Specialist Report for the Mountain Top PCT CE ~Silviculture~ Chris Roy, Forester March 15, 2015

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1 Specialist Report for the Mountain Top PCT CE ~Silviculture~ Chris Roy, Forester March 15, 2015 Introduction The Mountain Top PCT Project is located on the Bend-Ft. Rock Ranger District of the Deschutes National Forest, about 29 air miles SW of Bend s city limits. The legal description is T 21S, R 8E, portions of sections 19, 20, 29, and 30. The stands involved were planted in 1993 following harvesting. The purpose of this project is to enhance the individual tree growth and vigor within these developing young stands by reducing small tree density. An additional important driver of this project is to provide research study sites for one of Region 6 s partners, the Intermountain Forest Tree Nutrition Cooperative, to investigate the effects of density management and treatment timing on site carrying capacity for several conifer species throughout the Inland Northwest. The Bend-Ft. Rock Ranger District is proposing to non-commercially thin two treatment units totaling 68 acres along with mastication of the created activity fuels. The thinning treatment would favor the largest and healthiest ponderosa pine, Douglas fir, and western white pine with target post- treatment densities ranging within the stands from about 110 to 225 trees per acre. The units are number 2 (38 acres) and 7 (30 acres) from the Mountain Top Timber Sale. Existing Condition Vegetation in the Mountain Top PCT project area consists primarily of dry mixed conifer plant association groups (CW-S1-15 and CW-H1-11 in Volland 1988). The stands in the project area are generally more productive and diverse in tree species composition than most other areas of the district. Adjacent late successional, dense stands generally have ponderosa pinedominated overstories along with white and Douglas fir midstories and varying levels of white fir seedlings and saplings below. The two treatment stands are comprised primarily of a young cohort of conifers initiated following logging in Scattered residual older overstory ponderosa pine, white fir and a few Douglas firs were left in the logging. Informal walk-through sampling suggests there are about 5-10 trees/acre of these residual overstory trees. In 1993, the treatment units were planted with mostly ponderosa pine along with lesser amounts of Douglas fir and, in the case of Unit 7, also some western white pine. In addition to the planted trees, natural regeneration of lodgepole pine, ponderosa pine, and white fir has occurred. Stand conditions are fairly dense, averaging over 1000 trees/acre (range from sample plots 400 to 2900). Rough estimates of species composition for Unit 2 is about 60% ponderosa pine, 35% lodgepole pine, and 5% Douglas and 1

2 white fir. In Unit 7, composition is roughly 35% ponderosa pine, 55% lodgepole pine and 10% white fir, Douglas fir, or western white pine. Among codominant trees from the younger age class, heights range from about and diameters from about 4-8, with codominant trees tending to be slightly larger in Unit 7 than Unit 2. Laws, Regulations, and Policy Applicable to the Project The National Forest Management Act of 1976 (NFMA) establishes standards for how the US Forest Service is to manage its land base and directs individual National Forests to develop their own Forest-specific land management plans. Among the requirements of NFMA is that all forested lands in the National Forest System shall be maintained in appropriate forest cover with species of trees, degree of stocking, rate of growth, and conditions of stand designed to secure the maximum benefits of multiple use sustained yield management in accordance with land management plans (National Forest Management Act of 1976). Management direction for the Deschutes National Forest is set forth in the Deschutes National Forest Land and Resource Management Plan (USDA Forest Service 1990), hereafter Forest Plan. The following is a summary of key management direction pertinent to this non-commercial thinning project. Deschutes National Forest LMRP Forest-Wide Standards/Guidelines (S&Gs) Timber Management Goal: To manage the timber resources of the forest in a way that is consistent with other resource objectives, environmental constraints, and economic efficiency. from TM-1: Silvicultural prescriptions will be prepared for all management activities proposing management of forest vegetation from TM-7: The optimum stocking level shall be based on the maximum cubic volume production unless other resource objectives are identified and documented during the project planning process the minimum stocking level will be based on the total number, distribution, and conditions of trees needed to carry out the least intensive silvicultural strategy from TM-54: in the mixed conifer community types strong consideration should be given to maintenance of stands dominated by early successional species including ponderosa pine, Douglas fir, western white pine, and western larch Management Area Standards/Guidelines (S&Gs) Deschutes National Forest lands are compartmentalized into areas with similar capabilities and management emphasis. The proposed Mountain Top PCT project falls entirely within Management Area (MA) 9- Scenic Views. 2

