BASELINE FOREST GROWTH & MORTALITY ASSESSMENT

Transcription

1 BASELINE FOREST GROWTH & MORTALITY ASSESSMENT Prepared for: Oregon Forest Resources Institute November 2005 E. D. Hovee & Company, LLC Economic and Development Services

2 BASELINE FOREST GROWTH & MORTALITY ASSESSMENT Prepared for: Oregon Forest Resources Institute 317 SW 6 th Avenue, Suite 400 Portland, OR (503) Prepared by: E.D. Hovee & Company, LLC P.O. Box Main Street Vancouver, Washington (503) / (360) Eric Hovee, Principal Tess Jordan, Economic Planner November 2005

3 EXECUTIVE SUMMARY Improving the understanding of forest growth and mortality by geographic region of the state has been identified as a research priority by the Oregon Forest Resources Institute (OFRI). The objective of this study is to conduct a baseline assessment of natural biological growth and mortality in Oregon s forests by ownership, species and geographic region of the state. This assessment is to be overlaid with an analysis of potential economic and environmental risks and benefits for varied forest management scenarios. What follows is an abbreviated summary of observations and findings from this baseline forest growth and mortality assessment. Public Policy Context. Oregon forest growth and mortality is affected by changing public priorities regarding forest land management including the 1994 Northwest Forest Plan (for western Oregon), the 2003 Healthy Forests Initiative and the 2003 Forestry Program for Oregon (FPFO). The FPFO is intended to address forest growth and mortality through a series of benchmark indicators now being developed. With federal policy initiatives, there is not yet a clear view regarding an appropriate sustainable objective for forest growth in excess of long-term mortality and removals. The absence of a consensus vision poses risks for Oregon forests, particularly as fuel loads increase on federal lands to levels not previously seen. Existing Conditions & Trends. Baseline information on forest growth and mortality for public and private lands is generated from the Forest Inventory and Analysis (FIA) and the Continuous Vegetation Survey (CVS) of the U.S.D.A. Forest Service: Available data indicates average annual gross growth of 2.3 billion cubic feet (approximately 10.3 billion board feet) for sawtimber on non-reserved forests statewide during the 1990s, the most recent time period for which data is available. Total removals across all lands, statewide totaled about 3.9 billion board feet (bbf) annually over the decade. The difference between removals and the 10.3 billion bf of gross growth is about 6.4 bbf. Total mortality is about 2.4 bbf, leaving approximately 4 bbf of net annual growth statewide. Forest growth and mortality patterns vary substantially by land ownership and region of the state. Western Oregon appears to experience the most positive pattern of overall net annual growth. Eastern Oregon reports negative net growth for private lands with annual mortality and removals exceeding growth through the 1990s. This combination of factors, not sustainable long-term, may be viewed as an anomaly due both to issues of infestation and extensive harvest activity. The experience of the 1990s also suggests need for particular focus on eastern Oregon issues of forest health, economic viability and sustainability in the years ahead. Baseline Forest Growth & Mortality Assessment Page i

4 Removal rates as a percentage of gross growth are uniformly higher on private especially industry forest lands. Not surprisingly, removal rates on non-federal (or other public) lands fall between those of private and federal lands. Mortality is substantially higher on public than private lands in western and eastern Oregon. On federal lands, mortality far exceeds harvest removals on both sides of the Cascades. This condition may not be sustainable long-term due to adverse implications for forest health and risk of uncharacteristically intense forest fire. Implications to Forest Fire Risk. Growth and mortality intersect with forest health and fire risks through fuel loading or stand density. While not directly a part of the FIA inventory, the Forest Service has separately characterized fire condition classes. Of Oregon s 16.9 million acres of treatable timberland, 5.6 million acres (or 33%) currently are in fire condition class III, indicating a significant departure from the forest s natural fire regime. Another 6.6 million acres (39%) are in the moderately altered fire condition class II. Statewide, approximately 12.2 million acres in FRCC Class II-III lands could be considered for treatment as a means to reduce infestation and fire risk thereby improving long-term forest health and sustainability. Growth-Mortality Management Options. Models for growth-mortality management range from thinning (to encourage growth and reduce fire risk) to management for biodiversity (which encompasses a larger set of objectives). Outcome indicators may be useful to determine how public reserve and multi-resource lands can be most effectively addressed via passive or active management. In this baseline analysis, comparisons are made across three sets of management values and associated performance indicators: Ecosystem covering a range of geophysical and habitat indicators. Social notably community and non-use values. Economic for volumes of usable timber/biomass, recreation, employment and output values as well as economic risk. Findings & Implications. While preliminary, a series of initial findings and implications may be drawn from this baseline forest growth and mortality assessment: 1. Currently available data demonstrate two areas of concern for balanced growth-mortality across Oregon s forests negative net growth experienced on private eastern Oregon lands during the 1990s and mortality exceeding harvest removals on federal timberlands both west and eastside. On private (eastside) lands, high levels of harvest plus mortality exceeding growth are not sustainable without jeopardizing forest resources for the future. On federal timberlands, high levels of growth combined with high mortality and low levels of removal may jeopardize long-term ecosystem health with increased risk of infestation and high severity fire as well as foregone economic opportunities. Baseline Forest Growth & Mortality Assessment Page ii

