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Soil Formation and Best Land Use Practice

Recommendations:

The Northstar Middle School Site, Eau Claire, Wisconsin

By:

Eric Craft, Department of Geography and Anthropology, UW – Eau Claire

Brian Hull, Department of Biology, UW – Eau Claire

Kristin Haider, Department of Biology, UW – Eau Claire

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Table of Contents

Section Page Number

I. Abstract 2

II. Introduction 2

III. Methods 9

IV. Results 15

V. Discussion 25

VI. Conclusion 32

VII. Biography 33

VIII. Bibliography 34

IX. Acknowledgements 34

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I. Abstract

This investigation looked at the relationship between slope and soil morphology

on a forested sandstone bedrock ridge behind Northstar Middle School in Eau Claire,

Wisconsin and made best land use recommendations for this site based on the soil type

and the landscape. To do this, three pits were excavated by hand. Pit #1 was located

high on the slope with Pit #2 at an intermediate position and Pit #3 being on the lowest

portion of the slope. Soil profiles had a fining of particle size and a thickening of the A

horizon down slope due to fluvial action. The soil at the study site was composed of

mostly sand from the Mt. Simon Sandstone formation along a steep slope. Since sand

has high permeability, the soil was very well drained. The steepness of this particular

slope allows for water to easily erode the soil once the vegetation and sod layers have

been disturbed. The low water capacity and its slope allows for very limited use,

especially for agriculture and urban development. The best land use for the slope would

be to leave it alone for wildlife habitat because of its fragility.

II. Introduction

Land use is changing in Eau Claire County. There is increasing pressure from

population growth and urban sprawl on rural areas (Thomas, 1977). Increasing demand

for residential, industrial, and recreation sites near to cities could lead to the

development of marginal sites. Therefore, lands subpar for development that were

previously unappealing to developers are becoming more valuable. This increasing

demand for land to develop, and the fact the much of the Eau Claire County landscape

is characterized by hill slopes makes it important to understand how slope impacts soil

morphology.

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Eau Claire County, located in west-central Wisconsin (Figure 1), is dividable into

two main physiographic areas. The first physiographic area, which makes up 34% of the

county, is broad lowland. This lowland is located in the north and central part of the

county. The remaining majority of the county is a sloping upland. Slopes in this part of

the county range from nearly level (about 1% slope) to very steep (up to 45% slope)

(Thomas, 1977). Steep slopes in these uplands may make undeveloped sites

unsuitable for development or farming.

Figure 1: Location of the Northstar Middle School study area. The position of the site within the state of Wisconsin as well as within the city of Eau Claire is shown in the

above figure. The approximate location of the study pits along the hill side at Northstar Middle School is also depicted. Figure produced by Eric Craft.

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Slope refers to the deviation of the land surface from the horizontal. A sequence

of soils present along a slope from the top of a hill to the bottom of a hill is called a

catena (Schaetzl and Anderson, 2005). Soils morphology varies with slope position

along a catena due to drainage and sediment fluxes as well as the location of the water

table relative to the soil surface (Schaetzl and Anderson, 2005). A typical slope can be

divided into five slope positions: summit, shoulder, backslope, footslope, and toeslope

(Figure 2). However, it is important to note that any given slope may not contain all of

these slope positions. By studying how soil morphology differs along a catena we may

be able to predict how soil morphology will change in catenas where similar slopes

occur.

Figure 2. Typical positions on a slope.

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To study the relationship between slope and soil morphology, a study site in an

undeveloped forested area was established on a bedrock ridge at Northstar Middle

School (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W), Eau Claire, WI. The bedrock

ridge exhibits all five slope positions but the study site was set up on the footslope and

toeslope positions. Soils in the study site are mapped as Plainfield loamy sand, 6 to 12

percent slope, Plainfield Series, Elkmound-Eleva soil association (Thomas, 1977).

We investigated two main research objectives at the Northstar Middle School

study site. First, determine to what degree, if any, and in what manner slope position

influenced the soil morphology across the study site. Second, use information about soil

variation across the study site to make recommendations about best land use at the

study site. Another goal of this investigation is to be able to extrapolate results to areas

with similar soils and slopes to make best land use recommendations for other sites as

well.

Soil Forming Factors

Soil formation results from a complex suite of processes so it is helpful to

consider the factors influence soil formation. Hans Jenny devised a model of soil

formation as a function of five interwoven factors:

S= f(cl, o, r, p, t,…)

Where: S= soil or morphological characteristics, f = function, cl = climate, o = organism, r = relief, p = parent, and t = time.

Although this investigation is focused on the relationship between slope and soil

morphology all main soil forming factors must be considered in order to understand the

cause(s) of variation in soil morphology across the study site.

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Climate

Eau Claire County has an average annual temperature of 6.7 degrees Celsius

although there is seasonal variation in temperature during the year. Eau Claire County

has four distinct seasons including spring, summer, fall, and winter. Summer is the

warmest season and occurs during June through August with the warmest average

temperatures in July (Table 1). Conversely, winter, which takes place in December,

January, and February, is the coldest season and January is typically the coldest month

during the year (Table 1).

