Carbon Conversion - Take 3: CAFRI-AGB Training

Modeling forest carbon pools as a function of aboveground biomass and static climate and topographic predictors.

Lucas Johnson
2022-07-16

Changes

This round differs from the last iteration in the following ways:

AGC Model

Random Forest Model - Test Set 1:1

Params

$formula
agc ~ .

$num.trees
[1] 1250

$mtry
[1] 18

$min.node.size
[1] 1

$replace
[1] TRUE

$sample.fraction
[1] 0.3

Test Set Accuracy

Prediction
RMSE 26.848
MAE 18.101
MBE -0.523
R2 0.523

BGC Model

Random Forest Model - Test Set 1:1

Params

$formula
bgc ~ .

$num.trees
[1] 750

$mtry
[1] 14

$min.node.size
[1] 1

$replace
[1] TRUE

$sample.fraction
[1] 0.8

Test Set Accuracy

Prediction
RMSE 5.240
MAE 4.064
MBE 0.083
R2 0.467

Deadwood C Model

Random Forest Model - Training Set 1:1

Random Forest Model - Test Set 1:1

Params

$formula
deadwood ~ .

$num.trees
[1] 250

$mtry
[1] 3

$min.node.size
[1] 1

$replace
[1] FALSE

$sample.fraction
[1] 0.9

PC Regression - Test set 1:1

Params


Call:
lm(formula = pc_train_deadwood$deadwood ~ ., data = pc_train_deadwood[, 
    1:which(props > 0.99)[1]])

Residuals:
    Min      1Q  Median      3Q     Max 
-8.7386 -3.4746 -0.8526  2.5924 17.2229 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept)  5.95494    2.74589   2.169  0.03063 *  
PC1         -0.39452    0.80037  -0.493  0.62230    
PC2          0.73318    0.57908   1.266  0.20612    
PC3         -0.06246    0.18406  -0.339  0.73449    
PC4         -0.79785    0.13087  -6.097 2.33e-09 ***
PC5         -0.45798    0.16133  -2.839  0.00473 ** 
PC6          0.03258    0.16349   0.199  0.84216    
PC7          0.20250    0.46855   0.432  0.66581    
PC8          0.21959    0.30954   0.709  0.47844    
PC9          0.10898    0.23191   0.470  0.63863    
PC10         0.10103    0.21204   0.476  0.63396    
PC11         0.09455    0.24413   0.387  0.69873    
PC12         0.20723    0.22736   0.911  0.36253    
PC13        -0.65312    0.26627  -2.453  0.01455 *  
PC14        -0.42890    0.25317  -1.694  0.09093 .  
PC15        -0.17342    0.28309  -0.613  0.54044    
PC16        -0.51297    0.29701  -1.727  0.08483 .  
PC17         0.82333    0.31087   2.648  0.00837 ** 
PC18         0.16248    0.37297   0.436  0.66330    
PC19         0.27971    0.41584   0.673  0.50151    
PC20         0.56508    0.50417   1.121  0.26296    
PC21        -0.77770    0.54989  -1.414  0.15797    
PC22         0.06209    0.57659   0.108  0.91430    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 4.701 on 452 degrees of freedom
Multiple R-squared:  0.2529,    Adjusted R-squared:  0.2166 
F-statistic: 6.956 on 22 and 452 DF,  p-value: < 2.2e-16

Test Set Accuracy

lm RF
RMSE 5.159 4.669
MAE 4.128 3.651
MBE 0.172 0.096
R2 0.069 0.237

Litter C models

Random Forest Model - Training data 1:1

Random Forest Model - Testing data 1:1

Params

$formula
litter ~ .

$num.trees
[1] 90

$mtry
[1] 5

$min.node.size
[1] 5

$replace
[1] FALSE

$sample.fraction
[1] 0.5

Test-set Accuracy

Prediction
RMSE 11.893
MAE 7.816
MBE -2.946
R2 -0.003

PC Regression - 10-Fold-CV 1:1

Params


Call:
lm(formula = pc_all_litter$litter ~ ., data = pc_all_litter[, 
    1:which(props > 0.99)[1]])

