Tillicum Watershed Restoration Project
Vegetation Report
Prepared by:
Eireann Pederson
Forester
for:
Entiat Ranger District
Okanogan Wenatchee National Forest
April 2016
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Contents
Introduction ................................................................................................................................. 1 Resource Indicators and Measures .......................................................................................... 1 Methodology ........................................................................................................................... 2
Affected Environment ................................................................................................................. 3 Existing Condition ................................................................................................................... 3 Management Direction ............................................................................................................ 9
Environmental Consequences ..................................................................................................... 9 Alternative 1 – No Action ....................................................................................................... 9 Alternative 2 – Vegetation Proposed Action ........................................................................... 9 Alternative 3 – Proposed Action ........................................................................................... 13
Regulatory Framework ............................................................................................................. 18 Land and Resource Management Plan .................................................................................. 18 Federal Law ........................................................................................................................... 20 Other Guidance or Recommendations ................................................................................... 20 Compliance with LRMP and Other Relevant Laws, Regulations, Policies and Plans .......... 20 Summary ............................................................................................................................... 20
Degree to Which the Purpose and Need for Action is Met ....................................................... 20 Summary of Environmental Effects .......................................................................................... 21 Summary of Road decommissioning/closing effects to vegetation management ..................... 23 References Cited ....................................................................................................................... 24
Tables
Table 1: Resource indicators and measures for assessing effects.................................................... 2 Table 2 Forest Structural Classes Represented in the Planning area. *Descriptions taken from
FRS. ......................................................................................................................................... 4 Table 3: Resource indicators and measures for the existing condition ........................................... 5 Table 4 Stand Density Limits .......................................................................................................... 7 Table 5 Wenatchee NF Plant Associations and their maximum SDI rating represented in the
Project area. ............................................................................................................................. 7 Table 6 Lists the acreage of Silvicultural Prescription for each stand .......................................... 11 Table 7: Resource indicators and measures for Alternative 2 ....................................................... 13 Table 8: Summary comparison of how the alternatives address the Purpose and Need ............... 21 Table 9 Stand 44 Diameter Distribution comparison using the different alternatives................... 21 Table 10. Summary comparison of environmental effects to Vegetation resources. .................... 22
Figures
Figure 1 Tillicum EMDS Derived Stand Structure (existing conditions). ...................................... 4 Figure 2 Areas represented by Understory Reinitiation .................................................................. 5 Figure 3 Areas represented in the treatment area with >35% SDI .................................................. 6 Figure 4 Areas represented in the treatment area with 10TPA >20 inch DBH trees present. ......... 8 Figure 5 Tillicum Watershed Restoration Vegetative Proposed Actions ...................................... 10 Figure 6 Stand 44 Existing & Projected SVS and diameter distributions. .................................... 14 Figure 7 Stand 99 Existing & Projected SVS and diameter distributions. .................................... 15 Figure 8 Stand 55 Existing & Projected SVS and diameter distributions. .................................... 16
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Introduction The Tillicum Watershed Restoration Project identified a purpose and need to modify the vegetative
structure, promote medium to large trees and restore resiliency within the planning area. The following
analysis will focus on the vegetation conditions within the Tillicum watershed. The analysis will compare
the No Action to the Proposed Alternatives. Alternative 2 and Alternative 3 are the same with respect to
vegetation and will be discussed in this analysis as the proposed alternative. Attachments included are the
following spreadsheets 2015 Existing Vegetation Conditions, 2020 Projected Post Treatment Conditions,
2045 Projected Conditions and the No Action 2045 Projected Conditions. Other attachments include: The
Okanogan-Wenatchee National Forest Restoration Strategy (FRS), Background and Definitions.
The vegetative objectives for the Tillicum Watershed Restoration Project are designed to alter the
homogeneous state of the forest cover type and stand structure, in order to increase resiliency to
disturbance; protect existing and accelerate the development of large to medium trees, to provide habitat
for associated species; protect and enhance unique habitats to diversify composition and biodiversity;
protect and encourage the development of Northern Spotted Owl habitat across the Tillicum watershed.
To meet the above objectives the project proposes to reduce stocking by mechanical thinning
approximately 6,701 acres. Thinning prescriptions would be designed to distribute individuals, clumps
and openings across the stand in a variable fashion. Only trees less than 10 inches Diameter at Breast
Height (DBH) would be cut, using a chainsaw, within these acres. A portion of the residual trees would be
pruned to reduce ladder fuels. Lopping, scattering and handpile burning would be used to treat existing
and activity created fuels. The largest and healthiest trees within the stand would be retained. The
treatments would target the removal of ladder fuels and competition near the larger trees that currently
exist across the treatment areas and would be designed to increase residual tree diameter growth rates.
The activities listed below would be designated across the watershed with the following Silviculture
Prescription Objectives
1. Promote Diameter Growth (Rx1) - Residual stocking would range from 50 to 200 TPA, only
trees less than 8” DBH would be cut, created openings would generally be less than ½ acre in
size.
2. Shaded Fuel Break (Rx2) - Residual stocking would range from 10 to 50 TPA, only trees less
than 10” DBH would be cut, created openings would generally be less than ½ acre in size.
Approximately 1,076 acres.
