appendix c soils -...

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Appendix C – Soils Resources Report

Bybee Vegetation Management Project

High Cascades Ranger District, Rogue River-Siskiyou National Forest

/s/ Joni Brazier Date: July 11, 2011

Joni Brazier, Soil Scientist Revised: April 2012; October 2012


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I. Introduction The Bybee Project proposes to treat approximately 4,089 acres with a variety of silvicultural and fuels treatments designed to achieve the purpose and need of this project (see EA chapter I). Commercial harvest activities, natural fuels treatments, and other connected and associated actions have the potential to affect soils and site productivity through detrimental soil disturbance and effects to organic matter. The analysis area for this analysis is defined as the Bybee project planning area, identified in chapter I. Much of the information for geology and soils in the project planning area was summarized from the document “Soil Resource Inventory for the Rogue River National Forest” (Badura and Jahn 1977). This Soil Resource Inventory (SRI) also provides guidance relating to land management activities and potential soil effects which was reviewed and incorporated into this analysis. A copy of the SRI is available at the Forest Supervisor’s Office in Medford, Oregon.

An Ecological Unit Inventory (EUI) was also conducted in the 1990s across an area of the High Cascades Ranger District that includes the Bybee Vegetation Management project planning area. The purpose of the EUI was to provide integrated resource information for management of the forest landscape, and included identification and mapping of soils, geology/geomorphology, and plant ecology (Matrix Technical Staffing, Inc. 1997). The EUI has not been completed or published, but information from the soil plot field forms (unpublished data) and draft soil mapping (Matrix Technical Staffing, Inc. 1998a; Matrix Technical Staffing, Inc. 1998b) was also reviewed and incorporated into the analysis of the soils in the proposed treatment units. The EUI data is located at the Forest Supervisor’s Office in Medford, Oregon.

II. Existing Condition

A. Geological Overview The Bybee project planning area lies within the High Cascades Physiographic Province, which is comprised of a long, north to south oriented plateau bounded by the Western Cascades Physiographic Province to the west and by the Klamath Basin to the east. The geology in the area of the Bybee Project is further defined in the Upper Rogue River Watershed Analysis (USDA Forest Service 1995) as the Mazama Pumice Province, which consists of deposits of pumice and ash flows up to 300 feet thick, originating from the eruption of the former Mount Mazama (now Crater Lake) to the east.

The majority of the project planning area consists of areas where these deposits filled and frequently overtopped the pre-existing valleys, leaving broad, smooth, gently inclined surfaces, dissected by streams which over time have cut down through the pumice deposits creating steep pumice canyon walls. Also present are remnant residual landforms that rise above the pumice deposits consisting of basalts and andesites, most notably between Castle and Deer creeks and Deer and Bybee creeks, and mixed grain sediments from glacial and glaciofluvial activity. Elevations range from roughly 3,500 feet to the southwest, to 5,200 feet to the east.

Appendix C

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B. Soils The soils in the project planning area can be broken into three main categories based on the parent materials they are developing from: soils developing in the relatively young flow pumice deposits; soils developing in older basalts and andesite; and soils developing in mixed grain sediments from glacial deposits and glaciofluvial outwash materials. There are also small areas of permanently wet meadows associated with a high water table or ponded surface water (landtype 6). These landtype 6 areas are avoided and buffered to assure protection from any management activities. Figure C-1 displays the approximate locations of these soil categories and the landtype units associated with them. Figure C-2 displays how the soil landtypes in the project planning area are associated with the topography of the area.

Note that the GIS mapping of the locations of soil landtypes are approximate, and based on mapping scale may not line up accurately with other map features such as percent slope or stream drainages that help to define landtypes. The landtype unit descriptions in the SRI are used to refine the location of the soil landtype units in the field during implementation.

Figure C-1. SRI landtypes within the Bybee project planning area


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1. Flow Pumice Soils The majority of the project planning area is covered in soils developing in these deposits, which also include varying levels of sandy alluvial deposits, and consist of SRI soil landtype units 0, 26, 26H, 27, and 27H (within landtype complex 270/270H). Landtype 0 soils consist of easily defined, very steep pumice canyon walls along incised stream drainages, and are very unstable and subject to sloughing and raveling erosion processes. Due to their highly erosive nature and association with Riparian Reserves, these landtypes are avoided and buffered to assure protection from management activities.

Landtypes 27 and 27H are deep, excessively drained sandy loams on 20 to 55 percent slopes, forming in flow pumice and alluvial deposits. Landtypes 26 and 26H are the dominant landtype in this group, consisting of deep, excessively drained sandy loams and loamy sands on 5 to 20 percent slopes, also forming in flow pumice and alluvial deposits. Due to their low water holding capacity, lack of cohesiveness, and low level of nutrients, organic matter is very important for helping to retain soil moisture, build and cycle nutrients, and increase development of soil structure in these soil types. Organic matter and vegetation cover retention is also important for insulating against the unique, low conductive heat rates of pumice and ash soils which makes vegetation prone to frost damage.

Past harvest and site preparation methods (typically from the 1970s and earlier) often involved heavy machine piling of slash and/or use of a hot burn, which adversely affected the shallow topsoil, organic matter, and litter layers. Soils that experienced these treatments in the past are in a state of slow recovery.

These soils can also be subject to compaction. Soil structure deformation has been observed on the High Cascades Ranger District in these soil types on temporary roads, main haul skid trails, and landings. In field reviews, it was more difficult to locate evidence of residual detrimental compaction from past activities outside these main areas, despite past harvest methods that utilized heavy equipment operations throughout the unit. Overall, these soils are not as sensitive to compaction as fine textured soils with a higher clay content. Preliminary findings from the first 10 years of The North American Long-Term Soil Productivity Experiment had some unexpected initial results related to soil compaction and effects to soil productivity, leading to speculation that on droughty soils in particular, some level of soil compaction may improve water holding capacity (Powers et al. 2004).

Appendix C

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Figure C-2. SRI landtypes in relation to topography in the Bybee project planning area

2. Basalt and Andesite-Derived Soils These soils are predominately located on a relatively gentle ridge between Castle and Deer creeks, and Deer and Bybee creeks. Landtype 31H is the dominate landtype and consists of deep, well drained loams and clay loams on 10 to 35 percent slopes. These soils are developing from residuum (in place) and have not been influenced by glacial processes. Landtype 36H (within landtype complex 369H) consists of moderately deep, well drained loams and sandy loams on 50 to 80 percent slopes. They are located on the north and west facing basalt/andesite slopes above Deer Creek, and are associated with upper glacial trough walls.

Landtype 39H consists of deep, well drained loams and sandy loams on 45 to 80 percent slopes. They are located on the north and west facing basalt/andesite slopes above Deer Creek (within landtype complex 369H), as well as part of the north facing basalt/andesite slopes of Bybee Creek. They are forming in talus and colluvium and are associated with the middle to lower slopes of glacial trough walls. Landtypes 36H and 39H are moderately stable to stable but can be subject to ravel, rock fall, and occasional debris slides. Compaction, displacement, and loss of effective groundcover on these soils make them very susceptible to accelerated erosion due to steep slopes and the weak cohesive nature of the surface soil. Landtype 31H is unique in the project planning area in that these soils are more sensitive to the detrimental effects of puddling, caking, rutting, and compaction under wet soil moisture conditions due to a much higher clay content than other soils in the project planning area. Because of the more cohesive nature of the soil particles and the gentler slopes, these soils are typically stable and erosion potential is slight.


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However, these soils can be very sensitive to compaction from heavy equipment under wet soil moisture conditions, and displaced surface organic matter and soil can result in localized erosion.

Historic (typically from the 1970s and earlier) harvest and site preparation methods often utilized heavy equipment and did not always consider soil moisture concerns during operations, sometimes resulting in detrimental impacts to soil productivity from compaction, displacement, and/or erosion. Soils that experienced these treatments in the past are in a state of slow recovery.

3. Glacial Deposits, Outwash and Alluvium-Derived Soils These soils are predominantly located running parallel to the major stream drainages in the project planning area. Landtypes 14/14H and 15/15H consist of deep, excessively drained sandy loams and loamy sands. Landtypes 14/14H are developing on the flat glaciofluvial and outwash terraces with 0 to 15 percent slopes whereas 15/15H (within landtype complex 145 and 145H) are developing on 15 to 50 percent slopes where these terraces are being dissected by fluvial processes. Landtype 23 consists of deep, well drained loams and sandy loams on 50 to 80 percent slopes. This landtype is found along the upper southfacing slope above Castle Creek, and is developing in colluvium and glacial till deposits. Landtype 11H can be locally very stony and bouldery, and is composed of deep, well drained sandy loam glacial till deposits on 20 to 45 percent slopes. It is located in a couple of areas that extend into the project planning area from the east near the upper ends of Copeland and Castle creek.

Landtypes 14/14H and 15/15H are very similar to the pumice soils of landtypes 26/26H and 27/27H, minus the issues with low conductive heat rates, with the same level of importance for retention of organic matter and similar past impacts. Landtype 11H is generally a very stable soil with slight erosion potential, but can be adversely impacted by compaction, displacement, loss of effective groundcover, and localized erosion. Landtype 23 ranges from moderately stable to unstable and has the potential for debris avalanches. These soils are more highly susceptible to erosion and ravel where compacted and surface organic matter is lost or displaced.

Tables C-1 and C-2 identify the landtypes associated with the proposed silviculture and natural fuels units in alternative 2 (proposed action). Also identified in this table is the previous management history, which is useful to the subsequent discussion of how these activities have influenced soil characteristics.

Table C-1. Soil landtype units located within Bybee Project silvicultural treatment units

Unit Landtype (approximate percent of unit) Previous entry history

1 26 (100 percent) Yes


3 26H (100 percent) No



6 26H (100 percent) Partial

7 26H (97 percent), 11H (3 percent) No

8 26H (100 percent) Yes





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16 26 (90 percent), 14 (10 percent) No




20 26 (100 percent) No






26 26 (100 percent) Partial

27 26 (100 percent) No

28 26 (99 percent), 145 (1 percent) Yes

29 26 (61 percent), 145H (34 percent), 145 (5 percent) Yes

30 26 (44 percent), 369H (42 percent), 23 (14 percent) No


32 31H (75 percent), 369H (25 (percent) Yes









41 31H (85 percent), 270H (7 percent), 39H (8 percent) Yes

42 369H (95 percent), 270H (5 percent) Partial

43 31H (74 percent), 369H (26 percent) Yes

44 369H (85 percent), 31H (8 percent), 270H (7 percent) Yes

45 31H (95 percent), 369H ( 5 percent) Yes






51 31H (70 percent), 039H (29 percent), 270H (<1 percent), 26H (<1 percent)

No

52 270H (87 percent), 31H (10 percent), 26H (3 percent) No

53 369H (51 percent), 145H (34 percent), 26 (10 percent), 31H (5 percent)

No


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54 26 (83 percent), 145 (17 percent) Partial



57 26 (66 percent), 145 (34 percent) Partial




61 26 (75 percent), 26H (16 percent), 270H (9 percent) No






67 23 (61 percent), 31H (33 percent), 270H (6 percent) No

68 23 (69 percent), 31H (31 percent) No

69 26H (95 percent), 23 (5 percent) Yes


71 11H (88 percent), 23 (7 percent), 31H (5 percent) No








Appendix C

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Table C-2. Soil landtype units located within Bybee Project natural fuels treatment units


1a 26 (50 percent), 270 (50 percent) No

1b 26 (99 percent), 270 (1 percent) Yes

1c 26 (100 percent) Yes

1d 26 (100 percent) Yes

7a 26H (100 percent) Yes

7b 26H (100 percent) Yes

7c 26H (100 percent) No

7d 26H (100 percent) No


8b 26H (100 percent) Partial

8c 26H (100 percent) Yes


9b 26H (100 percent) Yes

9c 26H (100 percent) No

9d 26H (100 percent) Partial

4. Organic Matter and Coarse Woody Material Organic matter is critical for soil productivity. Due to the cold winters and dry summers in the project planning area, the organic matter at these sites is slow to decompose and a relatively thick mat of duff is able to accumulate on top of the soil. This duff layer prevents erosion, holds moisture, and is a nutrient sink, especially important on ash, pumice, and sandy soils. Opening the stand canopy to allow solar heating of the forest floor can decrease the amount of organic matter by increasing the decomposition rate, conversely allowing more nutrients to cycle. Coarse woody material is most important where canopy cover is reduced, particularly on the droughty ash, pumice, and sandy soils, to store heat from solar radiation more effectively than coarse soil can, store nutrients, and provide microsites of higher soil moisture. Refer to Appendix F – Terrestrial Wildlife Analysis for more information on coarse wood in the project planning area.