3 MA 9- Scenic Views Goal: To provide Forest visitors with high quality scenery that represents the natural character of Central Oregon. M9-21: To produce or perpetuate the desired visual condition through time, mixed conifer stands require more frequent management than ponderosa pine stands. Thinnings and other tree removal practices will be done to maintain species diversity, and to promote the health and visibility of larger old growth trees. from M9-27 & 44: In Partial Retention logging residues or other results of management activities will not be visible to the casual forest visitor two years after project completion Northwest Forest Plan The Northwest Forest Plan of 1994 amended the current management plans of federal land management agencies in the Pacific Northwest to include increased habitat protection measures within the range of the northern spotted owl. The Mountain Top PCT project area falls within the landscape covered by the Northwest Forest Plan (NWFP). As a result of the NWFP, federal lands within the range of the northern spotted owl were incorporated into one of 6 different allocations. Though the stands proposed for non-commercial thinning are in an early seral condition, they fall within a Late Successional Reserve (LSR). As stated in the NWFP: In Late-Successional Reserves, standards and guidelines are designed to maintain late successional forest ecosystems and protect them from loss due to large-scale fire, insect and disease epidemics, and major human impacts. The intent is to maintain natural ecosystem processes such as gap dynamics, natural regeneration, pathogenic fungal activity, insect herbivory, and low-intensity fire. These standards and guidelines encourage the use of silvicultural practices to accelerate the development of overstocked young plantations into stands with late-successional and old-growth forest characteristics, and to reduce the risk to Late-Successional Reserves from severe impacts resulting from largescale disturbances and unacceptable loss of habitat (USDA Forest Service and USDI Bureau of Land Management 1994). The affected LSR is known as Brown s Mountain LSR. A multidisciplinary Deschutes National Forest assessment of the Brown s Mountain LSR along with other LSR s in the same watershed was conducted as required after the NWFP was issued. The activities proposed in this project are consistent with the authors restoration recommendations for Brown s Mountain LSR. The assessment includes recommended management activities, where appropriate, within the LSR such as those proposed in this project including: reducing fuel loads, thinning trees to reduce density stress, and release and culturing of individual trees (Deschutes National Forest 1997). Desired Future Condition For both potential treatment units, the desired future condition is a vigorous, developing stand comprised primarily of younger long-lived early seral species, along with scattered remnant 3

4 older and larger trees. Stands would be dominated by ponderosa pine but also maintain a Douglas fir and western white pine component, as well as minor amounts of white fir and lodgepole pine. Stocking levels should allow for rapid growth in the younger age class and will maintain lower susceptibility to insect damage and crown fire hazard for a minimum of 20 years. Key Issue: Density Management and Stand Development It is a very basic principle of forestry that thinning treatments can have major effects on the growth and development of the remaining trees in the stand. At the individual tree level, increases in growing space resulting in more light and water availability generally lead to the residual trees expanding their crowns and increasing foliage density as well as increasing radial growth (Tappeiner and others 2007). At the stand level, thinning can be conducted to meet a wide variety of management objectives including accelerating the development of wood products, improving wildlife habitat, and reducing risks to mortality due to natural disturbances (Emmington and others 2005). As mentioned previously, currently there over 1000 small trees per acre in the both of the proposed treatment stands. A commonly used measure of inter-tree competition is stand density index (SDI). SDI is a measure of relative density that describes the degree of crowding within a stand, where measured stand structure attributes are compared to a reference level for a normally stocked stand of a given forest type (Tappenier and other 2007). Upper density limits or management zones can then be calculated based on when a suppressed class of trees begin to develop, e.g. above 75% of a normally stocked stand (Cochran and others 1994). When stand conditions are above the upper management zone, there is not enough growing space available for all the trees in the stand and growth of many of the individual trees declines as well as overall stand vigor (Cochran and others 1994). Stands with very high SDIs are also at greater risk for bark beetle attack and may be more prone to high severity wildfire. The following table is based on informal walk-through data and should be considered only an approximation of true present SDI: Table 1. Current Small Tree Densities in Mountain Top PCT Project. Unit Plant Association a Upper Management Zone (SDI) b Lower Management Zone (SDI) b TPA c Estimated QMD d Estimated Current SDI e 2 CW-S to CW-S to CW-H to a: see volland 1988 b: calculated following procedures in Boozer and White c: trees per acre- based on 10 1/100 th acre plots d: quadratic mean diameter- visual estimate at plot e: stand density index- calculated using the following equation: TPA * (QMD/10)^1.765 For both potential treatment units, existing densities and level of competition between trees is well above the upper management zone. Within LSRs, second growth stands resulting from harvesting are a focal point for active management with the objective being to accelerate the 4

