Trees Essay, Research Paper

Wes Gale

5th Hour

Evaluation of Relative Importance Values of the Tree Species Found in Three Different Habitats at Weldon Springs Wildlife Area by Calculating Importance Values

Introduction:

While on our field trip we hoped to evaluate three different forest habitats by calculating individual tree species importance values. We were at Weldon Springs Wildlife Area in St. Charles. We evaluated three different microhabitats: Upland East Facing Slope, Upland West Facing Slope, and River Bottomland. A microhabitat is a habitat inside of a larger, more diverse habitat like the eastern forest. We were to evaluate each microhabitat in terms of the tree species present, the number of individuals present per species, the size of the trees, and the distribution of the tree in the habitats. These four factors all together determine the importance value of a tree species. Tree species present is finding what tree species are found in the particular microhabitats. We had expectations on what species of tree we would find in the microhabitats before we went to Weldon Springs. We took note of the number of individuals per tree species found which is the population. We found the size of the tree using diameter breast height in centimeters. Also, we looked at the distribution of the tree in these three microhabitats. This field trip would give us the frequency, density, and cover of all of the trees found in the habitats.

Materials and Methods

In order to be able to make all of the observations and collect all of the data one would need to have many supplies and methods to take and use in the forest. The materials we needed to bring were a tape measure or measuring string, paper and pen/pencil to write results, a transect string, a tree book or paper to key out particular trees. The most important resource in the forest is a knowledge of what you re observing and looking for. You would need to know about each of the habitats; what trees species are usually found there and why and why are these species found here. You would have to be familiar with most of the trees found and definitely know how to key out an unknown tree. Once you get into a specific microhabitat you would lay out your transect string by tying one end to a tree by the trail and walking into the forest lay it out all of the way and tie it to another tree. You would then key out every tree that is within arms length away from the string and at least 10DBH. DBH is diameter breast height and our measure was our hands making a circle. Once we came back with all of our data, which was the trees listed and their circumference next to it we could start working on our data. We first needed to calculate our basal area of every single tree. To do this you take the circumference squared and divide it by 12.57. After this we then found the frequency of the trees by taking the totals number of transects containing the tree in a particular microhabitat and multiplied it by 100 and divided by the total number of transects which was six in our case. Next, you would find the density, which is the total number of tree species and divide it by the total number of transects. After this you would find the cover in adding up the basal area of the all of trees of the same species and divide it by the total number of transects. After you find all of these you must then find the relative frequency, density, and cover. To do this you would take the frequency, density, or cover of a species and multiply it by 100 and then divide it by the sum of the frequency, density, or cover of all of the species. Once you have done this you can find the importance value of a species by adding up its relative frequency plus the relative density plus the relative cover. That is the final step you would need to make.

Observations and Results

Each microhabitat will have its own observations and results that greatly vary it from another habitat.

Eastern Facing Slope Importance Values

Sugar Maple-127.23

Northern Red Oak-39.3

White Oak-17.7

Black Oak-17

Shellbark Hickory-16.14

Shagbark Hickory-15.82

Mockernut Hickory-15.17

Sassafras-11.44

Slippery Elm-10.36

Hornbeam-9.5

White Ash-9.17

Chinkapin Oak-7.8

Red Maple-7.54

PawPaw-7.18

The East Facing Slopes most important tree is by far the Sugar Maple with an importance value of 127.23. It is a climax tree, which is expected to be found on this slope because of its moisture. The PawPaw was the least important tree with an importance value of 7.18. It is usually found in the bottomland areas. This area was very shaded and dark near the ground because of the canopy trees. The sun does not shine on this slope very much during the day due to its position. The undergrowth was thicker here than the west facing slope and there was more leaves on the ground. The dirt and soil was very moist here also. The sugar maple being so dominant in this area shows most of this microhabitat is climax forest.

