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Kimball Thin Silvicultural Diagnosis
PREPARED BY
STEPHEN F. BOYER PACIFIC ZONE SILVICULTURIST
OCTOBER 23, 2015
Introduction Kimball Thin (KT) is located on the Gold Beach Ranger District of the Rogue River-Siskiyou National
Forest. The project area is within the Lower Rogue River 5th-field watershed and the Quosatana Creek-
Rogue River and Gold Beach-Rogue River 6th-field watersheds. The Quosatana Creek-Rogue River 6th-
field watershed, where the majority of treatment units are located, is a Tier 1, Key Watershed in the 1994
Northwest Forest Plan (NWFP). A portion of this watershed outside of the treatment area is in the Wild
and Scenic land allocation. Adjacent private timber company lands owned by South Coast Lumber are
south, west and east of the Planning Area. A private residence is in proximity on Kimball Hill
approximately ½ mile northwest of proposed treatment units.
The proposed action is an intermediate harvest of 9 units totaling 268 acres using variable density
thinning treatments with skips and gaps, and prescribed fire to enhance development of late successional
structures in 60 to75 year old Douglas-fir forest stands. Planting tree seedlings resistant to Port-Orford-
cedar root disease, Phythopthora ramorum, for forest health and species diversity objectives is part of the
proposed action.
Kimball Thin Planning Area and Proposed Units
The Planning Area is primarily accessed by NFS 3300, 3300-090 and 3313-100. To implement vegetation
treatments the following road work is proposed:
road maintenance on five (5) miles of gravel-surfaced roads and 0.1 mile of paved road
reconstruction and reopening three (3) miles of closed maintenance level 1 roads
building 2800 feet of new temporary roads.
Proposed logging systems are ground-based on 219 acres within 8 units and skyline on 49 acres within 3
units.
Kimball Thin Acres and Proposed Logging Systems
Stand # Acres Proposed Logging System
Skyline Acres
Tractor Acres
New Proposed
Temporary Roads (feet)
122 21 Skyline/Tractor 19 2 817
123 10 Tractor 10 0
124 23 Tractor 23 0
125 21 Tractor 21 0
126 22 Skyline 22 1449
127 111 Tractor 111 0
128 37 Tractor 37 0
129 14 Tractor 14 0
130 9 Skyline/Tractor 8 1 534
Totals: 268 49 219 2800
AFFECTED ENVIRONMENT
Location
Kimball Thin is located on Kimball Hill approximately seven (7) air miles northeast of Gold Beach,
Oregon. The project area is some of the closest Forest Service land to the Pacific Ocean on the district.
The Rogue River is 1.5 miles to the north. The legal description is Township 36 South, Range 13 West,
Sections 5 and 8, Willamette Meridian; Curry County, Oregon.
Topography
Treatment units are on a gently rounded, north-south trending ridgetop at an average elevation of 2100
feet. This ridgetop is broad and relatively flat, with most slopes ranging 10-25% with some steeper areas
with slopes up to 50%. Aspects range northerly and east to westerly with very little south facing slopes.
To the west of this ridgetop are tributaries that drain into Kimball Creek, while to the east tributaries drain
into Quosatana Creek.
Physiography
Kimball Thin is in the Lower Rogue Basin. The Lower Rogue Basin lies entirely within the Klamath
Mountains physiographic province, which contains some of the oldest rocks in western Oregon
(Weinhold, 1995). The Klamath Mountains is an elongate north-south trending area of which three fifths
is in northern California and the remainder in southwestern Oregon. The province is bordered to the north
by the Coast Range and to the west by the Pacific Ocean (Orr et al. 1992). The Klamath region is
typically mature and rugged with narrow winding valleys and sharp divides.
Geology Bedrock geology in the project area consists of Colebrooke schist which covers the largest part of the
Quosatana Creek watershed in the northwest, center and eastern edge of this watershed. Colebrooke schist
is metamorphic rock derived mainly from fine-grained sedimentary rocks and subordinate amounts of
submarine basalt. The rocks of this formation are made primarily of fine-grained schist or phyllite with
abundant quartz veins (USDA Forest Service, 1996).
Precipitation
The west side of the Klamath Mountains is subject to considerable marine influence due to its proximity
to the Pacific Ocean (Meyer, Amaranthus, 1979). Average annual precipitation is 85 to 135 inches
occurring primarily between October and May (USDA Forest Service, 1996).
Soils
Soils are deep to very deep, well drained, silty clay loams with 30 to 35% clay that have developed in
siltstones and sandstones. Coarse fragment content (i.e. gravel and cobble) is less than 25% in much of
the area. The primary management concern is impacts to soil quality through loss of soil structure and
reduced infiltration due to puddling and compaction of these fine-textured soils during harvest operations
(Gross, 1988).
The soils are developing from Colebrooke Schist formation (DOGAMI v5,gis cite), a highly folded
blueschist that was originally a mixture of thin-bedded shale and sandstone, and associated minor
components of deep sea tuffs, cherts, and pillow lavas before being metamorphosed in the early
Cretaceous (Orr et al. 1992).
NRCS soil mapping for treatment units have the following map unit composition and soil characteristics
(USDA-NRCS, 2005). See soil scientist report for details.
MU# Map Unit* %Component Surface texture/thickness
Depth/AWC
%Component Surface
texture/thickness Depth/AWC
%Component Surface
texture/thickness Depth/AWC
73F Deadline-Barkshanty-Nailkeg 30-60% south slopes
45% Deadline very channery loam/ 8” deep, AWC 4”
25% Barkshanty, channery loam/ 5” very deep/ AWC 6”
20% Nailkeg very channery loam/ 6” mod deep/ AWC 3”
103D Edson-Barkshanty complex, cool 0-15% slopes
55% Edson, channery clay loam/ 13” very deep/ AWC 8”
30% Barkshanty, channery loam/ 5” very deep/ AWC 6”
103E Edson-Barkshanty complex, cool 15-30% slopes
50% Edson, channery clay loam/ 13” very deep/ AWC 9”
35% Barkshanty, channery loam/ 5” very deep/ AWC 6”
Very Deep = 60+”
Deep = 40-60”
Mod Deep = 20-40”
Shallow = 0-20”
AWC = Available Water Capacity
* see 1994 Soil Survey of Curry County for inclusions in map units.
The project area is mapped in the Siskiyou National Forest Soil Resource Inventory as Landtype 52. This
landtype was field verified during development of the initial commercial thinning project (Gross, 1988)
and typically supports Site Class II and III Douglas-fir (Meyer, Amaranthus, 1979).
Stand History
Kimball Thin treatment units are naturally regenerated forest stands established following fires in the late
1930s. There are scattered remnant and legacy trees present from previous stands that had developed in
open grown conditions resulting in large branches and gnarly crown forms, many with multiple tops from
past wind injuries. Post-fire uniform second-growth stand conditions established and grew into the stem-
exclusion stage of stand development (Oliver et al., 1996) into the 1990s.
Past Management Intermediate commercial thinning treatments to improve stand growth were implemented 1990 to 1992
for stocking-level control and sustainable timber harvest objectives. The following table displays previous
commercial thinning treatments:
Stand #
Acres Previous
Entry Sale Unit Year
Acres Treated*
FACTS
NUMBER
Comments
122 21 None N/A N/A 0
123 10 Thin Kimball Thin #3 1990 7 1130140258
124 23 None N/A N/A 0
125 21 Thin Kimball Thin #2 1990 19 1130140257
126 22 None N/A 0
127 111 Thin Kimball Thin #1 1990 67 1130140256 Portion on east side of road
128 37
Thin Kimball Thin II #1 1992
73 1130140280
129 14 Thin Kimball Thin #5 1990 12 1130140259
130 9 None N/A N/A 0
Total: 268
* stand treatments and acres queried from FACTS.
Past thinning treatments resulted in good diameter growth compared to unthinned stand, though lack
horizontal and vertical heterogeneity desired for late-successional characteristics in this area.
Approximately 72% of treatment acres are proposed for a second commercial thin entry to develop
structural complexity. The remaining 28% consist of unthinned stands with the same desired treatment
objectives plus additionally increasing individual tree growth into larger diameters.
Unit # (unthinned)
Quadratic Mean
Diameter
Unit Acres
Unit #
(thinned)
Quadratic Mean
Diameter
Unit Acres
122 15.7 21 123 20.7 10
124 15.4 23 125 22.1 21
126 13.9 22 127 20.5 111
130 15.7 9 128 22.9 37
Average: 15.2 75
(28%) 129 24.7 14
Average: 22.2 193
(72%)
Vegetation
Overstory vegetation is dominantly composed of Douglas-fir (Pseudotsuga menziesii) -comprising over
97% of the stand exam tree species composition- with thickets of hardwoods, mostly tanoak
(Notholithocarpus densiflorus), interspersed in the overstory and mid-story. Other overstory hardwoods
include golden chinquapin (Chrysolepis chrysophylla), Pacific madrone (Arbutus menziesii); and red alder
(Alnus rubra)-mostly occurring in riparian areas outside treatment unit boundaries and within roadside
ditches. Other minor species present are Port-Orford-cedar (Chamaecyparis lawsoniana), western white
pine (Pinus monticola), knobcone pine (Pinus attenuate), western hemlock (Tsuga heterophylla), and
canyon live oak (Quercus chrysolepis).