Average Temperature

(°C)

Average Frost Free Days (Min

Temp > 0 °C)

Average Precipitation

(cm)

Average Snowfall

(cm)

Jan. -11.2 0.0 2.64 35.81

Feb. -7.4 1.1 2.03 19.81

Mar. -0.7 4.5 4.72 23.37

April 7.2 15.8 7.39 6.35

May 14.4 28.7 9.37 0.00

June 19.3 30.0 10.85 0.00

July 21.9 31.0 10.01 0.00

Aug. 20.6 31.0 11.89 0.00

Sept. 15.2 28.8 9.50 0.00

Oct. 8.5 20.4 5.69 0.76

Nov. -0.1 5.5 4.88 15.75

Dec. -8.0 0.5 2.62 26.67

Annual 6.7 197.3 81.58 128.52

Table 1. Monthly and annual average temperature (°C), frost free days, precipitation (cm), and snowfall (cm) for Eau Claire County, WI. The information is based on

temperatures and precipitation amounts recorded at the Eau Claire FAA Airport, WI weather station and were averaged from data taken 1971-2000. (Young, 2008)

Precipitation also varies between the seasons. Eau Claire County receives an

average of 81.58 centimeters of precipitation during the course of the year. On average

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about 40% of the precipitation occurs during the summer months (Table 1). Winter

typically has the least precipitation of the seasons and most of its precipitation occurs as

snowfall.

The seasonality of Eau Claire County climate limits the growing season to late

spring through early fall. Typically, there are 197.3 frost free days a year (Table 1). The

United States Department of Agriculture placed Eau Claire County in the 4A hardiness

zone for plant growth, characterized by an average annual minimum temperature

between -31.7 and -34.4 degrees Celsius (Cathey, 1990)

Vegetation

The Eau Claire County pre-settlement vegetation was characterized by oak-pine

forests and barrens (Finley 1976). Most of the forests of Eau Claire County were

logged throughout the 19th and 20th centuries. The Northstar Middle School site was

most likely logged at some point during this period. However, there is no evidence of

this seen in the soil profiles. The trees currently at the site are second or even third

growth stands. This is evident by their small size (diameter and height) and fairly close

proximity to each other. Time has allowed the oak trees to choke out first order, sun

loving trees like aspen and smaller shrubs.

Currently, the Northstar Middle School study site’s canopy is comprised mainly of

hills oak (Quercus ellipsoidalis) and jack pine (Pinus banksiana), but also contains few

red maple (Acer rubrum) and other oak species such as bur oak (Quercus macrocarpa).

The understory vegetation includes sparse grasses and shrubs. The ground is mostly

covered with dead organic matter (leaves and branches).

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Relief

Relief affects depth, organic matter content and the drainage of soils. The relief

of the area around our soil pit is rolling hills. Elevations range from about 750 ft to about

1120 ft through the Eau Claire area. The Chippewa River has down cut through the

landscape to form the Wissota Terrace. The ridge that our study site is along is a north-

south trending ridge with the west facing, concave slope (Figure 3) above the Wissota

Terrace.

Figure 3. Google Earth image of the north/south trending ridge where the soil pits were located. Figure produced by Eric Craft.

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Parent Material

The parent material of the soil is course to fine grained Mount Simon Sandstone.

This rock formation was deposited during the late Cambrian when Western Wisconsin

and much of the Mid-west was under a shallow sea. Physical and chemical weathering

has broken down this formation to produce the soils along the ridge. Also, windblown

loess caps on top of the ridge have added to the soil horizon by being transported down

the slope by wind and water.

Time

The parent material for the soil in the area was deposited during the late

Cambrian meaning it was deposited over 500 million years ago. While the deposition

occurred millions of years ago the soils in Eau Claire County are not this old. The

landscape stabilized after the last glacier retreated around 10,000 years ago and the

current soils began to form.

III. Methods

Field Methods

Before field work began, an aerial photograph of the study site was obtained for

use in the field. At the study site, the wooded hillside behind Northstar Middle School in

Eau Claire, Wisconsin, three locations for soil pit excavation were designated. On the

hillside there was a series of fluves and interfluves created by the drainage of water

down the slope (Figure 4). To avoid adding in additional variables related to the

variation between fluves and interfluves all three of the soil pits were positioned at the

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top of an interfluve (Figure 5). Additionally, the soil pit locations selected for

investigation were thought to be representative of the study site as a whole in terms of

vegetation and relief. The sites for the pits were selected based on their location along

the slope (Figure 6) and designated numbers. Pit 2008-1was located in the high location

on the slope, pit 2008-2 was in the middle, and 2008-3 was the lowest location on the

slope.

Figure 4. Diagram of fluves and interfluves on a bedrock ridge. The fluves are lower areas where water drains down the slope cutting channels into the side of the slope.

The interfluves are higher areas in between the fluves. Diagram made by Kristin Haider.

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Figure 5. Cross view of and interfluve inbetween two fluves. The relative location of the soil pits in relation to the fluves and interfluves on the landscape at the Northstar Middle

School Site is indicated with a yellow star. Diagram made by Kristin Haider.

Figure 6. Soil pit locations and horizonation in respect to landscape position at the

Northstar Middle School Site. Soil profiles are not to scale to show horizons. Diagram

made by Brian Hull.

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Once the three pit locations were selected, each pit was excavated using a

spade and square point shovel. The sod layer was carefully removed and put to the side

so it could be put back in place when each pit was backfilled. All of the other soil

removed from the pit was piled to the side of the pit. The soil profile was exposed in this

manner until it was clear that a C horizon of weathered parent material had been

exposed. C horizons were reached at a depth of at least 85 cm. The four walls in the

soil pit were carefully cleaned off with a hand trowel from top to bottom to be sure

material from farther up the wall was not coating the lower sections of the wall. Any

obtrusive roots were also cleared from the pit walls using a hand held root clipper. Once

each wall was cleared of debris a representative wall in each pit was selected for

description. This wall was chosen reason such as having clearly differentiated horizons,

being a good representative of all of the walls, for having good lighting, and for having

the least potential effects of rainwater run-off. The representative wall in pit 2008-1 was

the northwest wall, in pit 2008-2 it was the north wall, and in pit 2008-3 it was the north

wall. For safety concerns and so the pits would not be disturbed, four fence posts,

snow fence and plywood was used to secure the pits.