C. Past Forest Management Activities and their Influence on Soil Characteristics Past forest management activities have affected soils in the project planning area through compaction, displacement, removal of organic matter, burning, and erosion. Based on agency records, approximately 8,660 acres (53 percent) of the project planning area has had previous harvest entries.

Table C-3 summarizes the vegetation management history of proposed silvicultural and natural fuel treatment units associated with the proposed action. Past management history was determined through agency records and review of low elevation aerial photos, as well as field review of much of the project planning area. Past management included clear cuts as well as varying types of partial tree removal (such as shelterwood removal), dating back to the 1950s, but mostly occurring in the 1970s and 1980s. A potential for soil restoration activities exists in areas that have had past management.


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Table C-3. Vegetation management history within Bybee Project units

Management history Proposed Bybee silvicultural and fuels treatment units

No past management history 3, 4, 5, 6 (partial), 7, 9-11, 14, 16, 20, 26 (partial), 27, 30, 37, 38, 40, 42 (partial), 46, 49-53, 57 (partial), 61, , 67, 68, 70, 71, and 77 (partial); 1a, 7c, 7d, 8b (partial), 9c, 9d (partial)

Past management history – clear cuts 28, 29, 32, 41, 56, 60, 62, 63, 65 (partial), and 78 (partial); 1c, 1d (partial)

Past management history – all other commercial treatments (shelterwood, shelterwood removal, partial removal, seed tree, etc.)

1, 2, 6 (partial), 8, 12, 13, 15, 17-19, 21-25, 26 (partial), 31, 33-36, 39, 42 (partial), 43-45, 47, 48, 54, 55, 57 (partial), 58,59, 64, 65 (partial), 66, 69,72, 73, 74, 75, -76, 77 (partial), and 78 (partial); 1b, 1d (partial), 7a, 7b, 8a, 8b (partial), 8c, 9a, 9b, 9d (partial)

1. Detrimental Compaction, Puddling, Displacement, Erosion and Burning Past logging, site conversion, and site preparation activities—all using ground-based mechanical equipment—have led to compaction (which creates denser soils with a higher specific gravity) on many acres in the project planning area. Puddling is the destruction of soil structure (primarily when wet) by compaction, to the point where ruts or imprints are made. Detrimental displacement is defined as removal of more than 50 percent of a soil’s ‘A’ horizon (topsoil) from an area greater than 100 square feet that is at least 5 feet wide (USDA Forest Service 1998). All can result in reduced site productivity.

Prior to the 1990 Rogue River National Forest Land and Resource Management Plan, harvest and site preparation operations were conducted without present day standards and guidelines. Harvesting equipment may have had no restrictions on where to operate or under what soil moisture conditions. Historical management practices utilized heavy equipment and methods which often resulted in detrimental impacts to the soil beyond what would be allowed today. Areas that were harvested during wet conditions in these soils may have resulted in detrimental compaction, displacement, and surface erosion.

Residual soil impacts are typically greatest on landings, main skid trails, and where machine piling or windrowing removed the shallow organic topsoil layer of coarse textured sandy loam and loamy sand soils. Windrowing is a historical practice that utilized heavy equipment to remove and pile brush, often severely disturbing surface soil layers.

Though some areas within the project planning area were undoubtedly detrimentally burned in the past (i.e., the mineral soil surface changed color and the next ½ inch of organic matter was charred), little evidence of such effects are observable today, and usually only in areas that doubled as landings where large slash piles were burned. Evidently, soils have recovered over time, with vegetation recycling organic matter and microbes incorporating organic matter into the mineral soil. The size of areas still exhibiting characteristics of detrimental burning is estimated to be from 0 to less than 1 percent of any burned area.

Besides the naturally erosive, very steep pumice canyon walls, the majority of erosion in the project planning area is associated with existing roads. Roads are compacted surfaces that allow water to run overland rather than naturally infiltrate at the point of raindrop impact, and particularly if they are unsurfaced, will transport surface soils.

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The majority of this erosion occurs as sheet erosion off the road surface, cutbanks, ditches, and fill slopes. Since much of the project planning area is comprised of excessively drained sandy soils, this erosion is typically localized due to rapid infiltration as well as interception of coarse soil particles by neighboring soil and litter. In addition, the average watershed relief of the project planning area is also relatively flat to gentle sloping (4.5 percent), which also minimizes the extent of soil movement. Vehicle traffic during wet weather can increase erosion rates off the road surface from wheels loosening road surface soils, making them more susceptible to being moved by water, as well as causing tire rutting that channels water flows.

2. Characteristics of Proposed Units The silvicultural and natural fuels treatment units associated with alternative 2 (proposed action) have existing soil conditions that are presented in this section. Past management activities, the percentage of land that is detrimentally compacted, displaced, burned or eroded, sensitivity to compaction rating, and sensitivity to loss of organic matter rating for each unit (alternative 2) are listed in table C-4 and discussed below.

Past forest management activities are displayed below for each proposed unit. If any unit was machine piled (including windrowed) or burned as a site preparation activity, that is indicated (yes or no) for each unit. The estimated percentage of the units that are in a condition which is detrimentally compacted, puddled, displaced, eroded or burned, consistent with regional definitions, is also displayed for each unit.

Sensitivity to compaction and sensitivity to loss of organic matter are also displayed. The units that have a high sensitivity to compaction have high clay content and a moisture regime that is more likely to compact during treatment operations. The units that have a high sensitivity to loss of organic matter are on droughty coarse textured soils that are low in organic matter in the soil profile, thus are highly reliant on surface organics for the majority of its nutrients for site productivity.

Table C-4. Existing soil conditions of proposed silvicultural and natural fuels treatment units

Unit Machine

piled Burned

site prep Percent in detrimentally compacted, displaced, burned, or eroded areas

Sensitivity to compaction

Sensitivity to loss of OM

Silvicultural treatment units

1 Yes Yes 50 percent Low to Mod High

2 Likely No 25 percent Low to Mod High

3 No No 0 percent Low to Mod High









12 Yes No 60 percent Low to Mod High



15 No Yes 15 percent Low to Mod High


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Unit Machine

piled Burned
















28 Likely Yes 75 percent Low to Mod High

29 Likely Likely 75 percent Low to Mod High

30 No No 0 percent High High


32 Yes No 44 percent High High








40 No No 0 percent High Low to Mod

41 Yes Yes 75 percent High Low to Mod


43 No No 6 percent High Mod to High




47 Yes No 65 percent High Low to Mod










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Unit Machine

piled Burned










63 No Yes` 50 percent Low to Mod High















78 No Yes 29 percent Low to Mod High Natural fuels treatment units

1a No No 0 percent Low to Mod High

1b Yes No 45 percent Low to Mod High

1c Yes Yes 100 percent Low to Mod High

1d Yes Yes 36 percent Low to Mod High

7a Yes No 34 percent Low to Mod High

7b No Yes 14 percent Low to Mod High

7c No No 0 percent Low to Mod High

7d No No 0 percent Low to Mod High

8a No Yes 16 percent Low to Mod High

8b No No 9 percent Low to Mod High


9a No Yes 17 percent Low to Mod High

9b No No 8 percent Low to Mod High


9d No No 5 percent Low to Mod High

For the proposed silvicultural and natural fuels treatment units, the percent of area that was found to be detrimentally compacted, puddled, or displaced were identified on 1 inch = 400 feet scale aerial photographs, as well as reviewing historic NAIP satellite imagery in Google Earth.


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Roads, skid trails, and landings were measured in Google Earth, using the 1 inch = 400 feet scale photos as a guide. This method was not uniformly reliable as the canopy cover, where dense, would occlude the view. In these cases, additional percentages were added for detrimental compaction, puddling, burning, and soil displacement based on stand management history recorded in agency files (FACTS database), and where there was on-the-ground knowledge of past management activities and existing ground conditions.

Activities such as machine piling, windrowing, and piling and burning are all site preparation treatments that were accomplished with heavy ground-based equipment that often covered more than 20 percent of the unit treated. For these areas, an estimate of the severity of the treatment was made based on the type of treatments done, the length of time since the last treatment (time for recovery), and number of entries. In addition, soil disturbance level information that was gathered during field work for an Ecological Unit Inventory (EUI) in the 1990s (unfinished and unpublished) that included the project planning area also provided information for the final disturbance ratings. The disturbance levels from the ecological unit inventory correlate somewhat with the final estimates, though sometimes the EUI underestimates the actual disturbance and in other cases overestimates the disturbance level. This combined approach was selected as the most reasonable, cost effective, and scientifically sound process available.

3. Organic Matter and Coarse Woody Material Past management activities have impacted the amount and distribution of organic matter and coarse (large) woody materials in the project planning area. The majority of tractor piled or windrowed sites, and sites broadcast burned, had the highest impacts to surface organic matter. Organic matter levels are slowly rebuilding and recovering site productivity based on the rate of each site’s vegetation inputs. In areas where forest stands are experiencing infection and mortality from insects and disease, these trees would provide new coarse woody material over time to soils as they fall over and decay, in the absence of high intensity fire.

III. Effects Mechanisms and Analysis Framework

A. Silvicultural Treatments The proposed silvicultural treatments have the potential to affect soil productivity, organic matter, and large woody material through changes to vegetation. Detrimental disturbance as it relates to these silvicultural treatments will be discussed under ‘Harvest Systems’, below.

Vegetation uptakes nutrients from the soil in a mostly soluble, inorganic form and converts them into an organic form for metabolism. Most of a tree’s nutrients are distributed in the leaves, twigs, and branches. As the tree discards leaves, branches, and bark, or dies, the plant’s nutrients are returned to the soil. Organic material returned to the soil is decomposed and the nutrients are mineralized (i.e., converted to an inorganic form) by soil organisms depending on the soil’s physical conditions (moisture, temperature, aeration, etc.) (Farve and Napper 2009). All silvicultural treatments manipulate to various extents the vegetative component of a soil’s nutrient cycle.