Natural conifer regeneration is unevenly distributed in the project area. Units 127 and portions of 128
have thick Douglas-fir regeneration established following previous thinning treatments. Other units have
scattered Douglas-fir regeneration. Tanoak regeneration is ubiquitous throughout all units.
Understory species include salal (Gaultheria shallon), Pacific rhododendron (Rododendron
macrophyllum), evergreen huckleberry (Vaccinium ovatum), Cascade barberry (Mahonia nervosa),
beargrass (Xerophyllum tenax). Minor species include hairy manzanita (Arctostaphylos columbiana),
baldhip rose (Rosa gymnocarpa), red huckleberry (Vaccinium parvifolium) and California hazel (Corylus
cornuta). Understory vegetation cover is scattered and noticeably taller and denser in previously thinned
stands. Unthinned stands are in stem exclusion with scarce understory vegetation present.
Plant Associations
Plant association mostly keyed to a wet Douglas-fir/Tanoak co-climax plant association LIDE3-
PSME/GASH-VAOV2 with some PSME/GASH-RHMA3 (USDA Forest Service, 1996). Total species
richness for these plant associations is considered low to very low respectively.
Plant Series Plant Association Stand Numbers
Tanoak Tanoak-Douglas-fir / Salal-Pacific Rododendron
122, 123, 124, 126, 128, 129, 130
Douglas-fir Douglas-fir / Salal – Pacific Rhododendron
125, 127
Key Species
Vegetative ground cover is dominated by salal indicating generally warm and dry, well-drained sites of
moderate productivity possibly in areas with summer moisture stress. This shrub species responds to
canopy openings with vigorous growth (Atzet et al., 1989).
Thick Pacific rhododendron indicates relatively lower productivity, gravelly, well-drained soils low in
nutrients with high summer moisture stress. Clumpy thickets of golden chinquapin are associated with
rocky, shallow soils.
Current Stand Condition
There are four tree age classes represented in Kimball Thin. Current stand conditon mostly consist of
single-layered, homogenous second growth Douglas-fir with uniform horizontal and vertical structure.
Overstory Douglas-fir has a quadratic mean diameter of 22.2 inches in previously thinned stands and 15.2
inches in unthinned stands. There are scattered remnant and legacy conifer trees throughout the project
area (see map) and advanced Douglas-fir regeneration 4 to 7 feet tall. Tanoak is present in the
seedling/sapling, mid-story and overstory layers.
There is a distinction that legacy trees* (generally 60+ inch DBH) are the oldest trees (300+ years) to be
‘skipped’ with a 70- foot no treatment buffer and remnant trees (40+ inch DBH) that are a younger age
class where thin from below and understory treatments in proximity can occur1.
*Legacy trees typically have a “wolfy” structure, sometimes with fire scars or charred bark because
they’ve survived several fires. Bark is thick and furrowed; crowns tend to be flat topped and less “pointed”
than the younger trees. Limbs are > 5-6” in diameter in the upper two-thirds of the tree (≥ 33-feet above
ground level) and often moss-covered, creating potential nesting platforms. Trees can be single or in small
groups. These older trees are an important structural component of current stand conditions.
Note: map below does not diplay all of the legacy trees in the project area.
1 Wildlife feedback from Holly Witt, District Wildlife Biologist.during field review of the Kimball Thin project
area, August 19, 2015. Field notes in appendix.
Stand Development
Field observations of the project area indicate that around 1900, this ridgetop was either in young sapling
stages, brush-field, or as prairie. The watershed assessment for Quosatana Creek (USDA Forest Service,
1996) states that about 40% of the watershed burned as stand replacement fires. Large fires burned
between 1930s and 1950s. Scattered remnants from the previous stands survived these fires and appear to
have beene open grown during early tree development. No large snags, down wood, or old stumps
(predating 1990) were observed in the project area. Fire adapted species like knobcone pine exist in the
project area suggesting stands were maintained by fire in open canopy conditions before the establishment
of the current second growth stand. Uniform, dense stand conditions occurred as the stands developed
through the stem-exclusion stage before commercial thinning treatment were implemented in 1990-1992.
The resulting stand structure and has developed larger trees though lacks structural complexity. Some
portions of previously thinned units seeded in with profuse thickets of Douglas-fir regeneration. Height
growth (<6 inches) of natural regeneration has stagnated due to tree canopies closing back in post-1990’s
harvest. There is little conifer regeneration in unthinned-stands.
2014 Timber Stand Exams
Timber stand exams were conducted in 2014 to supplement previous 2010 exam plots. Following are the
stand summary metrics:
Stand #
Breast Height
Age
Total TPA (>7")
DF TPA (>7")
BA, ft2
/acre SDI
RD
Quadratic Mean
Diameter (inches)
Avg Height
Height to Dia. Ratio
Avg Crown Ratio
CC
122 71 199 187 268 412 63 15.7 88 67 44% 88
123 70 137 137 320 440 68 20.7 90 52 55% 84
124 59 198 198 258 398 61 15.4 81 63 63% 99
125 67 111 111 295 396 61 22.1 107 58 42% 83
126 69 222 211 235 378 58 13.9 75 65 34% 87
127 63 96 94 220 304 47 20.5 102 60 53% 75
128 67 63 63 180 238 37 22.9 103 54 51% 58
129 67 69 69 230 295 45 24.7 115 56 50% 73
130 71 199 187 268 412 63 15.7 88 67 44% 88
Avg: 67 137 134 251 358 56 19 95 59 49% 82
TPA=Trees per Acre DF=Douglas-fir BA=Basal Area SDI =Stand Density Index RD=Relative Density
QMD=Quadratic Mean Diameter CC=Canopy Cover (calculated in Forest Vegetation Simulator, ICASCA variant)
Discussion
SDI values range 238 to 440 resulting in 34% to 63% RDs (maximum SDI=700). Calculated RD numbers
describe stand competition as follows (Ellen 1984).
RD
70%+ Grossly overstocked (unmanaged mature stands)
60% Approximate “normal” stocking
50-70% Stand density sufficient to cause competition-related mortality
35-50% Stand vigor and growth are maximized
<35% Individual tree growth maximized
RD>50% indicate stand density sufficient enough to cause competition between trees that reduces live
crown ratios , decreases tree diameter growth and causes competition-induced tree mortality. Such stands
will potentially remain in a stem-exclusion stage for extended periods, perhaps a century or longer
(Andrews et al. 2005), before mortality agents begin to create canopy gaps suitable for recruitment of
understory vegetation and development of large crowns in overstory trees (Franklin and Van Pelt 2004).
Tree heights of co-dominant and dominant crown classes range from 75 to 115 feet. Legacy and remnant
tree heights are close to the same height as co-dominant trees of the 70 year-old cohort, though many
have multiple tops. Height-to-diameter ratios range from 52 to 67. Maintaining the height-to-diameter
ratio below 80-100 is considered desirable for reducing susceptibility to wind-throw and stem breakage
(Cremer et al., 1982, Lohmander and Helles, 1987; Wilson and Oliver, 2000). Live crown ratios range
from 34% in un-thinned stands to 55% in previously thinned stands. Maintaining crown ratios at 40% or
greater is considered desirable for sustaining vigorous growth (Smith, 1986)
Existing canopy closure varies 58% in previously thinned stands to 88% canopy closure in un-thinned
stands. Higher canopy cover decreases height growth of advanced conifer regeneration and shrubs.
Forest Health
Port-Orford-Cedar Root Disease
Port-Orford-cedar (POC) root disease, Phytophthora lateralis (PL), and uninfected ‘measurably
contributing’ POC are present in Kimball Thin Planning Area. PL is adjacent to the south boundary of
unit #127 outside of the treatment area (see map). Within this infection area, numerous (12+) medium to
large (16-24+ inch) POC snags are present in the creek drainage west of NFS Road# 3313-110. Several
(40+) dead POC seedlings and saplings were observed within road drainage ditches on both sides of this
road at the creek crossing and to the north for approximately 200 feet along this road. This portion of NFS
Road# 3313-110 is not intended to be used for the haul route for Kimball Thin2.