Next, the representative wall in each of the soil pits was described. A metric tape

measure was secured at the top of the pit and draped down the wall. Horizon

boundaries were marked by making lines with a trowel based on distinctions in color

and texture and each horizon was classified with a master horizon designation,

O,A,E,B,C, or R (NRCS, 1993). For each master horizon, color, texture, structure,

consistence, roots, clasts, and boundaries were observed and recorded. Color was

described in terms of hue, chroma, and value using the Munsell Book. A 10x hand lens

was used to view the maximum grain size (µ), minimum grain size (µ), and typical grain

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size (µ) of the sand in each horizon was described. Also, grain shape and sorting were

observed with the 10x hand lens. The texture of the soil in each horizon was assigned

class based on NRCS categories. Next, it was determined if there was a structure to the

soil in the horizon. If there were no peds, texture was either labeled single grain or

massive. If peds were present, the shape, size, and grade of the peds were described

according to NRCS standards. Consistence (rupture resistance, stickiness, and

plasticity) of the peds were observed and recorded. Horizon boundaries were

determined standards. Roots or clasts were quantified by NRCS standards based on

size, shape, orientation and frequency. All field observations were recorded in field

notebooks.

Samples of each horizon were collected for analysis in the lab. A trowel was

used to collect a soil sample bag full of soil from each horizon. Horizons with differences

on either side, two or more samples were taken from the regions. Each sample bag was

labeled with group number, member names, date, location, the horizon designation,

depth within the horizon, and where within the horizon the sample was collected. The

soil pits were photographed using a digital camera. The photographs included a

measuring tape, two trowels strategically placed to show horizon boundaries, and a

human element (ours was a hand) for scale for later reference. Each photograph was

logged in a field note book which included the exposure number, photographer, date,

and time. All pits were back filled when soil pit work was completed.

To finish the field work, a study area profile was taken using a laser level

manufactured by Topcom. A transect from pit 2008-1 to pit 2009-2 with a bearing of

312o. A second transect was shot from pit 2008-2 to pit 2008-3 with a bearing of 324o.

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Thirty-five readings were taken along these two transects. Figure 5 shows those

transects meshed together to achieve a profile of the slope from the study site.

Lab Methods

Around fifty grams of each soil sample was placed into beakers and dried

overnight in an oven (104oC). Soil sample color was double checked under controlled

lighting area. After oven drying was complete, soil samples were poured into a mortar to

be lightly crushed using a pestle. Also, if present, organic material that could be

removed was removed by hand and by sifting. The remaining sample was placed into a

Gilson Sonic Sifter (Figure 7). Two stacks of sieves were

used. The first set of sieves included screen sizes: 2000,

1400, 1000, 710, 500, 355, and 250 microns. The second

set of sieves contained screen sizes: 180, 125, 90 and 63

microns. Samples first were in the sonic sifter for 5

minutes. Particles that passed through the smallest sieve

were run through the second set in the sonic sifter.

Particles left on each sieve were weighed to the nearest

hundredth of a gram and recorded in our lab notes.

IV. Results

Each soil profile was described (Tables 2-4) and photographed (Figures 8-10).

Significant characteristics of each soil profile, such as presence of horizons and the

Figure 7: An example of a sonic sifter that was used in the lab for particle analysis.

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changes in size and depth of horizons in the solum, were used to better interpret the

study area.

Each profile exhibited a weak A horizon. A horizon thickness ranged from 10 cm

to 20 cm. There is a notable increase in top A horizon thickness downslope. The slope

of between the pits at the Northstar Middle School study site is 11.7% as determined

from laser level data. The A1 horizon in pit 2008-1 had a thickness of 4 cm, while the A

horizon in pit 2008-2 had a thickness of 6 cm. Pit 2008-3 (farthest downslope) had an A

horizon with a thickness of 10 cm. Pit 2008-1 contained a second A horizon (A2),

whereas pits 2008-2 and 2008-3 contained AB horizons. E horizons were virtually

absent in each profile, though pit 2008-1 had a BE. The B horizon was thick in pit 2008-

1(40 cm) and in pit 2008-2 (55 cm), but was much thinner in pit 2008-3 (15 cm).

There was a great difference in solum thickness between profiles, though with

respect to elevation, no pattern is observed (pit 2008-1 = 50 cm, pit 2008-2 = 70 cm, pit

2008-3 = 35 cm). Weak, medium, granular peds were present in the A horizon of each

profile. Remaining horizons exhibited loose or massive structure.

Most of the color and texture variation was seen in the A horizons. Pit 2008-1

had an A horizon with a very dark grayish brown color while pit 2008-2 had a dark

brown A and pit 2008-3 had a very dark brown A. Texture of the horizons stayed

consistent being loamy sand with the exception of the A horizon in pit 2008-2, which

was sandy loam. The only other texture difference seen was in the C horizon in pit

2008-3 which was sand.

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Table 2. Detailed description of the soil profile exposed in soil pit 2008-01, Northstar Middle School Site, Eau Claire, Wisconsin (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W).

Depth(cm) Horizon Description

0-4 A1 10YR3/2 (very dark grayish brown); loamy sand; *mU, fU, vfL, subrounded; weak, medium, granular; very friable, sticky, nonplastic; roots – fine - many; smooth, abrupt.

4-10 A2 10YR3/2 (very dark grayish brown); loamy sand; *mU, fU, vfL, subrounded; massive; roots – fine - moderately few; wavy, abrupt.

10-20 BE 7.5YR3/4 (dark brown); loamy sand; *mU, mL, vfU, subangular-subrounded; massive; roots – fine - moderately few; smooth, abrupt.

