Tables: Master's thesis

Is there an answer to mapping old growth?

An examination of two projects conducted with remote sensing and GIS

Robert A. Norheim

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Table 4-1

Comparison of the two old growth mapping projects and an earlier USFS inventory

The Wildeness Society "ancient forest" v. Pacific Meridian "old growth"

(1000s of acres)

                                Pacific  Wilderness                  
                               Meridian    Society     PMR    Total  
       Forest         Haynes     "old     "ancient      /    Forest  
                      (USFS)    growth"     forest"    TWS   Acreage 

Olympic                 205     147.65      189.5      128%     651 

Mt. Baker-Snoqualmie    433     725.28      585.7       81%   1,716 

Gifford Pinchot         232     447.15      341.9       76%   1,331 

Mt. Hood                218     363.25      334.5       92%   1,060 

Willamette              338     783.55      605.0       77%   1,667 

Umpqua                  219     619.34      306.3       49%     988 

Siuslaw                  10      91.86      133.7      146%     625 

Siskiyou                171     277.89      332.4      120%   1,093 

Rogue River              50     267.95      150.1       56%     638 

   Total              3,858   3,723.92    2,979.1 *     80%   9,769 

* Morrison also found 798,300 acres on the three forests in northern California, for an overall total of 3,777,400 acres of "ancient forest"
Sources: Haynes 1986, Pacific Meridian Resources 1991, Morrison et al. 1991
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Table 5-1

Comparison between old-growth acreages in published reports and those calculated from datasets

(acres of ancient forest/old growth)
     Forest         Value in     Value    Not mapped  Conver-  Base for  
                    published  calculated  by other    sion   comparison 
                      report   from data     study    change             

The Wilderness Society
    Olympic           189,500    196,745     -5,490      -20    191,235 

    MBS               585,700    586,132     -8,310      -97    577,725 

    Gifford           341,900    341,931    -50,552*      97    291,476 
    Pinchot                                                             

    Mt. Hood          334,500    334,483   -103,240*      17    231,260 

    Total           1,451,600  1,459,291   -167,592       -3  1,291,696 

Pacific Meridian Resources
    Olympic           147,650    148,919       -640     -142    148,137 

    Mt. Baker-        725,280    720,260    -60,597†     -26    622,338 
    Snoqualmie                              -37,299‡                    
 
    Gifford           447,150    440,558       -350      -21    477,486 
    Pinchot                                 +37,299‡                    

    Mt. Hood          363,250    357,600       -346       25    357,279 

    Total           1,683,330  1,667,337    -61,933     -164  1,605,240 

Notes: * East of Cascade crest; † Pasayten area; ‡ MBS lands administered by G. Pinchot
Sources: Pacific Meridian Resources 1991, Morrison et al. 1991
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Table 5-2

Acreage differential as published and as corrected

(TWS ancient forest acreage vs. PMR old growth acreage)
  Forest            Published   Corrected

Olympic                128%        129%

Mt. Baker-Snoqualmie    81%         93%
 
Gifford Pinchot         76%         61%

Mt. Hood                92%         65%

Total                   86%         80%
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Table 5-5

Confusion matrices

Pacific Meridian in rows, The Wilderness Society in columns
(acres)

(a) Olympic National Forest

                         Low       Other     High      Other             
                      elevation   ancient  elevation   than      Total   
                         old      forest      old     ancient            
                        growth              growth    forest             

Low elevation old growth  64,474    26,112     9,489    38,267   138,341 
% of array                   10%        4%        2%        6%       22% 
% of column                  69%       35%       41%        9%           
% of row                     47%       19%        7%       28%           

High elevation old growth    641       246     3,655     5,253     9,796 
% of array                    0%        0%        1%        1%        2% 
% of column                   1%        0%       16%        1%           
% of row                      7%        3%       37%       54%           

Other than old growth     28,921    47,430    10,267   388,593   475,211 
% of array                    5%        8%        2%       62%       76% 
% of column                  31%       64%       44%       90%           
% of row                      6%       10%        2%       82%           

Total                     94,037    73,788    23,410   432,113   623,348 
% of array                   15%       12%        4%       69%           

(b) Mt. Baker-Snoqualmie National Forest

                         Low       Other     High      Other             
                      elevation   ancient  elevation   than      Total   
                         old      forest      old     ancient            
                        growth              growth    forest             

Low elevation old growth 209,935    69,168     7,714    96,834   383,650 
% of array                   12%        4%        0%        6%       22% 
% of column                  71%       50%        5%        8%           
% of row                     55%       18%        2%       25%           