POC and PL Distribution in Kimball Thin Planning Area
Green = Uninfected POC Red = Infected POC
PL is also present:
west and outside of the treatment area along a tributary that drains into Kimball Creek,
west of NFS Road #3300-090 along the Frances Schrader Old Growth trail to the northwest of
treatment units. This gravel road will be used for the haul route.
PL spreads through transporting infected soil or water to uninfected areas principally via vectors (i.e.
automobiles, equipment, personnel) traveling along roads from infection sites. PL can cause mortality
within weeks of infection in small trees and in one (1) to four (4) years when large trees are infected
(Roth et al., 1987). Trees usually lose all foliage two (2) to three (3) years after death. In areas where the
disease has been active for several years, dead and dying trees with all degrees of foliage symptoms are
visible (Hadfield et al., 1986).
White Pine Blister Rust
White pine blister rust (WPBR), Cronartium ribicola, a branch and stem canker disease of five-needle
pines was observed infecting a western white pine sapling along the bank of NFS Road# 3300-090 that
borders unit #126 and outside of treatment unit boundaries. WPBR occurs in lower quantities than the
adjacent Lawson and Pistol watersheds (USDA Forest Service, 1996).
Sudden Oak Death (SOD)
No symptomatic or dead tanoaks, the main host for SOD in Oregon, were observed in the treatment area.
The closest SOD infection area is located in Hunter Creek area approximately 8 miles to the south. The
risk of spread of SOD in the project area is modeled to have a moderate and high rating (Vaclavik, et al.,
2010). The SOD quarantine area boundary expanded July 2015 and incorporates the Kimball Thin
planning area. Treatments that reduce or eliminate tanoak and manage for Douglas-fir are preferred as a
2 Pers. conv. Matt Timchak, presale forester, Westside Zone Vegetation Module, August 2015.
proactive treatment for reducing SOD risk in this project area3. Treatment activities will need to comply
with state and federal quarantine regulations.
Windthrow Potential
Windthrow is an indirect effect of density management treatments (i.e. thinning). The risk of windthrow
increases as stands become more open on landforms more exposed to prevailing winds, particularly on
shallow soils, that are subjected to increased wind flow conditions following stand treatments.
Prevailing winds in the Kimball Thin project area are mostly coming from the west due to the marine
influence of the Pacific Ocean. The majority of Kimball Thin units are situated on the easterly, lee ward
side of Kimball Hill with some portions of units (124 and 128) located on the broad ridgeline flat of
Kimball Hill.
Very little windthrow was observed in treatment units, a minor amount was noted in the southwest corner
of unit 128 (see Kimball Thin IDT notes, August 19, 2015 in appendix of the silvicultural diagnosis).
Soils in treatment units are deep to very deep, well drained, silty clay loams with 30 to 35% clay that have
developed in siltstones and sandstones. Coarse fragment content (i.e. gravel and cobble) is less than 25%
in much of the area.
Stand exam data taken in 2014 shows measured tree height-to-diameter ratios ranging from 52 to 67.
Maintaining the height-to-diameter ratio below 80-100 is desirable for reducing stand susceptibility to
wind-throw (Cremer et al., 1982, Lohmander and Helles, 1987; Wilson and Oliver, 2000).
Stand #
Breast Height
Age
Total TPA (>7")
DF TPA (>7")
BA, ft2
/acre SDI
RD
Quadratic Mean
Diameter (inches)
Avg Height
Height to Dia. Ratio
Avg Crown Ratio
CC
122 71 199 187 268 412 63 15.7 88 67 44% 88
123 70 137 137 320 440 68 20.7 90 52 55% 84
124 59 198 198 258 398 61 15.4 81 63 63% 99
125 67 111 111 295 396 61 22.1 107 58 42% 83
126 69 222 211 235 378 58 13.9 75 65 34% 87
127 63 96 94 220 304 47 20.5 102 60 53% 75
128 67 63 63 180 238 37 22.9 103 54 51% 58
129 67 69 69 230 295 45 24.7 115 56 50% 73
130 71 199 187 268 412 63 15.7 88 67 44% 88
Avg: 67 137 134 251 358 56 19 95 59 49% 82
TPA=Trees per Acre DF=Douglas-fir BA=Basal Area SDI =Stand Density Index
RD=Relative Density QMD=Quadratic Mean Diameter CC=Canopy Cover (calculated
in Forest Vegetation Simulator, ICASCA variant)
Previous commercial thinning in the early 1990’s has increased diameter growth of leave trees over the
last 25 years (and reduced tree height to diameter ratios) within a majority of the treatment acres thus
reducing windthrow susceptibility from currently proposed treatments.
Variable density thinning treatments will be leaving a high amount of no treatment skips around legacy
trees, NRF habitat for spotted owls and unique features (i.e. cave). Windthrow is not anticipated to be a
3 Pers. conv. Ellen Goheen, Forest Pathologist, Southwest Oregon Forest Insect and Disease Service Center, August
2015.
problem with proposed treatments and conversely, some windthrow may be beneficial as the area is
currently lacking in down wood desired for late successional species habitat and long term site
productivity.
Snags and Down Wood
Down wood and standing dead trees (i.e. snags) are a critical components of stand structure and site
productivity when managing forest ecosystems. The Rogue River-Siskiyou National Forest uses ecology-
plot data from unmanaged forests to help quantify natural levels of snags and down wood for each plant
series and plant association group. The snags and down wood recommendations are summarized by plant
series.
These tables display the minimum, maximum, and mean lengths found in the ecology plots within each
plant series. It is important to recognize that this ecology-plot data comes from a small number of plots
and some of the data is highly variable with wide standard deviations from the mean. Minimum levels are
identified.
Down wood data from ecology plots
SERIES Diameter Class
# Plots MIN length (ft)/ acre
MAX length (ft)/ acre
MEAN length (ft)/ acre
Standard Deviation length (ft)/ acre
Douglas-fir 1-10.9 7 0 1303 931 438
Douglas-fir 11-19.9 7 0 652 186 256
Douglas-fir 20+ 7 0 977 140 369
Tanoak 1-10.9 90 0 3258 997 485
Tanoak 11-19.9 90 0 2607 295 429
Tanoak 20+ 90 0 977 143 242
Snag data from ecology plots
SERIES Diameter Class
# Plots MIN TPA
MAX TPA
MEAN TPA Standard Deviation TPA
Douglas-fir 1-10.9 14 0 254.65 39.54 65.31
Douglas-fir 11-19.9 14 0 37.01 7.46 10.54
Douglas-fir 20+ 14 0 20.75 2.39 5.44
Tanoak 1-10.9 105 0 2207.84 52.51 224.99
Tanoak 11-19.9 105 0 19.93 2.8 4.7
Tanoak 20+ 105 0 14.45 2.38 3.16
Objectives for snags and down wood recommendations specify what should remain following a final
removal regeneration harvest. Since this project is proposing intermediate harvests; the prescription needs
to ensure that enough trees per acre are retained for snag and down wood recruitment and incorporating
snag creation as part of the treatment prescription. Existing snags and down woody debris will be retained
to the extent practicable.
A wildlife habitat prescription for the initial commercial thinning entry indicated units deficient in
wildlife trees and snag components comprised primarily of large soft snags > 36” diameter and 20-30 feet
tall at the time the report was written (Ford, 1988). The prescription specified retaining all wolfy, remnant
trees as future large snag habitat and creating two (2) snags per acre through topping or girdling. Two
medium-sized (16-24 inch) topped snags have been observed in unit #125.
Walk-through exams noted large snags densities are low across all proposed treatment units though stand
exam data for units #127 and #128 indicate a high number of medium-sized snag numbers present (see
stand exam snag data table). Previously unthinned stands in stem exclusion will continue to create small-
diameter snags and down wood from inter-tree competition for light as individual trees continue to
differentiate during stand development (i.e. self-thinning) as indicated by stand exam snag data for units
#122, 126 and 130.
Observations across the landscape indicate that mixed severity fire effects from the Biscuit Fire (2002),
influence the presence of down wood and snags at the landscape-scale resulting in amounts likely above
mean levels at this larger scale. Additionally, the 2015 annual insect and disease aerial flight observed
many pockets of recent tree mortality (i.e. new snags) caused by bear damage at the landscape-scale.
Large (30+ inch) POC snags, due to PL infection, are present by the Frances Schrader Old Growth trail
approximately ½ mile northwest of treatment units. Snags are also present within the PL infected drainage
adjacent to the south boundary of unit #127 (see Port-Oford-Cedar Root Disease section). Additionally,
the 2015 annual insect and disease aerial flight noted some recent tree mortality attributed to PL within
proximity.