20-50 B 7.5YR3/4 (dark brown); loamy sand; *cL, mL, vfU, subangular; massive; roots – fine - moderately few; wavy, abrupt.

50-65 C1 7.5YR4/4 (brown); loamy sand; *cL, mL, vfU, subrounded; massive; roots – fin - moderately few; wavy, abrupt.

65-91+ C2 7.5YR4/6 (strong brown); loamy sand; *cL, mL, vfU, subrounded-subangular ; massive; roots – fine - very few.

*Sand sizes observed in hand specimens (10x hand lens) (diameter of largest grain, average grain, smallest grain).

Subdivisions within sand fraction: vcU = very coarse upper (2.0-1.41 mm), vcL = very coarse lower (1.41-1.0 mm), cU = coarse upper (1.0-0.71 mm), cL = coarse lower (0.71-0.5 mm), mU = medium upper (0.5-0.35 mm), mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower (0.177-0.125 mm) , vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625 mm).

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Figure 8. Soil profile exposed in the NW wall of pit 2008-1, Northstar Middle School Site (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W). Master horizon and sub horizon modifiers are shown on the right. Depth is shown on the left. The yellow lines mark the approximate boundaries between each horizon. The tape measure shown is not indicative of horizon depth but is open to illustrate scale. The finger is pointing at the BE master horizon. The trowel is inserted in the middle of the B horizon. The soil knife is inserted at the lower boundary of the C1 horizon. Photograph taken by Kristin Haider, September 24, 2008.

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Table 3. Detailed description of the soil profile exposed in soil pit 2008-2. Northstar Middle School Site, Eau Claire, WI (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W).

*Sand sizes observed in hand specimens (10x hand lens) (diameter of largest grain, average grain, smallest grain). Subdivisions within sand fraction: vcU = (very coarse upper (2.0-1.41 mm), vcL = very coarse lower (1.41-1.0 mm), cU = coarse upper (1.0-0.71 mm), cL= coarse lower (0.71-0.5 mm), mU = medium upper (0.5-0.35 mm), mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower (0.177-0.125 mm), vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625).

Depth (cm) Horizon Description

0-6 A 10YR3/3 (dark brown); sandy loam; *mU, mL, vfU, subangular-subrounded; weak, medium, granular; very friable, slightly sticky, nonplastic; roots – fine - many; smooth, clear.

6-15 AB 7.5YR2.5/2 (very dark brown); loamy sand; *cL, mL, vfU, subangular-subrounded; loose; roots – fine - very few; smooth, clear.

15-30 B1 7.5YR3/4 (dark brown); loamy sand; *mU, mL, fL, subangular-rounded grains; loose; roots – medium - common; smooth, gradual.

30-40 B2 10YR3/6 (dark yellowish brown); loamy sand; *cU, mL, vfU, subrounded-rounded; loose; roots – fine - few; broken, clear.

40-70 B3 7.5YR4/6 (strong brown); loamy sand; *mU, mL, fU, subrounded-rounded; loose; roots – very fine - very few; smooth, gradual.

70-100+ C 10YR4/6 (dark yellowish brown); loamy sand; *mU, mL, vfU; loose; subrounded-rounded; roots – very fine - very few.

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Figure 9. Soil profile exposed in the North wall Pit 2008-02, Northstar Middle School

Site, Eau Claire, Wisconsin (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W). Master

horizon and sub horizon modifiers are shown on the right. Depth is shown on the left.

The tape measure shown is not indicative of horizon depth but is open to provide scale.

Yellow lines represent horizon boundaries. The finger shown is pointing to the B1

horizon. The trowel is inserted at the AB horizon lower boundary. Photograph by Karl

Ruesch, October 8, 2008.

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Table 4. Detailed description of the soil profile exposed in soil pit 2008-03, Northstar

Middle School Site, Eau Claire, Wisconsin (SE ¼, SW ¼, SW ¼, Section 3, T27N,

R9W).

Depth (cm) Horizon Description

0-10 A 7.5YR2.5/2 (very dark brown); loamy sand; *mL, fU, fL, subrounded; weak, medium, granular; very friable, slightly sticky, nonplastic; roots – very fine to fine - many; smooth, clear.

10-20 AB 7.5YR2.5/3 (very dark brown); loamy sand; *mL, fL, vfU, subangular-subrounded; massive; roots – very fine to fine - common; broken, clear.

20-35 B 7.5YR3/3 (dark brown); loamy sand; *mL, fU, fL, subangular-subrounded; massive; roots – very fine to medium - few; wavy, gradual.

35-85 C1 7.5YR4/4 (brown); sand; *mL, fU, vfU, subangular-subrounded; massive; roots – very fine - common, coarse - very few; smooth, diffuse.

85 + C2 7.5YR4/6 (strong brown); sand; *mL, fU, vfU, subangular-subrounded; loose; roots – medium to coarse - very few.

*Sand sizes observed in hand specimens (10x hand lens) (diameter of largest grain, average grain, smallest grain). Subdivisions within sand fraction: vcU = very coarse upper (2.0-1.41 mm), vcL = very coarse lower (1.41-1.0 mm), cU = coarse upper (1.0-0.71 mm), cL = coarse lower (0.71-0.5 mm), mU = medium upper (0.5-0.35 mm), mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower (0.17-0.125 mm), vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625 mm).

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Figure 10. Pit 2008-03 of the Northstar Middle School Site. Master horizon and sub

horizon modifiers are shown on the right. Depth Scale is shown on the left. The tape

measure shown is not indicative of horizon depth but is open to provide scale. The

finger is pointing to the AB horizon. The upper trowel is inserted at the AB lower

boundary. The lower trowel is inserted at the B lower boundary. Photograph taken by

Kevin Smith on September 29, 2008.