3. Initiate Stand Structure Change (Rx3) - Residual stocking across 50% of the area would range
from 5 to 15 TPA and occur in areas 1 to 5 acres in size. These areas would be receptive to the
establishment of new seedlings. The remaining 50% of the area would be aligned with the
“Promote Diameter Growth Rx-1”
4. Restore and Maintain Fire Return Intervals (Rx4) - Thinning with prescribed fire. Acceptable
mortality ranges across the stands would be < 5% for trees greater than 16” DBH; < 10% for trees
between 8”- 16” DBH; < 40% for trees less than 8” DBH.
Resource Indicators and Measures
The resource indicators chosen are structure class distribution, stand density index (SDI) and diameter at
breast height (DBH). The structure class distribution identifies the stratification of the landscape into
process based structure classes to further analyze the landscape patterns and ecological processes, i.e.
disturbance and succession (FRS 2012). Stand density is a term that refers to an absolute measure of tree
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occupancy per unit area; it also measures the intensity of inter-tree competition for site resources.
Measurements of stand density quantify aspects of stand structure by describing a combination of the
average number of trees occupying a unit of forestland and their size (Tappeiner et al. 2015). Stand
Density Index (SDI) is based on Reineke’s 1933 concept of self- thinning and is expressed as a
competitive equivalent number of 10 inch trees/per acre. DBH is the diameter at 4.5 feet above ground
and is the standard method for expressing the diameter of a standing tree.
Table 1: Resource indicators and measures for assessing effects
Resource
Element
Resource Indicator Measure
(Quantify if possible)
Used to address:
P/N, or key
issue?
Source
(LRMP S/G; law or policy,
BMPs, etc.)?
Forest Health-
Structure and Composition
Structure Class
Distribution
Portion of the landscape
meeting the desired future
structure class
(Understory Reinitiation)
Yes
OKA-WEN National Forest
2012 Restoration Strategy
Stand Density Index
(SDI)
% of treatment area
>35% Stand Density
Index (SDI)- Lower limit of Full Site Occupancy
Yes
OKA-WEN National Forest
2012 Restoration Strategy,
Dry Forest Restoration Principles.
Promoting
Medium & Large Trees
Diameter at Breast
Height (DBH)
% treatment area with
minimum 10TPA >20in DBH
Yes
NWFP, OKA-WEN
National Forest 2012
Restoration Strategy,
Okanogan Wenatchee NF Large Tree Policy
Methodology
The Okanogan-Wenatchee National Forest Restoration Strategy (FRS) and the Ecosystem Management
Decision Support (EMDS) tool was used to initiate the analysis. For detailed information on the FRS
background and process, as well as the EMDS Tillicum Landscape Assessment reference Appendix A,
(Veg Report Appendix A Landscape Assessment.pdf) and Appendix B, (Appendix B Tillicum Landscape
Assessment Visual Display.pdf) filed in the Project Record.
The FRS analysis provided details to the interdisciplinary team (IDT) to pursue a restoration project and
identify a potential landscape treatment area (PLTA). After the PLTA was decided on field surveys began.
Several stands within the project area were surveyed in 2014/2015 using the Region 6 Common Stand
Exam (CSE) principles. Plots were taken throughout the project area on a scale of approximately one plot
per 20 acres. Data collected at these plots followed the procedures for the R6 CSE Intensive Survey.
Data was then entered into the USDA Forest Management Service Centers, Forest Vegetation Simulator
(FVS). FVS is a modeling system used by several agencies for predicting forest stand dynamics across
the United States. FVS modeling is based on semi-distance-independent individual tree growth and yield
models (Dixon 2010). The East Cascades Variant 1987, updated in 2012, was used to account for local
conditions during FVS simulations. Stands were selected for analysis based on their proposed treatment
and data availability.
The next steps of the analysis were to compare the FVS projected stand dynamic results from the No
Action to the Proposed Alternative. The FVS analysis looked at different thinning densities to meet the
desired future condition. The effects where modeled over the course of 30 years, 2015-2045. This
timeframe was selected to show the treatment effects.
The treatments simulated in FVS were analyzed under the following parameters:
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All thinning was done in 2017, using the Fire and Fuels extension Thin with fuel piled and
burned.
Variable thinning densities were modeled and included: Thin to a residual 25 TPA, 50 TPA, 100
TPA or a thin everything less than 8 inches. Thinning treatments pertained to trees taller than 12
inches and/or a DBH less than 8 inches. Tree preferences during treatment favored ponderosa
pine and Douglas-fir.
Pile Burn: Percent piled (70%), timing (burn one year after piling), acceptable small tree
mortality (0.1%), largest tree killed (4” DBH)
2019 Prescribed Fire conditions: Temperature (70 degrees), wind speed (10 mph), fuel moisture
conditions (Dry), timing (Before green up), percent of stand burned (70%)
Information Sources
Region 6 Common Stand Exam data collection (field season 2014/2015)
Okanogan Wenatchee National Forest Restoration Strategy 2012
LRMP Wenatchee National Forest Plan 1990
Field Guide for Forested Plant Associations of the Wenatchee National Forest 1995
Incomplete and Unavailable Information
Not all stands within the analysis area had Region 6 CSE data collected. Walk thru exams were
conducted on the stands that did not receive the full stand exam. Data was then imposed onto the stands
without the full exam on the basis of like structure, canopy cover, species composition, plant association,
aspect and elevation.