Field observations noted large Douglas-fir and western hemlock snags > 24 inches diameter outside of
treatment units in an upland area north and adjacent to NFS Road #3313-118 south of the PL infected
creek drainage described above. Neighboring live overstory Douglas-fir appear to have short needles,
dead branches and uncharacteristic growth forms hypothesized to be related to some edaphic, soil-related
nutrient deficiency (i.e. ultra-mafic influenced). This site potentially keys to LIDE3- PIMO3/QUVA/
XETE – Tanoak-Western White Pine/Huckleberry Oak/Beargrass (though no QUVA present) a plant
association associated with ultramafic parent material or metamorphosed rocks influenced by ultramafics.
It occurs on sites that are moderated by the Oceanic influence (USDA Forest Service, 1996).
Snag data from stand exams
Stand # Acres Previous
Entry Snags
per acre
Basal Area per
acre
Quadratic Mean
Diameter (inches)
Avg Height
122 21 None 18 5.7 7.6 45
123 10 Thinning 0 0 0 0
124 23 None 0 0 0 0
125 21 Thinning 0 0 0 0
126 22 None 33 20 10.5 66
127 111 Thinning 8 13.3 17.3 53
128 37 Thinning 14 11.4 12.1 34
129 14 Thinning 0 0 0 0
130 9 None 18 5.7 7.6 45
Averages 268 10.1 6.2 6.1 27
MANAGEMENT DIRECTION
Proposed treatment units are located in Management Areas (MA) 8, Designated Wildlife Habitat, in the
Siskiyou National Forest Land and Resource Management Plan (LRMP) (USDA, 1989) and the Late
Successional Reserve (LSR) land allocation as amended by the Northwest Forest Plan (NWFP) (USDA-
USDI, 1994).
The primary management goal for Designated Wildlife Habitat is to protect mature and old-growth
habitat for all dependent flora and fauna. LSR are managed to protect and enhance old-growth forest
conditions.
No programmed timber harvest is allowed inside LSR except thinning or other silvicultural treatments in
stands up to 80 years of age when treatments are beneficial to the creation and maintenance of late-
successional forest conditions. Thinning or other silvicultural activities must be reviewed by the Regional
Ecosystem Office and the Regional Interagency Executive Committee (ROD, pg 8).
The programmatic Record of Decision and LRMP amendment for Management of Port-Orford-Cedar in
Southwest Oregon, Siskiyou National Forest (USDA Forest Service, 2004) is applicable to Kimball Thin.
This ROD amended Standards and Guidelines to have the following objectives for management of Port-
Orford-cedar:
Maintain POC on sites where the risk for infection is low.
Reduce the spread and severity of root disease in high-risk areas to retain its ecological function
to the extent practicable.
Reestablish POC in plant communities where its numbers or ecosystem function have been
reduced.
Reduce the likelihood of root disease becoming established in disease-free 7th field watersheds.
Project-specific NEPA analysis will appropriately document the application of the Port-Orford-Cedar risk
key and the consideration of the available management practices. Application of the risk key and
application of resultant management practices will make the project consistent with the mid- and large-
geographic and temporal-scale effects described by the SEIS analysis, and will permit the project analysis
to tier to the discussion of those effects (ROD, p 33).
Other MAs within the planning area, outside and north of proposed treatment units are MA 4, Botanical,
for the Frances Schrader Old Growth trail. These botanical areas are managed to protect areas of the
Forest with important botanical resources. Forest Service land adjacent to the Rogue River is allocated to
MA 7, Supplemental Resource, applicable to areas on the Forest considered highly productive or critical
habitats for wildlife and fish; are critical for the maintenance of watershed condition; or have special
recreation values. These areas are allocated to Administratively Withdrawn in the NWFP.
Desired Future Condition
The desired future condition is stands with multiple-canopy layers, complex stand structure, vigorous and
resilient trees, increased plant diversity and spatial complexity. Desired conditions and features include
large diameter trees, gaps in the forest canopy, a well-developed understory and shrub component,
diversity in species and age classes, and adequate levels of snags and dead wood.
Silvicultural Objectives
Develop late successional conditions, primarily multi-layered canopy structure, through variable
density thinning strategies and post-harvest stand improvement treatments to meet the intent of
the NWFP for management in LSRs.
Improve landscape-level forest health issues by planting resistant POC seedlings to introduce
resistance genetics in low risk areas to meet the intent of LRMP plan amendment objectives for
management of POC (USDA Forest Service, 2004). See POC risk key in appendix.
Create stand conditions along main roads that provide for safe ingress and egress for public and
fire suppression personnel in the event of a wildfire.
Silvicultural Treatments
Variable Density Thinning (VDT)
VDT uses a combination of low and crown thinning to release larger dominant and co-dominant trees.
Spacing between trees is variable or clumpy depending on tree diameter distribution on the ground and
thinning intensity. Individual stand characteristics will be heterogeneous post-harvest. VDT will be
applied to approximate natural disturbance events.
Gap Development
VDT treatments for Kimball Thin include creation of irregular shaped openings (i.e. gaps) up to ¾ acre in
size and interspersed within thinning units to release understory advanced conifer regeneration to expedite
development of understory canopy layers. Gaps will consist of no more than 20% of treatment acres
(including openings created by roads and landings). Gaps will not be created in Fire Management Zones
(FMZs).
Skips
Skips can be strategically placed to protect large legacy trees, unique features (e.g. cave in unit 130),
nesting, roosting foraging habitat for northern spotted owls (unit 127), and concentrations of existing
snags and/or down wood (unit 128). Skips will consist of at least 15% of the treatment area.
Fuel Management Zones (FMZ)
FMZs are secondary fuels treatments along main roads that overlap VDT unit boundaries to mitigate
activity-created slash. Treatment areas are approximately 100 feet on each side of NFS Roads #3300-090
and #3313-100.
POC planting
Planting treatments designed to restore POC within its natural range by planting non-PL infected areas
and low risk areas with disease-resistant POC. Recommended planting spacing is twenty-five (25) feet
apart or in approximately ten (10) tree clusters at 100-150 foot spacing to lessen the potential for root
grafting (USDA 2004, ROD, pg. 36). These spacing guidelines can be flexible to meet site-specific
conditions. Avoid stagnant water and plant POC in areas that maximize chances of maintaining moist
surface soil year-round.
Regional Ecosystem Office (REO)
Kimball Thin units are growing on very productive site conditions as described in the resource attributes
of the Affected Environment section. The proposed action mostly involves implementing a second
commercial thin on 72% of treatment acres. Field sampled plots to comply with the existing 20-inch
diameter limit for LSRs (REO memorandum, July 9, 1996) noted this constraint would not thin stands
heavily enough to create the desired site-specific canopy diversity objectives for this LSR treatment area.
A REO exemption to this 20-inch diameter limit was requested May 2014 with follow-up stand growth
modeling required from the district to demonstrate the need for this diameter limit exemption.
Forest Vegetation Simulator (FVS)
Stand harvest and growth attributes were modeled using Forest Vegetation Simulator (USDA FS: Dixon
2002; Keyser 2008) to determine the number of trees cut greater than 20 inches diameter and the largest
diameter tree cut to achieve treatment objectives. Two alternative treatment scenarios were modeled:
crown thin to create space between tree crowns to release overstory and understory trees while
maintaining an average 40% canopy cover across units,
thin from below to 160 ft2/acre* residual basal area while maintaining an average 40% canopy
cover across units (* basal area based on empirical field observations where existing understory
development appears to correspond with this residual density).
These modeled treatment scenarios approximate silvicultural treatments in draft alternatives 2 and 3.
There is an additional diameter limit constraint in alternative 3 to not cut trees > 20” to comply with REO
direction in LSRs. Harvest modeling resulted in revision to alternative 3 by dropping treatment units due
to this diameter limit constraint (see Simulated Treatment Discussion). The following table displays the
modeling results:
Kimball Thin - treatment comparison
unit # # TSE plots
Current BA
(100%)
CT BA (% left)
TB BA (% left)
CT CC
TB CC
CT >20" TB >20"
CT-TB >20" CT larg diam TB larg diam
122 7 269
(100%) 106
(40%) 160
(60%) 38 49 13 0 13 0.6 tpa - 29" n/a
123 3 320
(100%) 167
(52%) 173
(54%) 44 45 32.6 13.6 19 3.5 tpa- 30" 10 tpa- 27"
124 9 258
(100%) 104
(40%) 160
(62%) 40 53 7.1 0 7.1 1.1 tpa- 26" n/a
125 8 295
(100%) 150
(51%) 160
(54%) 43 43 31.3 22.5 8.8 0.6 tpa - 30" 8.8 tpa- 23"
126 8 235
(100%) 145
(62%) 160
(68%) 44 47 3.3 0 3.3 0.2 tpa- 29" n/a
127 30 220
(100%) 160
(73%) 161
(73%) 44 42 12.1 8.2 3.9 0.3 tpa- 30" 2.1 tpa- 22"
128 14 180
(100%) 174
(97%) 160
(89%) 46 41 0.2 0 0.2 0.1 tpa- 28" n/a
129 4 230
(100%) 160
(70%) 160
(70%) 43 42 17 13.6 3.4 0.9 tpa- 29" 6.3 tpa- 24"
130 0
AVE: 146 162 43 45 116.6 57.9
CT= crown thin BA= basal area per acre larg diam= largest diameter cut Green= unthinned
TB= thin below,160 BA TSE=timber stand exam CC= canopy cover tpa=trees per acre
Simulated Treatments Discussion
Crown thin treatments cut about twice as many trees per acre > 20” across all the treatment units (116.6)
compared to thinning from below treatments (57.9) to get space between tree crowns to release understory
and overstory trees.