In the forest, precipitation is intercepted, retained, and redistributed by the tree canopy. Water ultimately evaporates from the canopy (interception) or drips through (through-fall) or runs down the stems (stem flow) to the forest floor. Tree canopies intercept precipitation, moderating and metering its fall to the soil surface. They also redirect this intercepted moisture toward the drip line of the tree, and away from the base of the trunk.

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In extreme rainfall conditions in the absence of deep-crowned tree cover, such as following clear cut or shelterwood logging, the rate of water striking the surface could exceed the rate of the soil’s ability to absorb it, with localized sheet erosion a likely result. Such effects are generally only relevant to degrees of canopy removal associated with clear cutting or shelterwood logging, or high intensity stand replacement fire.

As discussed in chapter II, prescribed amounts of snags and downed wood would be left on a per-acre basis consistent with plant association group capabilities where existing amounts are below such levels. However, this mitigation is only effective where such snags are available in adequate numbers. Where they are not available, they would be created from remaining live trees. Snag creation would have a positive effect on long-term soil productivity since snags are a source of future down logs, which are a critical component of long-term soil productivity. However, there is a limit to this mitigation. Snag creation invariably creates “hard” snags, not those in advanced stages of decay.

Ideally, a stand would have representatives of snags in all stages of decay at any one time. Since silvicultural treatments and logging exert a disproportional impact on soft snags (since they are most likely to be felled as hazards) than hard snags, and they can only be replaced with created or retained hard snags, the inevitable result is an imbalance between the number of snags in advanced decay (near-term down logs) and hard snags (likely to remain hard as either a snag or down log) for a few decades.

B. Harvest (Logging) Systems Logging systems (ground-based, skyline-cable, and aerial) have the potential to adversely impact soil productivity through detrimental compaction, displacement, erosion, and loss of effective ground cover/organic matter. Ground-based systems typically have the greatest potential for effects, whereas aerial systems typically have the least potential for effects.

1. Ground-based Systems (tractor, rubber-tired skidder, harvester-forwarder) Ground-based logging systems have the greatest potential to adversely affect short and long-term soil productivity. Ground-based systems can be managed to result in 10 percent detrimental disturbance or less, in compliance with Forest Plan standards and guidelines.

Logging and other equipment can compact and ‘puddle’ the soils over which they operate (landings, skid roads, roadways, etc). Tractor, or ground based logging has the greatest potential to cause soil compaction, which decreases soil volume and pore space and modifies soil structure. This results in decreased gas, water, and nutrient exchange, slower root penetration, and can aggravate soil drought, especially in Mediterranean climates such as southwest Oregon (Atzet et al. 1989). Puddling is where soil structure is damaged, primarily when wet, by severe compaction, to the point where ruts or imprints are made and the soil structure has been so damaged that water cannot infiltrate into the soil profile.

Compaction may inhibit occupation of the soil by organisms that assist in the decomposition of wood to soil organic material that improves site productivity, and helps to aerate soil. Compaction can also inhibit the growth of beneficial fungi (mycorrhizae) that provide nutrients to plant roots (Keslick 1997). Ectomycorrhizal fungi form an essential interface between soil and trees. They usually colonize over 90 percent of a host plant’s feeder roots (Goodman and Trofymow 1998). Plant development is also restricted in compacted soils due to poor aeration and impeded root growth, adversely affecting soil productivity (Floch 1988).


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Soil moisture content, soil characteristics, and force affect the level of compaction that can occur from harvest systems. Fine-textured soils dominated by expandable clay minerals, and well-graded, coarser textured soils are most likely to compact when moist, whereas finer textured soils dominated by non-expandable clay minerals, and poorly graded, coarser textured soils such as most pumice and coarse ash soils, are less affected by soil moisture (Atzet et al. 1989).

Compaction from logging activities is routinely mitigated, by:

Designating and minimizing the number of skid trails used; Requiring logging equipment to use roads and skid trails created during past timber

harvest where feasible; Using equipment and/or techniques effective in preventing or minimizing compaction

(such as low psi (pounds per square inch) or operating on slash to disperse weight); and Allowing operations only during conditions when soils are unlikely to be detrimentally

compacted beyond LRMP allowances (such as on dry or frozen ground or over deep snow with a firm base).

These mitigations have been proven successful and would be applied to all action alternatives.

Detrimental displacement is defined as the removal of more than 50 percent of a soil’s ‘A’ horizon (topsoil) from an area greater than 100 square feet that is at least 5 feet in width. This displacement occurs by natural means, such as heavy rains causing erosion on exposed surfaces (such as skid trails and skyline corridors), or by mechanical means such as churning tractor treads or logs dragged across the ground. Erosion is a form of detrimental displacement. The majority of erosion occurs by sheet erosion (the even removal of thin layers of soil by water moving across extended areas of gently sloping land) and is difficult to detect, as there are no dramatic effects to indicate when it is occurring. Rills and gullies, however, are dramatic examples of erosion that are easily detected. Detrimental displacement is routinely mitigated by:

Designating and minimizing the number of skid roads and skyline corridors used; Requiring a minimum of one-end log suspension to prevent soil gouging; and Placing percent slope limitations on ground-based harvest equipment.

Additionally, erosion associated with skid trails and skyline corridors can be effectively mitigated by placing cross drains (water bars), drainage dips, and down wood and slash and performing erosion control seeding (or any vegetative cover on exposed soil). These measures have been used for many decades and there has been considerable monitoring and demonstration of their effectiveness.

Coarse woody material, such as large logs, and standing snags (future large down logs), are critical components in the development and retention of productive soils. Snags are routinely felled if they are believed to be a safety hazard to operations. Operation of logging equipment can mechanically damage/destroy downed logs in advanced stages of decay. Logging thus has the potential to eliminate these features, particularly those in advanced degrees of decay, from the landscape if care is not taken to retain them in adequate sizes, numbers, and distribution across the landscape.

2. Skyline-Cable Systems Using cables to suspend one or both ends of a log as they are pulled from a stand to a landing largely eliminates the potential for compaction and puddling within a stand. What remains, however, is the potential for detrimental soil displacement if one or both ends of a log are dragged across the ground from the stump to a landing.

Appendix C

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Skyline systems can be managed to result in compliance with Rogue River National Forest LRMP standards and guidelines, and typically result in approximately 5 percent detrimental disturbance or less. Full suspension (where the log is lifted entirely off the ground during yarding to the landing) and one-end suspension (where one end of the log is allowed to drag along the ground), and use of a pre-designated skid trail or skyline corridor layout, are effective mitigations that are now regularly employed to minimize detrimental displacement.

3. Aerial Systems Helicopter logging has the least impact of all logging systems on soil productivity. This is a form of full suspension, with no part of the log being drug across the ground, except for very short distances as logs are lifted off the ground from a central point between logs. Such logging eliminates any potential for equipment-generated detrimental soil displacement, compaction, or puddling and their attendant erosion effects. Aerial systems typically result in approximately 2 percent detrimental disturbance or less. Helicopter logging does, however, require larger, though fewer landings, with the associated compaction and displacement effects.

An exception to this is the practice of pre-bunching in helicopter units. Pre-bunching is the short-distance yarding (using small and lightweight yarding equipment) of numerous logs to a reduced number of collection sites within the stand where they would then be picked up by the helicopter. The potential soil benefit is the elimination of skid roads, with their multiple soil compacting and soil displacing passes by heavy equipment with logs in tow. However, the practice still causes some soil compaction and displacement for short distances in single passes (approximately 2 percent or less detrimental conditions).

C. Road Access

1. Classified Road Maintenance and Reconstruction Existing system roads are considered a long-term commitment of the soil resource to something other than soil productivity. The use of existing system roads during implementation of this project would not result in a change to the current condition of the soils that are committed to supporting the transportation system. However, where system roads have been closed for a period of years, some level of road reconstruction and maintenance would be necessary to make them suitable for treatment access. Road reconstruction generally requires vegetation removal and reshaping the former road prism, possibly including ditches, from a road in disrepair. The road may have achieved some degree of restoration from past use, which would be reversed. The condition of roads in need of reconstruction varies greatly, from those with near complete restoration to those with hardly any. Reconstruction of these routes, however, has far less impact to soil productivity (since it has already been compromised) than to native soil sites, and that is the benefit of reusing them over new construction. Nonetheless, soil is compacted and short-term erosion from newly exposed soils is likely.

2. Temporary Roads and Landings Construction of temporary roads (and their associated landings) detrimentally compacts soils and contributes to erosion by allowing water to run overland rather than naturally infiltrating at the point of raindrop impact. Roads are an example of detrimental soil compaction with adverse indirect impacts on water movement pathways. Properly designed and constructed roads (including temporary roads) require structures for channeling this now-redirected water flow to desired locations.


C-18

Temporary roads and landings are expected to have an irretrievable reduction in soil productivity since they are bladed (soil is mixed and displaced) and compacted. Once rehabilitated, the hydrologic function of the soil profile may be re-established, but the soil profile in relation to organics and nutrient cycling is modified to a degree that may take many decades to return to the productive state of the undisturbed forest soils adjacent to it.

Landings also, with their likely deep compaction, and soil mixing from construction and recurrent disturbance are expected to cause an irretrievable decrease in soil productivity. Nonetheless, their use is temporary, with the expectation that following use they would be returned to the highest degree of productivity reasonably achievable.

The Rogue River National Forest Plan establishes that no more than 10 percent of an activity area should be compacted, puddled, or displaced upon completion of a project (not including permanent roads and landings), and no more than 20 percent of the area should be displaced or compacted under circumstances resulting from previous management practices, including roads and landings (but not counting permanent facilities including recreation facilities).

3. Temporary Roads Located on Existing Non-System Road Template Temporary roads located on existing non-system road templates typically result in detrimental disturbance and decreased site productivity. By using these routes as temporary roads where feasible during project implementation, instead of creating new temporary roads, the area of new detrimental soil disturbance would be minimized. The reconstruction of these routes as needed to support harvest or treatment equipment would be similar to the effects discussed above under ‘Classified Road Maintenance and Reconstruction’.

D. Activity and Natural Fuels Treatments Activity fuels treatment refers to the slash and accumulated fuel loading resulting from the proposed silvicultural treatments. Natural fuels are fuel accumulations which have built up in the project planning area over time. The same fuels treatment methods could be used to treat both types of fuels.

1. Lop and Scatter This treatment is expected to have no adverse impacts on soil productivity as it is accomplished through handwork, not mechanical treatment. Chainsaws are used to break down the size of slash and workers scatter those smaller sizes across a large area. There is no risk of compaction or displacement from machine use. In areas where past management activities resulted in a detrimental loss of organic matter, lop and scatter treatments can have a positive effect on soil productivity by providing an increase of litter for nutrient cycling, soil moisture retention, and soil insulation.

This treatment would be applied where fuel loadings are light and such additions are unlikely to increase the risk of stand loss to high intensity wildfire with its attendant adverse effects to soil productivity.