5 2. While useful as a starting point for analysis, the data sets currently available provide a partial yet incomplete perspective on forest growth, removals and mortality; further if not more expedited research is suggested as a combined federal and state priority. 3. Forest health and economic contributions may be improved by more active forest management albeit with varied approaches for wood production, multi-resource and reserve forests. 4. For some reserve forests, such as wilderness areas, a more passive management approach may be most appropriate essentially letting nature take its course. High value reserve areas often have received less human management intervention (logging and fire suppression) in the past, maintaining the risk of fire and infestation at essentially unaltered levels. 5. More active management will not necessarily generate positive economic returns across all forest types. However, improved forest health can yield both market and non-market values across the entire Oregon forest landscape. Further Research. Interaction with Growth & Mortality Assessment Task Force members has generated interest in expanding the focus from the technical data and analysis to a broader dialogue that can describe a more dynamic approach to sustainable forestry practices. A longterm assessment of management for growth, removal and mortality will require both quantitative data and qualitative research extending beyond one point in time. This more dynamic assessment might include: Research of historic FIA, harvest and other forest data and possibly expert interviews to assess how forest growth, mortality and indicators of sustainability have changed over time. Incorporation of other current information such as USDA Forest Service Continuous Vegetation Survey (CVS) reporting of stand density index (SDI) to reach supportable conclusions regarding potentially slowing growth and increased mortality. Assessment of future harvest projections including those of the Oregon Department of Forestry and U.S. Forest Service Timber Assessment. Inclusion of a literature review and possibly expert interviews to generate more of a macro perspective of larger ecological trends and issues affecting forest biodiversity, fire/disease risk, and long-term sustainability. Utilization of this expanded assessment of forest sustainability as a platform from which to make policy and management recommendations for consideration by state and federal policy makers. Baseline Forest Growth & Mortality Assessment Page iii

6 Table of Contents EXECUTIVE SUMMARY i I. INTRODUCTION TO GROWTH & MORTALITY ASSESSMENT 1 II. PUBLIC POLICY CONTEXT 4 III. EXISTING CONDITIONS & TRENDS 6 IV. GROWTH-MORTALITY & FOREST HEALTH 17 V. GROWTH-MORTALITY MANAGEMENT OPTIONS 23 VI. FINDINGS & IMPLICATIONS 34 VII. FURTHER RESEARCH 37 APPENDIX A. PUBLIC POLICY GROWTH & MORTALITY CONTEXT 39 APPENDIX B. SUPPLEMENTAL FIA GROWTH & MORTALITY DATA 45 APPENDIX C. REFERENCES REVIEWED 48 ENDNOTES 60 Table of Figures Figure 1. Growth & Mortality Assessment Task Force 2 Figure 2. Annual Growth & Mortality of Sawtimber on Non-Reserved Timberland 9 Figure 3. Annual Growth & Mortality of Sawtimber on Non-Reserved Timberland as Percentage of Gross Growth 10 Figure 4. Western Oregon Timber Removals (as % of Gross Annual Growth) 13 Figure 5. Mortality as % of Gross Annual Growth by Forest Type for all Growing Stock on Non-Reserved Timberland ( ) 14 Figure 6. Oregon s Fire Condition Classes & Associated Acreage 19 Figure 7. Market & Non-Market Values & Costs of Fire Risk Reduction 21 Figure 8. Eastern Oregon National Forest Thinning Alternatives & Outcomes 24 Figure 9. Forest Area in Seral Stages According to Management Alternative 28 Figure 10. Net Present Value of Management Scenarios Considered 29 Figure 11. Comparative Implications of Passive & Active Forest Management 32 Figure 12. Growth & Mortality Detail for Sawtimber on Reserved & Non-Reserved Timberland ( ) 47 Figure 13. Ratio of Gross Growth to the Sum of Mortality & Removals (1990s) 52 Baseline Forest Growth & Mortality Assessment

7 I. INTRODUCTION TO GROWTH & MORTALITY ASSESSMENT In June 2004, E. D. Hovee & Company completed a study of Oregon Forest Sector Contributions and Potential on behalf of the Oregon Forest Resources Institute (OFRI). The project involved economic modeling of forest management, benchmarking of the state s forest sector clusters, identifying opportunities for branding and eco-labeling, and discussion of market and non-market values for economic, environmental and social sustainability. The 2004 study also involved approximately 50 interviews with a cross-section of stakeholder interests including forest land owners, primary and secondary industrial operators, and public agency and environmental organizations. The 2004 forest sector study provided a brief review of biological growth potential of Oregon s forests across a range of ownership and management categories. One outcome of this work was a suggested series of follow-up projects for further research. Included was a recommendation to develop a more thorough understanding of forest growth in excess of harvest by region and by management objective including assessment of the implications for increased harvest and for increased risk of uncharacteristically severe wildfire. Research Questions. The central questions intended to be addressed by this assessment of forest growth and mortality in Oregon are: How do growth and mortality affect the composition of Oregon s forests under current management practices? To what degree does available information about growth and mortality portray a static versus dynamic landscape? How do growth and mortality impact the economic value of forests under current management practices? How do growth and mortality impact the ecological value under current management practices? What policy implications to management, environmental or economic policy are suggested from this analysis? Growth-Mortality Definitions. Terms used throughout this report are intended to be consistent with those of the U.S.D.A. Forest Service Pacific Northwest Forest Inventory and Analysis (FIA). Key terms are described below; terms relating to forest characteristics here describe sawtimber (softwood trees 9 diameter at breast height and hardwood trees 11 diameter at breast height). Gross Annual Growth This term refers to the average annual increase in sawtimber volume between two inventory periods. Periodic gross growth includes: a) the increment in net volume of sawtimber stock alive in both the prior and current inventories; b) ingrowth, the net volume of trees reaching sawtimber size during the survey interval; c) mortality, the net volume of sawtimber trees that died during the survey interval; and d) removals, the net volume of sawtimber trees that were harvested during the survey interval. Baseline Forest Growth & Mortality Assessment Page 1