Affected Environment
Existing Condition
The Tillicum Creek sub-watershed has been impacted by past management activities including; timber
harvest, wildfire, salvage logging, road building, grazing and recreation. These disturbances have shaped
the watershed into its current homogenous state. These disturbance regimes have left a variation of forest
ages scattered throughout the project area. The most recent Tyee Fire in 1994 has provided areas of stand
initiation with ages ranging from 13-21 years old. Areas that survived the Tyee fire but had burned in the
1970 Gold Ridge fire are in a state of young forest multi story and stem exclusion with ages ranging from
21-80 years old. The remnant overstory that survived past disturbances ranges in age from 80-300 years
old.
The dominant forest type throughout the project area consists of 87% dry mixed conifer and 13% mesic
mixed conifer. The dry mixed conifer is dominated by Douglas fir and ponderosa pine. The mesic areas
reside in higher elevations (above 4500ft) and consist mostly of Douglas fir, grand fir and lodgepole pine.
Other species within the project area consists of lodgepole pine, western white pine, western larch,
Engelman spruce, subalpine fir, aspen and scattered pockets of western red cedar.
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Structure stages modeled from EMDS are represented in Figure 1. The EMDS modeling system
projected that the majority of the area is in two stages, young forest multi story and stem exclusion open
canopy. These stages are over represented in comparison to understory reinitiation and stand initiation.
Table 2 describes the forest structural classes represented in the planning area.
Table 2 Forest Structural Classes Represented in the Planning area. *Descriptions taken from FRS.
Structure Class
Description *
Acres
% Land within
Treatment area
Young-forest multistory
(YFMS)
Two or more cohorts are present
through establishment after periodic
disturbances. Large and/or old seral
trees are often at reduced density from
fire or logging.
5060
35%
Stem exclusion open canopy
(SEOC)
Below ground competition limits
establishment of new individuals.
6120
43%
Understory reinitiation (UR)
Initiation of a new cohort as the older
cohort occupies less than full growing
space.
951
7%
Stand Initiation (SI)
Growing space is reoccupied following
a stand replacing disturbance.
2010
14%
Figure 1 Tillicum EMDS Derived Stand Structure (existing conditions).
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Table 3: Resource indicators and measures for the existing condition
Resource Element Resource Indicator
(Quantify if possible)
Measure
(Quantify if possible)
Existing Condition
(Alternative 1)
Forest Health- Structure and
Composition
Structure Class Distribution Portion of the landscape meeting
the desired future structure class (Understory Reinitiation)
7%
Stand Density Index (SDI) % of treatment area >35% Stand
Density Index (SDI)- Lower limit of Full Site Occupancy
83%
Promoting Medium & Large Trees
Diameter at Breast Height (DBH)
% treatment area with minimum 10TPA >20in DBH
56%
Figure 2 Areas represented by Understory Reinitiation
Resource Indicator or Measure 1
Structure class distribution is an important indicator and one that is the most manipulated in managing
forest ecosystems. Forest structure includes the variety and spatial arrangement of live trees, snags and
logs. Structure provides evidence of key functions for wildlife, forest productivity, and helps define the
value of providing goods and services (Franklin et al. 2002).
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The current structure class distribution is modeled through EMDS and identifies that the existing
condition has only 7% of understory reintiation (UR) represented in the planning area. The FRS
highlights seven structure classes that where identified by Hessburg et al. 2000, and of these seven UR is
lacking in representation across the planning area. Other structure classes such as young forest multi
story and stem exclusion open canopy are over represented. Under these current homogenous conditions
the desired future condition of a healthy forest with structure variation is unattainable.
Figure 3 Areas represented in the treatment area with >35% SDI
Resource Indicator or Measure 2
Stand Density Index is the resource indicator and will be measured by the percent of the treatment area
that currently has greater than 35% of the maximum SDI. Thirty five percent was chosen because
research and literature states that this number is relative to full site occupancy (Tappeiner et al. 2015,
Franklin et al. 2011, Franklin et al. 2007). Full site occupancy dictates the amount of resources (light,
water, air) available to allocate to the trees occupying the site. It also identifies the beginning stage in
which no new individuals will establish. Maximum SDI’s are based on plant associations identified in the
stand exams and are provided in Table 5.
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FVS modeled results show that currently 83% of the treatment area has reached full site occupancy.
Within the 83%, 28% is already in a self-thinning stage (>60% of Max SDI), where competition induced
mortality is actively taking place. Table 4 identifies the current acres within each stand density limit.
Existing stand densities for all treatment areas have been identified and are found in the attachments
under 2015 Existing Vegetation Conditions.
Table 4 Stand Density Limits
Stand Density Limits Acres
Lower limit of Self Thinning- 60% MAX SDI 1970
Zone of Imminent Competition- 55% MAX SDI 237
Lower Limit Full Site Occupancy- 35% MAX SDI 3849
High End Crown Closure- 30% MAX SDI 123
On Set of Competition-25% MAX SDI 66
Lower limit of Crown Closure- 15% MAX SDI 269
Table 5 Wenatchee NF Plant Associations and their maximum SDI rating represented in the Project area.