Appendix C

C-19

2. Handpile Burning, Underburning, and Jackpot Burning Heat produced during combustion of aboveground fuels (i.e., dead and live vegetation, litter, and duff) is transferred to the soil surface and downward through the soil by several heat transfer processes (radiation, convection, conduction, vaporization, and condensation). As heat is transferred downward into and through the soil, it raises soil temperature. The greatest increase in temperature occurs at, or near, the surface. Within a short distance, however, temperatures can rapidly diminish so that within 2.0 to 3.9 inches (5 to 10 centimeters) of the soil surface temperatures are scarcely above ambient temperature (Neary et al. 2005).

Project activities that could cause effects to soils from fire include underburning, pile burning, and/or jackpot burning. Underburning involves the controlled application of fire onto the landscape; pile and jackpot burning are similar in their effects in that it involves burning isolated concentrations of vegetation debris, whether in piles or concentrated slash. Typical physical effects to soil that can occur from fire include changes to soil structure (particularly as a result of loss of organic matter), changes in porosity and bulk density, loss of cover (i.e., canopy, litter, duff), water repellency, and runoff and erosion vulnerability.

Organic matter plays a key role in soil structure in the upper part of the mineral soil at the duff-upper A-horizon interface, in that it acts like glue helping to hold mineral soil particles together to form aggregates. Fire can impact the organic matter content in soil by killing the living organisms at temperatures as low as 122 to 140 oF, and by destructively distilling to completely consuming nonliving organic matter at temperatures of 224 oF and 752 oF, respectively (Neary et al. 2005).

Loss of the soil’s organic matter component breaks down the soil structure, which in turn results in reduced amount and size of soil pore space. When the soil structure collapses, it particularly reduces the amount of macropore spaces, and increases the bulk density of the soil, resulting in a loss of soil productivity.

When fire results in the loss of canopy, litter, and duff cover, it exposes the mineral soil to erosion processes. The litter and duff layers also act as an insulator protecting the underlying soil layers from heating, and if they are consumed, it exposes the mineral soil to greater soil heating impacts. Fire-induced water repellency may occur when combustion of organic matter vaporizes hydrophobic organic substances that then move downward in the mineral soil and condense into a water repellent layer. This in turn increases the risk of soil erosion. Water repellent layers have the greatest impact within the first year after fire, as they tend to break down fairly quickly.

Typical chemical effects to soil that can occur from fire include nutrient losses, cation exchange capacity loss, and changes to pH. Nitrogen (N) is the most limiting nutrient in wildland ecosystems, and as such requires special consideration when managing fire. N loss increases with increasing temperatures through volatilization, with no loss of N at temperatures below 392 oF all the way up to complete loss of N at temperatures above 932 oF (Neary et al. 2005). The amount of N lost is generally proportional to the amount of organic matter combusted, and burning during moist litter and soil conditions have shown a decrease in the amount of total N lost compared to dry conditions (DeBano et al. 1979, cited in Neary et al. 2005).

Nitrogen that is not volatized either remains as part of the unburned fuel or is converted to highly available NH4-N remaining in the soil (Covington and Sackett 1986; DeBano and others 1979, cited in Neary et al. 2005; DeBano 1991; Jutiel and Naveh 1987). This temporary increase in fertility from available N is usually short-lived and is quickly utilized by vegetation within the first few years after burning (Neary et al. 2005).


C-20

The cation exchange capacity of soil can be impacted by fire through destruction of organic matter. Negatively charged particles of organic matter adsorb otherwise highly soluble positively charged cations, which prevent them from being leached out of the soil. As the amount of organic matter is destroyed from fire, so too is the soils’ cation exchange capacity.

Cation nutrients (e.g., Ca, Mg, Na, K, and NH4) become concentrated in the ash following fire, and can be lost in several ways such as volatization (at very high temperatures), and particulate loss in smoke, runoff, and erosion. Also, there can be a long-term loss of cations to leaching due to the soil’s reduced cation exchange capacity. Cation exchange capacity rebuilds over time with new accumulations of organic matter. Release of soluble cations from organic matter during combustion can temporarily increase soil pH, but this is dependent in part upon the amount and chemical composition of the ash. Thick layers of ash (termed the ash-bed effect) found from severe burning conditions tends to have the greatest impact on raising soil pH.

Typical biological effects to soil that can occur from fire include loss of microorganisms, loss of meso- and macrofauna, and loss of roots and reproductive structures such as seed banks. Impacts from fire to microorganisms as well as their recovery can be very complex because so many variables are involved. In general it can be stated that “intense wildfire can have severe and sometimes long-lasting effects on microbial population size, diversity, and function,” whereas at the other end of the spectrum, “low-severity underburning generally has an inconsequential effect on microorganisms” (Neary et al. 2005). This range of effects is in part related to the amount of organic matter impacted by fire, and the temperature and depth of soil heating. If both of these can be minimized, so would impacts to the microbial population in the soil. Effects of fire to meso- and macrofauna, such as mites, insects, and earthworms, are also highly variable, depending in part on species, habitat, and adaptations.

Whether or not plant roots and seed banks are destroyed by fire depends on how deep in the soil they reside, the fire severity and amount of soil heating, and the moisture content of the plant tissues and the soil. Higher moisture content tends to lower the temperature at which living biomass can be killed. Plant tissue can be killed at as low as 104 oF, and seeds can be killed at as low as 122 oF. Moist soil is a better conductor of heat into the soil so lethal temperatures may extend deeper into the soil surface. However, high moisture content in the litter and duff aids in facilitating a low severity underburn, which results in very little impact to roots and seeds except at the very surface of the litter layer.

The 1998 Regional Supplement to the Forest Service Manual (FSM 2520 R-6 Supplement 2500-98-1, Effective August 24, 1998) defines detrimentally burned soil as:

The condition where the mineral soil surface has been significantly changed in color, oxidized to a reddish color, and the next one-half inch blackened from organic matter charring by heat conducted through the top layer. The detrimentally burned soil standard applies to a contiguous area greater than 100 square feet, which is at least 5 feet in width.

Detrimental burning occurs when high intensity fire consumes organic matter above and within the soil, heating the soil to the point where the mineral soil surface changes color and the next ½ inch deeper of soil organic matter is charred. This can happen under natural high-intensity wildfire conditions or by management actions beneath burn piles or ‘prescribed burns’ when the prescriptions are applied incorrectly or “escape” the parameters of their prescription and become overly intense.

Appendix C

C-21

Pile/concentrated slash burning increases the residence time of the fire due to concentrated fuels, which can lead to more consumption of organic matter, higher soil heating temperatures, heating deeper into the soil profile, and thus resulting in isolated patches of severely burned soils directly under the slash pile. Mitigations, minimizing to the extent possible, the size of the piles and burning during moist soil moisture conditions can reduce these impacts by keeping burn temperatures and soil heating as low as possible. Smaller burn scars tend to recover quicker as well due to the high amount of un-impacted soil around them that contribute to recolonization of soil microorganisms and other soil biota. Burning slash piles should not exceed the detrimentally burned soil standard since individual burn piles are designed to be discontinuous and not greater than 10 feet in diameter.

Underburning is designed to retain a mosaic pattern, and to be applied when fuel moisture, soil moisture, and weather and atmospheric conditions allow fire to be applied to the landscape as a low severity burn that maintains soil organic matter. A burn is considered low severity when: small diameter woody material is consumed; litter/duff may be charred but original forms of materials are still visible; root crowns remain; essentially no soil heating occurs; and the overstory may have none, slight, or moderate mortality.

Jackpot burning is the burning of accumulations of fuels that are scattered across the area to be treated, but not continuous enough to support an underburn, nor heavy enough to require hand piling. Effects are generally as described for handpiling above, though the risk for detrimental burning and loss of large woody debris is greater, since fuels are generally treated where they occur. Some provision may be made to scatter such fuels when such concentrations are evident and the risk of adverse effects to vegetation, large wood, or soils is recognized.

Coarse woody material, such as large logs, and standing snags (future large down logs), are critical components in development and retention of productive soils. Burning can eliminate these features, particularly those in advanced degrees of decay, from the landscape if care is not taken to retain them in adequate sizes, numbers, and distribution across the landscape.

3. Biomass Removal With the increased interest in harvesting biomass, there has been an increased need to understand how removing the branches and needles from the site might be affecting short and long-term soil productivity. Most studies have been based on models and/or nutrient budgets which forecast likely effects. However, long-term field studies have also been started. In a review of literature regarding the effects of whole tree harvesting on soil productivity, Farve and Napper (2009) refer to a summary of effects by Waring and Running (2007) that found that “a whole-tree harvest can remove as much as three times the nutrients as compared to a conventional bole-only harvest….however, since the soil nutrient (below ground) pool contains most of the nutrient capital of a forest ecosystem (by several orders of magnitude), in general, removal of the whole tree during timber harvesting should result in only a small percentage of nutrient loss from the forest ecosystem.” With implementation of the Bybee Vegetation Management Project, where only a portion of trees are being removed instead of all the trees, the impacts of whole tree yarding and leaving tops attached is expected to be even less, and likely immeasurable. Therefore, the effects of biomass removal will not be discussed further in this analysis.


C-22

E. Post-Harvest Treatments

1. Soil Restoration Subsoiling is a restoration/rehabilitation practice that involves shattering a compacted layer of soil by drawing subsoiling shanks through the soil just below the compacted layer, without turning over or tilling in the surface soil layers. This practice targets compaction that has developed deeper in the soil profile, typically 12 to 22 inches below the surface, and fractures compacted soil to improve water infiltration, eliminate surface erosion from runoff, and encourage root growth of native vegetation over time (Archuleta and Baxter 2008; Kees 2008). Immediately after implementation, the loosened soil may be more susceptible to localized erosion. However, the risk is mitigated through use of a broken surface pattern and application of slash where possible, to increase surface roughness and reduce raindrop impacts.

Figure C-3. Examples of subsoiling on the High Cascades Ranger District, 2011 (C-1, C-2, C-3, C-4)

Clockwise from top left: Photo C-1 shows the excavator and subsoiling shanks and coulter blades mounted on the bucket. Photo C-2, excavator subsoiling an area with detrimental compaction in the subsurface soil, minimizing disturbance to surface vegetation and organic matter. Photo C-3, severe compaction beginning at approximately 6 inches, shown by resistance to penetration by shovel. Photo C-4, penetration by shovel through the previously compacted layer, in soil between subsoiler shank furrows.

There are many different variations of equipment that have been developed for subsoiling, many of which were originally developed for agricultural applications and involve pulling subsoiler shanks behind a tractor, or the use of a dozer-mounted ripper system (Archuleta and Baxter 2008; Kees 2008).

Appendix C

C-23

These systems can be limited in their effectiveness in forested areas however due to uneven terrain, variations in soil depth and rock content across a treatment area, and the need for maneuverability around remaining trees and other vegetation. The recommended subsoiling equipment for the Bybee project planning area would be use of a single or two subsoiling shanks with coulter blades, mounted on an excavator and with the capability to also be able to pick up and spread woody debris across the treatment area, similar to the designs in Archuleta and Baxter (2008) and on the USDA Forest Service Technology and Development Program website (http://www.fs.fed.us/t-d/programs/forest_mgmt/projects/subsoiling/).

This kind of subsoiling equipment mounted on an excavator has been used with success on the High Cascades Ranger District for soil restoration, where historic management methods created detrimental compaction (refer to photos C-1 through C-4).