8 Mortality Average annual mortality is the annual net volume of sawtimber trees that died between the previous and current inventories. Removals Average annual net volume of sawtimber trees harvested between the previous and current inventories. For both primary data sources that this report relies on, surveys do not distinguish whether trees were alive or dead at the time of removal. Net Annual Growth This is defined as gross annual growth, the net volume of trees reaching sawtimber size during the survey interval, less b) mortality, the net volume of sawtimber trees that died during the survey interval, less c) removals, the net volume of sawtimber trees that were harvested during the survey interval. Federal land Land managed by the USDA Forest Service, USDI Bureau of Land Management and other federal agencies. Does not include tribal lands managed by the USDI Bureau of Indian Affairs. Federal lands described by this report typically do not include congressionally reserved lands. Other public land Lands managed by state, county or local governments. Private land Land owned by private industry, family forestland owners, Indian Tribes, and other private organizations. East Land east of the crest of the Cascade Mountains. West Land west of the crest of the Cascade Mountains. Reserved Lands that are congressionally withdrawn from timber harvest, such as wilderness areas and national parks. This does not include administratively withdrawn lands such as under the Northwest Forest Plan (e.g. Late Successional and Riparian Reserves). Assessment Oversight. Management of this assessment has been provided by OFRI. The study has also benefited from the involvement of a Growth & Mortality Assessment Task Force. With agency, university, industry and environmental organization participation, task force members have provided a diversity of input including identification of pertinent data sources and agency contacts together with review of preliminary and final draft documents. Figure 1. Name Russ McKinley Rick Brown David Cox Gary Lettman Linc Cannon Darius Adams Dave Azuma Greg Filip Jeannette Griese Growth & Mortality Assessment Task Force Organization Boise Cascade Defenders of Wildlife Mason, Bruce & Girard Oregon Department of Forestry Oregon Forest Industries Council OSU Forest Resources Department PNW Research Station, Portland Forest Sciences Lab R-6 USDA Forest Service USDI Bureau of Land Management Baseline Forest Growth & Mortality Assessment Page 2

9 Report Organization. The remainder of this report is organized to cover the following topics: Public Policy Context Existing Conditions & Trends Growth-Mortality & Forest Fire Risk Growth-Mortality Management Options Findings & Policy Implications Further Research Three appendices are provided with this report. Appendix A contains a more detailed discussion of the public policy growth and mortality context. Appendix B provides supplement FIA forest growth and mortality data. Appendix C gives a synopsis of references reviewed for this report. Baseline Forest Growth & Mortality Assessment Page 3

10 II. PUBLIC POLICY CONTEXT Federal and state policies provide the primary framework for this assessment of Oregon s forest management practices. Federal Forest Policy Federal forests constitute 57% of Oregon s forests. As such, federal legislative initiatives have formed the basis of discussion, planning, and management of Oregon s forests. Three primary federal legislative acts provide federal policy guidance for the management of federal forest lands: The National Forest Management Act (NFMA) of 1976 requires the Secretary of Agriculture to assess forest lands, develop a management program based on multiple-use, sustained-yield principles, and implement a resource management plan for each unit of the National Forest System. It is the primary statute governing the administration of national forests. The 1998 Farm Bill included provisions affecting forest land inventories with a shift from periodic to annual inventories. In 1994, the Northwest Forest Plan amended forest plans (developed pursuant to the NFMA) covering the range of the northern spotted owl. The Northwest Forest Plan was designed as an integrated comprehensive plan for western Oregon, with principal plan components covering topics of forest management, economic development and interagency cooperation. The more recent Healthy Forests Initiative was adopted primarily as a means to reduce risks of uncharacteristically severe wildfires prompted by major fire seasons in 2000 and again in State Forest Policy At the state level, the primary policy directive is the 2003 Forestry Program for Oregon (FPFO), which represents a State Board of Forestry initiative to set for a mission and vision for Oregon s forests. The FPFO provides values and strategies intended to guide board decisions over an eight-year period. The policy document s vision statements concern a sustainable flow of environmental, economic, and social outputs and benefits and outline the administrative structures and funding required to achieve this vision. Eight strategies are encompassed by the FPFO: Strategy A. Promote a sound legal system, effective and adequately funded government, leading-edge research, and sound economic policies. Strategy B. Ensure that Oregon's forests provide diverse social and economic outputs and benefits valued by the public in a fair, balanced, and efficient manner. Strategy C. Maintain and enhance the productive capacity of Oregon's forests to improve the economic well-being of Oregon's communities. Baseline Forest Growth & Mortality Assessment Page 4