Forested Plant Associations of
the Wenatchee National Forest
(Lillybridge et al.1995)
MAX
SDI
SPECIES TYPE
Acres
% of
Treatment
Area*
CDG131 530 PSME*/Pinegrass 2182 30.1%
CDG134 430 PSME/Pinegrass-Blue bunch
wheatgrass
446 6.2%
CDS412 450 PSME/Pachistima/pinegrass 178 2.5%
CDS639 550 PSME/shiny-leaf spirea/pinegrass 1864 25.7%
CES112 820 Subalpine fir/pachistima/ 527 7.3%
CWF444 785 Grand fir/heartleaf arnica 351 4.8%
CWG124 635 Grand fir/pinegrass 1396 19.3%
CWG125 750 Grand fir/pinegrass- lupine 123 1.7%
*PSME- Pseudotsuga menziesii
*Treatment Area- Areas covered with Stand Exam data.
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Figure 4 Areas represented in the treatment area with 10TPA >20 inch DBH trees present.
Resource Indicator and Measure 3
Diameter at Breast height is a measurement indicator relative to identifying trees greater than 20 inches in
diameter. This measure will indicate the amount of large to medium trees across the landscape. Large
trees are defined as 20-24 inches; very large trees are defined as anything greater than 25 inches (FRS
2010). EMDS identifies medium trees as 16- 25 inches and large trees as anything greater than 25 inches.
Currently 67% of the treatment area has large to medium trees scattered throughout the overstory.
Although large to medium trees exists on the landscape the total number is low relative to the desired
future condition. The FRS identifies that a desired condition of 11-17 TPA greater than 20 in DBH exist
in the structure classes represented in the planning area for the dry and mesic plant association groups.
The existing amount of TPA greater than 20 inch DBH have been identified and are found in the
attachments under 2015 Existing Vegetation Conditions.
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Management Direction
Desired Condition
The immediate desired future condition is one in which stand densities will be reduced (<35% of max
SDI) allowing for available growing space amongst the residual stands to increase, in order to optimize
growth rates.
The long term desired future condition is one in which the homogenous cover type and stand structure is
reduced providing heterogeneity and resiliency to disturbance across the watershed. Large to medium
trees (>20in. DBH) will be promoted and represented at a minimum density ranging from 11-17 TPA in
both the Dry and Mesic forest types (FRS 2012). Unique habitats such as aspen groves, springs, fens and
meadows will be promoted across the watershed.
Environmental Consequences
Alternative 1 – No Action
Under Alternative 1, no thinning, activity fuel treatments, prescribed burning, road improvements, road
closures, road decommissioning, stream restoration or other connected actions would take place.
Ongoing and future activities, such as routine road maintenance, recreation use, and noxious weed control
would be expected to occur
The No Action alternative would maintain the homogenous cover type and stand structure that currently
exists creating a highly susceptible area to major disturbances (wildfire, insect outbreaks). Stand densities
would continue to reach their maximums causing competition induced mortality (>60% of Max SDI).
Understory vegetation in these dense stands will continue to become dominated by shade tolerant species.
Stands that are degrading will continue to degrade with a high possibility of losing the large to medium
trees that currently exist across the landscape. The loss of these large trees will have a ripple effect on
wildlife by removing key components of their habitat.
Alternative 2 – Vegetation Proposed Action
Non-commercial thin (NCT), Handpile: This project proposes to reduce stocking by
mechanical thinning approximately 6,701 acres. Only trees less than 10 inches Diameter at
Breast Height (DBH) would be cut, using a chainsaw, within these acres. A portion of the
residual trees would be pruned to reduce ladder fuels. Lopping, scattering and handpile burning
would be used to treat existing and activity created fuels. The largest and healthiest trees within
the stand would be retained. The treatments would target the removal of ladder fuels and
competition near the larger trees that currently exist across the treatment areas and would be
designed to increase residual tree diameter growth rates.
o Residual tree stocking would range from 5 to 200 Trees per acre (TPA) and would be
distributed across the stand in a variable fashion including individuals, clumps ranging
from 2 trees up to 20 trees and openings (generally less than 1/2 acre and up to 5 acres in
size).
Prescribed Burn: On up to 7,393 acres, prescribed fire will be used to restore or maintain the
desired fire return intervals and fuel loadings consistent with historical fire regimes. These
treatments would be designed to reduce the potential wildfire intensity by reducing the amount of
existing dead and down woody material (<3” diameter). Historically, these stands burned on a
frequent basis; this treatment would help return them to their natural fire return interval.
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Figure 5 Tillicum Watershed Restoration Vegetative Proposed Actions
Proposed Action Silviculture Prescription Objectives
1. Promote Diameter Growth (Rx1) - Residual stocking would range from 50 to 200 TPA, only
trees less than 8” DBH would be cut, created openings would generally be less than ½ acre in
size.
2. Shaded Fuel Break (Rx2) - Residual stocking would range from 10 to 50 TPA, only trees less
than 10” DBH would be cut, created openings would generally be less than ½ acre in size.
Approximately 1,076 acres.
3. Initiate Stand Structure Change (Rx3) - Residual stocking across 50% of the area would range
from 5 to 15 TPA and occur in areas 1 to 5 acres in size. These areas would be receptive to the
establishment of new seedlings. The remaining 50% of the area would be aligned with the
“Promote Diameter Growth Rx-1”
4. Restore and Maintain Fire Return Intervals (Rx4) - Residual fuel loading of coarse wood
greater than 3 inches diameter would be 3 and 10 tons (Dry Forest) and 5 to 10 tons per acre
(Mesic Forest). Acceptable mortality ranges across the stands would be < 5% for trees greater
than 16” DBH; < 10% for trees between 8”- 16” DBH; < 40% for trees less than 8” DBH.
