Evaluation of sampling alternatives to quantify riparian areas of Western Oregon Forests

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Evaluation of sampling alternatives to quantify
riparian areas of Western Oregon Forests

• Theresa Marquardt
• June 19, 2007

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OUTLINE

• Introduction
• Objectives
• Methods
• Sampling Alternatives
• Analysis Methods
• Preliminary Results

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Background

• B.S. Forest Management
• Oregon State University, 2005
• M.S. Forest Biometrics
• Oregon State University
• expected August 2007

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Introduction
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Density Management Study

• The (DMS) began in 1994
• BLM
• Pacific Northwest Research Station (PNW)
• US Geological Survey (USGS)
• Oregon State University (OSU)

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Cissel et. al. (2006)
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Objectives of the DMS

• Evaluate effects of forest density
• management treatments in 4080
• year-old stands for the development of
• late-successional attributes
• (Cissel et. Al. 2006).
• Assess the effects of density management and
  alternative riparian buffer widths on aquatic and
  riparian ecosystems
• (Cissel et. Al. 2006).

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Sites Completed
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Site Attributes Densities

• Tree Density
• Control 200-350 Trees per Acre (TPA).
• Moderate density
• 60-65 of the stand thinned
• Approximately 80 TPA.

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Site Attributes Buffers

• One and two Site Potential Tree Height Buffers
  (SPTH)
• Measured in slope distance from the stream
• Based on the 50 year site index height of trees
  for each site.
• The one SPTH is 73 m and two SPTH is 146 m (Bruce
  1981).

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Site Attributes Buffers

• Variable Width Buffer
• Buffer width of at least 50 feet (15.24 m)
• Buffer Width Fluctuates
• Sensitive Areas
• Landslide
• Threatened Species

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Objectives
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Objective 1

• Examine the accuracy and suitability of selected
  sampling methods to quantify forest structure and
  diversity, which can be used for future
  monitoring of riparian areas.

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Objective 2 and 3

• Examine relationships between arrangement of
  forest structure and microclimate and micro-site
  attributes.
• Influence of tree density, slope, and aspect on
  microclimate in riparian areas of western Oregon.

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Objectives 2 and 3 (Cont.)
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Vegetation, Microclimate LICOR

• Percent cover 1 m2 for shrubs (lt1.4 m, 1.4m to
  3m, gt 3m), forbs, ferns and seedlings.
• Species presence and absence 2 m2 plots.
• Two transects with 3m spaced plots and three
  transects with 10m spacings.
• GPSE 301-203 made by AR Harris
• LICOR LAI-2000

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Methods
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Methods Sampling Design

• Five Parts
• 1. Stem Mapping
• 2. Vegetation Plots
• 3. Sample Additional Tree Attributes
• 4. Microclimate LICOR

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Methods Block Layout

• Each sampling block 72 x 72 m
• Randomly located on selected reach
• Centerline is oriented along average aspect of
  stream

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Methods Block Layout

• Example

Random Starting Point
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Methods Stem Mapping

• Total Station Survey Equipment
• Two GPS points were found using a Trembull survey
  grade GPS
• The azimuth in the total station was set using
  the two GPS points
• The reflector was placed on the bole of the tree
  for mapping

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Methods Tree Attributes

• Attributes Recorded for Each Tree
• DBH
• Species
• Canopy Classification (Dominant, Co-dominant,
  Intermediate, Suppressed)
• Condition (Dead, Live)

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Methods Tree Attributes

• Decay Class Rating
• 1, . . . , 5
• U.S. Forest Service
• Crown Class
• Full crown, multiple tops, snag
• Washington Department of DNR

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Sampling Alternatives
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Sampling Alternatives Trees

• Simple Random Sampling
• Grid-based square plots
• Fixed radius circular plots
• Strips
• Parallel
• Perpendicular
• Perpendicular, alternate
• Perpendicular on half the stream
• Systematic Sampling
• Fixed radius plots
• Horizontal Line Sampling (Lynch 2006)
• Block Design

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Simple Random Sample

• Grid-based Design
• 18x18m Plots
• Area Sampled
• Approximately 10, 20

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Simple Random Sampling

• Fixed Area Plot
• Radius of 10.64 m and 5.64 m
• Sample 10 and 20 of the area.

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Strips Parallel to the Stream

• Strip widths of 3m and 9m
• Stratified by Distance from the stream
• Sample approximately 10 to 20 of the area

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Strips Perpendicular

• Strip widths of 4m and 8m
• Simple random sample of strips
• Sample 10, 20 of the area

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Perpendicular Alternate Strips

• Strip widths of 4m and 8m
• Sample 10 and 20

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Perpendicular One Side

• Strips widths of 4m and 8m
• Sample 10, 20 of the area

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Systematic Sampling

• Fixed radius plot of 10.64m and
• 5.64 m
• Sample approximately 10, 20 of the area

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Horizontal Line Sampling

• Lynch (2006)
• Can be used to estimate trees or volume per acre
  without a known area
• Uses transects along which a prism is used to
  select trees

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Horizontal Line Sampling

• BAF of 9 metric (40 imperial)
• Transects run perpendicular to the stream and a
  known baseline length
• Integration is used to
• estimate tree attributes

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Block Design

• Design adapts to curvature in the stream and
  bankfull channel edge

From Roorbach et. Al. (2001)
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Block Design

• Plot width from stream of 30 m and 50 m in length
• Area sampled will be site specific
• Both sides of the stream will be measured
• Use stream center rather than bankfull width

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Analysis Methods
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Evaluating Sampling Alternatives

• Size Classes
• Diameter Class Distribution
• 25 cm classes
• Height Class Distribution
• 10 m classes
• Calculate MSE, Bias, Relative Efficiency
• Volume
• Merchantable Volume
• Basal Area
• Merchantable TPA
• TPA

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Analysis Methods

• MSE

Temesgen, H. (2003)
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Analysis Methods

• Bias

Temesgen, H. (2003)
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Analysis Methods

• Percent Error
• Relative Efficiency
• Nonparametric Methods
• Fisher Exact Test
• Kruskal-Wallis Test

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Analysis Methods

• Spatial Patterns
• Tree
• Ripleys K
• Neighborhood Indices
• Moving Window Analysis

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Preliminary Results
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Preliminary Results
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Preliminary Results
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Preliminary Results
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Summary

• Possible reasons for high variation
• Changes in stream channel width
• Only 30 replications were used for these results

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Questions ?
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Sources

• Bruce, D. 1981. Consistent Height-Growth and
  Growth-Rate Estimates for Remeasured Plots.
  For. Sci. 27(4) 711-725.
• Cissel, J., Anderson, P., Berryman, S., Chan, S.,
  Puettman, K., and Thompson, C. BLM Density
  Management and Riparian Buffer Study
  Establishment Report and Study Plan. U.S. Dept.
  Interior, U.S. Geological Survey. 2006. 161 p.
  
• Lynch, T. B. 2006. Horizontal line sampling for
  riparian forests without land area estimation.
  For. Sci. 52(2) 119-129
• Roorbach, A., Schuett-Hames, D., Haight, R., and
  McGowan, M.. Field Procedures for the Pilot
  Study to Validate the DFC Performance Targets
  for West-Side Riparian Prescriptions in
  Washington's Forest Practices Rules. Northwest
  Indian Fisheries Commission, 2001.
• Temesgen, H. 2002. Evaluation of sampling
  alternatives to quantify tree leaf area. Can.
  J. For. Res. 33 82-95.