11 Strategy D. Protect, maintain, and enhance the soil and water resources of Oregon's forests. Strategy E. Contribute to the conservation of diverse native plant and animal populations and their habitats in Oregon's forests. Strategy F. Protect, maintain, and enhance the health of Oregon's forest ecosystems, watersheds, and airsheds within a context of natural disturbance and active management. Strategy G. Enhance carbon storage in Oregon's forests and forest products. A more in-depth review of these policy documents focused on issues related to forest growth and mortality is provided by Appendix A to this report. Growth & Mortality Implications. There are several implications that can be drawn from the review of the changing policy context for growth and mortality in Oregon forests conducted for this assessment: The Northwest Forest Plan envisioned a broad landscape of interconnected late reserve forests in public ownership and expedited timber harvests on private lands. Growth and mortality was not specifically discussed within the plan; however, the plan was to be implemented with considerable flexibility to unique conditions at the individual forest level and with active management, particularly of fire prone areas. There is growing recognition that the flexibility to manage as intended has not been fully realized to date. Harvest levels have been reduced to levels well below those anticipated with the plan. The long-term implications of added net (western Oregon) growth in excess of mortality have not yet been explicitly addressed with forest plans. The Healthy Forests Initiative aims to address perceived negative effects of forest overstocking by streamlining approvals for thinning, harvests and other projects, particularly by limiting the appeals process and prioritizing vegetation treatment of atrisk land. The initiative also encourages development of private sector infrastructure by authorizing forest service entities to enter into 10-year contracts for projects such as thinning. Through the broad-based Forestry Program for Oregon (FPFO), forest growth and mortality is being addressed though a series of benchmark indicators are currently being developed. With federal policy initiatives, there is not yet a clear long-term view regarding an appropriate sustainable objective for forest growth in excess of long-term mortality and removals. The absence of a consensus vision poses risks for Oregon forests, particularly as fuel loads on federal lands increase to levels not previously seen prior or subsequent to human management intervention. Baseline Forest Growth & Mortality Assessment Page 5

12 III. EXISTING CONDITIONS & TRENDS With this brief review of Oregon-related public forest management policy in mind, this analysis proceeds to a more technical review of existing conditions and trends affecting Oregon forest growth and mortality. A major purpose of this report is to summarize the state of the data currently available on growth and mortality within Oregon s forests, as well as data generation projects planned and underway. The analysis then summarizes findings on the implications of growth and mortality to forest health. 1 EXISTING GROWTH-MORTALITY DATA The most comprehensive source of data on Oregon s forests is available through the Pacific Northwest Forest Inventory and Analysis (FIA), a department within the U.S.D.A. Forest Service (USFS) established to conduct a census of the nation s forest lands. The department represents the most comprehensive, long-term and well funded effort to date to collect data on Oregon s forest lands (which fall within FIA s Region 6 along with Washington State). For Oregon, much of this data compilation and analysis is conducted through the Pacific Northwest Research Station based in Portland. The FIA originally focused surveying efforts on private lands, while other departments within the USFS focused on public land (USFS and Bureau of Land Management) surveying efforts through the Continuous Vegetation Survey (CVS). These two surveying efforts are in the process of being merged. As of spring 2005, the FIA is involved with two primary data products describing Oregon s forests: The Integrated Database (IDB) an effort to combine numerous surveys conducted throughout the 1990s into one comprehensive data source. This database includes information on federal lands from the CVS in the mid-1990s, but no remeasurement data for federal land. The Annual Inventory an ongoing and comprehensive survey effort begun in 1999 but yet to complete a full survey sample. Integrated Database the 1990s. Within Oregon, the IDB incorporates data from four different sources collected between 1993 and Data includes information on growth and mortality, although actual remeasurement (necessary to measure growth and mortality) only occurred on private land; estimates were developed for sampled public land. The primary caveats associated with this data source are: 1) The IDB is now somewhat out of date; 2005 forest growth and mortality likely looks different in light of the continued decline in logging on federal lands that began in the early 1990s. Baseline Forest Growth & Mortality Assessment Page 6

13 2) FIA staff describes the reliability associated with public land growth and mortality estimates as limited due to lack of remeasurement, particularly when disaggregated to sub-state levels and ownership classifications. 3) Forest growth and mortality may look somewhat different on state and private lands than on federal lands due to different databases and measurement time periods, as further described below. Annual Inventory 2000 & Beyond. The Annual Inventory is the FIA s current effort to collect comprehensive forest data within a single survey, although the survey s primary component (Phase II) currently takes 10 years to complete. Annual Inventory plots do not correspond with previous IDB plots some are located near IDB plots, but each follows a different design which means that many of the plots, even if co-located, do not overlap. Consequently, for attributes requiring remeasurement such as growth and mortality a single cycle of the Annual Inventory will not be sufficient. Additional cycles will be necessary to provide a dynamic view of changing forest growth and mortality over time. There are three phases to the inventory process. Phase I is based upon satellite imagery, essentially involving an assessment of existing land use; this covers non-forested land as well. Phase II comprises a survey of forested or potentially forested sample plots. There is one plot per 6,000 acres (roughly three miles apart) with a total of 6,200 plots. Data collection associated with Phase II plots is also referred to as the Annual Inventory, and includes tree, stand and vegetation characteristics including associated estimates of growth and mortality 2. Currently one-tenth of Oregon plots are sampled each year, meaning that a complete assessment of all plots requires ten years to finish and a comprehensive initial time series comparison requires 20 years. Information collected over the 10-year period is described as a moving average. In Oregon, the inventory will be completed every 10 years, if fully funded. 3 The current administration budget calls for full funding, but it is unclear if this will be maintained throughout the budget ratification process. The existing default national method for reporting current estimates (the annual inventory) is to not adjust or weight the data according to the year it was collected, and to report the year associated with the data as the full 10-year range. Finally, Phase III of the annual inventory includes fewer plots than previously one every 96,000 acres or roughly every 16 miles but with more intensive data collection for the selected plots. Phase III plots are also referred to as Forest Health Monitoring plots. This Phase III inventory (a subset of the Phase II inventory) is to be field checked every five years (or at a rate of 20% field coverage each year). Characteristics recorded for Phase III plots include such items as evidence of ozone injury, details of lichen communities, soil attributes, crown condition, vegetation diversity and structure, and downed woody material. 4 Phase III data collection began in Since this initial inventory was completed in five years, a second round of data collection is now in progress. Baseline Forest Growth & Mortality Assessment Page 7