Management actions such as subsoiling and providing coarse woody material (where the site is deficient), in combination with natural processes such as frost heaving and root growth, can accelerate the rate of rehabilitation in areas of detrimental compaction or disturbance. Though successful to a degree, it is not expected that these actions would return these soils fully to their original condition and function.

Subsoiling can restore some degree of soil permeability to compacted soils. Some areas, however, may not be fully reparable by subsoiling. Compaction in these areas may be deeper than subsoiling equipment can reach and is the result of operating heavy equipment with high contact pressure (pounds per square inch on the soil surface) under wet conditions. Other areas may contain too many large boulders to effectively break up the compaction with the tool available. Such areas are not identifiable above ground and use of old skid trails there could set back any vegetative recovery from past management. However, subsoiling these areas may still improve on the past compaction, though not as effectively as soils with shallower compaction layers and fewer boulders.

2. Planting Planting trees in openings created by sanitation treatments or small group selection would have no adverse effect on soil productivity. The work would be by hand, with the only effect being the minimal displacement caused by the tree planter at each individual planting site. There could be a very modest beneficial long-term effect concerning precipitation interception as discussed above by establishing forest cover on the site faster than might naturally occur. Therefore, the effects of planting will not be discussed further in this analysis.

3. Animal Damage Control Activities, Precommercial Thinning, Wildlife Habitat Enhancement These actions have no measurable direct or indirect effect on soil productivity, detrimental disturbance, or organic matter.

4. Road Decommissioning As discussed above under temporary roads, road decommissioning has the goal of removing the road from a usable state for motor vehicles and restoring the site to some degree of productivity for forest restoration. Existing conditions of these roads vary greatly, with some already naturally closed and soil restoration well advanced, where all that is needed for restoration is installation of an effective closure. In such cases, mechanical treatment could be more of a setback for soil productivity than a benefit.


C-24

Some roads are just the opposite, where mechanical treatment is necessary to make the road impassable, and to break up the compacted layers to improve permeability and facilitate tree root growth deeper into the soil profile. Such actions are likely to produce short-term erosion from newly exposed soils, but long term benefits of re-established site productivity over a quicker timeframe than what would typically be achieved with passive restoration.

IV. Environmental Consequences

A. Effects of Alternative 1 (No-Action) If no-action is taken, passive restoration of detrimentally compacted and displaced areas from past management activities would occur, and these areas would continue to recover through the action of root growth and frost heaving. There would not be an opportunity to accelerate the rate of rehabilitation in areas of detrimental compaction or disturbance. There would be no additional soil productivity effects from temporary road systems.

The absence of treatment would not improve site productivity through immediate coarse wood recruitment to sites that are low in coarse wood from past management. However, no additional areas of detrimental soil compaction or displacement would be created. Erosion from road surfaces, if not checked by routine road maintenance, may increase over time.

If no-action is taken, the amounts of large wood would continue to increase due to growth and mortality, at unnatural rates, due to past fire exclusion. The possibility of future wildfires with increased severity would provide a future flux of dead large woody material. Future wildfires could occur with increased severity due to dense stands and organic matter accumulations. Potential wildfires could produce areas of detrimental soil conditions at a rate higher than historical wildfire behavior. It is not uncommon for 40 percent or more of a burned area to be detrimental to soils in areas that have missed several fire cycles. For example, the 2008 fires near this area on the High Cascades Ranger District led to widespread loss of mature and old growth forest, and high burn severity soil effects across relatively large areas with some amount of erosion. Together, these natural and management actions led to widespread vegetation change.

Displacement can occur with high intensity wildfire by loss through the smoke plume. Such fires can remove inches of soil from the ground surface with the fire’s own high intensity winds, consume its organic components, and loft the remaining soil particles into the atmosphere. Research on the Biscuit Fire in southwestern Oregon demonstrated such loss.

Under no-action, effects to soil productivity (physical, biological, and chemical properties), effects on hydrology, and the indirect effects to plant and animal habitats would not occur. Rainfall, plants, and animals would continue to input nutrients into the system. Hydrologic conditions would continue to passively improve with vegetative growth and recovery. The indirect effects to habitat would be a continued accumulation of large wood and organic matter. The increasing potential for severe wildfire could impact soil productivity, hydrology, and plant/animal habitats. As much as 40 to 50 percent of a severe wildfire’s area could adversely affect soil productivity, increase runoff and erosion, and set back vegetative conditions to early seral conditions.

Appendix C

C-25

B. Direct and Indirect Effects of Action Alternatives

1. Alternative 2 (Proposed Action)

Silvicultural Treatments Effects

The silvicultural treatments being proposed include a combination of free thinning, overstory removal, modified shelterwood with reserves, and group selection. Since all of these treatments would maintain a component of the original forest system, including some overstory vegetation and the forest floor organic litter layer, no measurable direct or indirect effects to soil productivity as it relates to nutrient cycling from these silvicultural treatments are expected. For the same reasons, no measurable direct or indirect effect to how precipitation is intercepted, retained, and redistributed by the tree canopy to the forest soil is expected, since measurable effects are generally only seen with more extensive vegetation removal associated with activities such as clearcutting.

Harvest (Logging) Systems Effects

Alternative 2 would treat an estimated 3,622 acres with ground-based, skyline, and aerial logging systems: 3,095 acres with tractor systems, 83 acres with skyline systems, 410 acres with a combination of tractor and skyline systems, and 34 acres by helicopter.

Table C-5 shows the logging system for each unit, and shows the expected estimated level of new detrimental disturbance from the project activities, combined with the current condition. For tractor logging (T), 10 percent disturbance was used; for skyline (S), 5 percent, and for helicopter (H), 4 percent (assuming pre-bunching would also be utilized, as discussed under the Effects Mechanisms section in this Soil Resources Report). For combined skyline and tractor units (T/S), the greater amount of 10 percent was used to analyze the greatest amount of possible disturbance. Mitigation measures require that areas of past disturbance, such as previous skid trails and landings, be re-used to the highest extent possible during layout and implementation of new activities. Exactly how much of this past disturbance can be re-used in units that are not extensively impacted from past activities cannot be known for sure until the sale is being laid out, so a range is shown in table C-5 for those applicable units.

Where a unit is already estimated to be over 20 percent detrimentally disturbed from past impacts, Forest Plan Standards and Guidelines and the Region 6 Manual require that “the cumulative detrimental effects of project implementation and restoration must, at a minimum, not exceed the conditions prior to the planned activity and should move toward a net improvement in soil quality” (USDA 1998). In these units, it is required that no new detrimental disturbance is created, and this requirement guides how the logging system can be laid out and implemented (chapter II, section F, mitigation measures and project design criteria). These units would benefit from active soil restoration activities to move these sites towards a net improvement in soil quality over time. These total 26 units and include units 1, 2, 8, 12, 19, 21-25, 28, 29, 32, 36, 41, 47, 55, 56, 58-60, 62, 63, 65, 72, and 78.


C-26

Table C-5. Estimated amount of detrimental disturbance to soils in proposed treatment units, identification of active soil restoration, and mitigation measures

Unit Estimated

acres Logging system

Activity fuels treatment

Estimated percent of area detrimentally

impacted (current condition)

Estimated percent of area detrimentally impacted after implementation

(cumulative)

Active restoration prescribed

(yes/no)

Soil productivity mitigation

recommendations

1 55 T HPB, B, or LS 50 percent 50 percent Yes 1, 2, 3

2 32 T HPB or LS 25 percent 25 percent Yes 1, 2, 3

3 44 T HPB, B, LS, or UB 0 percent 10 percent No 1



6 75 T HPB, LS, or UB 5 percent 10 to 15 percent No 1*

7 106 T HPB, LS, or UB 0 percent 10 percent No 1






13 42 T HPB, B, LS, or UB 4 percent 10 to 14 percent No 1*






19 56 T HPB, B, LS, or UB 40 percent 40 percent Yes 1, 2



22 21 T HPB, LS, or UB 40 percent 40 percent Yes 1, 2


24 37 T HPB, LS, or UB 40 percent 40 percent Yes 1, 2

Appendix C

C-27

Unit Estimated






(cumulative)


(yes/no)


recommendations






30 57 T/S HPB, B, LS, or UB 0 percent 10 percent No 1




34 50 T HPB, B, LS, or UB 20 percent 20 percent No 1*



37 21 T HPB, B, LS, or UB 1 percent 10 to 11 percent No 1










47 39 T/S HPB, LS, or UB 65 percent 65 percent Yes 1,2




C-28

Unit Estimated






(cumulative)


(yes/no)


recommendations


51 162 T/S HPB, LS, or UB 0 percent 10 percent No 1


53 48 T/S HPB, B, LS, or UB 0 percent 10 percent No 1














67 36 S HPB, B, LS, or UB 0 percent 5 percent No 1

68 47 S HPB, B, LS, or UB 0 percent 5 percent No 1

69 34 T/S HPB, B, LS, or UB 12 percent 12 to 20 percent No 1*

70 70 T/S HPB, LS, or UB 0 percent 10 percent No 1

71 34 H HPB, LS, or UB 0 percent 4 percent No 1




Appendix C

C-29

Unit Estimated






(cumulative)


(yes/no)


recommendations





*During project implementation if a higher level of residual disturbance is found than what could be determined through the review completed for this analysis, these units may also be prescribed active soil restoration and site specific mitigation measures.

Codes for above table: T = tractor HPB = hand pile and burn S = skyline B = biomass T/S = tractor and skyline LS = lop and scatter H = helicopter UB = underburn 1 = Project design criteria, mitigation measures, and best management practices 2 = Consult Soil Scientist during project implementation planning 3 = No underburning recommended based on level/type of past impacts, soil type, and sensitivity to loss of OM, unless reviewed and approved by soil scientist


C-30

With implementation of alternative 2 on the Bybee project planning area, tractor and combined tractor and skyline treatments would create an estimated 350 acres of detrimental disturbance from the project activities; skyline treatments would create an estimated 4 acres of detrimental disturbance, and helicopter treatments would create an estimated 1 acre of detrimental disturbance from project activities.

Road Access Effects

Classified Road Maintenance and Reconstruction

Since existing system roads are considered a long-term commitment of the soil resource to something other than soil productivity, maintenance and reconstruction would have no effect to the current condition of the soils that are committed to supporting the transportation system. During maintenance and reconstruction activities, some temporary and short-term soil erosion could occur. Best management practices and mitigation measures have been developed that are highly effective at minimizing these effects, and would be implemented to greatly minimize erosion and the movement of sediment from these activities. Any potential effects are expected to be localized and short-term in duration.

Temporary Roads and Landings

Approximately 4.1 miles of new temporary road and associated landings would be constructed; at an average width of 12 feet, this would result in an estimated 6.1 acres of soils becoming detrimentally disturbed through compaction and displacement. This effect would be mitigated as these roads, following use, would be returned to the highest degree of productivity reasonably achievable. Table C-6 displays the soils each new temporary road segment would cross, and engineering interpretations of how certain road characteristics could affect erosion or slope stability for each Landtype Unit along each segment of road. Interpretations are from the Rogue River National Forest Soil Resource Inventory (Badura and Jahn 1977).