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Table 6 Lists the acreage of Silvicultural Prescription for each stand
Stand
Total
Acres
Rx-1 (acres)
Promote Diameter Growth
Rx-2 (acres)
Shaded Fuel Break
Rx-3 (acres)
Stand Structure Change
Rx-4 (acres)
Restore and Maintain
Fire Return Interval
7614 5219 1076 406 912
2 100 97 3
3 19 18 1
3 28 23 5
4 9 1 8
8 29 26 3
9 30 30
10 36 34 2
11 29 26 3
13 10 2 8
17 3 3
20 16 16
21 14 1 13
22 11 11
22 99 92 7
23 26 15 11
24 61 57 4
26 59 56 3
28 10 10
28 5 5
29 2 2
30 82 77 5
30 13 13
32 18 10 8
32 5 5
33 1 1
35 30 29 1
36 48 44 4
37 1 1
38 3 2 1
39 116 94 22
40 61 60 1
41 266 261 5
42 2 2
42 43 43
43 61 52 9
44 138 116 22
46 3 3
48 33 26 7
50 200 198 2
51 145 38 107
52 94 84 10
54 95 89 6
54 51 43 8
55 243 30 213
56 122 122
57 104 18 86
58 18 16 2
59 133 114 19
60 26 24 2
62 2 2
62 35 31 4
63 10 10
63 412 396 16
64 21 1 20
66 <1 1
67 52 52
68 97 81 16
69 42 40 2
70 72 54 18
71 63 60 3
71 26 26
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Stand
Total
Acres
Rx-1 (acres)
Promote Diameter Growth
Rx-2 (acres)
Shaded Fuel Break
Rx-3 (acres)
Stand Structure Change
Rx-4 (acres)
Restore and Maintain
Fire Return Interval
73 8 8
74 3 3
75 20 20
75 14 11 3
76 33 27 6
77 15 15
78 2 1 1
78 41 25 16
80 79 79
81 70 61 9
82 83 80 3
83 72 67 5
84 43 37 6
86 124 101 23
87 29 15 14
88 136 125 11
89 114 102 12
90 105 93 12
91 80 78 2
92 67 60 7
93 4 4
95 60 56 4
99 30 28 2
100 157 143 14
101 8 4 4
103 117 85 32
104 8 5 3
105 19 18 1
106 26 26
107 45 44 1
112 63 60 3
113 8 6 2
114 50 37 13
115 170 21 149
116 13 5 8
117 208 199 9
118 91 79 12
119 69 40 29
122 474 11 463
122 258 21 237
124 77 68 8
127 64 64
128 1 1
129 36 33 3
130 47 47
131 3 2 1
132 100 90 10
134 179 174.00 4
137 21 19.00 2
138 114 98.00 16
USFS Poly 161 161
Road
Easements
213 213
Total 7614 5219 1076 406 912
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Alternative 3 – Proposed Action
Alternative 3 is the same as Alternative 2 for vegetation resources.
Project Design Features and Mitigation Measures
The following mitigation measures will be applicable:
A site specific silvicultural prescription shall be prepared for all activities proposing the
management of trees or timber stands to meet resource objectives. All prescriptions will be
prepared or approved by a certified silviculturist.
A clump and gap method will be used in thinning prescriptions to mimic what may have occurred
on the landscape naturally rather than a plantation with set spacing requirements.
Western red cedar, western larch, western white pine shall be retained during small tree thinning
operations. These species provide diversity across the watershed.
Where feasible, Rx fire ignition patterns should be adjusted to avoid mortality to western red
cedar, western larch, and western white pine.
Direct and Indirect Effects
Direct effects occur at the time and place the action is implemented. Indirect effects occur off-site or later
in time.
The direct effects under Alternative 2 would reduce stand densities throughout the planning area to meet
the desired less than 200 TPA and reduced SDI. Other direct effects would include a reduction in total
canopy cover, although not in the larger overstory.
The indirect effects under Alternative 2 would be increased diameter growth rates among the residual
trees and a less homogenous landscape that has improved resiliency to major disturbances such as
wildfire and insect outbreaks. Understory vegetation would respond to the new open areas with providing
shade intolerant species to reestablish.
Table 7: Resource indicators and measures for Alternative 2
Resource Element Resource Indicator
(Quantify if possible)
Measure
(Quantify if possible)
Alternative 2
Forest Health- Structure and
Composition
Structure Class Distribution Portion of the landscape meeting
the desired future structure class (Understory Reinitiation)
10%
Stand Density Index (SDI) % of treatment area >35% Stand
Density Index (SDI)- Lower limit of Full Site Occupancy
61%
Promoting Medium & Large
Trees
Diameter at Breast Height
(DBH)
% treatment area with minimum
10TPA >20in DBH
80%
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Resource Indicator and Measure 1 Alternative 2 reduces the percent of stem exclusion open canopy and promotes understory reinitiation by
increasing its representation on the landscape from 7% to 10%. Promoting UR in areas where feasible
will help to establish the historic and desired overlap of structure classes. Creating areas of different
structure classes will help provide defense against disturbance processes as well as providing structure
variation that builds multi layers with a clump and gap mosaic of forest ages.