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Particle size distribution of each horizon was acquired through soil particle

analysis, shown on tables 5-10. The majority of the particles in each soil sample were

medium lower to fine upper (0.35-0.177mm). Only soil profile 2008-3 differed in that it

had a higher percentage of very fine (0.0125-0.0625mm) sand fractions as well as silt

and clay fractions (<.063mm). These results also found all soil samples to be well sorted

with no large gaps between size distributions of particles.

Particle Size Analysis, Fine Earth Fraction (weight in grams)

Sieve Size (mm)

1.4 1.0 0.71 0.50 0.355 0.25 0.18 0.125 0.09 0.063 <.063 Starting Sand Subfraction* silt & Sample

Horizon vcU vcL cU cL mU mL fU fL vfU vfL clay Weight A1 0.20 0.82 1.39 2.29 3.93 9.75 8.29 4.26 1.78 1.05 0.89 34.79 A2 0.01 0.25 0.53 1.32 3.48 9.48 9.16 4.71 2.14 1.41 1.91 34.53

BE (left) 0.02 0.00 0.20 0.97 3.75 11.15 10.66 5.36 2.04 1.11 2.22 37.83

BE (right) 0.00 0.02 0.16 0.86 3.16 9.60 9.02 4.65 1.81 1.00 1.61 32.31 B 0.02 0.00 0.14 0.82 3.11 10.11 9.78 5.35 2.10 1.11 1.90 34.73

C1 0.00 0.00 0.15 0.82 3.27 11.23 11.16 6.01 2.29 1.16 1.98 38.44 C2 0.05 0.00 0.05 0.73 3.44 15.41 15.63 7.05 1.97 0.73 0.83 46.43 *Subdivisions within sand fraction: vcU = very coarse upper (2.0-1.41 mm), vcL = very coarse lower (1.41-1.0 mm),

cU = coarse upper (1.0-0.71 mm), cL = coarse lower (0.71-0.5 mm), mU = medium upper (0.5-0.35 mm),

mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower (0.17-0.125 mm), vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625 mm).

Table 5. Particle size analysis of samples from the soil profile exposed in pit 2008-1, Northstar

Middle School Eau Claire, Wisconsin (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W). Data presented by weight (grams).

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Particle Size Analysis, Fine Earth Fraction (weight in grams) Sieve Size (mm)


Horizon vcU vcL cU cL mU mL fU fL vfU vfL clay Weight

A 0.03 0.4 0.56 1.21 3.8 11.45 9.4 4.46 1.6 0.8 1.09 35.28

AB 0.23 0.23 0.32 1.45 3.45 11.21 8.77 3.73 1.32 0.67 1.28 32.65 B1 0.00 0.05 0.26 1.06 3.90 10.65 9.59 4.13 1.41 0.69 1.46 33.40 B2 0.09 0.07 0.37 1.34 4.58 12.61 10.07 4.71 1.60 0.71 1.23 37.73 B3 0.00 0.01 0.06 0.46 3.08 13.51 12.26 4.95 1.06 0.34 0.41 36.06

C 0.06 0.04 0.07 0.65 4.40 13.90 11.26 0.02 0.01 0.00 0.12 30.23 *Subdivisions within sand fraction: vcU = very coarse upper (2.0-1.41 mm), vcL = very coarse lower

cU = coarse upper (1.0-0.71 mm), cL = coarse lower (0.71-0.5 mm), mU = medium upper (0.5-0.35 mm), (1.41-1.0 mm), mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower

(0.17-0.125 mm), vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625 mm).


Middle School Eau Claire, Wisconsin (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W). Data

presented by weight (grams).

Particle Size Analysis, Fine Earth Fraction (percent) Sieve Size (mm)

1.4 1.0 0.71 0.50 0.355 0.25 0.18 0.125 0.09 0.063 <.063 Sand Subfraction* silt & Percent

Horizon vcU vcL cU cL mU mL fU fL vfU vfL clay Error ( +)

A1 0.57% 2.36% 4.00% 6.58% 11.30% 28.03% 23.83% 12.24% 5.12% 3.02% 2.56% 0.40%

A2 0.03% 0.72% 1.53% 3.82% 10.08% 27.45% 26.53% 13.64% 6.20% 4.08% 5.53% 0.38% BE (left) 0.05% 0.00% 0.53% 2.57% 9.93% 29.51% 28.22% 14.19% 5.40% 2.94% 5.88% 0.79%

BE (right) 0.00% 0.00% 0.06% 0.50% 2.66% 9.78% 29.71% 27.92% 14.39% 5.60% 3.10% 1.02% B 0.06% 0.00% 0.40% 2.36% 8.95% 29.11% 28.16% 15.40% 6.05% 3.20% 5.47% 0.84%

C1 0.00% 0.00% 0.39% 2.13% 8.51% 29.21% 29.03% 15.63% 5.96% 3.02% 5.15% 0.96% C2 0.11% 0.00% 0.11% 1.58% 7.47% 33.44% 33.92% 15.30% 4.28% 1.58% 1.80% 0.41%

*Subdivisions within sand fraction: vcU = very coarse upper (2.0-1.41 mm), vcL = very coarse lower (1.41-1.0 mm),

cU = coarse upper (1.0-0.71 mm), cL = coarse lower (0.71-0.5 mm), mU = medium upper (0.5-0.35 mm), mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower (0.17-0.125 mm), vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625 mm). **Percent error refers to material lost or gained from the Sample Starting Weight during particle size analysis.


Middle School Eau Claire, Wisconsin (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W). Data presented by percent.