5 development of late successional conditions while making the future stand less susceptible to natural disturbances (USDA Forest Service and USDI Bureau of Land Management 1994). Current conditions in the understory are sufficiently dense that, without thinning, the LSR management goal of accelerated development of large tree structure is not being met and stand vigor is being compromised. In order to maintain stand vigor and balance individual tree growth versus stand level growth, a common density management strategy for stands with a timber management emphasis involves defining an appropriate upper limit of growing stock (e.g. using SDI) and a lower limit (where the site has enough trees to be considered fully occupied), and attempting to keep the stocking between these limits (Long 1985). Individual trees grow more rapidly when densities are maintained on the low end. In order to use the upper and lower stocking limits concepts for designing treatments, a forester usually starts with a desired condition sometime in the future and works backwards to determine the intensity of thinning (or thinnings) needed to meet those future objectives. Table 2 is an example that determines target residual trees per acre to thin to in 2015, based on appropriate stocking levels for the year 2035 given an estimate of the growth of the trees over that 20 year time frame. Table 2. Desired Stocking for Mountain Top PCT in Unit Upper Limit TPA a Lower Limit TPA b QMD post-thinning 2015 c QMD 2035 d a: trees per acre corresponding to upper management zone in table 1 based on estimated QMD in 2035 b: trees per acre corresponding to lower management zone in table 1 based on C: visually estimated post-treatment quadratic mean diameter (average of 10 plots/unit) d: assumes 1.5 inches of diameter growth per decade, added to QMD post thinning in 2015 The numbers in Table 2 or similar exercises should only be taken as rough guide, as they are based on estimates of stand averages and assumptions about growth over time. Because the Mountain Top PCT Project falls within an LSR and the timber production is not a driving management goal it is appropriate for non-commercial thinning intensities to be based on lower management zone targets (or even temporarily below) in order to maintain stand vigor for longer time frames and to grow larger trees. Embedded within both of the Mountain Top PCT treatment units are research sites that are a part of the Intermountain Forest Tree Nutrition Cooperative s (IFTNC) Paired-Plot Density Management Study. The IFTNC is a research cooperative comprised of public land management agencies, private timberland managers, and the University of Idaho. Region 6 is a member of the cooperative and provides for some research installations on National Forest land. For the Mountain Top PCT project, these study sites include three one acre plots that will be special treatment areas within the proposed non-commercial thinning units. The study sites include: (1) an untreated control, (2) a 14 average spacing thinning, and (3) an 18 average spacing thinning. 5

