Western Juniper Woodlands Reconnaissance Form
Western Juniper Woodlands Reconnaissance Form
Lost River Ranch, Bonanza, OR.
1. File Data
Project: Western Juniper Harvest Systems Comparisons Proj., Lost River Ranch, Bonanza, OR.
Date: September & October, 1996
By Whom: Larry Swan, U.S. Forest Service (with assistance from Bill Hopkins, U.S. Forest
Service, Zone Ecologist)
2. Location Information
Legal: T39S, R11 1/2 E, SE 1/4 of SW 1/4 of Section 22, Northern Geodetic Vertical Datum
of 1929
Access: Unit located on private land adjacent to North Poe Valley Rd. Dirt road bisects unit.
Map Ref.: USDI, Geological Survey, Diary Quad, OR. (1985). Scale = 7.5'
Aerial Photos: 7-6-93, BLM, 12 , 6-93-BLCI, 2-16A-6, 7
1990, NRCS, P35, Tract 852
3. General Description
Acres:
Scabrock = 0.8 ac
Low Density Juniper (0-49 trees/ac) = 4.5 ac
Medium Density Juniper (50-99 trees/ac) = 3.8 ac
High Density Juniper (100-150+ trees/ac) = 5.6 ac
Total = 14.7 ac (per NRCS aerial photo)
Elevation: 4,140 ft.
Aspect: Southwest
Slope: 0-5%
Soil Type/ Depth: See soils report (Nicita 1996)
Low Density Stand = Loamy overburden (20 in. deep)
Medium Density Stand = Clay to clay loam
High Density Stand = Lithic, clayey
Rock:
Visible Scabrock = 0.8 ac in NW corner of unit
High Density Stand, Very lithic = 5.6 ac.
Timber:
See acres summary above. Even-aged western juniper overstory, ranging from low density to high density.
Brush: <1% (scattered sagebrush and a few scattered Ribes sp.)
Other: Project site is located on a portion of the west-facing slope of a low-lying peninsula of
western juniper woodlands. The peninsula is surrounded on three-sides by irrigated
pasture and crop lands. Three small ephemeral drainages are present in the northwest
portion of the project site.
4. Stand Data
Site Index (per Sauerwein 1982): 29-33 (medium high to high for medium and high density stand
areas)
Site Index Samples | |||
Stand Density | Tallest Tree Per 1/5 Acre Plot | Age at DBH | Index |
High Density | 43 | 73 | 33 |
Medium Density | 45
42 |
73
80 |
33
29 |
*Low Density | 38
40 |
75
73 |
28
29 |
*Special Note: Site index not considered valid for low density portion of stand. According to
Sauerwein (1982), site index curves were calculated for "well-stocked" stands, "mostly in the 65-100
range, while on higher sites, up to 250 trees per acre were counted". Low density stand in this case
averaged 35 trees/acre.
Narrative Description of Overstory/Understory:
Western juniper entirely dominates the overstory, ranging from 25-35 stems/acre in the lowest density
area to 120-160 stems/acre in the highest density area. Shrub cover is sparse, consisting of a few big
sage brush (Artemesia tridentata) and current (Ribes sp.). A dense carpet of cheat grass (Bromus
tectorum) dominates the groundcover. Medusahead (Taeniatherum captu-medusa), a noxious weed,
was observed in patches adjacent to the project site and was sparsely present in a small area of
scabrock in the northwest corner of the project site. No harvest activities occurred in areas with
medusahead.
Juniper canopy cover was estimated from aerial photographs to be less than 10% in the low density
area and greater than 60% in the high density area. Juniper reproduction is sparse. Older junipers are
present just east of the project site in an area of scab rock, however ages were not determined. Based
on previous experience, they appeared to be at least 200 years old.
Previous Logging: None. Very few stumps evident.
Animal Damage: None observed.
Competing Veg.: See "narrative description" above.
Overstory Stand Data: See Table 4: Lost River Ranch Stand Data Summary
- Species Comp: Western juniper.
- Age: 77 at DBH; 89 at stump height
- Ht./DBH Range: Sapling-48 ft.; Sapling-24.7 in.
- Distribution: Stand is even age; reprod. is scattered and sparse.
- Density: Scabrock = 125/ac (0-9" DBH; 0-25 ft.)
- Low Density = 35-49 trees/ac
- Medium Density = 50-99 trees/ac
- High Density = 100-150+ trees/ac
- Growth Vigor:
- Low Density = 10/20 last 10 years
- Med Density = 10/20 last 10 years
- High Density = 8-16/20 last 10 years
- Pathogens: None observed.
- Miscel. Comments:
Stand is even-aged. A few scattered old growth located to east of unit in scabrock. See table labeled "growth samples" for growth history - usually peaks before 50 years and then tapers. A few snags noted in SE corner of unit. No visually obvious reasons for mortality evident.
Understory Stand Data:
- Species Comp.: Western juniper.
- Age: Unknown
- Ht/DBH Range: Seedling/Sprout/Sapling
- Distribution: Scattered
- Density: Sparse
- Growth/Vigor: Growth = Unknown; Vigor = Seemed browsed.
- Pathogens: None noted.
- Narrative: Very sparse juniper reproduction, mainly stump sprouts and a few saplings; more reproduction in scabrock in NW portion of unit.
5. Proposed Treatment
Landowner Objectives: Improve forage for cattle and horses, and maintain cover for domestic
livestock and wildlife, especially resident deer herd.
Silvicultural Prescription: Seed before harvest operations with dryland pasture mix (lbs/acre?) and
thoroughly scarify ground surface after harvest (see attached FAX
message from Mike Borman, OSU Range Extension Agent, regarding
cheatgrass treatment options).