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Particle Size Analysis, Fine Earth Fraction (weight in grams) Sieve Size (mm)


Horizon vcU vcL cU cL mU mL fU fL vfU vfL clay Weight

A 0 0.05 0.25 0.97 2.96 9.02 9.49 8.29 6.55 4.29 3.91 46.24 AB 0 0.04 0.16 0.76 2.31 6.93 7.59 6.32 4.71 2.99 2.05 34.1 B 0.01 0.03 0.22 0.91 3.07 9.46 10.7 8.95 6.98 4.71 3.15 48.54 C (Upper)

0 0.07 0.24 0.97 3.07 9.47 11.02 9.16 7.39 5.19 2.82 49.69

C (Lower)

0 0.02 0.23 0.75 2.49 7.04 8.38 7.48 5.73 3.91 2.77 39.41

C2 0 0.07 0.33 1.29 3.8 10.52 10.34 8.16 6.48 5.03 2.92 48.94

*Subdivisions within sand fraction: vcU = very coarse upper (2.0-1.41 mm), vcL = very coarse lower

cU = coarse upper (1.0-0.71 mm), cL = coarse lower (0.71-0.5 mm), mU = medium upper (0.5-0.35 mm), (1.41-1.0 mm), mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower

(0.17-0.125 mm), vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625 mm).


Middle School Eau Claire, Wisconsin (SE ¼, SW ¼, SW ¼, Section 3, T27N, R9W). Data

presented by weight (grams).


1.4 1.0 0.71 0.50 0.355 0.25 0.18 0.125 0.09 0.063 <.063 Sand Subfraction* silt & Percent

Horizon vcU vcL cU cL mU mL fU fL vfU vfL clay Error ( +)

A 0.09% 1.13% 1.59% 3.43% 10.77% 32.45% 26.64% 12.64% 4.54% 2.27% 3.09% 1.36%

AB 0.70% 0.70% 0.98% 4.44% 10.57% 34.33% 26.86% 11.42% 4.04% 2.05% 3.92% -0.03% B1 0.00% 0.15% 0.78% 3.17% 11.68% 31.89% 28.71% 12.37% 4.22% 2.07% 4.37% 0.60%

B2 0.24% 0.19% 0.98% 3.55% 12.14% 33.42% 26.69% 12.48% 4.24% 1.88% 3.26% 0.93% B3 0.00% 0.03% 0.17% 1.28% 8.54% 37.47% 34.00% 13.73% 2.94% 0.94% 1.14% -0.22%

C 0.20% 0.13% 0.23% 2.15% 14.56% 45.98% 37.25% 0.07% 0.03% 0.00% 0.40% -0.99% *Subdivisions within sand fraction: vcU = very coarse upper (2.0-1.41 mm), vcL = very coarse lower


(1.41-1.0 mm), mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower (0.17-0.125 mm), vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625 mm). **Percent error is result of rounding error and discrepancies between initial total sample mass and sum of sand sub fraction mass.



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V. Discussion

All of the soil pits had weakly expressed A, B, and C horizons in their profiles.

This lack of development of horizons in the soil profile can most likely be attributed to

the parent material that they formed in. The parent material of the soil at the study site

was sandstone therefore there was not much material available to weather into soil.

Additionally, since the soil is located under a forest, there is not much organic matter to

weather into more strongly expressed soil horizons. Since the parent material is limiting

the development of horizons in soils, parent material seems to be the dominant factor

affecting soil morphology at the Northstar Middle School study site.

While slope did not appear to affect overall soil morphology as much as the

parent material, it did seem to affect the soil morphology of the A horizon and soil

particle size of the three pits. The A horizon of the pit profiles increased in thickness



Horizon vcU vcL cU cL mU mL fU fL vfU vfL clay Weight A 0% 0.10% 0.50% 2.10% 6.40% 19.50% 20.50% 17.90% 14.20% 9.30% 8.50% 0.99% AB 0% 0.10% 0.50% 2.20% 6.80% 20.30% 22.30% 18.50% 13.80% 8.80% 6.00% 0.70% B 0.02% 0.06% 0.50% 1.90% 6.30% 19.50% 22.00% 18.40% 14.40% 9.7 6.50% 0.72% C (Upper)

0% 0.14% 0.48% 1.95% 6.18% 19.06% 22.18% 18.43% 14.87% 10.44% 5.68% 0.58% C (Lower)

0% 0.05% 0.60% 1.90% 6.30% 17.90% 21.30% 19.00% 14.50% 9.90% 7.00% 1.55% C2 0% 0.10% 0.70% 2.60% 7.80% 21.50% 21.10% 16.70% 13.20% 10.30% 6.00% 0.00% *Subdivisions within sand fraction: vcU = very coarse upper (2.0-1.41 mm), vcL = very coarse lower


(1.41-1.0 mm), mL = medium lower (0.35-0.25 mm), fU = fine upper (0.25-0.177 mm), fL = fine lower (0.17-0.125 mm), vfU = very fine upper (0.0125-0.088 mm), vfL = very fine lower (0.088-0.0625 mm). **Percent error is result of rounding error and discrepancies between initial total sample mass and sum of sand sub fraction mass.



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from the top to the bottom of the slope. This is most likely caused by fluvial action

moving smaller sediment sizes in suspended load as the water moves down slope due

to the force of gravity. Small sediments from the A horizon at high places on the slope

are eroded and then later deposited at lower, more level places along the slope

resulting in the thinning of the A horizon at high locations along the slope and the

thickening of A horizons at lower locations along the slope. Fluvial action also caused a

fining of particle size down the slope.

Additionally, differences in the development of the B horizons among the pits

were observed although it is not clear what is causing the differences in development.