14 The Continuous Vegetation Survey (CVS) will complete its final data collection cycle in After that, the Annual Inventory will represent the only data collection effort, intended to be comprehensive. This merger will involve increasing the amount of information collected on USFS land together with the geographic frequency of USFS land plots. Annual Inventory Availability. The FIA has been expected to begin generating reports from the Annual Inventory data by fall 2005, when five years of data are collected on all plots. The survey was not initiated on USFS lands until 2001 (private land surveys began in 2000); the CVS and Annual Inventory will thus overlap in their collection of data on USFS land for a few years. The FIA has decided not to produce reports more frequently than the five-year intervals its implementing legislation calls for due to the high sampling errors that are calculated or result from fewer than five panels (or years) of data collection. The FIA also is not expected to analyze mortality data (due to the high level of variance with which it is associated) until the entire 10-year data collection process is complete. FIA continues to investigate methods of making this data available in a more timely manner. Finally, it is noted that the FIA is working on a software system that will provide sampling errors associated with the reports that can be downloaded via the internet allowing users to understand the reliability of FIA data as it is available but has just starting contracting for that programming. An initial set of data products is expected by no earlier than October Disadvantages to the Annual Inventory system at present are that fewer than five panels of data are available for both private and public lands public lands will not be available until fall 2005 or In the meantime, CVS data (including remeasurement) is available for public lands. With the sampling process now in place and at current funding levels, a complete set of growth and mortality data for all land ownerships is not expected to be complete until S GROWTH & MORTALITY RESULTS What follows is a condensed version of what appears in FIA statistical reports (summarizing data from the Integrated Database) combined with Continuous Vegetation Survey results for public land (not yet available through the FIA). The CVS data is for a slightly later time period (with initial surveying and remeasurement ), and also excludes reserved land due to lack of availability at this point in time (remeasurement has not yet been completed). Throughout this report, net forest growth is calculated as gross annual growth less average annual mortality and removals (via harvest). Growth & Mortality by Region & Ownership. Figure 2 describes private timberland, other public timberland, and federal timberland separately. Forest land legislatively reserved (e.g. wilderness areas) are excluded from timberlands; administratively reserved lands such as riparian buffers are included. The following data is calculated through remeasurement as reported by FIA periodic data (private and other public land) and by the USDA Forest Service Region 6 office, based on reassured Continuous Vegetation Survey plots (public federal land). Baseline Forest Growth & Mortality Assessment Page 8

15 Figure 2. Annual Growth & Mortality of Sawtimber on Non-Reserved Timberland Private ( ) Federal ( ) Other Public ( ) All Ownerships (mixed dates, ) West East West East West East West East Total Million board feet Net Growth 563 (152) 2, , ,385 Mortality , , ,011 Removals 2, , ,898 Gross Growth 3, ,918 1, ,019 2,275 10,294 As % of Gross Growth: Net Growth 16% -33% 70% 45% 63% 61% 46% 30% 43% Mortality 2% 19% 26% 44% 5% 19% 14% 38% 20% Removals 81% 114% 4% 10% 32% 20% 40% 32% 38% Source: U.S.D.A. Forest Service Pacific Northwest Research Station, Timber Resource Statistics for Western Oregon, 1997, Resource Bulletin PNW-RB-237; Timber Resource Statistics for Eastern Oregon, 1999, Resource Bulletin PNW-RB-238; Continuous Vegetation Survey special run prepared by U.S.D.A. Forest Service, R6 and BLM Oregon State Office (data for public federal land); E.D. Hovee & Company. Statewide, private and public non-reserved forests approximate 10.3 billion board feet (bbf) of gross annual growth and 4.4 billion board feet of net annual growth. There is substantial difference in the productivity of west versus eastside forests. Gross annual growth is over 8.0 bbf per year on the westside, about 3.5 times greater compared with less than 2.3 bbf of gross on the eastside. However, mortality on the westside exceeds that on the eastside by a ratio of only about 1.3:1 due to a much higher mortality rates east of the Cascades. One important caveat associated with this table is that data availability required separate surveying efforts to be combined, resulting in survey periods that are not fully matched. Private and non-federal (or other public) lands reflect average annual growth during the 1990s whereas federal land reflects average annual growth over a later time period, extending through Total removals across all lands statewide totaled about 3.9 billion board feet (bbf) annually over the decade. The difference between this and the 10.3 billion bf of gross growth is about 6.4 bbf. Total mortality is about 2.0 bbf, leaving 4.3 bbf of net annual growth statewide. The breakdown of gross growth into mortality, removals and net growth is the summation of policy decisions at several levels. Forests where removal and mortality combined exceed gross growth will have negative net growth and a decrease in standing timber or growing stock. Forests with low net growth will have stable levels of growing stock. Forests with highly positive net growth will have increasing levels of growing stock. In young forests where inventory is building such as on other public land in western Oregon, increasing levels of growing stock can be good. In older forests such as on federal forest lands, high positive net growth and increasing growing stock will exacerbate over stocking problems leading to a worsening forest health situation and even higher levels of mortality in the future. Baseline Forest Growth & Mortality Assessment Page 9

