environmental impact of different loggingg methods in the bankhead national forest, alabama

108 Pages·2014·3.36 MB·English

ENVIRONMENTAL IMPACT OF DIFFERENT LOGGING
METHODS IN THE BANKHEAD NATIONAL FOREST, ALABAMA:
A COMPARATIVE ANALYSIS.

by
THOMAS MBELI. TENYAH

A THESIS

Submitted in Partial fulfillment for the requirements for the degree of
Master of Science in the Department of Natural Resources and
Environmental Sciences in the School of Graduate Studies

Alabama A&M University
Normal, AL 35762
May 2009
Submitted by THOMAS MBELI TENYAH in partial fulfillment of the
requirements for the degree of MASTER OF SCIENCE specializing in
FORESTRY/GIS.
Accepted on behalf of the Faculty of the Graduate School by the Thesis
Committee:

Major Advisor

________________________________________ Dean of the Graduate School

_______________________________________ Date
ii
Copyright by
THOMAS MBELI TENYAH
2009
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This work is dedicated to my late father Jonas Tenyah Werengoh and to my family for
supporting me through the program.
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ENVIRONMENTAL IMPACT OF DIFFERENT LOGGING METHODS IN THE
BANKHEAD NATIONAL FOREST, ALABAMA: A COMPARATIVE ANALYSIS
Thomas Mbeli Tenyah, M.S. Alabama A&M University, 2009. 103 pp.
Thesis Advisor: Dr. Kozma Naka

The main goal of our study was to evaluate the environmental impacts of two
different harvesting methods on site characteristics. Two different methods, the cut-to-
length and the tree-length logging systems were compared. The fundamental question
was which of these two harvesting methods causes less soil disturbances, least residual
tree damage, and was more productive and cost effective than the other. This question
was answered by examining the following specific objectives: (1) compare the effects of
the tree-length and cut-to-length harvesting methods on the soil surface and physical
properties of the harvested areas, (2) compare the residual tree damage between these two
harvesting systems, and (3) compare the productivity and cost-effectiveness of the two
harvesting systems.
To attain these objectives, the environmental impacts caused by these harvesting
operations were measured and compared through statistical analysis. A visual inspection
was conducted before and after harvesting. Pre-harvest data indicated about 98 percent of
the treatment area was undisturbed while post-harvest analysis showed about 79 percent
was disturbed. Statistical analysis using Generalized Linear Model (GLM) showed no
significant difference in the soil disturbance between the two logging methods. However,
there was significant variation in the plot to plot disturbance among the various soil
disturbance classes disturbed with litter (DC2), disturbed with soil exposed (DC3),
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disturbed with rock and stumps (DC5), and disturbed with slash (DC6). There was also
subplot variation in the amount of undisturbed area (DC1), disturbed with litter (DC2),
and disturbed with slash (DC6).
Soil compaction analysis did not indicate any significant difference between the
two harvesting methods, but there was a significant difference between the heavily and
lightly impacted areas within the treatments and there was significant difference between
the disturbed and undisturbed areas. Residual stand damage was determined, by counting
the number of injured trees, and assigning a damage classification before and after
harvesting. Statistical analysis results obtained indicated a significant difference between
the two systems. The cut-to-length (CTL) harvesting system had a higher incident of
residual tree damage than the tree-length (TL) harvesting system.
There was a considerable difference in the productivity and costs analysis of the
two harvesting methods with the CTL system costing less to own and operate than the TL
system but the TL machines had a higher productivity rate per productive machine hour
(PMH) than those of the CTL system. However, the TL harvesting method yielded a
higher net gain to the operator than the CTL system.
KEY WORD: harvesting methods, soil disturbance, residual stand damage, machine
productivity and cost.

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TABLE OF CONTENTS
CERTIFICATE OF APPROVAL ............................................................................ ii
DEDICATION .......................................................................................................iv
ACKNOWLEDGEMENT .......................................................................................xi
CHAPTER I
1.1 Statement of the problem .................................................................................. 3
1.2 Significance of Study ........................................................................................ 5
1.3 Purpose and Objectives ..................................................................................... 6
CHAPETER II
2.1 Environmental Impacts of Logging Operations ................................................ 8
2.2 Soil Impacts ...................................................................................................... 9
2.3 Residual Stand Damage .................................................................................. 13
2.4 Productivity and Cost ...................................................................................... 15
CHAPTER III
MATERIAL AND METHODS .............................................................................. 21
3.1 Study Site ........................................................................................................ 21
3.2 Background and Management History of the Research Site .......................... 24
3.3 Experimental Design ....................................................................................... 25
3.4. Soil Impact ..................................................................................................... 28
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3.4.1 Visual Estimation: ........................................................................................ 29
3.4.2 Soil Compaction: ......................................................................................... 30
3.4.3 Soil Disturbance ........................................................................................... 32
3.4.4 Soil Compaction........................................................................................... 42
CHAPTER IV
RESIDUAL STAND DAMAGE ............................................................................ 47
4.1 Data collection ................................................................................................ 47
4.2 Statistical Analysis .......................................................................................... 48
RESULTS ........................................................................................................... 49
CHAPTER V
PRODUCTIVITY AND COSTS ........................................................................... 58
4.1 Data Collection ............................................................................................... 59
4.3 Data Calculations and Analysis ...................................................................... 63
CHAPTER VI
SUMMARY AND CONCLUSIONS ..................................................................... 74
RECOMMENDATIONS ...................................................................................... 78
APPENDICES .................................................................................................... 80
BIBLIOGRAPHY ................................................................................................. 94

VITA

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LIST OF TABLES
Table Page
1: Experimental plot area sizes .................................................................................... 28
2: Soil Disturbance classes ........................................................................................... 30
3: Percentage of area with surface soil disturbance ..................................................... 36
4: Percentage of mean soil disturbance for each logging method ................................ 37
5: ANOVA for Surface soil disturbance classes .......................................................... 38
6: Percent variance accounted for by sources of variance ........................................... 41
7: Percentage Means by Orientation per each soil disturbance classes ....................... 42
8: Average soil compaction measured in pounds per square inch (psi) ....................... 44
9: ANOVA for Soil Compaction ................................................................................. 45
10: Number of trees damage in each class per plot and total number of trees ............... 50
11: Residual tree damage of each harvesting method per 100 acres ............................. 52
12: Number of residual tree damaged per treatment plot (Per 100 acres) ..................... 53
13: Contingency table for residual tree damage ............................................................. 56
14: Machine Productivity ............................................................................................... 60
15: Total Machine Utilization ........................................................................................ 61
16: Machine rate calculations for TL harvesting system ............................................... 67
17: Operator performance .............................................................................................. 73
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LIST OF FIGURES

Figure Pages

1: Location of Bankhead National Forest .................................................................... 23
2: Distribution of study plots in Bankhead National Forest. ........................................ 26
3: Distribution of residual tree damage in to the various classes ................................. 54
4: Use ArcGIS to determine the number of points on a treatment area . ..................... 80
5: Selecting Six Sampling plots of 9 points each (total = 54) ...................................... 81
6: Using DME to measure soil disturbance 10m in each direction .............................. 82
7: Movement of the Harvester and Forwarder inside Somerville treatment. ............... 83
8: Skidder……………………………………………………………………………..85
9: Skidder……………………………………………………………………………..79

10: Feller Buncher……………………………………………………………….. ........ 85
11: Forwarder…………………………………………………………………………..79

12: Shows pictures of landing areas in the TL system one year after harvesting has been
completed. ................................................................................................................ 92
13: Shows pictures of center of main activity in the CTL system one year after
harvesting has been completed…………………………………………………….93
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