Remove 60-80% of stand, concentrating on leaving clumps and
screening along fence lines. Leave all trees with bird nests or cavities.
Concentrate clumps to maximize solar protection and protection from
storm track winds from west. Delimb all leave trees to 6 ft. to improve
cover access for livestock and deer.
Slash Treatment: Leave scattered clumps and piles for wildlife (2-4/ac) and scatter
remainder of slash. Maintain existing heavily-traveled animal trails
along fence lines.
Monitoring: Establish series of exclosures with landowner permission, and monitor
once per year for seeding success and reestablishment of native species.
Establish photo points and record annually in spring. Landowner does
not report any immediate plans to graze livestock in area, other than a
few horses in the spring and summer. Cattle are fed on peninsula to
east during winter months, but do not appear to come into area very
often (very few cow plops).
6. Harvest Plan
System: Chainsaw fall; manually delimb on site or skid to central landing and
mechanically delimb; remove and scatter slash back onto site.
7. Red Flags
Noxious Weeds: Medusahead observed on peninsula uphill and to east of unit where cattle are
fed during winter months; a few sprouts observed in scabrock area in NW
corner of unit.
Fence Lines: Protect existing fence lines.
Drainages: Three ephemeral drainages in northern portion of unit - dry during Sept. and
Oct.
8. Other Resource Information
Archaeological Sites: None. Only one obsidian flake observed. Small rock wall outside SE corner
of unit.
Recreation: None
Wildlife: Resident herd of deer (10-15); large owl (great horned?); lots of small birds
and robins feeding on berries; up to 25 deer in area during harvest.
Soils Sensitivity: None expected - lithic and dry.
Boundaries: Well established and marked by fence lines.
9. Unit Layout
Marking: Tried blue paint, but switched to flagging clumps due to difficulty seeing paint
under low crowns.
Boundaries: Clearly evident - fence lines to west and north; scabrock to east; road to south.
Sketch Maps: None produced.
Bonanza, Oregon
Timing & Stand Density | DBH Range (in) | DBH Average (in)(1) | Height Range (ft) | Height Average (ft) | Trees/Acre (Live) | Volume/Acre (cu ft)(2) |
Preharvest Low Density Med. Density High Density |
5.0-18.5 9.6-16.7 Sap-20.1 Sap-17.6 Sap-24.7 |
10.4 13.6 13.0 14.1 11.7 |
11-38 23-45 Sap-47 Sap-48 Sap-47 |
24.7 36.4 32.3 38.0 35.8 |
35 35 60 160 120 |
220 420 730 1175 810 |
Summary | Sap-24.7 in | Avg 12.6 in | Sap-48 ft | Avg 33.4 ft | Avg. 82 | Avg 671 cu ft |
Post Harvest Low Density Med. Density High Density |
13.1-17.4 10.2-18.6 10.2-15.7 5.6-22.9 6.4-14.7 Seed-12.1 10.7-24.7 4.4-16.9 6.7-15.9 |
15.9 15.5 13.2 14.9 9.6 9.2 14.8 9.9 10.4 |
35-44 19-41 34-42 20-47 26-48 Seed-40 30-47 28-47 21-50 |
39.3 33.8 40.0 37.7 37.3 28.3 36.2 36.6 36.5 |
20 20 15 15 15 45 25 50 40 |
300 275 173 275 110 155 380 353 298 |
Summary | Seed-24.7 in | Avg 12.6 in | Seed-50 ft | Avg 36.2 ft | Avg 27 | Avg 258 cu ft |
1. Averages for DBH and height do not include seedling/saplings.
2. Cubic-foot tree volume from 12 in. stump to 4 in. top (Chittester and MacLean 1984).
September 4, 1996
To: Larry Swan
From: Mike Borman
Subj: Juniper treatment options
After visiting with Bill Krueger and Lee Eddleman, we have some options to consider. However, recognize that the risk of failure is quite high (>50%). We haven't been on the ground to evaluate soils, potential other vegetation, longevity of cheatgrass on site, etc. You might consider trying more than one option on different parts of the area you have available.
Option 1: If you can wait until spring to do the juniper treatment, cut and scatter in the spring, then bum it all in the fall to get the nutrient flush. This is not a normal recommendation, however, Lee suspects a nutrient deficiency that burning the juniper would help rectify. Then use a half-width rangeland drill to drill in a desired species as late as possible in the fall.
Option 2: If the cheatgrass still has the majority of its seed intact, burn now, drill a desirable species, then do the juniper treatment.
Option 3: If the cheatgrass has dropped most of its seed, use a propane burner to kill the seed on the ground, drill a desirable species, then do the juniper treatment.
Option 4. Thoroughly scarify the ground (to about 2") to bury much of the cheatgrass seed, then drill a desirable species, then do the juniper treatment. If drilling a desirable species is not an option, then broadcast seed and drag over it to get soil coverage.
Recognize that making these recommendations from a distance is risky. Also recognize that the probability of success for achieving a good forage stand iq low given the current cheatgrass, dominance,
Good Luck.
Mike Borman
Years | Sample No. 1 (High Density Area) |
Sample No. 2 (High Density Area) |
Sample No. 3 (High Density Area) |
---|---|---|---|
0-10 | NA | 27 | 26 |
10-20 | 13 | 45 | 38 |
20-30 | 16 | 53 | 37 |
30-40 | 21 | 40 | 31 |
40-50 | 21 | 28 | 12 |
50-60 | 19 | 20 | 17 |
60-70 | NA | 10 | 8 |
70-80 | NA | 8 | 8 |
80-90 | NA | 7 | 8 |