Thinning from below to achieve the target 160 ft2/acre basal area density to expedite understory
development into multiple canopy layers could not be done in the previously thinned stands without
cutting trees > 20” (except for #128). Conversely, thinning from below treatments to achieve this target
density can be implemented in unthinned stands #122, 124, 126, 130 (est) without cutting trees > 20”.
The following table displays the percentages of trees > 20”within previously thinned units #123, 125,
127, 128 and 129 by two-inch diameter classes. . Approximately 52% of trees are > 20”.
Unit #128 appears to be an anomaly with wider spaced, larger trees and substantial advanced conifer
regeneration relative to the other previously thinned stands. This stand was thinned under a different 1992
timber sale, Kimball Thin II. Gap treatments would be effective for releasing the existing advanced
conifer regeneration to develop into a mid-story layer. This vegetative response was observed in the
southwest corner of this unit where a windthrown area created a natural canopy gap and understory trees
are substantially taller with noticeably more vigorous terminal leader height growth > 6”.
Largest Diameter
The largest tree diameters cut in each of the treatment scenarios are as follows:
ThinBelow- largest diameter cut is 27” in unit 123. Additional tree diameters cut > 20” are 23” in
unit 125, 22” in unit #127, 24” in unit #129. FVS modeling did not include gap creation
treatments.
CrownThin- largest diameter cut is 30” in units 123, 125 and 127. Additional tree diameters cut >
20” are 28” in unit 128, 29” in unit #129. FVS modeling did not include gap creation treatments.
Understory Response
A 50-year understory response comparison was simulated between thinning to 160 ft2/acre basal area and
no treatment. Stand Visualization System (McGaughey, 1997) diagrams displaying projected stand
conditions and understory development are displayed below:
No Action- Understory Response Thin 160 ft2/ac- Understory Response
Year 2065 – end of 50 year FVS simulation Year 2065 – end of 50 year FVS simulation
The following bar chart displays modeled results from these diagrams that show higher quantities
(trees per acre) of larger diameter, taller more developed understory 2-10 “trees from the thinning
treatment compared to no treatment.
Gap Treatments
Understory tree regeneration response was simulated for 50 years following overstory removal of trees to
simulate potential affects from gap treatments. Projected stand growth show tree diameters up to
20”within gap treatment areas (without any stocking level control - i.e. precommercial thinning). This
modeled growth response is likely overestimated as FVS is constrained to inputting 1,000 trees per acre
for simulating understory regeneration growth where field observations in Kimball Thin noted natural tree
regeneration over ten-fold this number. Post-harvest noncommercial thinning is recommended to culture
understory tree development within approximately 20 years of gap treatments to develop this cohort into
desirable tree characteristics (i.e. large branches, wider spaced, etc.) for late successional wildlife species.
Gap Treatments - end of 50 year FVS simulation (year 2064) Tree
Diameters Trees per Acre
(TPA) % of total TPA
2 0 0
4 0 0
6 8.3 2%
8 67.1 17%
10 80.2 21%
12 85.5 22%
14 51.2 13%
16 37 9%
18 54.8 14%
20 6.4 2%
TOTAL: 390.5
ALTERNATIVES
Alternative 1, No Action
Alternative 1 would result in no management actions to modify stand conditions. This would result in
continued closed canopy conditions with little development of multiple canopy layers, and limited gaps
where early seral plant communities may occur. These continued homogenous stand conditions could
continue on for a century or longer until gap dynamics or a disturbance introduces variability to the stand.
Individual tree growth will slow, live crown ratios will decrease, and trees will be less resilient to drought,
insects and disease, and fire disturbances.
Continued competition in higher density stand conditions will result in natural mortality, therefore
naturally recruiting more dead and down wood than action alternatives. The bar charts below show snag
numbers in the 10+”, 20+” and 30+” diameter categories projected into the next century.
Previously Thinned Stands Unthinned Stands
There is a projected increase in snag densities from no treatment as stand growth increases inter-tree
competition. Note the number of 30+” snags in the previously thinned stands being much higher due to
the initial commercial thinning in 1990-92 that contributed to larger tree diameters in the existing stands
being available to become future snags as stand relative densities exceed 70% in less than 20 years.
Understory Response
Additionally, understory development into multi-layered canopies is less developed in Alternative 1 as
noted in the 50 year FVS modeled understory response bar chart (see Simulated Treatment Discussion)
that shows the majority of trees <= 4” diameter by the end of the simulation. There would not be any
created gaps that could further expedite multi-layered canopy conditions and early seral vegetation.
Alternative 2, Crown Thin, treatment to include cutting trees up to 30” diameter
Alternative 2 would treat approximately 268 acres within 9 stands. Variable density thinning (VDT) will
be implemented using treatments to expedite development of late-successional stand characteristics,
particularly multi-layered canopy conditions.
Treatments include:
VDT using a combination of low and crown thinning to release larger dominant and co-dominant
trees. Spacing between trees is variable or clumpy depending on tree diameter distribution on the
ground and thinning intensity. VDT will be applied to approximate natural disturbance events.
Skips will be strategically placed to protect large legacy trees (>300 yrs old), unique features (e.g.
cave in unit 130), nesting, roosting foraging habitat for northern spotted owls (unit 127), and
concentrations of existing snags and/or down wood (unit 128). Skips will consist of at least 15%
of the treatment area.
Gap treatments will create irregular shaped openings up to ¾ acre in size and interspersed within
thinning units to release understory advanced conifer regeneration to expedite development of
understory canopy layers and early seral vegetation. Gaps will consist of no more than 20% of
treatment acres (including openings created by roads and landings). Gaps will not be created in
Fire Management Zones (FMZs).
FMZ treatments on approximately 100 feet on each side of NFS Roads #3300-090 and #3313-
100. Fuel treatment would involve piling and burning activity-created slash-piles and existing
fuels to reduce current fuel-loads to 5-10 tons per acre in the 1” to 6” diameter and removing
ladder fuels.
Tree planting up to 100 acres of disease resistant Port-Orford-cedar within gaps and other low
risk sites (USDA Forest Service, 2004) within the planning area.
Snag recruitment is lower with Alternative 2 relative to Alternative 1 due to release of overstory trees
through crown thinning treatments. Large diameter snags will be available in the future as ‘skipped’
legacy trees die from inter-tree competition and age. Additionally snag producing processes are present
on the landscape (i.e. bears, PL, edaphic). Snag creation to meet desired snag levels is recommended as
needed.
Previously Thinned Stands Unthinned Stands
Relative densities (see Relative Density Diagram in Alt 1) would be lowered below the zone of density
related tree mortality to allow for increased individual tree growth. Tree diameter growth would increase
from thinning treatments as trees have more growing space and less competition for site resources.
Understory Response
As noted in the 50 year FVS modeled understory response bar chart (see Simulated Treatment
Discussion) the understory layer would be more developed at the end of the simulation with the majority
of trees being >= 6” diameter and some trees up to 10” diameter. Additionally there would be created
gaps in Alternative 2 that would expedite development of multi-layered canopies with larger tree
diameters (>10”) and early seral vegetation. Port-Orford-cedar root disease-resistant genetics would be
introduced into gaps and other low risk areas to manage for healthy POC and contribute to improving
forest health issues identified in the Quosatna watershed analysis (USDA Forest Service, 1996).
Alternative 3, Thin from Below, cut trees <= 20” diameter
Alternative 3 would treat approximately 75 acres within 4 unthinned units # 122,124,126 and 130.
Variable density thinning (VDT) will be implemented using treatments to expedite development of late-
successional stand conditions with the additional objective of expediting the development of larger
diameter trees. No trees > 20” diameter will be cut.
Treatments include:
VDT using a combination of low and crown thinning to release larger dominant and co-dominant
trees. Spacing between trees is variable or clumpy depending on tree diameter distribution on the
ground and thinning intensity. VDT will be applied to approximate natural disturbance events.
Skips will be strategically layed out to protect large legacy trees (>300 yrs old), unique features
(e.g. cave in unit 130). Skips will consist of at least 15% of the treatment area.