16 Private lands account for 38% of average gross annual growth, the vast majority on the westside. Western Oregon represents 78% of gross annual (non-reserved) forest growth statewide. Statewide, net forest growth equates to 43% of gross annual growth with higher ratios of net to gross growth found on public versus private lands. Private lands east of the Cascades represent the only category for which net growth is negative for the time frame indicated. A somewhat different picture is presented by mortality data. Mortality represents just 4% of gross annual growth on private lands compared with 32% of gross growth on federal lands. For other (non-federal) public lands, annual mortality equates to 6% of gross forest growth. Distribution of Growth & Mortality. The relationship between mortality, removals and net growth as a percentage of gross annual growth is graphically displayed in Figure 3 below. When there is positive net growth, the combination of mortality and removals will be less than 100% of gross annual growth. Conversely, where net growth appears to have been negative (as in eastern Oregon private lands), the combination of mortality plus removals exceeds 100%. Figure 3. Annual Growth & Mortality of Sawtimber on Non-Reserved Timberland as Percentage of Gross Growth 140% 120% 100% 80% 60% 40% 20% 0% -20% -40% Private West Private East Federal West Federal East Other Public West Mortality Removals Net Growth Other Public East Source: U.S.D.A. Forest Service Pacific Northwest Research Station, Timber Resource Statistics for Western Oregon, 1997, Resource Bulletin PNW-RB-237; Timber Resource Statistics for Eastern Oregon, 1999, Resource Bulletin PNW-RB-238; Continuous Vegetation Survey (CVS) special run prepared by U.S.D.A. Forest Service, R6 and BLM Oregon State Office; E.D. Hovee & Company. Baseline Forest Growth & Mortality Assessment Page 10

17 Private Timberlands. On private timberland, western Oregon gross growth exceeded the sum of mortality and removals during the 1990s. Thus, net annual growth is positive at 16% or about 563 million board feet (around 125 million cubic feet) of net growth per year. On eastern Oregon private timberlands, the combination of harvest and mortality exceeded gross growth during the 1990s, resulting in calculated negative net growth approximating 33% of gross annual growth over this period. This equates to an annual average of 152 million board feet or roughly 34 million cubic feet of negative net growth annually over this 10-year period. A number of factors appear to have influenced results in eastern Oregon during the 1990s. These include high mortality rates associated primarily with infestation issues such as the spruce budworm that in turn led to slower gross annual growth and higher harvest levels to remove dying trees. High removals also may reflect the effects of extensive harvest activity and subsequent liquidation or land sales by some private owners. This combination of factors, not sustainable long-term, may be viewed as an anomaly. Conversely, the experience of the 1990s also suggests need for particular focus on eastern Oregon issues of forest health, economic viability and sustainability in the years ahead. Federal Public Timberlands. In western Oregon, non-reserved federal land accounts for 49% of western gross growth. Removals as a percentage of gross growth are the lowest of any land ownership and geography at 4%. Conversely, mortality is higher than any western land ownership at 26%, second only to mortality on federal lands in eastern Oregon. Factors influencing higher mortality rates potentially include denser stands and a lower rate of removing diseased and dying trees. Low harvest and high mortality result in a net growth percentage slightly higher than for nonfederal public lands in the west at 70%. This equates to 2.7 billion board feet or just over 600 million cubic feet net annual growth. For eastern Oregon non-reserved federal forests, net growth is lower both as a percentage of gross growth and in terms of total annual board feet. Net annual growth equals 45% of gross growth or 0.8 billion board feet (180 million cubic feet). Gross growth is close to one-half the board feet of western Oregon s non-reserved federal lands. Both removals and mortality rates are higher. At 10% of gross growth, removals remain below all other geographies and land classes (other than western Oregon federal land). At 44% of gross growth, mortality on eastern Oregon federal lands is the highest of the geography and land classes considered. Again, mortality rates are likely due both to variations in stand densities and the extent to which diseased or dying trees are harvested. Other Public Timberlands. As the smallest category of land ownership, other (non-federal) public timberlands account for only 6% of total gross growth in western Oregon and 1% in eastern Oregon. Other public timberlands include holdings of state and county entities. Baseline Forest Growth & Mortality Assessment Page 11

18 Across both eastern and western Oregon, net growth is positive and fairly consistent at 61% - 63%. Mortality is very similar to mortality on private lands at 5% and 19% in western and eastern Oregon (compared with 2% and 19% for private lands). Rates of removal are substantially below those of private timberlands both west and eastside. Western & Eastern Oregon Mortality Comparisons. This data depicts substantial differences between the relationship of growth to mortality east and west of the Cascade Mountains. For private lands, west side mortality equates to only 2% of gross annual growth. On the eastside, mortality is calculated at about 19% of gross annual growth. While the drier species of the eastside typically could be expected to experience higher levels of mortality, the rates for the 1990s are also influenced by major infestation. For federal (non-reserve) public lands, mortality ranges from 26% (westside) to 44% (eastside). Overall mortality on federal public lands appears to be greater than for private lands both west and east of the Cascades. This is not unexpected since public lands (even non-reserve forest lands) are managed for multiple purposes which typically involve longer rotation with less harvest and consequently more mortality from natural sources. For private and public lands combined, there is a tradeoff between removals and mortality in western Oregon. Mortality is highest (26%) on federal lands where removal is lowest (4%). Conversely private land has 80% removal and only 2% mortality. Western Oregon Harvest by Ownership. More detailed characterization of removal (or harvest) patterns in western Oregon are useful to further illustrate major differences by timberland ownership. Similar detailed characterization for eastern Oregon is not as useful due to unsustainable infestation and harvest issues during the 1990s. Baseline Forest Growth & Mortality Assessment Page 12