The B horizon transitions from thin to thick and back to thin down the slope. However,

we are not sure why this is. It is possible that the nearby footpath (Figure 6, Figure 4)

had impacts on the soil morphology of pit 2008-2. There was erosion of the footpath as

evidenced by lack of vegetation and the creation of an artificial channel where the

footpath is located (Figure 11), but the results of this investigation did not provide clear

evidence of if or how the footpath affected the morphology of nearby soils.

Soils at the Northstar Middle School site were mapped as Plainfield loamy sand,

6 to 12 percent slopes, Plainfield Series, Elkmound-Eleva soil association (Thomas,

1977). The soils in this map unit are different than the representative profile of Plainfield

loamy sand (Figure 11) in that they have less fine material and that plowing has

exposed a lighter colored subsurface material.

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Figure 11. Footpath between pit 2008-1 and pit 2008-2. The photograph is looking down slope and in the

western direction. Photograph was taken by Kevin Smith on 9/24/08.

The description of the Plainfield series was similar to the descriptions of the soil

pits at the Northstar Middle School site although the descriptions did vary in a few ways

(Table 2, Table 3, Table 3, Table 11). The representative profile of Plainfield loamy

sand had an Ap horizon which means it was plowed. There was no evidence found at

the Northstar Middle school site that the area was ever plowed or used for any type of

agriculture. Also, the A and B horizons of the representative profile of Plainfield loamy

sand had more structure than the A and B horizons of any of the pits excavated at the

Northstar Middle School site. With the exception of pit 2008-2, the pits excavated at the

Northstar middle school site had solums at least 24 centimeters thinner than the solum

of the representative profile of Plainfield loamy sand. Finally, the horizons of the pits

excavated at the Northstar Middle School site were generally more yellow than the

horizons representative profile of Plainfield loamy sand.

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Table 11. Representative profile of Plainfield loamy sand with 1 to 6 percent slope, in a cultivated field, 100 feet north and 100 feet west of the center sec. 24, T. 26., R. 10 W. as described in Eau Claire County, Wisconsin soil survey (taken from Thomas, 1974, p 49).

Depth(in) Horizon Description

0-6 Ap Dark grayish brown (10YR 4/2) loamy sand; weak fine granular structure; very friable; strongly acid; abrupt smooth boundary

6-15 B2 Dark brown (10YR 4/3) light loamy sand; weak fine subangular blocky structure; very friable; strongly acid; gradual wavy boundary

15-29 B3 Dark yellowish brown(10YR 4/4) medium and fine sand; single grained; loose; medium acid; gradual wavy boundary

29-36 C1 Yellowish brown (10YR 5/4) medium and fine sand; single grained; loose, medium acid; gradual smooth boundary

36-60 C2 Light yellowish brown (10YR 6/4) fine and medium sand; single grained; loose; medium acid

Although the Northstar Middle School site was mapped as Plainfield loamy sand,

6 to 12 percent slopes it may actually be a hybrid between Plainfield loamy sand, 6 to

12 percent slope and Boone-Plainbo complex, 6 to 12 percent slopes. The Boone-

Plainbo complex, 6 to 12 percent slopes, Boone Series, Elkmound-Eleva soil

association map unit is described as sloping soils on the crest and sides of a sandstone

ridge (Thomas, 1977) and was mapped slightly higher on the bedrock ridge than the

Northstar Middle school study site. The Boone-Plainbo complex, 6 to 12 percent slopes

has slightly thicker surface layers and contains more loam than the representative

profile of Boone sand (Table 12).

The pits excavated at the Northstar Middle School site are more similar to the

representative profile of Boone sand than the representative profile of Plainfield loamy

sand in some respects. Neither of them have a plowed A horizon and they both lack

structure below the A horizon. Additionally, the thickness of the solums of the Northstar

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Middle School pits did not match either map unit but were somewhere in between. The

solums of the pits at the Northstar Middle School site were thicker than the solums

described in the representative profile of Boone sand and thinner than the

representative profile of Plainfield loamy sand.

Table 12. Representative profile of Boone sand in a wooded area of Boone-Plainbo complex, 12 to 45 percent slopes, 400 feet south and 700 feet west of the northeast corner of the SE1/4 sec. 28 T. 26 N., R. 10W. (taken from Thomas, 1974, p 49).

Depth(cm) Horizon Description

0-8 A1 Very dark grayish brown (10YR 3/2) sand; weak fine granular structure; very friable; strongly acid; abrupt smooth boundary

8-33 C1 Yellowish brown (10YR 5/6) fine and medium sand; single grained; loose; strongly acid; clear smooth boundary

33-66 C2 Yellow (10YR 7/6) fine and medium sand; single grained; loose; few small sandstone fragments in lower part; strongly acid; clear smooth boundary

66-152 C3 Very pale brown (10YR 8/4) and strong brown (7.5YR 5/8) weakly cemented sandstone bedrock; strongly acid

Best Land Use

Classification of the Northstar Middle School site soil as Plainfield loamy sand 6-

12 percent slope (PfC2) through using the Eau Claire County Soil Survey (1977) allows

for interpretation of best land uses of this area. These soils are usually sloped and the

available water capacity is very low because of its high permeability. This high

permeability means excessive drainage, which also negatively affects fertility because

many of the nutrients are washed away. Although these soils are limited by erosion,

slope, and lack of soil water and nutrients, if properly managed, they could be suited for

some uses in agriculture, recreation, woodlands, wildlife habitat, and development

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Agriculture

Use of the PfC2 soil for agriculture is very limited due to its low available water

capacity and lack of nutrients. Slope also causes problems with erosion and runoff.

Most of the areas with PfC2 soil were at one time used for crops, but were planted to

pine trees because of their low agricultural productivity. It is possible for these areas to

be suited to pasture or hay if managed properly, though production would be low

(Thomas et al, 1977).