Gap treatments will create irregular shaped openings up to ¾ acre in size and interspersed within
thinning units to release understory advanced conifer regeneration to expedite development of
understory canopy layers and early seral vegetation. Gaps will consist of no more than 20% of
treatment acres (including openings created by roads and landings). Gaps will not be created in
Fire Management Zones (FMZs).
FMZ treatments on approximately 100 feet on each side of NFS Roads #3300-090 and #3313-
100. Fuel treatment would involve piling and burning activity-created slash-piles and existing
fuels to reduce current fuel-loads to 5-10 tons per acre in the 1” to 6” diameter and removing
ladder fuels.
Tree planting up to 100 acres of disease resistant Port-Orford-cedar within gaps and other low
risk sites (USDA Forest Service, 2004) within the planning area.
Snag recruitment is lower with Alternative 3 relative to Alternative 1 and about the same as Alternative 2.
Thinning from below treatments generally remove suppression-related tree mortality by cutting the
intermediate and suppressed crown class trees and allowing larger dominant and codominat crown class
trees to release. Large diameter snags will be available in the future as ‘skipped’ legacy trees die from
inter-tree competition and age. Additionally snag producing processes are present on the landscape (i.e.
bears, PL, edaphic). Snag creation to meet desired snag levels is recommended as needed.
Unthinned Stands
Relative densities (see Relative Density Diagram in Alt 1) would be lowered below the zone of density
related tree mortality to allow for increased individual tree growth though would grow back to this density
threshold 10 years sooner in 2034 relative to Alternative 2. Tree diameter growth would increase from
thinning treatments as trees have more growing space and less competition for site resources (see Average
Diameter Growth Diagram in Alt 2).
Understory Response
Understory response would be less developed than Alternative 2 as canopy closure will occur sooner due
to thinning from below treatments that don’t impact spacing between tree crowns for larger trees by only
removing smaller trees. The understory response would be more developed than Alternative 1 by
releasing more understory vegetation compared to no treatment. Additionally there would be created gaps
in Alternative 3 that would expedite development of multi-layered canopies with larger tree diameters
(>10”) and early seral vegetation. Port-Orford-cedar root disease-resistant genetics would be introduced
into gaps and other low risk areas to manage for healthy POC and contribute to improving forest health
issues identified in the Quosatana watershed analysis (USDA Forest Service, 1996).
Cumulative Effects
Past Vegetation Management
The most recent vegetation management projects in the immediate vicinity of proposed treatment units
were implemented about twenty-five (25) years ago in the Kimball Thin and Kimball Thin II timber sales.
Approximately 186 acres of young Douglas-fir stands were thinned for stocking level control to maximize
timber productivity. These projects were the first commercial thinning stand treatments to occur along the
Kimball Hill ridgeline. The commercial thinning program on the Siskiyou National Forest was just
getting underway at that time (Ford, 1988). The current Kimball Thin project includes these previously
thinned stands which are proposed for a 2nd commercial thin using variable density thinning strategies.
Stand treatments prior to these timber sales were mostly regeneration harvests (i.e. clear cuts) with
subsequent tree planting to reforest sites to meet Forest stocking standards and sustainable timber harvest
objectives. The following map* displays past harvest activities on Forest Service land within 1 ½ mile
proximity to the proposed Kimball Thin treatment area. Approximately 82.2% (998.7 acres) of stand
treatments were HCC (Harvest Clearcut), 15.3% (185.6 acres) HTH (Harvest Thinning) and 2.6% (31.2
acres) HPR (Harvest Partial Removal) (Appendix A).
* past management from the Rogue River-Siskiyou NF managed stand GIS layer.
Equine Timber Sale
The Equine Timber Sale environmental assessment (USDA Forest Service, 2012) identified existing
conditions from past vegetation management projects that occurred in five 6th field subwatersheds,
including Quosatna Creek, where most of the proposed treatment units for Kimball Thin are located,. The
following information for Quosatana Creek 6th field subwatershed is derived from maps and tables
documented in this recent environmental analysis. * Private Acres. Recent clear cut harvest has been
observed on private lands adjacent to the southern boundary of Kimball Thin treatment area during
October 2015. Timber management on private lands is regulated by the Oregon Department of Forestry’s
Forest Practice Administrative Rules and Forest Practices Act. Private forest lands are assumed to have
been intensively managed for timber in the past, and currently harvested on 30-50 year rotations. Pre-
1996 harvest on private land in the Quosatna Creek subwatershed totaled 2,652 acres. Approximately
54% of the late-successional`habitat in the watershed has been harvested since 1956 (USDA Forest
Service, 1996).
Land Ownership by 6th field watershed (Table 3-2 excerpt, pg. 3-2)
Forest Service acres / (%)
BLM acres / (%)
Private acres* / (%)
Total 6th field acres /
(%)
Quosatana Creek 6th field 16,166 / (79%) 11 / (0%) 4,399 / (21%) 20,576 / (100%)
The following map displays land ownership and past treatment information for these five 6th field
subwatersheds, including Quosatna Creek (Appendix F, Map F-1, pg. F-1):
The following table excerpt displays past Forest Service activity information (1956-1992) that has
occurred within the Quosatana Creek subwatershed. About 20% (19.9%) of Forest Service land has been
previously harvested. Three-quarters (76%) of these stand treatments were regeneration harvests
(Appendix F, Table F-1, pg. F-2).
Clear Cut acres / (%)*
Thinning acres / (%)*
Partial Removal
acres / (%)*
Salvage
acres / (%)*
Total FS Treatment
acres / (%)*
Quosatana Creek 6th field
3,116 / (15.1%)
450 /
(2.2%)
528 /
(2.6%)
7 /
(0%)
4,101 /
(19.9%)
* percent of subwatershed acres
Future Planned Activities
The following map displays current and future Forest Service planned activities for the five 6th field
subwatersheds, including Quosatana Creek (Appendix G, Map G-1, pg. G-1):
The following table excerpt displays current and future foreseeable Forest Service activities occurring in
Quosatana Creek subwatershed (Appendix G, Table G-1, pg. G-2): Project Name General Actions Acres 6th field Watershed
Equine Thin Timber Sale
Commercial thinning of 52 to 100 year old second growth natural stands.
212 Quosatana Creek
Long Ridge/Sorrel Meadow restoration treatments including: commercial timber harvest, slash treatments, and prescribed fire.
54 Quosatana Creek
Punt Timber Sale Plantation thinning in 40-50 year old stands and associated fuel treatments, and road reconstruction activities.
526 Quosatana Creek Upper Hunter Creek
Hobby Timber Sale Plantation thinning in 40-50 year old stands and associated fuel treatments, and road reconstruction activities.
500 Quosatana Creek, Rogue River-Copper Canyon
Quosatana Creek Watershed Analysis (USDA Forest Service, 1996)
From 1910 to the mid-1930s ten human-caused fires burned over 30% of the watershed. About 40% of
the watershed has been burned by stand replacement events. Low intensity fires have occurred on
serpentine ground in the western half of the watershed, while higher intensity fires have created
brushfields in the eastern half. Ridgetop Douglas-fir stands along the eastern and northwest rim likely
originated from stand-replacement fires. Nine fires were recorded after 1956, none were over two acres.
Eden RidgeTimber Sales
The following information regarding cumulative effects (chapter III, pgs. III-40 to III-41) is from Eden
Ridge Timber Sales FEIS (USDA Forest Service, 2014). This cumulative effects analysis will use this
strategy. Italics added for emphasis.
Cumulative Watershed Effects
Effects of variable density management (thinning) treatments and other connected actions on the risk for
adverse cumulative watershed impacts.
Past activities are considered part of the existing condition. To understand the contribution of past actions
to the cumulative effects of the Proposed Action, this analysis relies on current environmental conditions
as a proxy for the impacts of past actions. This is because existing conditions reflect the aggregate impact
of all prior human actions and natural events that have affected the environment, and might contribute to
future cumulative effects. FEIS Appendix C (Hydrology Report, incorporated by reference) includes more
detail on current watershed and water quality conditions, characteristics, and risks for adverse cumulative
watershed effects.
Cumulative effects analysis does not attempt to quantify the effects of past human actions by adding up all
prior actions on an action-by-action basis. There are several reasons for not taking this approach. First, a
catalog and analysis of all past actions would be impractical to compile and costly to obtain at the scale of
the entire Forest. Current conditions have been impacted by many actions over the last century (and
beyond), and trying to isolate the individual actions that continue to have residual impacts would be
nearly impossible. Second, providing the details of past actions on an individual basis would not be useful
to predict the cumulative effects of the Proposed Action. In fact, focusing on individual actions would be
less accurate than looking at existing conditions, because there is limited information on the
environmental impacts of individual past actions, and one cannot reasonably identify each action over the
last century that has contributed to current conditions. By looking at current conditions, the residual
effects of past human actions and natural events can be recognized, regardless of which particular action
or event contributed to those effects.