West Facing Slope Importance Values

White Oak-50.49

Shagbark Hickory-28.97

Sugar Maple-23.15

Northern Red Oak-19.02

Shellbark Hickory-15.74

Flowering Dogwood-9.04

Mockernut Hickory-6.52

Chestnut Oak-6.52

White Ash-6.52

Pumpkin Ash-6.52

Black Oak-6.52

Chinkapin Oak-6.52

The West Facing slope s most important tree was the White Oak at 50.49. The White Oak is a tree found on both slopes that have a very high range and can survive different conditions. The Chestnut Oak, White Ash, Pumpkin Ash, Black Oak, and Chinkapin Oak all had importance values of 6.52. They all were only found one time in the whole microhabitat. The west facing slope didn t have nearly as many sugar maples as the east facing slope because of its dryness. The soil on this slope was very dry and so were the leaves. The sun was on us during the time we were surveying this slope.

River Bottomland Importance Values

Cottonwood-138.58

Box Elder-64.3

Silver Maple-39.54

American Elm-29.76

Sycamore-27.98

Sugar Maple-6.89

The most important tree in this area was the Cottonwood by far at 138.58. Its huge size was a reason for this. The Sugar Maple was the lowest and is not very popular in this area but can be found. The Silver Maple is much more popular in the River Bottoms than the Sugar Maple. These trees found here mainly only grow in very wet areas and are not usually found anywhere else. Sycamore and cottonwoods are huge trees that need to be near water. This area had very thick undergrowth and there was sand on the floor. This is due to the river flooding at many times. This was a climax forest with cottonwood ruling.

Discussion

On this field trip I found most of my expectations on what I would find to be true. All of the most important trees in each area are climax trees. The Sugar Maple in the east facing slope, the White Oak on the west facing slope, and the Cottonwood in the river bottomland. The east facing slope was typical in an eastern forest. The Sugar Maple was most important but not far behind was the oaks and hickories that we expected to find. The oaks and hickories are just behind the Sugar Maple in terms of stages of succession. The main oaks being the Red, White, and Black and the main hickories being Shagbark, Shellbark, and Mockernut. We also found the understory tree species we expected like Sassafras, PawPaw, and Hornbeam. The east facing slope was very complete. The west facing slope was very typical of what we expected to find also. The White Oak, which is very popular on both slopes, was the most important tree. Oaks and Hickories were the climax trees in this habitat. The oaks were White, Red, Chestnut, Black, and Chinkapin. The Chestnut Oak could have been a misidentification. They are not very regular in Missouri forest although they do turn up. The hickories found were Shagbark, Shellbark, and Mockernut. We also found the understory trees like flowering dogwood. We found a White Ash and a Pumpkin Ash. The White Ash is typical but the Pumpkin Ash is not usually found and could have been a mistake. Also, we had a group that names a hickory at random a Shellbark because they though they didn t see the shaggy bark. This could have also been an error in our findings. The east facing slope was very typical and what we thought we would find. The river bottomland was also a climax forest containing trees expected in the area. The Cottonwood was the most important with an importance value of 138.58. Its massive size contributed to this number. We found all typical trees of a river bottomland. The Sycamore, Silver Maple, Box Elder, Cottonwood, and American Elm all are mostly just found around the bottomland. We found many sugar maples in this area. They can be expected in the area because of the high moisture and because of the tree s range.

Conclusion

This field trip basically summed up everything we have learned about trees in the time in the class. We found everything true about trees being better adapted to live in certain areas. We saw the climax forest of Sugar Maples on the east facing slope, oaks and hickories on the west facing slope, and found the Cottonwoods and Sycamores we expected din the river bottomland. We found understory trees also like Flowering Dogwood, Sassafras, and Hornbeam. We saw the successional stages discussed with the sugar maple at the climax and oaks and hickories right below the climax stage. We observed trees in their natural habitat and not in our backyards. We found the most important trees as just would a forester and used similar methods as they would use also. We accomplished our goal and understood how we were doing so and this is what the field trip was about.