SOILS

Methods Our group had multiple methods for finding the soil types for the three different ecosystems (hardwoods, softwoods and wetland). First we dug a pit approximately three feet deep or until the soil color didn’t appear to be changing and took soil samples of the different layers. The different layers were determined by change in color and texture. Smearing was a method used for determining change in color. This was done by wetting the soil and rubbing it on the paper to see the color difference. Distance of layers was then measured and recorded in centimeters. pH of the soils was determined by using a Hellige-Truog Soil Reaction pH testing kit. The hole was then filled in after all data had been recorded. Results In the hardwood forest we found that there were four layers of soil. The first level was 2cm deep and had a pH of 5 and consisted of decomposing organic matter. The smudge test reveled that the soil was a dark brown. The second layer extended 6cm under the first layer, had a pH of 5.5 and was a dark olive brown. The soil was finer than the first but still contained decomposing matter. Layer three had a ph of 6 and was mustard brown collar that extended 8cm below the second layer and had a finer sand context. The fourth layer was 46cm and counting having a pH of 6.5 and was a bronze color. The soil was very fine. The softwood forest contained six soil layers. Layer one had decomposing matter much like layer one of the hardwoods. Small plants protruded the top layer and the context was very rough. The top layer continued 2cm into the pit was a dark brown and had a pH of 5.5. The second layer also was 2cm however it had a pH of 5.5 and was a finer gray brown finer soil. The third layer was 3cm with a pH of 6, a coarse clay soil with a grayish appearance. The fourth layer had a pH of 6 and was 8cm deep and had a fairly fine clay texture. The fifth layer was 10cm deep a brownish gray collar with a pH of 5.5. The final layer was 41cm deep had a pH of 6 was a very fine texture that was a light silvery gray collar. The wetland had five layers, all with a pH of 8.0. The first layer was 3cm deep and had roots from the invasive grass species embedded in it. The second layer extended for 7cm. The third level was 5.5 cm deep and had rust deposits spread throughout and was quite damp.  The fourth level was 21cm deep and contained a silt clay mixture that smelled of sulfur and contained more rust deposits. The hole began to fill with water after we reached the final layer that was 5.5 cm deep. This layer primarily constructed of clay. Conclusions The process of testing for the pH had large room for error. Samples of dirt were not tested in a lab or sterile condition. They were done in the field by multiple different people. The colors expressed by the different solutions of chemicals and soil were often different shades so it was hard to tell on the pH color scale. Further research led us to believe that our pH results were slightly off. Hemlocks prefer soils with lower the pH levels, or more acidic soils. However our tests suggested that the hardwoods had a lower pH than the softwoods. Most of our results were supported by further research. The Hemlock Forests prefer soils derived from basal till, abolition till out wash, bedrock and lake deposit and silt clay loam. Some soils are seasonally wet. Hemlocks forests occur on hillsides under the elevation of 1,800, this helps to keep the soil from eroding. The area of the softwoods was found on a soil classification map. Hartland E was described as gentle sloping along edges of high terraces near Winooski and Lamoille Rive. Description of the soils color, texture and depth were very similar as well. Slope was 12 – 25 percent.  Soils that host hardwood species are less acidic to the soils that host softwoods. Soils in this area were classified as Ada or Adams soils. Soils are formed in glaciolacustrine sands on terraces. This would hold true for us in the hardwoods location to the Winooski River. These soils are excessively drained. The roots of the trees help to conserve water in the soil and prevent erosion. Contrasting gravely deposits of clay are found under 40inches. The slope was 12 to 25 percent.   The wetland area soil was classified as Limerick. This series consist of soils that are deep and poorly drained. As stated in the results the hole began to fill with water only feet into the hole. The base is formed by silt loam and clay as we discovered in our digging and smear testing. Rust spots appear as water rises and falls and iron (soluble in water) deposits form until water level drops and iron becomes oxidized. This was found in our levels 3 and 4. Collars described in guides were the same size and depth as our digging as well. Slope was 0 to 3 percent.

Methods

            Three different ecosystems were identified in Centennial woods by looking at a variety of things such as soil and wildlife. Another very important thing to observe was the types of herbaceous plants, shrubbery, and trees in the area. By identifying these things we could specifically categorize the type of ecosystem. Our first test site was located on an elevated slope, but on the flat top part of the slope. We began identifying trees using different books and examining the bark, leaves, and branches. We matched tree observations to tree details in different books to ensure our identifications were correct. We used the same procedure to identify the ground cover and ferns in the three ecosystems as we did to identify the trees. We used the same identification methods in all three ecosystems.