19 Figure 4. Western Oregon Timber Removals (as % of Gross Annual Growth) 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Private Federal Other Public Removals as Percentage of Gross Growth Source: USDA FIA and CVS data, as detailed by Figure 2 and compiled by E.D. Hovee & Company. As indicated by the graph, removals account for 81% of gross annual growth on western Oregon private lands, compared to only 4% on federal lands and 32% on other (non-federal) public lands. Only on federal timberlands does mortality exceed removals, at 26% versus 4% of gross annual growth. Mortality by Forest Type. When viewed by forest type (designated by the dominant species), mortality rates vary considerably. The next chart ranks Oregon forest types by mortality rate as a percentage of gross annual growth (from highest to lowest). The table also indicates softwood/hardwood categorization, standard error (or variability) of measurement, and estimated net volume of growing stock. Species that were particularly affected by the spruce budworm infestation of the early 1990s are also noted. This chart reports modeled mortality (rather than mortality based on remeasurement); therefore, mortality is not necessarily distinct from harvest (not included). A second distinction is that the chart describes growing stock, or all trees greater than 1 inch diameter at breast height (DBH), rather than sawtimber (9 inches DBH for softwoods; 11 inches DBH for hardwoods). Mortality rates in excess of 50% are indicated for nine forest types, dominated by species of firs and pines. Trees within softwood forest types (comprising 87% of current non-reserved gross annual forest growth statewide) appear to be associated with the highest mortality rates during the 1990s. Baseline Forest Growth & Mortality Assessment Page 13

20 Figure 5. Mortality as % of Gross Annual Growth by Forest Type for all Growing Stock on Non-Reserved Timberland ( ) Mortality % of Gross Growth Gross Annual Growth Standard Error (Mortality) Net Volume of Growing Stock Forest Type Type Notes Thousand cubic feet Mountain hemlock 86% 10,901 softwood 12% 916,000 Budworm Subalpine fir 78% 4,228 softwood 18% 197,000 Budworm Western larch 76% 7,053 softwood 17% 344,000 Budworm Grand fir 71% 58,645 softwood 7% 2,520,000 Budworm Engelmann spruce 68% 11,586 softwood 17% 564,000 Budworm Whitebark pine 57% 200 softwood 56% 8,000 White fir 56% 55,561 softwood 6% 2,446,000 Budworm Shasta red fir 53% 9,631 softwood 15% 511,000 Western white pine 50% 950 softwood 33% 48,000 Pacific silver fir 49% 10,011 softwood 16% 596,000 Budworm Lodgepole pine 46% 41,192 softwood 6% 1,488,000 Ponderosa pine 35% 181,198 softwood 3% 6,643,000 Sugar pine 35% 2,200 softwood 29% 112,000 Western juniper 35% 640 softwood 24% 26,000 Jeffrey pine 32% 705 softwood 38% 36,000 Noble fir 32% 8,404 softwood 23% 377,000 Western red cedar 30% 12,113 softwood 23% 591,000 Redwood 29% 1,038 softwood 100% 38,000 Quaking aspen 28% 837 hardwood 51% 25,000 Knobcone pine 28% 722 softwood 55% 23,000 Oregon ash 22% 566 hardwood 61% 23,000 Oregon white oak 21% 12,893 hardwood 20% 441,000 Douglas-fir 19% 1,304,880 softwood 2% 47,054,000 Budworm Black cottonwood 18% 1,488 hardwood 51% 47,000 Redalder 18% 144,961 hardwood 9% 3,583,000 Western hemlock 17% 137,350 softwood 11% 4,078,000 Bigleaf maple 17% 20,836 hardwood 21% 610,000 Incense-cedar 17% 8,404 softwood 31% 240,000 California black oak 17% 5,237 hardwood 32% 168,000 Port-Orford-cedar 16% 3,068 softwood 55% 98,000 Sitka spruce 16% 25,505 softwood 29% 760,000 Pacific madrone 15% 37,894 hardwood 14% 1,067,000 California-laurel 14% 4,648 hardwood 47% 151,000 Canyon live oak 10% 4,467 hardwood 26% 114,000 Golden chinkapin 10% 4,928 hardwood 37% 93,000 Tanoak 9% 39,501 hardwood 13% 983,000 Cherry 9% 582 hardwood 47% 13,000 Willow 6% 298 hardwood 94% 5,000 Apples 6% 228 hardwood 81% 5,000 Source: Timber Resource Statistics for Oregon, November 2004, Resource Bulletin PNW-RB-242. Baseline Forest Growth & Mortality Assessment Page 14