High elevation old growth  6,689     4,371   108,664   118,964   238,689 
% of array                    0%        0%        6%        7%       14% 
% of column                   2%        3%       75%       10%           
% of row                      3%        2%       46%       50%           

Other than old growth     77,428    64,574    29,182   932,192 1,103,376 
% of array                    4%        4%        2%       54%       64% 
% of column                  26%       47%       20%       81%           
% of row                      7%        6%        3%       84%           

Total                    294,052   138,113   145,559 1,147,990 1,725,715 
% of array                   17%        8%        8%       67%           

(c) Gifford Pinchot National Forest

                         Low       Other     High      Other             
                      elevation   ancient  elevation   than      Total   
                         old      forest      old     ancient            
                        growth              growth    forest             

Low elevation old growth  88,584    64,197     6,165   198,312   357,258 
% of array                    8%        6%        1%       17%       31% 
% of column                  75%       70%        8%       23%           
% of row                     25%       18%        2%       56%           

High elevation old growth  1,590     1,940    61,528    55,169   120,228 
% of array                    0%        0%        5%        5%       10% 
% of column                   1%        2%       75%        6%           
% of row                      1%        2%       51%       46%           

Other than old growth     27,933    25,416    14,123   606,447   673,919 
% of array                    2%        2%        1%       53%       59% 
% of column                  24%       28%       17%       71%           
% of row                      4%        4%        2%       90%           

Total                    118,107    91,553    81,816   859,929 1,151,405 
% of array                   10%        8%        7%       75%           

(d) Mt. Hood National Forest

                         Low       Other     High      Other             
                      elevation   ancient  elevation   than      Total   
                         old      forest      old     ancient            
                        growth              growth    forest             

Low elevation old growth  74,424    75,591       950   175,222   326,187 
% of array                   10%       11%        0%       25%       46% 
% of column                  71%       68%        6%       36%           
% of row                     23%       23%        0%       54%           

High elevation old growth    208       208    11,382    19,295    31,093 
% of array                    0%        0%        2%        3%        4% 
% of column                   0%        0%       76%        4%           
% of row                      1%        1%       37%       62%           

Other than old growth     29,994    35,810     2,694   288,768   357,266 
% of array                    4%        5%        0%       40%       50% 
% of column                  29%       32%       18%       60%           
% of row                      8%       10%        1%       81%           

Total                    104,625   111,609    15,026   483,285   714,545 
% of array                   15%       16%        2%       68%           
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Table 5-6

Agreement rates by Forest depending on PMR assignment of TWS "Other Ancient Forest"

(percent)
"Other Ancient Forest"           Olympic   MBS    Pinchot   Mt. Hood
 counted as:                                                        

 Low elevation old growth          77.5    76.5     71.3       63.0 

 Low or high elevation old growth  77.5    76.7     71.5       63.0 

 Not old growth                    80.9    76.2     67.9       57.4 
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Table 5-7

Aggregated confusion matrices

Pacific Meridian in rows, The Wilderness Society in columns

(acres)


(a) Olympic National Forest

                  Ancient                    
                  Forest    Other    Total   

Old Growth         104,617   43,520  148,137 
   % array total       17%       7%          
  % column total       55%      10%          
     % row total       71%      29%          

Other               86,618  388,593  475,211 
   % array total       14%      62%          
  % column total       45%      90%          
    % row total        18%      82%          

Total              191,235  432,113  623,348 

(b) Mt. Baker-Snoqualmie National Forest

                  Ancient                       
                  Forest     Other     Total    

Old Growth         406,540   215,798    622,338 
   % array total       24%       13%            
  % column total       70%       19%            
     % row total       65%       35%            

Other              171,184   932,192  1,103,376 
   % array total       10%       54%            
  % column total       30%       81%            
    % row total        16%       84%            

Total              577,725 1,147,990  1,725,715 

(c) Gifford Pinchot National Forest

                 Ancient                     
                  Forest   Other     Total   

Old Growth       224,004  253,481    477,486 
   % array total     19%      22%            
  % column total     76%      29%            
     % row total     47%      53%            

Other             67,472  606,447    673,919 
   % array total      6%      53%            
  % column total     24%      71%            
    % row total      10%      90%            

Total            291,476  859,929  1,151,405 

(d) Mt. Hood National Forest

                  Ancient                    
                  Forest    Other    Total   

Old Growth         162,762  194,517  357,279 
   % array total       23%      27%          
  % column total       70%      40%          
     % row total       46%      54%          

Other               68,498  288,768  357,266 
   % array total       10%      40%          
  % column total       30%      60%          
    % row total        19%      81%          

Total              231,260  483,285  714,545 

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Last updated: September 30, 1996
Copyright 1996 Robert A. Norheim