Table C-6. Alternative 2 – New temporary road lengths, landtype, potential risk of effects based on soil type, and potential for subsoiling as a mitigation measure

New temp road

#

Approx acres*

Landtype unit

Erosion potential:

cutbank and ditch; road

waste and fill slopes

Susceptibility to cutbank and slough and ravel

Failure potential: cutbansk; road waste

and fill slopes

Potential for

subsoiling (yes/no)

2A 0.6 acres 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

2B 2.2 acres 26H (15 percent) 31H (85 percent)

Low; Low Low; Low

n/a1 n/a

n/a; Low n/a; Low

Yes Yes2

2C 1.9 acres 31H (10 percent) 26H (78 percent) 27H (12 percent)

Low; Low Low; Low Low; Low

n/a n/a1 High ravel

n/a; Low n/a; Low Very stable; Low

Yes2 Yes Yes

2D 1.2 acres 31H (100 percent) Low; Low n/a n/a; Low Yes2

2E 0.2 acres 369H (100 percent) Low; Low Low to Mod ravel

Stable; Low No – high rock

Total 6.1 acres

*Based on an average expected width of 12 feet. 1Cutbanks less than 10 feet. 2Soils have higher clay content; therefore more sensitive to compaction based on soil moistures.

Appendix C

C-31

The majority of these new temporary road segments would be constructed over stable soils and relatively flat terrain. Road segment 2C would partially cross through soils that have a high susceptibility for ravel if cutbanks are created, but due to the coarse texture of the soils, the overall erosion potential is low since these soils would be quickly intercepted and stabilized. Temporary road segments 2B, 2C, 2D, and 2E include soils that contain higher clay content in the subsoil, and thus have a higher susceptibility to compaction and rutting if constructed and driven over in wet soil conditions. Restoration of soil productivity on these sites would be more successful if operations are limited to dry soil moisture conditions, when soil strength is greater to withstand the weight of equipment. This would be achieved through implementation of special haul restrictions outlined in chapter II.

All but one of these road segments are on soil types that have a high potential for active restoration through subsoiling (table C-6). Temporary road 2E is on a higher clay content soil that is also high in cobble and stone, making subsoiling less successful as a method to advance recovery. However, if utilized only during dry soil moisture conditions, the higher soil strength due to the clay content, as well as the amount of larger rock spreading out the weight of equipment, has the potential to reduce the effects of soil compaction, allowing natural recovery over time of this road bed to be more successful.

Temporary Roads Located on Existing Non-System Road Template

Approximately 8.8 miles of temporary roads would be constructed on existing non-system road template. However, this would not result in new detrimental compaction or displacement, as these soils are already detrimentally impacted. Table C-7 displays the soils each temporary road segment would cross, and engineering interpretations of how certain road characteristics could affect erosion or slope stability for each landtype unit along each segment of road from re-using these road templates. Interpretations are from the Rogue River National Forest Soil Resource Inventory (Badura and Jahn 1977).

Table C-7. Alternative 2 – Temporary roads built on existing road template lengths, landtype, potential risk of effects based on soil type, and potential for subsoiling as a mitigation measure

Temp road #

Landtype unit

Erosion potential: cutbank and

ditch; road waste and fill slopes


Failure potential: cutbank; road waste and fill

slopes

Potential for

subsoiling (yes/no)

1A 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1B 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1C 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1D 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1E 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1F 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1G 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1H 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1I 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1J 31H (100 percent) Low; Low n/a n/a; Low Yes2

1K 31H (100 percent) Low; Low n/a n/a; Low Yes2

1L 31H (100 percent) Low; Low n/a n/a; Low Yes2

1M 26H (100 percent) Low; Low n/a1 n/a1; Low Yes


C-32

Temp road #

Landtype unit





slopes

Potential for

subsoiling (yes/no)

1N 31H (90 percent), 369H (10 percent)

Low; Low Low; Low

n/a Low to Mod.

ravel

n/a; Low Stable; Low

Yes2

No -high rock

1O 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1P 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1Q 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1R 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1S 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1T 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1U 369H (100 percent) Low; Low Low to Mod. ravel

Stable; Low No-high rock

1V 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1W 31H (100 percent) Low; Low n/a n/a; Low Yes2 1Cutbanks less than 10 feet. 2Soils have a higher clay content; therefore more sensitive to compaction based on soil moistures.

Using existing non-system road templates would require various levels of construction and reconstruction to make them suitable for treatment access. These actions have the potential to create short-term erosion from newly loosened and exposed soils. Considering the soil landtype units these activities would occur on and their potential for erosion and failure from road activities, effects would be expected to be localized and short-term. In addition, all temporary roads save 1U and a small section of 1N are on soils that have a high potential for active restoration through subsoiling. Temporary road 1U and a section of 1N is on a higher clay content soil that is also high in cobble and stone, making subsoiling less successful as a method to advance recovery. However, if utilized only during dry soil moisture conditions, the higher soil strength due to the clay content, as well as the amount of larger rock spreading out the weight of equipment, has the potential to reduce the effects of soil compaction from this project’s actions, allowing natural recovery over time of these road beds to be more successful.

Activity and Natural Fuels Treatment Effects

The natural fuels treatment units are shown in table C-8 and activity fuels treatments per unit are shown in table C-5. Since project design criteria, mitigation measures, regional direction and Forest Plan standards and guidelines defining detrimental burning and for maintaining effective groundcover would be applied to natural and activity fuels treatments, it is expected that no effects of these treatments would contribute detrimental soil disturbance to any of the treatment areas. Since all of the natural fuels treatment units are on soils that are sensitive to the loss of organic matter, extra review during implementation would be required to assure the treatment method prescribed would not set back site productivity, particularly in regards to underburning. Proposed activity fuels treatments per unit are shown in table C-5, and indicates which units that underburning is not recommended as a treatment, without a more detailed review at time of implementation planning.

Appendix C

C-33

For natural fuels treatment units 1c, 7a, and 8a, and for all of the silviculture treatment units that list lop and scatter as a possible activity fuel treatment, lopping and scattering has the potential to improve soil quality by providing a short-term influx of fine litter and woody debris for gradual incorporation and nutrient cycling, soil moisture retention, and soil insulation where these soils are currently lacking in organic matter.

Table C-8. Natural fuels treatment units (all action alternatives) – Estimated amount of detrimental disturbance to soils in proposed treatment units, identification of active soil restoration, and mitigation measures

Unit #

Estimated acres

Natural fuels

treatment


impacted (current

condition)

Estimated total detrimentally

impacted after implementation

(cumulative)


(yes/no)

Soil productivity mitigation measures

1a 50 S/HP/UB* 0 percent 0 percent No 1 1b 71 S/HP 45 percent 45 percent Yes 1, 2, 3 1c 15 S/LS* 100 percent <100 percent Yes 1, 2 1d 66 S/HP 36 percent 36 percent Yes 1, 2, 3 7a 22 S/LS* 34 percent <34 percent Yes 1, 2 7b 8 S/HP/UB* 14 percent 14 percent No 1**, 2 7c 33 S/HP/UB* 0 percent 0 percent No 1 7d 25 S/HP/UB* 0 percent 0 percent No 1 8a 4 S/LS* 16 percent <16 percent No 1**, 2 8b 19 S/HP/UB* 9 percent 9 percent No 1 8c 23 S/HP/UB* 10 percent 10 percent No 1 9a 9 S/HP/UB* 17 percent 17 percent No 1** 9b 24 S/HP/UB* 8 percent 8 percent No 1 9c 20 S/HP/UB* 0 percent 0 percent No 1 9d 78 S/HP/UB* 5 percent 5 percent No 1

*The second treatment would be underburning. **During project implementation if a higher level of residual disturbance is found than what could be determined through the review completed for this analysis, these units may also be prescribed active soil restoration and site specific mitigation measures.

Codes for above table: S/HP = Slash and hand pile S/HP/UB = Slash, hand pile, and underburn S/LS = Slash and lop and scatter 1 = Project design criteria, mitigation measures, and best management practices. 2 = Consult Soil Scientist during project implementation planning. 3 = No underburning recommended based on level/type of past impacts, soil type, and sensitivity to loss of OM, unless reviewed and approved by soil scientist.

Post-Harvest Treatment Effects

Soil Restoration

Active soil restoration activities would provide the opportunity to benefit long-term soil productivity in silvicultural treatment units and natural fuel treatment units that are currently exceeding Forest Plan standard and guidelines for detrimental soil disturbance from cumulative management impacts. Those units that have the potential to realize the most improvement from subsoiling are identified in tables C-5 and C-8, and total 30 units.


C-34

In addition, active soil restoration activities such as subsoiling have the potential to be prescribed on temporary roads as well. Those temporary roads that are on soils which would expect to be successful with subsoiling are shown in tables C-6 and C-7.

Effects of subsoiling in any of these potential treatment areas would include the potential for short-term localized erosion where surface soils are loosened and exposed, but this would be minimized through techniques that maintain effective ground cover by not overturning or displacing existing litter and duff, by incorporating extra woody debris or slash during subsoiling if needed, and by implementing the subsoiling in a broken surface pattern (versus straight furrows), all of which would maintain or increase surface roughness, maintain or increase water infiltration, and facilitate quick surface runoff interception. Indirectly, this action would create a long-term beneficial effect to site productivity by allowing new vegetation to more quickly establish root growth deeper in the soil profile.

Road Decommissioning

The majority of the roads being proposed for decommissioning are on soil landtype units which have low erosion potential, have ‘not applicable’ or low susceptibility to cutbank slough and ravel, and have ‘not applicable’ or low failure potential (refer to table C-9). During and immediately following decommissioning activities, soil erosion from loosened and exposed soils would be minimized not only through the application of effective BMPs and mitigation measures, but also since the soils naturally infiltrate water rapidly and they are coarser textured. Therefore, surface water has less opportunity to transport soil particles, and movement is typically localized. The majority of these roads are on soils that could be successfully subsoiled to break up deep compaction to allow faster recovery of site productivity for future vegetation establishment.

Two roads, 6260-750 and 6260-765, are on soils made up of loams and sandy loams with high rock content. The high rock content would likely make subsoiling infeasible as a decommissioning method; these two roads may require more passive restoration techniques. Site productivity on these road beds may take many years longer to reach the level of neighboring soils, depending on how deep and severe the residual compaction in the soil is and how quickly roots can penetrate through the restrictive layer.

Several roads have sections that are within or near soil landtype 0, which are highly erosive, steep pumice canyon walls. These roads include 6535-925, 9635-932, 6535-974, 6535-976, and 6535-987. Decommissioning these roads would have a beneficial effect to these sensitive soils by eliminating the risk of these roads causing accelerated erosion, as well as road waste and fill slope failures.