Kimball Thin Hydrology Report (January 9, 2015)
Italics added for emphasis.
Watershed Condition
A watershed analysis was completed for the Quosatana Creek watershed in 1996 in order to obtain
information on the condition of the watershed to guide future management projects. It was found that the
watershed was in good condition with some impact to smaller tributaries from roads and timber harvest,
which have decreased wood and increased sediment in some areas. However, very little impact from past
timber harvest or roads was seen in the larger perennial tributaries. The Rogue River is designated as
Wild and Scenic through the Quosatana Creek watershed.
In 2011 all watersheds within the Forest were analyzed using the Watershed Condition Framework
process (USFS 2010). This analysis found that the Gold Beach and Quosatana Creek watersheds are in
condition class I, properly functioning (FSM 2521.1).
Alternative 2 (Proposed Action)
Direct and Indirect Effects
Under Alternative 2 commercial thinning of up to 300 acres of 60 to 75 year old Douglas fir dominated
stands would occur using ground based tractor and skyline methods. Up to 3000 feet of temporary road
may be needed to access these stands. Table 2 shows the amount of harvest and temporary road proposed
by watershed. Slash may be treated through prescribed burning, and hand piling and burning. Up to 100
acres of planting of disease resistant Port-Orford-cedar could also occur within the gaps created during
harvest activities.
Table 2. Acres of proposed treatment by 6th level watershed.
Watershed Acres in
watershed
Acres of proposed
treatment
(% of watershed)
Miles of proposed
temporary road
Quosatana Creek-
Rogue River 20,576
200
(1%) 0.5
Gold Beach-
Rogue River 27,092
70
(0.3%) 0
The following table documents potential hydrologic issues associated with the project proposal and the
level of concern associated with them.
Table 3. Watershed issue and level of concern in relation to the proposed action.
Watershed Issue Level of
Concern Rationale
Watershed Condition None
The watershed analysis indicates a need for commercial
thinning in approximately 500 acres of LSR to improve
the stand’s ability to develop late successional
characteristics. It also states that prescribed fire could be
used to achieve the objectives in LSR. No harvest would
be done in riparian reserves. No new specified roads are
planned, maintaining the current road density. There
would be no impact to the wild and scenic character of
Quoasatana Creek. Watershed condition would be
improved or maintained.
Stream temperature None
No thinning is proposed within riparian reserves and all
overstory vegetation will remain intact. The proposed
actions are consistent with the TMDL for Quosatana
Creek.
Sediment delivery Low
The proposed units are located away from any streams
and on relatively flat, to moderately sloped ground. There
would be no new road construction, and all temporary
roads would be decommissioned at the end of the project.
All skid trails and landings would be treated following
soil scientist direction to minimize erosion from these
sites. Any increased erosion that occurs would be
unlikely to reach a stream channel and would not impact
stream health or water quality.
Riparian Reserves None No thinning is proposed within riparian reserves.
LITERATURE CITATIONS
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Service, September 1996. Field Guide to the Forested Plant Associations of Southwestern Oregon.
Technical Paper. R6-NR-ECOL-TP-17-96.
Atzet, T., Wheeler, D. 1989. USDA Forest Service. Key Species for Plant Associations on the Rogue
River, Siskiyou, and Umpqua National Forests. Compiled by Anita Seda. R6-TM-TP-009-89. Updated
1997. R6-NR-ECOL-TP-026-97.
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Ranger District, Mt. Hood National Forest.
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Unpublished, 3 pages.
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Northwest Region, Grants Pass, OR.
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Impact Statement on Management of Habitat for Late Successional and Old-Growth Forest Related
Species Within the Range of the Northern Spotted Owl. Two volumes and appendices. Portland, OR.
USDA Forest Service, 1996. Quosatana Creek Watershed Analysis, Iteration 1.0. 61 pp plus appendices.
USDA Forest Service, 2004. Record of Decision and Land and Resource Management Plan Amendment
for Managemento of Port-Orford-cedar in Southwest Oregon, Siskioyou National Forest. Portland,
Oregon. 485 pp.
USDA Forest Service and USDI Bureau of Land Management, 2004. Southwest Oregon Late-
Successional Reserve Assessment, May 12, 2004 update.
USDA Natural Resource Conservation Service, September 2005. Soil Survey of Curry County, Oregon.
303 pp.
USDA Forest Service, May 2007. Decision Notice, Coastal Healthy Forest Treatments, Chetco, Gold
Beach and Powers Ranger Districts. Rogue-Siskiyou National Forest. 17 pp.
USDA Forest Service, February 2012. Equine Thin Project, Environmental Assessment, Gold Beach
Ranger District Rogue-Siskiyou National Forest.
USDA Forest Service, February 2014. Eden Ridge Timber Sales, Environmental Impact Statement,
Powers Ranger District Rogue-Siskiyou National Forest.
Vaclavik, Tomas, Alan Kanaskie, Everett M. Hansen, Janet L. Ohmann, Ross K. Meentemeyer. 2010.
Predicting potential and actual distribution of sudden oak death in Oregon: Prioritizing landscape contexts
for early detection and eradication of disease outbreaks. Forest Ecology and Management 260 (2010)
1026-1035.
Weinhold, M., February 1995. Lower Rogue River Basin Watershed Condition Assessment. Prepared by
Lower Rogue Watershed Council Staff for State of Oregon Watershed Health Program. 96 pp.
APPENDIX
To: Kimball Thin Project Record From: Kimball Thin IDT
Subject: Notes from Field Review Meeting
Date: August 19, 2015
Attendees: Holly Witt (Wildlife Biologist), Gretta Smith (Environmental Coordinator), Steve Boyer
(Pacific Zone Silviculturist).
Notes: Holly made a distinction between ‘legacy’ trees and ‘remnant’ trees. Legacy trees are larger
diameter, open grown 40-60” trees likely over 300 years old. Remnant trees are large branchy trees that
survived the last large fire but are not as old as the legacy trees.
She would like ½ site potential tree (80-90 feet radius) no treatment buffer around legacy trees as
was recommended by Dave Clayton.
Remnant trees will not be cut though thinning from below and understory treatments could occur
in proximity.
With this distinction there are four age class tree cohorts in the Kimball Thin (KT) project, with active
treatments occurring for trees < 80 years old and some kind of stocking-control treatments, either through
chainsaw or Rx fire, for the understory conifer/hardwood regeneration.
Steve stated the project keyed to a wet Douglas-fir/Tanoak co-climax plant association (LIDE3-
PSME/GASH-VAOV2) with presence of both tree species in the seedling/sapling, mid-story and
overstory layers. Understory tanoak release was projected in FVS (Forest Vegetation Simulator) from
opening of the overstory canopy layer through thinning. We later observed this vegetative response in a
large canopy gap created by several windthrown trees in the southwest corner of unit #128.
Holly stated KT is in proximity to 3 owl sites (2 home ranges and 1 owl core). We looked at an area
adjacent to the 3313-100 road in unit#127 considered to be good NRF (nesting, roosting, forage) habitat
for spotted owls, possibly meeting the intent of RA-32. She stated this area had good late-successional
attributes except for large snag/down wood component.
She would like to have this area delineated as a skip (apprx 10 acres).
Steve thought this skip could be layed out to be contiguous with an area to the east, off the 3313-118
road, outside of proposed treatment units, that has numerous large snags present due to disease and
possible soil conditions.
We discussed the FMZ (fuel management zone) that is proposed on both sides of the 3313-100 and
whether or not prescribed underburning would occur. She is concerned about burning up any existing
snags and down wood in this skip.
Outside of the NRF skip, thinning treatments need to maintain 40% canopy cover.
Steve talked about possibly managing for tanoak in the overstory as there are opportunities to release tree-
size tanoak (and other hardwoods -madrone, chinkapin) by thinning back competing Douglas-fir (i.e.
hardwood release). Adjacent late-successional stands have clumps of hardwood trees interspersed in the
overstory. He will talk to Ellen Goheen about the possible consequences from SOD (sudden oak death)
from this strategy as the KT project area is within the new expanded quarantine area boundary.
We walked through unit 128 to determine suitability for NRF habitat. Holly didn’t feel the vegetation
structure made good NRF as the area likely burned hot from previous fires as evidenced by lack of legacy
trees, dry site indicators (white leaf manzanita), and landform position. There appeared to be parts of this
unit that were not treated from the first commercial thin 25+ years ago. There is also a portion of #128 in
the center of the unit that didn’t appear to be good tractor ground. Also discussed:
post-harvest snag creation in the larger 30-36 inch Douglas-firs @ about 2 trees per acre.
retaining deformed and broken topped trees .
possible diameter limit of 28 inches, as modeled in FVS last year, for thinning treatments.
