Model 1
Model <- aov(PHt~REGION+MANAGEMENT+REGION*MANAGEMENT, data=data)
summary(model)
                    Df      Sum Sq        Mean Sq    F value       Pr(>F)
REGION               2      0.05          0.0229       0.907        0.4039
MANAGEMENT           2      0.18          0.0884       3.494        0.0306 *
REGION:MANAGEMENT    4      3.34          0.8351      33.021        <2e-16 ***
Residuals           1744    44.10         0.0253

Model 2
aov(PHt~REGION*MANAGEMENT+Error(subject/(REGION*MANAGEMENT)),data=data)

SUMMARY:
  Df Sum Sq Mean Sq F value Pr(>F)
Residuals 195  4.714 0.02494

Error: subject_f:REGION
           Df Sum Sq Mean Sq F value Pr(>F)
REGION      2  0.066 0.03281   1.406  0.246
Residuals 388  8.822 0.02334

Error: subject_f:MANAGEMENT
            Df Sum Sq Mean Sq F value Pr(>F)
MANAGEMENT   2  0.205 0.10260   4.413 0.0127 *
Residuals  388  8.788 0.02325
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

Error: subject_f:REGION:MANAGEMENT
                   Df Sum Sq Mean Sq F value Pr(>F)
REGION:MANAGEMENT   4  3.451  0.8627   31.99 <2e-16 ***
Residuals         776 20.389  0.0270
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Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1