Msr Report Outline

DRAFTDRAFTDRAFT

MODEL SOLUTION REVIEW REPORT

North Cascade District

Alternative 1

February 10, 2006

Executive Summary: The North Cascade District’s review of Model Run #160, Alternative 1, determined that two factors will affectthe District’s ability to implement the strategies and generate the outputs associated with the model run.First, historical harvest volume per acre for North Cascade District timber sales is higher than the volume per acre predicted by the model. This suggests that the yield tables used for this model run were very conservative and may not provide a realistic estimate of current stand volumes.Second, the model did not consider Desired Future Condition (DFC) of harvest units. This has the effect of increasing the number of units available to the model for clearcutting, compared to the District strategy of thinning older, complex stands to reach DFC sooner.

The North Cascade District’s assessment is thatfor the remaining years in Period 1,

the District will be able to implement the Harvest Volume projected by Model Run 160, but will generate this volume from a different mix of clearcut and thinning acres than projected by the model. After the yield table issues are resolved, Period 2 harvest volume may increase if the mix of clearcut and thinning acres projected by the model is implemented.

The development of Complex Stand Structure using the strategies associated with Model Run 160 results in the attainment of DFC in 85 years. This is a reasonable estimate when compared to the District’s Implementation Plan (2003) estimate that DFC could be realized in 60-70 years.

2. Harvest Context: For fiscal years 2004, 2005, and 2006 (the first 3 years of Period 1), the North Cascade District has been planning an average of 20.5 MMBF annual harvest. Approximately two-thirds of this volume came from thinning 1,055 acres (average) per year, and the other third came from clearcutting 244 acres (ave.) per year. These harvest levels are consistent with the objectives in the District’s Implementation Plan (2003).

In comparison, Model Run #160 projects more clearcut and less thinning acreage, and less annual harvest volume for the remainder of Period 1 and all of Period 2. These values are included in Table 1 below. The model also projects lower harvest volumes per acre for both clearcutting and thinning than what the North Cascade District has experienced during the past 10 years. These values are displayed in Table 2.

Table 1. Harvest Outputs-Acres & Volume MMBF

1. Average annual harvest level based on an average model outputsfrom the first two periods.

2. Annual harvest levels from the approved (modified) implementation plan (March 2003). The top number is the mid-point of the range and the lowernumbers are the range of outputs.

Table 2. Average Harvest per Acres

1. Average volume harvest per acre for the first model period.

2. Based on the 10-year average volume harvested per acreusing "cut out" or timber cruise information.

3. Model Rules

3.1 Interpretation of Plans and Policies: The primary plans and policies that apply to the North Cascade District are the Northwest Oregon State Forest Management Plan (FMP), and the Draft Western Oregon Habitat Conservation Plan (HCP).

3.2 Operational Rules: The primary Operation Rule that affected the model runs for the North Cascade District is the Recent Thin Deferral rule. Another Operational Rule that affected model runs is the Clearcutting Constraint that requires a harvest unit to be delayed at least 10 years following a thinning.

3.3 Application of Rules: The model appears to follow the rules for the selection of harvest units. Possible exceptions are discussed in section 5.4 of this report.

4. Spatial Data

4.1 Currency of Data: The spatial data for the North Cascade District reflect the conditions as they existed on January 1, 2004 – the beginning of the first period of the model. The model data has not been updated for any changes that have occurred to the conditions on the North Cascade District since then.

4.2 DataIssues: There are two significant data issues associated with Model Run 160:strata-based stand age and volume per acre for clearcut harvests.

Due to a lack of inventory in certain strata (and therefore yield tables), some stands had to be assigned to another similar strata (called the proxy strata in the data). In some cases, the proxy strata had a significantly different age in the yield tables than the stand had in reality. As a result, this model run had four stands clearcut when their ‘real’ age was less than 50 years (even though they met the 50 year rule in the model data). This issue can be resolved with actual inventory to replace proxy strata.

Another strata related issue results in very low volume yields for a significant number ofclearcut units. Thisappears to be a result of a combination of factors includinginadequate inventory amount in some strata,use of strata to represent average conditions across a large number of stands,and insufficient time to develop yield tables that represent conditions unique to the North Cascade District. The low estimate of clearcut volume tends to be associated with the 1D3H (Douglas-fir stand averaging 14 to 20 inches DBH, SDI%>= 30) strata and possibly the DX3H (Mixed specie stand: Douglas-fir majority species, average stand DBH 14 to 20 inches DBH, SDI % >=30) strata. This average stand diameter classification covers a broad range of stand ages, and on the North Cascade District, a broad range of elevations as well. It appears that the volume per acre associated with these strata may understate the volume that has accumulated in older stands with diameters closer to the upper end of the range.