Recreation

Recreational use of this area is also very limited because of its difficulty to

maintain sod or other vegetation due to low water capacity and susceptibility to erosion.

Trails would be possible in areas with low slope, however they would be difficult to

maintain because of erosion (Thomas et al, 1977). Erosion can be easily seen in

several paths and trails, as well as on the disc golf course already located within the

study site (Figure 11).

Wildlife Habitat

Although PfC2 soils may not have many recreational or agricultural uses, it could

provide habitat for many forms of wildlife. Some grasses, legumes, wild herbaceous

plants, or grain/seed crops may be limited by low water and nutrients, but conifers and

other drought resistant trees, such as oak, that grow in these soils can provide

important cover and food sources for many animals (Thomas et al, 1977).

Woodland Suitability

Due to the sandy soils, vegetation in this area must be able to survive with low

water availability and low available plant nutrients. Species that may be suitable to live

in this area are jack pine, red pine, white pine, and black oak (includes northern pin

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oak). Logging and/or restoration is possible, but there are limitations due to erosion and

high seed mortality rates. Species used for restoration could include jack pine, eastern

white pine, and jack pine (Thomas et al, 1977).

Engineering

Development of areas with PfC2 soils can be limited due to slope and rapid

permeability. These restrictions make these soils unsuitable for septic tank absorption

fields, shallow excavations, dwellings in basements, sewage lagoons, and sanitary

landfills. The development of roads and streets is possible and is only moderately

limited because of slopes. These types of soils would be good sources for road fill or

sand (Thomas et al, 1977).

Study Limitations, Error, and Further Study

The main limitation of this study was time. The lab portion of the Soils 350 class

was only four hours long and took place in the afternoon. Being that Eau Claire is in the

mid latitudes, the fall semester in Wisconsin only allows for short study times. Cold

weather and the shortening of days set in fast after the start of the school year not

allowing adequate field time. Also one semester does not allow enough time for

students to fully investigate this question.

Potential for error of this study could come from the disturbance of the soil

profiles from rain water runoff down the slope. The pits were covered by plywood but

water still washed through. If the pits could be described in one day rather than several,

the runoff would not have affected the pits. Also, students from Northstar Middle School

science classes visited pits during classes to view what a soil profile looks like and

could have potentially disturbed the profiles.

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Further study of this area would include the excavation and study of more pits in

strategic places along the slopes of the ridge. More pits should be added to the studied

line of pits to determine affect of fluve and interfluve location in addition to slope on soil

morphology. Several lines of pits would need to be dug perpendicular to the pits from

this study across the interfluve. In the fluves adjacent to the studied interfluve,

perpendicular lines of pits would also need to be dug. This would hopefully give a good

cross sectional view of the slope area. This cross section would show how soils form

along an entire slope.

VI. Conclusion

At the Northstar Middle study slope only influenced the morphology of the A

horizon and particle sizes across the study site. There was a thickening of the A horizon

observed in the soil profiles from the top of the slope to the bottom of the slope.

Additionally, the pit farthest down slope had a greater proportion of fine particles than

the pits higher on the slope. It appears that slope did not have a greater affect on soil

morphology at the Northstar Middle School study site than was observed because soil

formation was limited by the parent material.

This investigation also determined that the Northstar Middle School site is a poor

site for any type development. Land use is limited by erosion, the slope, and the lack of

soil water and nutrients. Even light recreational use such as trail use and disc golf has

been shown to cause erosion. We recommend that the area around the Northstar

Middle School site and sites with similar soils and slopes are left as natural woodland

and wildlife areas.

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VII. Biography

Our group is comprised of three students from the University of Wisconsin – Eau

Claire (Figure 12). Kristin Haider is a biology major and environmental science minor

and is originally from Sauk Rapids, MN. Kristin will graduate in December 2008 and will

begin work as a stewardship intern at the Placer Land Trust in Auburn, CA. Eric Craft is

a geography major with a comprehensive resource management degree and is from

Lindsey, WI. Eric will graduate in December 2009 and plans on going to graduate

school. Brian Hull is a biology major and environmental science minor and is originally

from Marshfield, WI. Brian will graduate in May 2009.

Figure 12. Kristin Haider (left), Brian Hull (top right), Eric Craft (bottom right).

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VIII. References

Cathey, H.M. 1990. USDA Plant Hardiness Zone Map. The United States National

Arboretum. http://www.usna.usda.gov/Hardzone/hzm-nm1.html (accessed November 9, 2008).

Finley, Robert W., 1976. Finley’s Original Vegetation Cover Map. Wisconsin Transverse Mercator scale 1:2,750,000, 1 sheet.

Schaetzl, R., and Anderson, S., 2005. Soils: Genesis and Geomorphology: New York, Cambridge University Press, p. 469-477.

Thomas, D.D., 1977. Soil Survey of Eau Claire County, Wisconsin, United States Department of Agriculture, Soil Conservation Service.

Google Earth. Young, J. 2008. Wisconsin Climatology Office. Eau Claire Climate.

http://www.aos.wisc.edu/~sco/clim-history/7cities/eau_claire.html (accessed November 9, 2008).

IX. Acknowledgments

We would like to acknowledge the following people and organizations who

contributed to the success of this research investigation: The University of Wisconsin –

Eau Claire for funding and use of facilities, The UWEC Geography and Anthropology

Department, Dr. Garry Running for inspiring this project, Northstar Middle School and

the acting North Star Middle School principle Michelle Golden for allowing access to the

study area and the entire Geography 350 Soil’s class for research and writing support.

Finally, we would like to acknowledge the lives lost during the course of this

investigation. Our thoughts and prayers are with the families of Stewart Little, Fievel,

and Mickey who perished in bottomless pit 2008-2.

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