Appendix C

C-35

Table C-9. Proposed road decommissioning (all action alternatives) – Potential risk of effects from these roads that would be mitigated by decommissioning, based on soil characteristics, and potential for utilizing subsoiling for soil restoration

Proposed road decommissioning

Landtype unit Erosion potential:

cutbank and ditch; road waste and fill slopes

Susceptibility to cutbank and

slough and ravel

Failure potential: cutbank; road waste

and fill slopes

Potential for subsoiling

(yes/no)

6260-142 26 (20 percent) 145 (80 percent)

Low; Low Low; Low

n/a1

n/a1 to High ravel n/a1; Low

n/a1 to V. stable Yes Yes

6260-750 369H (100 percent) Low; Low Low to Mod ravel Stable; Low No -high rock

6260-765 31H (10 percent) 369H (90 percent)

Low; Low Low; Low

n/a Low to Mod ravel


Yes2 No -high rock

6500-110 26 (100 percent) Low; Low n/a1 n/a1; Low Yes 6500-235 26 (100 percent) Low; Low n/a1 n/a1; Low Yes 6500-265 26H (100 percent) Low; Low n/a1 n/a1; Low Yes 6500-270 26H (100 percent) Low; Low n/a1 n/a1; Low Yes 6535-904 26 (100 percent) Low; Low n/a1 n/a1; Low Yes 6535-911 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

6535-925 270 (30 percent) 26 (70 percent)

Low; Low or High; High Low; Low

High ravel n/a1

Very stable; Low to High n/a1; Low

Yes Yes

6535-932 270 (30 percent) 26 (70 percent)

Low; Low or High; High Low; Low

High ravel n/a1

Very stable; Low to High n/a1; Low

Yes Yes

6335-936 26 (100 percent) Low; Low n/a1 n/a1; Low Yes 6535-967 26H (100 percent) Low; Low n/a1 n/a1; Low Yes 6535-968 26H (100 percent) Low; Low n/a1 n/a1; Low Yes 6535-971 26H (100 percent) Low; Low n/a1 n/a1; Low Yes 6535-973 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

6535-974 26H (70 percent)

0 (30 percent) Low; Low High; High

n/a1

High n/a1; Low

V. stable; High Yes Yes

6535-976 26H (40 percent)

0 (60 percent) Low; Low High; High

n/a1

High n/a1; Low


6535-979 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

6535-987 26H (90 percent) 0 (10 percent)

Low; Low High; High

n/a1

High n/a1; Low


6535-995 26H (100 percent) Low; Low n/a1 n/a1; Low Yes 1Cutbanks less than 10 feet. 2Soils have a higher clay content; therefore more sensitive to compaction based on soil moistures.


C-36

2. Alternative 3


The silvicultural treatments being proposed include a combination of free thinning, mechanical girdling and precommercial thinning, and group selection. Since all of these treatments would maintain a component of the original forest system, including some overstory vegetation, some understory vegetation, and the forest floor organic litter layer, no measurable direct or indirect adverse effects to soil productivity as it relates to nutrient cycling from these silvicultural treatments are expected. For the same reasons, no measurable direct or indirect effect to how precipitation is intercepted, retained, and redistributed by the tree canopy to the forest soil is expected, since measurable effects are generally only seen with more extensive vegetation removal associated with activities such as clearcutting.

Mechanical girdling of large overstory mistletoe infected trees would occur in units 1, 8, 12, 25, 36, 55, 58, 72, 73, and 75. This treatment could have a beneficial long-term effect to soil productivity over time by maintaining more coarse wood and organic matter on these sites as these trees die, shed woody debris, fall over, and decay. All of these units are on soil types that are sensitive to the loss of organic matter, and they all are units that are exceeding 20 percent (units 1, 8, 12, 25, 36, 55, 58, and 72) or approaching 20 percent (units 73 and 75) soil residual detrimental disturbance in their current condition.


The effects of harvest systems on soils in the proposed units would be the same as for alternative 2 (refer to table C-5), except there are 14 less units being treated utilizing logging systems. The units dropped from utilizing logging systems in alternative 3 include: 28, 29, 31, 38, 47, 49, 50, 52, 54, 56, 59, 67, 68, and 71.

With implementation of alternative 3 on the Bybee project planning area, tractor and combined tractor and skyline treatments would create an estimated 300 acres of detrimental disturbance from the project activities.

Road Access Effects


Since existing system roads are considered a long-term commitment of the soil resource to something other than soil productivity, maintenance and reconstruction would have no effect to the current condition of the soils that are committed to supporting the transportation system. During maintenance and reconstruction activities, some temporary and short-term soil erosion could occur. BMPs and mitigation measures have been developed that are highly effective at minimizing these effects, and would be implemented to greatly minimize erosion and the movement of sediment from these activities. Any potential effects are expected to be localized and short-term in duration. These effects would be similar to alternative 2.


Approximately 1.6 miles of new temporary road would be constructed; at an estimated average width of 12 feet, this would result in approximately 2.4 acres of soils becoming detrimentally disturbed through compaction and displacement. This effect would be mitigated as these roads, following use, would be returned to the highest degree of productivity reasonably achievable.

Appendix C

C-37

Table C-10 displays the soils each new temporary road segment would cross, and engineering interpretations of how certain road characteristics could affect erosion or slope stability for each landtype unit along each segment of road. Interpretations are from the Rogue River National Forest Soil Resource Inventory (Badura and Jahn 1977).

Table C-10. Alternative 3 – New temporary road lengths, landtype, potential risk of effects based on soil type, and potential for subsoiling as a mitigation measure

New temp

road #

Approx acres*

Landtype unit

Erosion potential:

cutbank and ditch; road

waste and fill slopes


Failure potential: cutbansk; road waste

and fill slopes

Potential for

subsoiling (yes/no)

2A 0.6 acres 26H (100 percent) Low; Low n/a1 n/a1; Low Yes 2B 1.6 acres 31H (100 percent) Low; Low n/a n/a; Low Yes2

2E 0.2 acres 369H (100 percent) Low; Low Low to Mod.

ravel Stable; Low

No – high rock

Total 2.4 acres *Based on an average expected width of 12 feet. 1Cutbanks less than 10 feet. 2Soils have a higher clay content; therefore more sensitive to compaction based on soil moistures.

The majority of these new temporary road segments would be constructed over stable soils and relatively flat terrain. Temporary road segments 2B and 2E include soils that contain higher clay content in the subsoil, and thus have a higher susceptibility to compaction and rutting if constructed and driven over in wet soil conditions. Restoration of soil productivity on these sites would be more successful if operations are limited to dry soil moisture conditions, when soil strength is greater to withstand the weight of equipment. This would be achieved through implementation of special haul restrictions outlined in chapter II.

All but one of these road segments are on soil types that have a high potential for active restoration through subsoiling (table C-10). Temporary road 2E is on a higher clay content soil that is also high in cobble and stone, making subsoiling less successful as a method to advance recovery. However, if utilized only during dry soil moisture conditions, the higher soil strength due to the clay content, as well as the amount of larger rock spreading out the weight of equipment, has the potential to reduce the effects of soil compaction, allowing natural recovery over time of this road bed to be more successful.


Approximately 7.8 miles of temporary roads would be constructed on existing non-system road template. However, this would not result in new detrimental compaction or displacement, as these soils are already detrimentally impacted. Table C-11 displays the soils each temporary road segment would cross, and engineering interpretations of how certain road characteristics could affect erosion or slope stability for each landtype unit along each segment of road from re-using these road templates. Interpretations are from the Rogue River National Forest Soil Resource Inventory (Badura and Jahn 1977).


C-38


Temp road #

Landtype unit





slopes

Potential for

subsoiling (yes/no)




1E 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1F 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1G 26H (100 percent) Low; Low n/a1 n/a1; Low Yes


1I 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1J 31H (100 percent) Low; Low n/a n/a; Low Yes2

1K 31H (100 percent) Low; Low n/a n/a; Low Yes2

1L 31H (100 percent) Low; Low n/a n/a; Low Yes2

1M 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1N 31H (90 percent), 369H (10 percent)

Low; Low Low; Low

n/a Low to Mod.

ravel


Yes2

No -high rock


1R 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1S 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1T 26 (100 percent) Low; Low n/a1 n/a1; Low Yes

1U 369H (100 percent) Low; Low Low to Mod.

ravel Stable; Low No-high rock

1V 26H (100 percent) Low; Low n/a1 n/a1; Low Yes

1W 31H (100 percent) Low; Low n/a n/a; Low Yes2

Using existing non-system road templates would require various levels of construction and reconstruction to make them suitable for treatment access. These actions have the potential to create short-term erosion from newly loosened and exposed soils. Considering the soil landtype units these activities would occur on and their potential for erosion and failure from road activities, effects would be expected to be localized and short-term. In addition, all temporary roads save 1U and a small section of 1N are on soils that have a high potential for active restoration through subsoiling. Temporary road 1U and a section of 1N is on a higher clay content soil that is also high in cobble and stone, making subsoiling less successful as a method to advance recovery. However, if utilized only during dry soil moisture conditions, the higher soil strength due to the clay content, as well as the amount of larger rock spreading out the weight of equipment, has the potential to reduce the effects of soil compaction from this project’s actions, allowing natural recovery over time of these road beds to be more successful.


Natural fuels treatment effects would be the same for alternative 3 as described for alternative 2.

Appendix C

C-39

The activity fuels treatment effects would be similar to alternative 2, with the only changes being that in the units which would now be mechanical girdled, activity fuels treatments would be limited to hand pile and burn or biomass utilization. Soil productivity mitigation recommendations would remain the same for each of the units in alternative 3 as they are displayed in alternative 2.


Soil Restoration

Active soil restoration activities would provide the opportunity to benefit long-term soil productivity in silvicultural treatment units and natural fuel treatment units that are currently exceeding Forest Plan standard and guidelines for detrimental soil disturbance from cumulative management impacts. Those units that have the potential to realize the most improvement from subsoiling are identified in table C-5, except that in alternative 3, units 28, 29, 56, and 59 are dropped from treatment, and in table C-8, totaling 26 units.

In addition, active soil restoration activities such as subsoiling have the potential to be prescribed on temporary roads as well. Those temporary roads that are on soils which would expect to be successful with subsoiling are shown in tables C-10 and C-11.

Effects of subsoiling in any of these potential treatment areas would include the potential for short-term localized erosion where surface soils are loosened and exposed, but this is minimized through techniques that maintain effective ground cover by not overturning or displacing existing litter and duff, by incorporating extra woody debris or slash during subsoiling if needed, and by implementing the subsoiling in a broken surface pattern (versus straight furrows), all of which would maintain or increase surface roughness, maintain or increase water infiltration, and facilitate quick surface runoff interception. Indirectly, this action would create a long-term beneficial effect to site productivity by allowing new vegetation to more quickly establish root growth deeper in the soil profile.


Effects of road decommissioning are the same for all action alternatives. Refer to the effects discussion under alternative 2.

3. Alternative 4


The silvicultural treatments being proposed include a combination of low thinning (thinning from below, and retaining patches for hiding cover), and precommercial thinning. Since all of these treatments would maintain a component of the original forest system, including overstory vegetation and the forest floor organic litter layer, no measurable direct or indirect effects to soil productivity as it relates to nutrient cycling from these silvicultural treatments are expected. For the same reasons, no measurable direct or indirect effect to how precipitation is intercepted, retained, and redistributed by the tree canopy to the forest soil is expected, since measurable effects are generally only seen with more extensive vegetation removal associated with activities such as clearcutting.


C-40


The effects of harvest systems on soils in the proposed units would be the same as described for alternative 2, except there would be 15 less units being treated utilizing logging systems. The units dropped from utilizing logging systems in alternative 4 include: 6, 28, 29, 31, 38, 47, 49, 50, 52, 54, 56, 59, 67, 68, and 71.