21 Major forest types with significant mortality (including Grand fir, White fir, Lodgepole pine and Ponderosa pine) occur primarily east of the Cascades. For these forests, indicated mortality rates range from 35% to over 70% of gross annual growth. It should be noted that the standard error associated with softwood forest types varies considerably between 2% and 56%; for example, the redwood forest type is an outlier with a 100% standard error of estimate. Conversely, the standard error is only 2% for Douglas-fir. These margin of error estimates tend to be greater for species which are less prevalent in Oregon with resulting lower levels of plot sampling. Douglas-fir forests, predominant on the west side, experience a lower mortality rate than many eastside forest types at 19%. Hardwoods, predominantly west side, also tend to experience mortality at the lower ends of the scale. High standard errors are associated with forest types in both regions of the state and within both less prevalent softwood and hardwood forests. Note that gross growth and net volume are reported in thousand cubic feet in Figure 4, as opposed to million board feet for Figure 2. As conversion factors from cubic to board feet vary by species, the margin of error in converting a disaggregated list increases significantly. CHANGES IN GROWTH & MORTALITY OVER TIME As previously described, actual remeasurement for both growth and mortality data is limited to private lands only during the 1990s. Given the decline in removals from public lands since 1989, it can be expected that the relationships between gross growth, mortality and removals within Oregon s forests look different than during peak harvest years (the 1980s). The pattern of logging also may have been unusually high on some portion of private lands during the 1990s. At the individual forest level, there may be periods of relatively intense logging followed by a long period of regeneration (and net growth). 5 Over the landscape of an entire region (such as western Oregon), these variations typically are evened out by different rotation patterns on other forests in the region. Recent post-2000 patterns also are likely different than during the early years of reduced federal logging in which changed patterns of competition between trees (and understory, etc.) had potentially not yet materialized. To summarize the extent to which harvesting practices have changes over the past 20 years from the peak year of 1986 through 2001 harvest levels declined from 8.7 to 3.4 billion board feet, a reduction of 61%. Most, though not all, of this reduction has occurred on federal public lands of the U.S.D.A. Forest Service and Bureau of Land Management. 6 While new FIA Annual Inventory data may be available by late 2005, it will be a number of years before time series data is available to more reliably assess the longer-term likely or desired relationship between growth-mortality and harvest on public and private lands. This presents considerable challenge for land managers and policy makers at federal, state/local and private levels. It also increases the challenge of weighing the advantages and disadvantages Baseline Forest Growth & Mortality Assessment Page 15

22 of various passive versus active management strategies especially on reserve and multiresource forests. IMPLICATIONS FOR FOREST GROWTH-MORTALITY MANAGEMENT Key conclusions of this growth-mortality overview and resulting implications for Oregon forest management can be summarized as follows: Gross annual forest growth exceeds the combination of mortality and removals in western Oregon with a substantially higher ratio of net to gross growth for public (especially federal) than for private lands. In eastern Oregon, the situation appears to have been reversed at least for private lands with mortality plus removals exceeding gross annual growth during the decade of the 1900s. While this pattern of the 1990s appears to be an anomaly, there are continuing concerns with infestation, fire risk and loss of forestry infrastructure that could hinder forest sustainability over a longer-term time horizon. Eastern Oregon forest lands experience higher rates of mortality than is the case west of the Cascades; public lands experience higher rates of mortality than do private lands throughout the state. Both areas deserve special emphasis to improve the timeliness and quality of growth-mortality data available as a means to better determine an appropriate forest management response. Conditions of high mortality and/or high net growth with forest overstocking can lead to concerns about increased fire and habitat risk issues of particular importance for eastern Oregon and for public (primarily federal) forest lands. The remainder of this report addresses fire related implications and then options for management of growth-mortality to address both market and non-market values. Baseline Forest Growth & Mortality Assessment Page 16

23 IV. GROWTH-MORTALITY & FOREST HEALTH Growth and mortality are often discussed within the context of forest health, a growing concern throughout the West. Our key dimension of the forest health discussion centers on the question of increased risk of high severity fires especially in forests with significantly or moderately altered fire regime condition classes. This section of the growth-mortality assessment focuses on the topic of fire risk; the next section considers management options to address a broader rang of forest health objectives. INDICATORS OF FIRE RISK Federal Forest Service data indicates that between 1996 and 2003 around 2.5 million acres were impacted by forest fires statewide. Fighting these fires involves high costs and risks to life and property; suppressing the 2002 Biscuit Fire alone is estimated to have cost over $150 million. Forest growth and morality intersect with forest fire and health risks primarily through Stand Density Index (SDI), a measure of a forest stand s density as a percentage of its maximum potential density. A stand s maximum density and the point at which mortality is introduced to a stand due to competition between plants or increased disease associated with increased density varies by forest type and ecoregion as well as other factors. High SDIs are associated with increased risk for both fire and disease; however, studies continue to investigate the interplay between these and other forest characteristics. For instance, there is some evidence that thinning stands a primary approach to fire risk reduction by removing fuels may in some instances increase wind speeds, which in turn would propel forest fire. 7 Another factor of importance is management of slash from timber harvest or thinning activity. Leaving slash in the woods instead of removal or other biomass treatment can increase the fuel load and risk of a major fire event. METHODOLOGIES TO ESTIMATE FIRE RISK To date, most studies estimating fire risk for a specific landscape employ specialized software to aid in the task of modeling vegetation growth and its implications (for fire risk, forest health or other attributes). The U.S.D.A. Forest Service has developed a Forest Vegetation Simulator that models changes in forest vegetation over time. A Fire and Fuels Extension can be used in conjunction to estimate fire characteristics such as Crowning Index, Torching Index and Basal Area Mortality. 8 Utilizing this software can be data intensive. One approach involves assigning plant association codes and corresponding SDIs to Condition Classes within the FIA s sample plots (there can be one or more condition class associated with each plot). The Seattle Fire Sciences Lab of the U.S.D.A. Forest Service is developing a Fuel Characteristic Classification System program, currently scheduled for release in mid The program can be used for any fuel bed or landscape with uniform characteristics with applications ranging from a Douglas-fir or pine forest landscape covering multiple states to a site specific clear cut. Baseline Forest Growth & Mortality Assessment Page 17