Skip around concentration of soft snags (Holly GPS’d).
When we finished our walk-thru Steve asked the group what they thought was good rationale for cutting
trees > 20 inches for KT. Holly said development of multi-layer canopies is needed in KT. This could be
accomplished by:
Gap treatments.
Hardwood or remnant tree release.
Thinning wider and developing the understory through management with fire or chainsaw.
We stopped by unit #123 and Holly determined that a portion along the northern boundary of this unit
meets marbled murrelet criteria (6 large trees with platforms within 5 acres). Steve agreed this area meets
the criteria. There was some discussion on redelineating occupied marbled murrelet habitat due to the
presence of these large trees and the possibility of this redelineation extending into unit #124 due to large
trees with platforms present in that unit.
August 20, 2015
Stephen F. Boyer
Pacific Zone Silviculturist
PORT-ORFORD-CEDAR RISK KEY
The POC Risk Key is used to clarify the environmental conditions that require implementation of one or
more of the disease controlling management practices listed in the 2004 Record of Decision (ROD) and
Land and Resource Management Plan Amendment for Management of Port-Orford-cedar in Southwest
Oregon Siskiyou National Forest. The objectives of the amended POC management Standard and
Guidelines are to:
Maintain POC on sites where the risk for infection is low.
Reduce the spread and severity of root disease in high-risk areas to retain its ecological function
to the extent practicable.
Reestablish POC in plant communities where its numbers or ecosystem function have been
reduced.
Reduce the likelihood of root disease becoming established in disease-free 7th field watersheds.
Program objectives are to maintain POC as an ecologically and economically important species on
National Forest (NF) lands. POC management will provide cost-effective mitigation for management
activities that create appreciable additional risk to important uninfected POC though not to reduce all risk
to all trees at all cost (USDA-FS 2004). In areas proposed for timber harvest and road building, mitigation
would be required as described in the POC Risk Key assessment (USDA 2004, Appendix A).
Project-specific NEPA analysis will appropriately document the application of the Risk Key and the
consideration of the available management practices. Application of the Risk Key and application of
resultant management practices will make the project consistent with the mid- and large-geographic and
temporal-scale effects described by the SEIS analysis, and will permit the project analysis to tier to the
discussion of those effects (USDA FS 2004).
Application of the Risk Key
1a. Are there uninfected Port-Orford-cedar (POC) within, near, or downstream of the activity area that’s
ecological, Tribal, or product use or function measurably contributes to meeting land and resource
management plan objectives? Yes.
Measurably contributing POC and PL infection is present west of the private inholding around Doe
Swamp. This area is proposed for commercial thinning treatments, road reconstruction of an
existing railroad grade and construction of a new system road to access ER Units# 326 and 327.
Harvest units and road building are within a wet western hemlock plant association (Atzet et al.
1996).
1b. Are there uninfected Port-Orford-cedar within, near, or downstream of the activity area that,
were they to become infected, would likely spread infections to trees whose ecological, Tribal, or
product use or function measurably contributes to meeting land and resource management plan
objectives? No.
Surrounding treatment areas near or downstream of the Doe Swamp area are inventoried as
canopy cover 1, which indicates POC as not measurably contributing to LRMP objectives at the
stand-level scale.
Whether or not areas with POC are considered measurably contributing in the ER Planning Area,
landscape-scale POC distribution should be considered as surrounding private timber company
land downstream from the Doe Swamp area is being managed for Douglas-fir regeneration on a 50
year rotation. The ecological value of maintaining healthy POC during treatment activities on
Forest Service land should be considered important for vegetation diversity.
1c. Is the activity area within an un-infested 7th field watershed as defined in Attachment 1? No.
2. Will the proposed project introduce appreciable additional risk of infection to these un-
infested Port-Orford-cedars? Yes.
Recommended Management Practices (Mitigation Measures)
Project Scheduling- schedule commercial treatments/road building west of Doe Swamp to occur during
the dry season (or wash project equipment).
Utilize Uninfested Water- Use uninfested water sources for equipment washing, road watering and other
water-distribution needs or treat water with Clorox bleach to prevent/reduce the spread of PL.
Unit Scheduling- Conduct work in all timber sale units where PL is not present before working in units
infested with PL.
Road Management Measures- Implement proactive disease-prevention measures including not building
roads (e.g., Road W through PL pockets in Units 326 and 327) or relocating the proposed road to avoid
these infested areas.
Resistant POC Planting- Silvicultural prescriptions for sites having potential for growing POC will
provide for the establishment of the species through natural or artificial regeneration and maintenance as a
viable stand component through the current and future rotations.
Washing Project Equipment- Wash project equipment prior to beginning work in uninfested project
areas, when leaving infested areas to work in uninfested areas, and when leaving the project area to
minimize the transportation of infested soil to uninfested areas.
Roadside Sanitation- Remove POC along both sides of the road. Recommended width is 25 feet above
the road or the top of the cut bank and 50 feet below the road. Remove POC 100 feet below the road
where crossing streams.
Site-Specific POC Management- Manage to favor POC uphill from creeks, on ridgetops and on well-
drained sites to emphasize management of POC on sites where conditions make it likely that trees will
escape infection. Emphasis may include priority retention during thinning or other silvicultural treatments
and planting to increase the presence of POC in areas unfavorable to PL.
Recommended Treatments
The following active treatments (Figure 8) are recommended:
Figure 8. Port-Orford-Cedar Root Disease Treatments
Roadside Sanitation Wide Thin Gaps
Wide-Thin Gap Treatments
Remove all live POC within PL infection sites. Leave non-susceptible tree species on site. Thin out all
live POC within 2 to 3 crown radii from last infected POC along the perimeter of infection sites to
separate healthy POC from potential root contact with infected POC. Pile and burn all POC slash and
follow-up underburn to potentially mitigate disease presence. Sites can be planted with non-susceptible
tree seedlings.
Roadside Sanitation
Manage for non-susceptible tree species by removing all POC along road sides and high risk sites as
follows:
100-feet each side of roads at stream crossings.
25 feet above roads and 50-feet below roads in areas.
Planting
Restore POC within its natural range by planting non-PL infested areas and low risk areas with resistant
POC. Gaps and root rot pockets may be site prepared and planted with Port-Orford-cedar seedlings for
stand health and enhance structural and species diversity within a stand.
Recommended planting spacing is twenty-five (25) feet apart or in approximately ten (10) tree clusters at
100-150 foot spacing to lessen the potential for root grafting (USDA 2004, ROD, pg. 36). These spacing
guidelines can be flexible to meet site-specific conditions. Avoid stagnant water and plant POC in areas
that maximize chances of maintaining moist surface soil year-round.
POC’s distribution in Coos County appears primarily to reflect edaphic conditions (Zobel, 2011). During
introduction of disease-resistant POC, the General Soil Type Digger-Preacher-Remote is an appropriate
soil type to plant POC (based on POC’s native distribution in historical cruise data in pre-harvest forests).
ER is within the ‘Oregon Transitional’ Block/Zone 340 (2,501-4,000 ft. elevation) for disease-resistant
seed (Hamlin, 2005). Seed is collected from seed orchards established since 2001 at the Dorena Genetic
Resource Center, USDA Forest Service, in Cottage Grove, Oregon. Seedlings should be grown primarily
from this seedlot.
Plant openings created by WTG treatments in PL pockets with Douglas-fir where openings > ¼ acre.
Western hemlock is anticipated to naturally regenerate in openings and does not need be planted. Do not
plant POC as these PL pockets are considered high risk and should be managed for non-host species to
reduce the potential for long-term PL disease persistence on site. Post-planting tree netting of seedling
terminal buds may be needed to reduce big game browse damage on Douglas-fir.
Climate Change Consideration
In anticipation of potential climate change and species migration, combine seedlots for sowing POC seed
for planting as follows:
Original Lower Southern
Zone Elevation Zone Latitude Zone
340 (50%) 325 (25%) 440 (25%)
If a lower elevation or southern latitude source is not available, then increase the original zone percentage
accordingly (Hamlin, 2009).
The Tyee Formation is the dominant geologic type in the coastal mountains in Douglas, Lane, and
Lincoln counties and extends as far north as Tillamook County. Tyee supports moderate performance of
POC in terms of both its incidence and volume. Knowing the relative performance of POC on these
edaphic units should help to decide where POC could be introduced during efforts to move its range north
as climatic warming continues (Zobel, 2011).
In areas proposed for timber harvest, road construction, reconstruction and maintenance; wash all vehicles
before entering work site and wash all vehicles after working in PL infection sites (see mitigation
measures in POC Risk Key assessment, EIS Appendix B for details).