Resource Indicator and Measure 2
Alternative 2 reduces the percent treatment area with greater than 35% of maximum SDI from 83% to
61%. The reduced SDI will help provide the structure variation that will allow heterogeneity in the
overall cover type and stand structure. SDI values will be reduced to a level allowing the residual stand to
grow creating variation amongst size classes and structure.
Resource Indicator and Measure 3
Alternative 2 would increase the amount of large to medium trees across the watershed. By reducing
stand densities to provide growing space, diameter growth in the residual stand is projected to increase.
FVS model outputs indicate that on average one new size class (2inches) is generated every twenty years
following treatment.
Figures 5, 6, & 7 show existing (2015) & projected (2045) Stand Visualization (SVS) Images followed by
diameter distributions for a group of representative stands within the project area. Projected treatments
are modeled using Alt 2.
Figure 6 Stand 44 Existing & Projected SVS and diameter distributions.
Stand 44 2015 Initial Conditions Stand 44 2045 Projected Conditions
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Stand 44 2015 Diameter Distribution Stand 44 2045 Diameter Distribution
Stand 44 was selected to represent areas where Northern Spotted Owl (NSO) habitat is being promoted
and protected. Silvicultural treatment objectives for the NSO area will follow the Rx1 prescription with
objectives to promote large trees and maintain multi layers with a minimum 40% canopy cover.
Treatments simulated in the model remove the smaller size classes to allow growth in the residual stand.
The current size class distribution for the existing condition ranges from 0-28 inches. Post treatment the
model projects the new range to be from 0-30 inches.
Figure 7 Stand 99 Existing & Projected SVS and diameter distributions.
Stand 99 2015 Initial Conditions Stand 99 2045 Projected Conditions
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Stand 99 2015 Initial Conditions Stand 99 2045 Projected Conditions
Stand 99 was selected to represent the general Rx1 silvicultural prescription. Stand 99 represents the
majority of the treatment applications throughout the project area. The current size class distribution
ranges from 0-34 inches. The projected post treatment size classes range from 0-36 with the majority of
growth in the medium tree category.
Figure 8 Stand 55 Existing & Projected SVS and diameter distributions.
Stand 55 2015 Initial Conditions
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Stand 55 2045 Projected Conditions Stand 57 2045 Projected Conditions
Stand 55 2015 Initial Conditions Stand 55 2045 Projected Conditions
Stand 55 is located in the structure change prescription area (Rx3). FVS does not have the capability to
model the complete desired prescription; therefore Stand 57 is included to show the variation in the
prescriptions. 50% of the structure change areas will be treated with modeled results represented by
Stand 55 and the remaining 50% will be treated and modeled as Stand 57. The silvicultural objective is to
promote understory reinitiation by creating openings 1-5 acres in size to allow for a new cohort to
establish as the remaining cohort occupies less space and the residual stand increases in diameter growth.
Cumulative Effects
Spatial and Temporal Context for Effects Analysis
The spatial boundary for analyzing the cumulative effects to the vegetation within the project area will be
where the effects of this and other projects have and will overlap. The temporal boundaries are modeled
Vegetation Report Tillicum Watershed Restoration Project
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at 30 years for the ability to show treatment effects on diameter grow. Effects timeframes are defined as:
short term- immediately following treatment; long term- modeled at 30 years.
Past, Present, and Reasonably Foreseeable Activities Relevant to Cumulative Effects Analysis
Previous activities with a direct effect to vegetation include wildfire, prescribed fire, small tree thinning,
timber harvest, salvage logging, and reforestation. Other previous activities include road building,
grazing, invasive weed treatments and recreational use. For the complete list of specific past, present and
reasonably foreseeable activities see the master list located in the appendix.
The effects of the previous impacts include but are not limited to soil compaction from mechanized
equipment use, causing degradation in the available growing space; previous wildfires in the project area
have impacted the composition and structure, creating areas of early seral species and homogenous
structure; management activities such as small tree thinning have reduced stand densities in some areas
promoting larger trees across the landscape.
Reasonably foreseeable impacts include but are not limited to continued wildfire suppression activities,
prescribed fire, small tree thinning, recreational use, grazing and invasive weeds treatments. Private and
State sections within the planning area may impact vegetation resources by timber harvest activities
and/or reforestation following such activities.
Regulatory Framework
Land and Resource Management Plan
The Entiat Ranger District is managed under the 1990 Wenatchee Forest Plan, as amended by the
Northwest Forest Plan (NWFP 1994).
The Wenatchee National Forest Land and Resource Management Plan (LRMP) provides standards and
guidelines for Timber and Vegetation management projects.
Intermediate Harvest (Non-commercial thinning for this planning project)
o Intermediate harvests should be designed to improve quality, vigor and value of the
residual stand and not necessarily to maximize return from the intermediate harvest.
Silvicultural Examination and Prescription
o The selected silvicultural system must be capable of providing special conditions, such
as a continuous canopy or continuous high density live root mats when required by
critical soil conditions, or conditions needed to achieve management objectives such as
streamside protection, wildlife needs, and visual resources.
o The selected silvicultural system must permit control of existing or potential vegetation to
a degree that establishment of numbers of trees, other desirable vegetation, and rates of
growth as identified in site specific silvicultural prescriptions for harvest areas, can be
achieved.
o The sivicultural systems selected must promote stand structure and species composition
which avoids serious risk of damage from mammals, insects, disease, or wildfire and will
allow treatment of existing insect, disease, or fuel conditions.