Results

 In our first ecosystem, we discovered many hardwood trees such as black cherry, white pine, oak, sugar maple, beech, birch, and striped maple. We also cored each tree species in order to find the age of the hardwood stand. Ages of these trees ranged from 25 to 79 years, with scattered trees of even older and younger ages that were unable to be cored. The oak tree was 42 years old and had a 94 cm circumference, the maples varied from 20 years old with a 34 cm circumference to 51 years old with a 43 cm circumference, and the beech was 41 years old with a 57 cm circumference. The black cherry was 25 years old with a 46 cm circumference, and the oldest tree cored was a 79 year old pine with a 47 cm circumference. As well as all the trees, we identified two types of ferns, the New York fern and the bracken. These covered the floor of the hardwood forest. Along with the ferns, poison ivy and buckthorn was also a large part of the ground cover. Buckthorn is a highly invasive species that grows and germinates easily  throughout woody areas.

In the second ecosystem, we identified almost all of the trees as hemlocks, with a few scattered pines. The cored hemlocks were all around the same age, which was around 100. Trees ranged from 99 years with a circumference of 78 cm, to 104 years with a circumference of 85 cm, to 107 years with a circumference of 108 cm. Ground cover in this ecosystem varied much more than the hardwood forest. We found four types of ferns: ostrich, new york, beech, and interruptive. As well as ferns, we identified partridgeberry, blueberry, and elderberry on the hemlock floor.

Our third and last ecosystem consisted of mostly phragmites, otherwise known as reeds. This invasive species covered the marshy area while jewelweed and bidden tried to make their way into the area and filled every space not already taken by the reeds. There were no trees or ferns in this ecosystem.

Conclusions

            The hardwood area was classified as a Northern Hardwood Forest. The types of trees found in Centennial Woods correctly corresponded with what is normally found in this type of ecosystem. The trees in the hardwood forest like the type of soil in which they have overtaken (which is acidic on top and alkaline towards the bottom) and help to preserve and balance the soil and its pH. The variety of trees and plants also help to regulate the amount of invasive species, such as buckthorn, which would have overpowered the entire ecosystem had there not been competition of flora (fighting for nutrients/water/sunlight/etc.). Also, all the plants in this ecosystem, as well as the others, create oxygen as a product of photosynthesis therefore providing breathable air for wildlife and humans and reducing the amount of carbon in air.

            The second ecosystem was classified as a Hemlock Forest because of its large population of hemlock trees and proper identifications of other flora.  This type of forest is mainly covered in hemlocks because of the large canopy cover the trees form. Other trees such as maples can’t grow in this environment because it is difficult for them to get enough sunlight through the canopy to grow and develop. Though other trees have a hard time growing, many berries grow on the floor of these forests, which is a large ecosystem service because it serves as a food source for the wildlife in Centennial Woods. Much of the flora in hemlock forests prefer acidic soils and the hemlocks and pines help to acidify the soil beneath them by dropping their needles and therefore spreading the acid from the needles into the ground.

            The last ecosystem was the marshy area, which was classified as a shallow emergent marsh. This type of ecosystem is especially important in the watershed because the flora takes up almost all the excess nutrients, such as phosphorous, from Centennial Brook. The flora also helps to stabilize the hillside and land surrounding the river in the marsh by planting its roots and decreasing the amount of erosion caused by the brook.

Methods

Results

             In the Northern Hardwood Forest community type the species of animals we discovered included a blue jay, and an eastern chipmunk. Both of theses species contributed to the ecosystem as well as depended on it to survive. The blue jay, Cyanocitta cristata, ranges from south Canada to the Rocky Mountains and to the Gulf states. Its habitat is in Oak and Pine woods, suburban gardens, groves, and towns.

            In the Hemlock Forest community type we observed a robin, Turdus migratorius, worms and mosquitoes. In this ecosystem we also saw signs of a woodpecker.