Residuals:
    Min      1Q  Median      3Q     Max 
-10.998  -2.962  -0.794   2.223  40.741 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)    
(Intercept) 13.63779    4.26254   3.199 0.001719 ** 
PC1          0.47658    1.14361   0.417 0.677541    
PC2         -1.89067    1.14459  -1.652 0.100910    
PC3         -0.28811    0.30903  -0.932 0.352856    
PC4          2.23189    0.39955   5.586 1.25e-07 ***
PC5          1.09095    0.40177   2.715 0.007492 ** 
PC6         -0.41942    0.39714  -1.056 0.292815    
PC7         -1.23072    0.66184  -1.860 0.065142 .  
PC8          1.06749    0.51248   2.083 0.039153 *  
PC9         -0.30149    0.58114  -0.519 0.604763    
PC10        -0.31558    0.58596  -0.539 0.591076    
PC11         0.52893    0.66984   0.790 0.431141    
PC12        -0.84674    0.57547  -1.471 0.143534    
PC13        -2.23716    0.65201  -3.431 0.000800 ***
PC14         1.16774    0.67869   1.721 0.087636 .  
PC15         0.07718    0.72489   0.106 0.915371    
PC16         0.82620    0.78967   1.046 0.297325    
PC17        -0.66106    0.89487  -0.739 0.461362    
PC18         3.08090    0.98110   3.140 0.002077 ** 
PC19        -7.03111    1.10089  -6.387 2.58e-09 ***
PC20         4.26695    1.17876   3.620 0.000417 ***
PC21         5.69022    1.25458   4.536 1.26e-05 ***
PC22        -1.08771    1.46851  -0.741 0.460175    
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 6.659 on 134 degrees of freedom
Multiple R-squared:  0.6428,    Adjusted R-squared:  0.5841 
F-statistic: 10.96 on 22 and 134 DF,  p-value: < 2.2e-16

10-Fold-CV Accuracy

Prediction
RMSE 7.289
MAE 4.751
MBE -0.121
R2 0.501

Soil C model

PC Regression - 10-Fold CV 1:1

Params


Call:
lm(formula = pc_all_soil$soil ~ ., data = pc_all_soil[, 1:which(props > 
    0.99)[1]])

Residuals:
   Min     1Q Median     3Q    Max 
-82.54 -30.97  -5.62  18.42 405.07 

Coefficients:
            Estimate Std. Error t value Pr(>|t|)  
(Intercept)   92.548     41.241   2.244   0.0279 *
PC1            1.179      7.349   0.160   0.8730  
PC2            4.231      3.045   1.390   0.1689  
PC3           -1.775      3.643  -0.487   0.6276  
PC4            5.748      4.479   1.283   0.2035  
PC5           10.965      5.352   2.049   0.0441 *
PC6            3.811      5.305   0.718   0.4748  
PC7            4.921      5.931   0.830   0.4094  
PC8           -7.503      6.131  -1.224   0.2250  
PC9           10.756      6.871   1.565   0.1218  
PC10           6.073      7.288   0.833   0.4074  
PC11          10.121      7.772   1.302   0.1969  
PC12           4.814      9.217   0.522   0.6030  
PC13          17.006      9.548   1.781   0.0790 .
PC14           2.197     10.767   0.204   0.8389  
PC15          -5.777     11.512  -0.502   0.6173  
PC16           5.804     14.642   0.396   0.6930  
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 62.15 on 73 degrees of freedom
Multiple R-squared:  0.2202,    Adjusted R-squared:  0.04928 
F-statistic: 1.288 on 16 and 73 DF,  p-value: 0.2281

10-Fold CV Accuracy

Prediction
RMSE 65.896
MAE 40.791
MBE -0.171
R2 -0.081

Corrections

If you see mistakes or want to suggest changes, please create an issue on the source repository.

Citation

For attribution, please cite this work as

Johnson (2022, July 16). CAFRI Labs: Carbon Conversion - Take 3: CAFRI-AGB Training. Retrieved from https://cafri-labs.github.io/acceptable-growing-stock/posts/carbon-conversion-take-3-cafri-agb-training/

BibTeX citation

@misc{johnson2022carbon,
  author = {Johnson, Lucas},
  title = {CAFRI Labs: Carbon Conversion - Take 3: CAFRI-AGB Training},
  url = {https://cafri-labs.github.io/acceptable-growing-stock/posts/carbon-conversion-take-3-cafri-agb-training/},
  year = {2022}
}