Transcript Big Walnut Creek Forest A study of soil and tree species

Big Walnut Creek Forest
A study of soil and tree species
Brett Bohlander
Brittany Mohrman
Tory Pavlovich
Introduction
• How does human land use affect a forest
ecosystem?
• Specifically, how has the DePauw Nature
Park been affected by its history of
degradation?
– Mining, clear-cutting, contamination,
recreational abuse, etc.
Objectives
• Measure any differences in soil quality and
vegetation composition in forested areas
along Big Walnut Creek
• Provide baseline data for future research
in the Nature Park concerning forest
health and stability
Location along Big Walnut Creek
• GIS map imposed on an aerial photograph
Plots
• Set up transect along Big
Walnut Creek
• 50m between the centers of
each plot
• 15m from the creek
• 11.3m radius per plot
• Recorded GPS point at center
of plot
• Total of 18 plots
• Divided into 3 sectors due to
natural divisions
• Sectors labeled North to South
as A, B, and C
15m
50m
11.3m
Soil Testing
• Nutrient Testing of Phosphorus and Nitrogen
with Hanna Soil Kit
• Percent water
• pH using pH meter from Hanna Soil Kit
Tree Sampling
• Based size on three
diameter categories
Small: 8-23 cm diameter
Medium: 23-38 cm
diameter
Large: > 38 cm diameter
• Identified species
# Plots
Comparison of Nutrient Levels
8
7
6
5
4
3
2
1
0
Nitrogen
Phosphorus
Trace TraceLow
Low
LowMed
Med
MedHigh
High
pH Comparison
8.6
8.4
8.2
pH
8
7.8
7.6
7.4
7.2
7
A
B
Sector
Averages and errors calculated by an ANOVA
 Difference between sectors is significant (p= 0.004)
C
Percent Water Comparison
40
35
Percent Water
30
25
20
15
10
5
0
Sector A
Sector B
Averages and errors as calculated by an ANOVA
Variance between groups is not significant
Sector C
Tree Species Diversity
Sector A
3% 1%
9%
31%
13%
19%
13%
24%
Sector B
6%
3% 1%
9%
3% 2% 1%
Box Elder
Sycamore
Eastern Cottonwood
Sugar Maple
Silver Maple
White Ash
Slippery Elm
Black Walnut
31%
American Basswood
Hackberry
Oak
Black Cherry
American Beech
Sector C
3% 2% 1%
11%
19%
39%
19%
24%
10%
5%
4%
2%
15%
5%
14%
10%
5%
1%
42%
Box Elder
Sycamore
Eastern Cottonwood
Sugar Maple
Silver Maple
White Ash
Slippery Elm
Black Walnut
American Basswood
Hackberry
Oak
Black Cherry
American Beech
Comparison of Tree Densities
0.08
# of Trees per m 2
0.07
0.06
0.05
Small
Medium
Large
0.04
0.03
0.02
0.01
0
Sector A Sector B Sector C
Discussion
• Results show no conclusive data
• The forest does exhibit signs of degradation and
low overall health
• Sector C shows the most similarity to Eastern
Deciduous Forests in tree species composition
• Soil quality may be low as indicated by low
nutrient levels and high pH levels
Soil pH
• pH plays major role in availability of
minerals and nutrients
– Phosphorus only readily available in soil with
pH around 6.5
– Nitrogen is affected by influence of pH on
activity of microorganisms necessary for plant
growth, specifically bacteria involved in
decomposition of organic matter
Eastern Deciduous Forests
• Most Common
Species:
–
–
–
–
–
–
–
–
American Beech
Sugar Maple
Lady Fern
Northern Arrowwood
Pecan
Shagbark Hickory
White Birch
White Oak
• In DePauw’s Nature
Park:
– American Beech
– Shagbark Hickory
– White Oak
Future Research
• Include research on the understory vegetation,
shrubs, and saplings
• Conduct longitudinal study to monitor
improvement or stagnation of the riparian forest
• Compare data gathered in the DePauw Nature
Park to an area of low human impact such as
the Big Walnut Nature Preserve
References
• State University of New York, College of Environmental
Science and Forestry.
www.usf.edu/PUBPROG/brochure/soilph/soilph.htm
• www.nearctica.com/biomes/edf/edfintro.htm
• Helm, B. and L. Howard. 2005. Presentation to SAB.
Acknowledgments
• Prof. Dudle
• Prof. Artman
• Park Ranger Brian Holsapple