            In the Shallow Emergent Marsh we observed animals both in the Centennial Brook and around it. We observed a Grey Cheeked Thrush, a robin, and a Rusty Blackbird. Crawfish, damsel flies, frogs, minnows, and benthic macro invertebrates were also found in the ecosystems of Centennial Brook, although not in large numbers.

Conclusions

            First, we were able to determine, by examining the plant and soil types in the area, what type of hardwood forest it was. We concluded that it was a Northern hardwood forest and then we found what animals were excepted to inhabit that type of forest. As expected, we saw a blue jay because they feed on berries and insects commonly found a hardwood forest. Their contribution to the northern hardwood ecosystem is to help spread the seeds of the oak, pine, maple, and other trees in the hardwood forest. By eating the seeds of these trees they were supplied with food and they carried the seed to a different location away from the parent plant, so it would not be competition. As well as getting food from the trees in the hardwood, the blue jay also receives shelter. Their nests are built in the protection of the pine and oak trees. The eastern chipmunk, Tamias striatus, is also and link in the ecosystem of the hardwood. It is most commonly found nesting in rotting logs on forest edges and in suburban areas. The chipmunk also eats fruits as well as grains, berries, seeds, nuts, and mushrooms. Its predators are fox, owls, crows, and coyotes. The chipmunk acts in the same way as the blue jay in spreading the seeds of the plants in the forest and receives food and shelter from the vegetation.

 In our observations of the ecosystems in Centennial Woods we did not see as many animals as we predicted. This is because Centennial Woods is surrounded by an urban area and the woods are inhabited by many people and dogs each day. Because of the bordering highways it limits the amount of deer, raccoons, and other animals that usually are found in a healthy Northern Hardwood forest. In the hardwood forest while we found blue jays and eastern chipmunks we should have also found traces of deer, oven bird, white warbler, scarlet tanager, masked shrew, eastern cottontail, black bear, next, salamander, frogs and the red bellied snakes. All these animal are very important links to the whole hardwood ecosystem and without these species providing and gaining from the Harwood forest it will not function as it should be. The lack of the species is the result of people urbanizing the area around the woods and harming the ecosystems which are important to both the species and humans.

        Again, after determining that we had a Hemlock Forest, we then found robins, mosquitoes, worms, and woodpeckers. Both the woodpecker and the robin find shelter in the hemlock trees as well as finding food. The robin feeds mainly on apple and berry trees, which help them, germinate. The woodpecker regulates the insects in the hemlock forest and gains food. All these species are very important to the ecosystem of the hemlock forest, though; there are many other animals that should inhabit the forest. By researching the plants that grew in the hemlock forest, such as the red elderberry, the blueberry, and the partridge berry we discovered that they should be eaten by the grouse, pheasant, red fox, mourning doves, and turkeys. Other animals that should be found in a hemlock forest are the hermit thrush, the red-breasted nuthatch, the saw-whet owl, the red squirrel, the deer mouse, and deer which use the hemlock for coverage in the winter. All these animals were not found in the Centennial hemlock forest and they are important to make that ecosystem healthy.

        In the Shallow Emergent Marsh we found frogs, minnows, BMI, crawfish, Grey checked thrush, a robin, and a Rusty blackbird. The Thrush feeds on invertebrates, insects and berries. It nests in dry grasses on the ground. The marsh supplies the thrush with food and a save shelter to build its nest. By inhabiting the marsh it regulates the insects and helps with the germination of the wetland shrubs. Grasshoppers as well as fruits and other insects make up the Rusty Blackbirds diet. It dwells along marshes and swamps that are sorrowed by agricultural field. Even though the bird with benefit from a forest fire, it will suffer severally in the forest around its habitat is clear cut. The rusty black bird has similar contributions as the thrush and the wetlands give the blackbird shelter food and protection.

        In other common marshes it is expected to be inhabited by beaver, mink, muskrats, red winged blackbirds, garter snake, moose, and black bear. With these animals lacking in the ecosystem it will not strive as it would with all the animals that provide and gain from the marsh. In the BMI test, few dragonfly larvae were found which is not a very good sign since they are intolerant to polluted water. Humans have dictated all these results. Because of the urban areas and the storm water run off the ecosystems in Centennial woods are not as healthy as they should be. These ecosystems not only provide for the species dwelling in the forest but for humans themselves so we should all seek to preserve ecosystems like Centennial Woods for future generations of tree, mammals, amphibians and people.