations done during the experiments that were done on both sides of Damian Bluff showed that there were only two species of trees that were observed on both sides of the bluff. The two species that were found on both sides of the bluff were the Black walnut, and the Hard maple. The two species show that they have a variety of capabilities in where they can survive. The south side of the bluff had a more open canopy, which lets more sunlight hit the ground causing the ground to be drier. The north side of Damian Bluff had trees that closes the canopy, so there was less sunlight able to hit the forest floor. The north side s soul had a higher rate of moisture.

The sources of error of the experiments were caused because of the errors in identifying the trees. This could have been resolved, if the groups that did not know what kind of tree they were observing, would have asked for help from the instructor. The circumferences of the trees were fairly easy to read, so there was any error in the readings. Some other inadequacies were that the beginning paths followed were not set in stone, but were imaginary lines to follow. If there was a tree in the way of the path, the person who was pacing off the random number of steps had to walk around the tree, and then get back on the right path.

The next steps in research on the Damian Bluff would be to go back in the general area that was observed and do more forestry research to see how the forest is changing. The more experiments done on the bluff would help minimize the amount of error that was received. The trees that were incorrectly identified, were the Tartarian maple (Acer tataricum), the Bur oak (Quercus macrocarpa), and the Pagoda dogwood (Cornus alternifolia). The more research that is done over a longer period of time would show how the forest is changing, like, what new tree species seems to be flourishing from year to year, and what species is dying off from year to year.

The methods that were used, were very well thought out and have been practiced for many years. So, the only improvements that could be accomplished would be to get the knowledge of the methods a little more in detail, and to make sure the people who are running the experiments understand how to do the methods fully. The key that was used to figure out what type of tree was used could be explained and practiced a lot more to ensure complete knowledge of the subject.

Summary

The experiments done were to fully understand how forestry methods of measuring and observing trees is done. The main function of the research was to figure out what trees were found in what types of environments. The trees that had the highest importance values for each side were: the Green ash (Fraxinus pennsyvanica, var. subintegerrima), the Hackberry (celtis occidentalis), and the Northern red oak (Quercus borealis, var. maxima) for the north side; the Black walnut (Juglans nigra), and the Red cedar (Juniperus virginiana) for the south side.

Literature Cited

Allen, Shirley W., Hendee, Clare W., & Sharpe, Grant W.

1976. Introduction to Forestry. McGraw-Hill inc., New

York, NY.

Rehder, Alfred 1927. Manual of Cultivated Trees and

Shrubs. The Macmillan Company, New York, NY.

Severin, Brother Charles 1980. A key to the Woody Plants

of Minnesota. St. Mary s College Press, Winona, MN.

Smith, Robert Leo, & Smith, Thomas M., 1998. Elements of

Ecology. Benjamin/Cummings Publishing Company, Menlo

Park, CA.