With implementation of alternative 4 on the Bybee project planning area, tractor and combined tractor and skyline treatments would create an estimated 292 acres of detrimental disturbance from the project activities.

Road Access Effects


Since existing system roads are considered a long-term commitment of the soil resource to something other than soil productivity, maintenance and reconstruction would have no effect to the current condition of the soils that are committed to supporting the transportation system. During maintenance and reconstruction activities, some temporary and short-term soil erosion could occur. BMPs and mitigation measures have been developed that are highly effective at minimizing these effects, and would be implemented to greatly minimize erosion and the movement of sediment from these activities. Any potential effects are expected to be localized and short-term in duration. These effects would be similar to alternative 2.


No new temporary roads and associated landings would be constructed as part of alternative 4; therefore there would be no detrimental effects to soils from new temporary road construction.


Approximately 2.3 miles of temporary roads would be constructed on existing non-system road template. This would not result in new detrimental compaction or displacement, as these soils are already detrimentally impacted. Table C-12 displays the soils each temporary road segment would cross, and engineering interpretations of how certain road characteristics could affect erosion or slope stability for each landtype unit along each segment of road from re-using these road templates. Interpretations are from the Rogue River National Forest Soil Resource Inventory (Badura and Jahn 1977).


Temp road #

Landtype unit





slopes

Potential for

subsoiling (yes/no)






1U 369H (100 percent) Low; Low Low to Mod.

ravel Stable; Low No-high rock

1Cutbanks less than 10 feet.

Appendix C

C-41

Using existing non-system road templates would require various levels of construction and reconstruction to make them suitable for treatment access. These actions have the potential to create short-term erosion from newly loosened and exposed soils. Considering the soil landtype units these activities would occur on and their potential for erosion and failure from road activities, effects would be expected to be localized and short-term. In addition, all temporary roads save 1U are on soils that have a high potential for active restoration through subsoiling. Temporary road 1U is on a higher clay content soil that is also high in cobble and stone, making subsoiling less successful as a method to advance recovery. However, if utilized only during dry soil moisture conditions, the higher soil strength due to the clay content, as well as the amount of larger rock spreading out the weight of equipment, has the potential to reduce the effects of soil compaction from this project’s actions, allowing natural recovery over time of this road bed to be more successful.


Natural fuels treatment effects would be the same for alternative 4 as described for alternative 2.

The activity fuels treatment effects would be similar to alternative 2, with the only changes being that in the units which would now be precommercial thinned, activity fuels treatments would be limited to hand pile and burn or biomass utilization. Soil productivity mitigation recommendations would remain the same for each of the units in alternative 3 as they are displayed in alternative 2.


Soil Restoration

Active soil restoration activities would provide the opportunity to benefit long-term soil productivity in silvicultural treatment units and natural fuel treatment units that are currently exceeding Forest Plan standard and guidelines for detrimental soil disturbance from cumulative management impacts. Those units that have the potential to realize the most improvement from subsoiling are identified in table C-5, except that in alternative 4, units 28, 29, 47, 56, and 59 are dropped from treatment, and in table C-8, totaling 25 units.

In addition, active soil restoration activities such as subsoiling have the potential to be prescribed on temporary roads as well. Those temporary roads that are on soils which would expect to be successful with subsoiling are shown in table C-12.

Effects of subsoiling in any of these potential treatment areas would include the potential for short-term localized erosion where surface soils are loosened and exposed, but this is minimized through techniques that maintain effective ground cover by not overturning or displacing existing litter and duff, by incorporating extra woody debris or slash during subsoiling if needed, and by implementing the subsoiling in a broken surface pattern (versus straight furrows), all of which would maintain or increase surface roughness, maintain or increase water infiltration, and facilitate quick surface runoff interception. Indirectly, this action would create a long term beneficial effect to site productivity by allowing new vegetation to more quickly establish root growth deeper in the soil profile.


Effects of road decommissioning are the same for all action alternatives. Refer to the effects discussion under alternative 2.


C-42

C. Cumulative Effects The cumulative effects analysis area for the soil resources are the proposed treatment units and proposed temporary roads within the Bybee project planning area, since effects to a particular soil is typically localized to defined areas where direct and indirect effects can be measured.

This cumulative effects area is considered adequate since there is no landflow mass wasting through the project planning area, and areas of natural channel scour and debris avalanche processes are contained within the project planning area and are avoided so that there would be no effect from project implementation.

The Rogue River National Forest Plan establishes that no more than 10 percent of an activity area should be compacted, puddled, or displaced upon completion of a project (not including permanent roads and landings), and no more than 20 percent of the area should be displaced or compacted under circumstances resulting from previous management practices, including roads and landings (but not counting permanent facilities including recreation facilities).

Tables C-1 and C-2 (above) identify the silvicultural treatment and natural fuels treatment units with previous harvest impacts which would be cumulative to this project, either by disturbing more ground in the unit, or by setting back past recovery through reduced organic matter, and increased compaction, displacement, and/or erosion.

In alternative 2 (proposed action) the units that have the potential for cumulative effects from other past, present, and reasonably foreseeable future activities are shown in table C-3, and include 63 units covering approximately 2,790 acres. In alternative 3, these units include all the units in alternative 2, minus the following units that have past impacts and are dropped from alternative 3 (units 28, 29, 31, 47, 54, 56, and 59), and include 56 units covering approximately 2,532 acres. In alternative 4, these include all the units in alternative 2, minus the following units that have past impacts and are dropped from alternative 4 (units 6, 28, 29, 31, 47, 54, 56, and 59), and include 55 units covering approximately 2,457 acres.

Tables C-5 and C-8 estimate the percent of area currently detrimentally impacted per treatment unit, and estimates the total percent detrimentally impacted after implementation, based on the expected level of detrimental disturbance that would occur from implementation of the proposed project activities. Where a unit is already estimated to be over 20 percent detrimentally disturbed from past impacts, Forest Plan standard and guidelines and the Region 6 Manual require that “the cumulative detrimental effects of project implementation and restoration must, at a minimum, not exceed the conditions prior to the planned activity and should move toward a net improvement in soil quality” (USDA Forest Service 1998). In these units, it is required that no new detrimental disturbance is created, and this requirement guides how the logging system can be laid out and implemented (chapter II, section F, mitigation measures and project design criteria). These units would benefit from active soil restoration activities to move these sites towards a net improvement in soil quality over time, which is prescribed in this project. In the rest of the units, Forest Plan standards and guidelines are also being met by not surpassing the cumulative allowable detrimental disturbance of 20 percent.

The re-use of existing non-system roads for temporary roads creates a negative cumulative effect to site productivity on those road beds where they had been slowly recovering, by setting recovery back. In alternative 2, 8.8 miles of existing non-system roads would be utilized, in alternative 3, 7.8 miles would be utilized, and in alternative 4, 2.3 miles would be utilized. With use for implementing this project, however, they would then be eligible for closure and decommissioning, and with the use of soil restoration techniques such as subsoiling, could see a final beneficial cumulative effect of improved long term soil quality on these road beds.

Appendix C

C-43

No other past, present, or reasonably foreseeable future actions are known that would have a cumulative effect with the effects of implementing the Bybee Vegetation Management Project on the soils in the proposed treatment units and temporary road locations.


C-44

Literature Cited Archuleta, J.G. and E.S. Baxter. 2008. “Subsoiling promotes native plant establishment on

compacted forest sites.” Native Plants Journal 9(2):117-122.

Atzet, T., R.F. Powers, D.H. McNabb, M.P. Amaranthus, and E.R. Gross. 1989. “Maintaining long-term forest productivity in southwest Oregon and northern California.” In: Maintaining the long-term productivity of Pacific Northwest Forest ecosystems. (Portland, Oregon: Timber Press), 185-201.

Badura, G.J. and P.N. Jahn. 1977. Soil resource inventory for the Rogue River National Forest. USDA Forest Service, Pacific Northwest Region.

Farve, R. and C. Napper. 2009. Biomass fuels and whole tree harvesting impacts on soil productivity – review of literature. 2000-Inventory & Monitoring 0920 1803-SDTDC. USDA Forest Service, National Technology and Development Program.

Floch, R.F. 1988. Shovel logging and soil compaction: a case study. Masters Thesis, Oregon State University.

Goodman, D.M. and J.A. Trofymow. 1998. “Comparison of communities of ectomycorrhizal fungi in old-growth and mature stands of Douglas-fir at two sites on southern Vancouver Island.” Canadian Journal of Forest Research 28: 574-581.

Kees, G. 2008. Using subsoiling to reduce soil compaction. Tech. Rep. 0834-2828-MTDC. Missoula, MT: USDA Forest Service, Missoula Technology and Development Center.

Keslick, J.A., Jr. 1997. “Fact sheets: ‘dozer’ blight. One absorptive structure, Mycorrhiza. How to Kill a Tree.”

Matrix Technical Staffing, Inc. 1997. Procedures and quality control/quality assurance manual, version 1.0. Winema and Rogue River National Forests, Ecological Unit Inventory.

Matrix Technical Staffing, Inc. 1998a. Map unit descriptions – Rogue River National Forest, Prospect Ranger District, Oregon. Unpublished data.

Matrix Technical Staffing, Inc. 1998b. EUI and soil plot maps for the Union Creek and Thousand Springs quadrangles. Unpublished data.

Neary, D.G., K.C. Ryan, and L.F. DeBano. 2005. Wildland fire in ecosystems: effects of fire on soils and water. Gen. Tech. Rep. RMRS-GTR-42-vol.4. USDA Forest Service, Rocky Mountain Research Station, Ogden, UT.

Powers, R.F., F.G. Sanzhez, D.A. Scott, and D. Page-Dumroese. 2004. The North American long-term soil productivity experiment: coast-to-coast findings from the first decade. In: Silviculture in special places. Proceedings of the National SilvicultureWorkshop. Proceedings RMRS-P-34: 191-206. Fort Collins, CO: USDA Forest Service, Rocky Mountain Research Station.

Appendix C

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United States Department of Agriculture, Forest Service. 1990. Rogue River National Forest Land and Resource Management Plan. USDA Forest Service, Pacific Northwest Region, Rogue River National Forest, Medford, Oregon. Available online at: http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5315122.pdf

United States Department of Agriculture, Forest Service, and United States Department of the Interior, Bureau of Land Management. 1994. Record of Decision for Amendments to Forest Service and Bureau of Land Management Planning Documents Within the Range of the Northern Spotted Owl. USDA Forest Service, Pacific Northwest Region, Portland, Oregon. Available online at: http://www.reo.gov/library/reports/newroda.pdf

United States Department of Agriculture, Forest Service. 1995. Upper Rogue River Watershed Analysis. USDA Forest Service, Rogue River National Forest, Prospect, Oregon. Available online at: http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5315609.pdf

United States Department of Agriculture, Forest Service. 1998. 1998 Regional Supplement to the Forest Service Manual FSM 2520 – Watershed Protection and Management, R-6 Supplement 2500-98-1, Effective August 24, 1998.

USDA Forest Service, Technology and Development Program website. Multipurpose Subsoiling Excavator Attachments. Available online at: http://www.fs.fed.us/t-d/programs/forest_mgmt/projects/subsoiling/ [Accessed on March, 24 2011].