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o Silvicultural prescriptions will be prepared on a site specific basis for all activities
proposing the management of trees or timber stands to meet resource objectives. All
prescriptions will be prepared or approved by a certified silviculturist.
o The silvicultural prescription shall consider integrated pest management. Pests include
insects, diseases, animals, and vegetation.
Timber Stand Improvement
o The actual number of trees for satisfactory reforestation may range from 150-500 TPA.
Variations depend on species and tree sizes found on site. Stands with more than 500
TPA normally need thinning to optimize growth.
o Release projects shall be governed by the Final Environmental Impact Statement for
Managing Competing and Unwanted Vegetation.
Management Area
GENERAL FOREST (GF) – Provide for long-term growth and production of
commercially valuable wood products at a high level of investment in silvicultural
practices.
SCENIC TRAVEL- RETENTION (ST-1)- To retain or enhance the viewing and
recreation experiences along scenic travel routes
SCENIC TRAVEL- PARTIALRETENTION (ST-2)- Provide a near natural appearing
foreground and middle ground along scenic travel corridors
RIPARIAN RESERVES overlay all other management allocations where streams, ponds,
and wetlands are present and treatments within them are designed to meet and not retard
attainment of the Aquatic Conservation Strategy (ACS) objectives. The Aquatic
Conservation Strategy and the Wenatchee LRMP soil standards and guidelines set forth
objectives relative to the maintenance and restoration of sediment regimes, in-stream
flows, and site productivity. Proposed activities must maintain the existing condition or
lead to improved conditions in the long-term.
Designated KEY WATERSHEDS overlay all other management allocations. Key
Watersheds were designated under the NWFP based on their ability to provide high
quality habitat or refugia for aquatic and riparian dependent species with an emphasis on
watersheds that would “directly contribute to conservation of at-risk stocks of
anadromous salmonids, bull trout and resident fish species”.
MATRIX - consists of those federal lands outside the six categories of designated areas
(Congressionally Reserved Areas, Late-Successional Reserves, Adaptive Management
Areas, Managed Late-Successional Areas, Administratively Withdrawn Areas, and
Riparian Reserves).
LATE-SUCCESSIONAL RESERVES (LSR) - will maintain a functional, interactive,
later successional and old-growth forest ecosystem. They are designed to serve as habitat
for late-successional and old-growth related species including the northern spotted owl.
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Federal Law
Endangered Species Act (1973)
Clean Water Act (1977)
Clean Air Act (1970)
National Historic Preservation Act (1966)
National Forest Management Act (1976)
Northwest Forest Plan (1994)
Other Guidance or Recommendations
Okanogan Wenatchee National Forest Restoration Strategy 2012 (recommendation strategy)
Compliance with LRMP and Other Relevant Laws, Regulations, Policies and
Plans
Alternative 2 complies with all relevant laws, regulations, and policies discussed above. It abides by all
relevant standards and guidelines from the LRMP of the Wenatchee NF. Specifically Alternative 2 is
designed to improve the quality, vigor and value of the residual stand following an intermediate harvest
and in this case a non-commercial thin. Alternative 2 is designed to reduce stand densities to values
within the 150 to 500 TPA range identified in the Timber Stand Improvement Standards and Guidelines
under the LRMP. Alternative 2 will comply with the Silvicultural examination and prescription criteria
and all treatment prescriptions will be written or approved by a certified silviculturist.
Summary
Alternative 2 improves vegetative conditions throughout the treatment area. The degree to which the
Purpose and Need for Action is attained is described below.
Degree to Which the Purpose and Need for Action is Met The purpose of this project as it relates to vegetation is to;
Alter the homogeneous state of the cover type / stand structure dominating the landscape to
increase the resilience to disturbance;
Protect existing and accelerate the development of large trees across the landscape to provide
habitat for associated species;
Alter the homogeneous state of the cover type / stand structure dominating the landscape to
reduce the threat of western spruce budworm outbreaks;
Protect and encourage the development of Northern Spotted Owl habitat.
Protect and enhance unique habitats to diversify composition and biodiversity;
There is a need for action because:
Cover Type / Stand Structure (ctxss): Across the Tillicum subwatershed, the stem exclusion open
canopy and young forest multi story ctxss is over represented and understory reinitation is under
represented, resulting in a more homogeneous vegetative landscape that is vulnerable to
disturbance.
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Medium-Large Trees: The medium and large tree structure across the subwatershed is under
represented resulting in decreased habitat potential and resilience to disturbance and reduced
habitat for associated wildlife species.
Insect Vulnerability: The homogenous ctxss across the subwatershed increases the risk for
western spruce budworm outbreaks.
Northern Spotted Owl (NSO): Habitat is under represented across the landscape.
Unique Habitats: Multiple unique habitats exist within the subwatershed (meadows, spring, fens,
aspen) and could be negatively impacted by disturbance.