6 These special treatment areas cover approximately 10% of the proposed treatment acres. The majority of the treatment acres would be thinned to about 20 average spacing, or about 109 trees per acre. Note that the spacing targets are not rigid and allow for some variation in order to retain the most desirable trees. Also there would be a 9 diameter cap in the 20 treatment and a 12 diameter cap in the 14 and 18 treatments which would result in occasional clustering of leave trees. Thus overall stocking would be somewhat heterogeneous. In addition to improving individual tree growth by reducing stand density, thinning also provides the opportunity to favor the preferred species and the most vigorous trees (e.g. most dominant, higher crown ratio, best form). In the mixed conifer community type, the Forest Plan grants management preference to early seral species such as ponderosa pine, Douglas fir, and western white pine when implementing silvicultural activities (p 4-47 in USDA Forest Service 1990). Long-lived early seral species are often favored in management activities in part because they were more dominant historically in areas with frequent interval, low to mixed severity fire regimes and they may be more resistant to insect and disease issues (Franklin and Johnson 2012). The Brown s Mountain LSR assessment states that the among the different potential vegetation groups within the LSR, the dry mixed conifer stand types show the greatest degree of departure from historical conditions. In many locations within the LSR, white fir has become more prevalent in stands formerly dominated by ponderosa pine and maintained at fairly low densities due to frequent low to moderate severity surface fires (Deschutes National Forest 1997). The young stands of the Mountain Top PCT project were planted primarily to ponderosa pine along with lesser amounts of Douglas fir and some western white pine in Unit 7. These species would be favored for retention in the proposed treatments and the resulting composition would be dominated by ponderosa pine. Lodgepole pine and white fir natural regeneration has also occurred in these areas; the proportion of these species would be reduced but not eliminated. Some late successional attributes that are important to maintain in LSRs are large diameter trees and snags and large downed logs. As younger stands continue to develop, desirable attributes include the maintained presence of multiple species and canopy layers, as well as trees with defects such as cavities, broken tops, and large limbs that have wildlife habitat value (USDA Forest Service and USDI Bureau of Land Management 1994). The stands in the Mountain Top PCT project have some legacy structure in the form of scattered larger trees that were not harvested in the previous entry (about 5-10 trees/ac). These include some trees of poor vigor, mostly white fir, that will likely become snags in the upcoming decades and eventually become large woody debris. Key Issue: Fuel Accumulation Given the fairly high number of small trees in the Mountain Top PCT project, a considerable amount of activity fuels would be created during implementation. Forest residue photo series provide a useful way to estimate potential fuel loadings. Post felling conditions in the Mountain Top PCT units could be approximated by photo number 1-PP-1-TH in Maxwell and Ward 6

7 (1976), though there are fewer stems per acre in this project than described in the photo. A rough estimate of potential activity fuels would be 4 to 8 tons per acre, most of which would be less than 3 inches in diameter. The appropriate Photo Series For Quantifying Forest Residues (Maxwell and Ward 1976) rates similar pre-commercial thinning slash levels as high to extreme for potential rate of fire spread and moderate to high for potential ability to control (hazard ratings defined in USDA Forest Service 1968). The levels of slash that would generated by the non-commercial thinning present a fire hazard. The project falls within the Deschutes National Forest s Scenic Views management area, specifically Partial Retention Foreground for most of Unit 2 and Partial Retention Middleground for most of Unit 7, both which require thinning residues to not be visible to the casual forest visitor two years following the activity (USDA Forest Service 1990). Without treatment, at one year post thinning, slash would be red and quite visible to the public. By year two, the activity slash would be less obvious as the needles fade to a greyish color though forest visitors would likely still notice that thinning had occurred. Mastication provides a means to both treat fuels and meet visual objectives. Hand felling is planned for the proposed thinning, mastication would occur afterward targeting the activity fuels and brush. There are several types of mastication equipment used in Central Oregon. The expected piece of equipment to be used in this proposed project is a horizontal drum masticator mounted on in front of a small, tracked dozer. Mastication maintains biomass on site and affects fire behavior by rearranging the orientation, depth, distribution, and size of fuels through the grinding and shredding of shrubs and downed woody fuels. Though mastication reduces flame lengths and rates of spread, fire hazard is not eliminated with mastication as hot, smoldering fires are still possible in the accumulations of fine fuels (Jain and others 2012). A benefit of mastication, though, is that nutrients remain on site and can small woody material can decompose fairly rapidly. Visually, post mastication treatment, a mulch layer of variable-sized shredded wood is evident along with an initially steep reduction in shrub cover. The larger bole wood from the cut trees remains though the branch wood and tops are largely eliminated. For the casual forest visitor the visual evidence of the mastication will not be obvious at two years post treatment, as the shrub layer begins to re-establish and no additional red or grey needles, piles, or burn scars are evident. In addition, though the treatment units are along open roads, public use is low as most visitors are travelling on Forest Road 42 on their way to recreation sites or to the Cascade Lakes Scenic Byway. The Mountain Top PCT project is not highly visible from Forest Road 42. 7