Another consideration in clearcut volume is that the model tended to select harvest units with a younger stand age than those the North Cascade District has been harvesting for the past several years. In the first period of the model run, 54% of the clearcut acres are less than 60 years old, and 35% of the clearcut acres are greater than 80 years old. In comparison, clearcut units selected by the District for recent AOP’s showed the following age groupings: 12% less than 60 years old; 67% ranged from 61-80 years of age; and 21% were older than 80 years.

4.3 Changes in Condition: Following completion of Northern Spotted Owl surveys in 2004, three new spotted owl circles were established on the North Cascade District. Two of these were an upgrade to previously known sites, and one was the result of a new pair becoming established. A different owl circle also shifted its location slightly as a result of locating the actual nest tree.Spotted owl surveys conducted during 2005 resulted in one owl circle being reclassed as historic. All other spotted owl sites remained unchanged.

5. Factors Not Considered by the Model

5.1 High Landslide Hazard Locations: The North Cascade District identified a few harvest units where an operation would not be planned because of landslide concerns. This probably represents less than 200 acres on the forest.

5.2 Focused Stewardship:Approximately 20% of the North Cascade District (9,524 acres) is classified as Focused Stewardship because of Visual, Recreation, or Domestic Water intake considerations. Although this review did not identify any specific harvest units that would be unavailable because of Focused Stewardship, this will be a factor in the pace at which harvest units can be scheduled in some locations.

5.3 Desired Future Condition: The District’s Implementation Plan (IP) identified areas for the development of complex structure and documented these areas on a Desired Future Condition (DFC) map. The District’s practice has been to develop or maintain complex structure in these areas primarily through thinning. A small amount of clearcutting has been scheduled in areas designated for complex DFC but only when current stand conditions clearly limit the possibility of accomplishing the desired result via thinning.This model run did not consider the DFC for specific harvest units and clearcut a number of units that wereplanned for complex structure in the IP.By not considering DFC, the model had a larger pool of acres available to clearcut than what the District considers available because of operational constraints on clearcutting complex structure stands. Clearcutting also tends to delay the attainment of DFC, although it by no means precludes growing a complex stand structure in the future.

5.4 Planned and Sold Operations: There were two main areas of concern with applying the model rules to Alternative 1 for the North Cascade District. The first concern had to do with Recent Thin Deferral. The model selected a number of thinning harvest units for Periods 1 and 2 that the District included in recent AOP’s. Period 1 “Planned and/or Sold” harvest units were considered available to the model for harvest scheduling and do not pose a concern. Recently “Completed” thinnings were considered unavailable to the model for Period 2 thinning, but available for Period 3 or 4: there were 11 units totaling approximately 450 acres in this category.

The second concern was the recently “Completed” clearcut units that the model scheduled for thinning operations in either Period 1 or 2. The District considered these unavailable for either thinning or clearcutting. There were 19 units totaling approximately 650 acres in this category.

6.0 Implementation: The North Cascade District will transition to Model Run #160, Alternative 1 outputs during fiscal years 2007 and 2008. The District will plan to harvest 13 MMBF annually for the remainder of Period 1. The mix of clearcutting and thinning that the District will use to produce this volume will probably be different than projected by the model. For FY 2007, the District’s AOP includes 270 acres of clearcutting and 698 acres of thinning. For FY 2008, the District will continue the transition toward the harvesting strategies (i.e. clearcut and thinning acres: 371 and 591 acres, respectively) that the model used in Run 160.

At this time, the District’s assessment is that Model Run 160 is implementable for Period 2. This could change based on the results of the analysis recommended under Improvements.

6.1 Analysis of the Alternate Acre Pool: not done for this review.

7.0 Improvements:As shown in Table 2,the North Cascade District has historically harvested higher volumes per acre than predicted by the model. The District plans to investigate this volume discrepancy by working with Staff to determine if the yield tables used by the model are overly conservative, or if the use of strata to represent average conditions across a large number of stands is responsible for the volume difference. If the yield tables are determined to be conservative and are adjusted toward higher volumes per acre, the annual harvest for the District will increase as well. [rn1] If the analysis determines that the use of average strata is responsible for the volume difference, a decision will be needed on how to proceed. This could involve additional stand level inventory, or using imputation to assign stand characteristics to similar stands. In either case,the District expects that per acre volumes will increase, and that the annual harvest level will increase as well.

Page 1 of 5

[rn1]I suggest we use this sentence (or something like it), instead of the first sentence.