Table 8: Summary comparison of how the alternatives address the Purpose and Need
Purpose and Need Indicator/Measure No Action Alt 2 Alt 3
Alter the homogenous
ctxss
Structure Class
Distribution
Remains the Same
Increases by 3%
Same as Alt 2
Provide Resiliency to
disturbance
SDI-% treatment area
>35%
Increases to 100%
Decreases by 37%
Same as Alt 2
Protect and Promote
large to medium trees
% treatment area with
minimum 10TPA >20in DBH
Increases by 23%
Increases by 24%
Same as Alt 2
Table 9 Stand 44 Diameter Distribution comparison using the different alternatives
Stand 44 No Action Stand 44 Alt 2 & 3
Summary of Environmental Effects The No Action Alternative will promote the current conditions and not address the purpose and need of
the planning project. This will continue to degrade the health of the forest by accelerating disturbance
processes such as insect outbreaks and an increased risk to wildfire. Under this alternative the forest
structure and composition will remain homogenous. Desired wildlife habitat components such as multi
layers, variation amongst age classes and/ or structure stages will not promoted or exist. Large and
medium trees will continue to be suppressed because diameter growth will be minimal if not stagnate as
Vegetation Report Tillicum Watershed Restoration Project
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available growing space is fully occupied. Stand densities will continue to promote shade tolerant species
encouraging non fire resistant species to exist causing concerns for wildfire risks. Unique habitats may
disappear due to conifer encroachment or extreme disturbances such as major insect outbreaks or wildfire.
Alternative 2 will promote the desired future conditions and address the purpose and need of the planning
project. To meet the purpose and need Alternative 2 will modify the homogenous structure and
composition to promote spatial variation across the project area. Spatial variation will help break the
continuity of the existing landscape and provide a more heterogeneous landscape that is resilient to insect
outbreaks and wildfire.
Alternative 2 is designed to apply treatments that will reduce stand densities to less than 35% SDI,
allowing available growing space in the residual stand. Available growing space will encourage diameter
growth and modify the existing structure stages providing the desired structure stages across the project
area. By modifying stand densities structure stages such as understory reintiation (UR) will be promoted.
Historically and in the predicted future the Tillicum landscape had more acres within the UR structure
stage and fewer acres within the young forest multi story and stem exclusion stages. Manipulating the
vegetation in areas where feasible will allow the UR structure stage to return to the landscape and
increase its representation by 4%, moving the existing condition from 7% to 10%.
Treatments under this alternative would also promote and protect the existing large to medium tree
component by removing smaller diameter trees from the understory and reducing the existing TPA across
the project area. Reducing stand densities and promoting large to medium trees will help provide the
desired habitat components for the northern spotted owl. Treatments will also address protecting unique
habitats across the project area by removing encroaching conifers and providing barriers where needed
from grazing.
Table 10. Summary comparison of environmental effects to Vegetation resources.
Resource
Element
Indicator/Measure No Action Alt 2 Alt 3
Forest Health-
Structure and
Composition
Structure Class
Distribution Under no action
structure classes will
remain the same.
Stem exclusion open
canopy will continue
to dominant the
landscape. This will
contribute to
increased risks to
disturbance and a
lack of spatial
variation across the
landscape.
Vegetation treatments
will manipulate the
current stem exclusion
open canopy structure
classes into the desired
understory reinitiation
class. Creating areas of
different structure
classes will help
provide defense against
disturbance processes
as well as providing
structure variation that
builds multi layers with
a clump and gap mosaic
of forest ages.
Same as Alt 2
Vegetation Report Tillicum Watershed Restoration Project
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Resource
Element
Indicator/Measure No Action Alt 2 Alt 3
Stand Density Index
(SDI), -% treatment
area >35%
No vegetation
treatments would be
implemented therefor
there will be no
reduction in SDI
values. This will
continue to degrade
the health of the
forest and continue
influence disturbance
processes such as
wildfire and insect
outbreaks.
Vegetation treatments
would reduce SDI
values across 37% of
the treatment areas.
This will have a
positive influence on
breaking the
homogenous structure
and composition of the
residuals stands.
Same as Alt 2
Promoting
Medium &
Large Trees
Diameter at Breast
Height (DBH), %
treatment area with
minimum 10TPA
>20in DBH
No action will not
promote or protect
medium to large
trees. There will
continue to be an
increased risk to
losing medium to
large trees to
disturbances. The
available growing
space will continue to
be fully occupied not
allowing for growth
in the residuals trees.
Reducing stand
densities will encourage
diameter growth in the
residual stand by
freeing up available
resources and growing
space. Removing the
smaller diameter trees
from the understory
will help to protect the
existing large to
medium trees.
Same as Alt 2
Summary of Road decommissioning/closing effects to vegetation
management
In Alternative one (no action) access would remain unchanged. Management of stands within the
subwatershed would likely be less expensive due to the existing road network.
In Alternative 2 (proposed action) access would be decreased due to the removal of 69 miles of the road
system. The remaining portions of the road system would be maintained and/or upgraded to prevent
negative impacts to aquatic resources and reduce the potential from mass wasting associated with road
wash-outs. Management of stands within the subwatershed would be more expensive. Handcrews that
access areas for small tree thinning would be required to hike further distances and future harvest
operations would have longer haul routes and skidding distances.
In Alternative 3, the access would be decreased due to the removal of 88 miles of the road system. The
remaining portions of the road system would be maintained and prevent negative impacts to the aquatic
resources and reduce the potential from mass wasting associated with road wash-outs. Management of
stands within the subwatershed would be more expensive. Handcrews that access areas for small tree
thinning would be required to hike further distances and future harvest operations would have longer haul
routes and skidding distances.
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Service, Forest Management Service Center. Fort Collins, CO
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Department of Agriculture, Forest Service, Northern Research Station. 44 p.
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