8 Notes for Prescription Preparation Treatment specifications will need to accommodate the research plots that are located inside the larger units. Three approximately one acre areas within each unit have a predetermined prescription. These are: ~14x spacing. Leave trees are marked with vertical blue stripes. Perimeters are not currently flagged, just indicated by the marked trees. Do not enter this area with the masticator. If needed, pull slash by hand from within painted area out into main unit for treatment. ~18x spacing. Leave trees are marked with vertical blue stripes. Perimeters are not currently flagged, just indicated by the marked trees. Do not enter this area with the masticator. If needed, pull slash by hand from within painted area out into main unit for treatment. Untreated control. No cutting and no entry with masticator. Perimeter currently flagged in blue and orange ribbon. Elements to Consider Incorporating into the Contract s Detailed Information Sheet: Yes, a target average spacing of 20 will provide a good result. Spacing should not be too rigid. Some variation (e.g. +/- 50% of target spacing) should be employed to keep the best trees. 8 or 9 dbh cap would allow for some clustering of dominant PP. Most cut trees are less than 6. PP will be the most common leave tree but precedence should be given to DF and WWP where they occur, even if they fall within the cutting radius of a larger PP. Suggest tighter spacing off of DF and WWP (e.g. 10 ) or ghosting of WWP (do not cut or count in the spacing). This reflects these species more mid tolerant nature and, in the case of WWP, the uncertainty of their survival to maturity due to blister rust. Also, some variation in spacing is desirable to create some heterogeneity. Monitoring Monitoring can be accomplished at the same time as contract administration. Important elements are noting proper tree selection and number of trees per acre retained. Mastication should retain larger downed woody materials (> 6 ) where they occur. Minimize pivoting and turning, long linear swaths with minimal passes are preferred to minimize soil displacement. 8

9 Citations Boozer, J. and White, J. Undated. Calculating maximum stand density index (SDI) for Deschutes National Forest Plant Associations. 9 p. Cochran, P.H. and others Suggested stocking levels for forest stands in northeast Oregon and southeastern Washington. USDA Forest Service PNW-RN-513. Deschutes National Forest Browns/Wickiup Watershed Analysis and Browns/Round Mountain Late-Successional Reserve Assessment. Bend-Fort Rock Ranger District. Emmington, W.H. and others Ecology and Management of Eastern Oregon Forests. Oregon State University Extension Service. Franklin, J.F. and Johnson, N.K A restoration framework for federal forests in the Pacific Northwest. Journal of Forestry 110(8): Long, J.N A practical approach to density management. Forestry Chronicle 61: Jain, T.B. and others A comprehensive guide to fuel management practices for dry mixed conifer forests in the northwestern United States. Gen. Tech. Rep. RMRS-GTR-292. Maxwell, W.G. and Ward, F.R Photo series for quantifying forest residues in the ponderosa pine type, ponderosa pine and associated species type, and lodgepole pine type. USDA Forest Service. Gen. Tech. Rep PNW-GTR-52. USDA Forest Service Guide for fuel type identification. Pacific Northwest Region. Portland, OR. 48 p. USDA Forest Service Land and Resource Management Plan. Deschutes National Forest. Pacific Northwest Region. USDA Forest Service and USDI Bureau of Land Management Standards and guidelines for management of habitat for later successional and old-growth related species within the range of the northern spotted owl. Volland, L.A Plant associations of the central Oregon pumice zone. USDA Forest Service. Pacific Northwest Region. R6-ECO

10 Appendix. Project Location Map. 10