Post on 23-Jan-2016
transcript
Big Walnut Creek ForestA 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 cmdiameter
Large: > 38 cm diameter
• Identified species
Comparison of Nutrient Levels
012345678
# P
lots
Trace Trace-Low
Low Low-Med
Med Med-High
High
NitrogenPhosphorus
pH Comparison
7
7.2
7.4
7.6
7.8
8
8.2
8.4
8.6
A B C
Sector
pH
Averages and errors calculated by an ANOVA
Difference between sectors is significant (p= 0.004)
Percent Water Comparison
0
5
10
15
20
25
30
35
40
Sector A Sector B Sector C
Per
cen
t W
ater
Averages and errors as calculated by an ANOVA
Variance between groups is not significant
Tree Species Diversity
Sector A
Sector B Sector C
Comparison of Tree Densities
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
# o
f T
ree
s p
er
m2
Sector A Sector B Sector C
SmallMediumLarge
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