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Diaz-Vallejo et al. Carbon Footprints 2026, 5, 12 Page 11 of 23

Table 4. Regression analysis results from testing SOC relationship to MAT, MAP, silt + clay %, and soil pH across a database of 586
pedons in Puerto Rico

Factors Estimate Standard error T-value P-value F value R 2
Agricultural lands
Intercept -6.952 0.820 -8.483 < 0.0001 11.050 0.107
MAT 0.109 0.033 3.324 0.001
Intercept -3.550 0.168 -21.150 < 0.0001 18.750 0.174
MAP 0.000 0.000 -4.330 < 0.0001
Intercept -5.919 0.263 -22.534 < 0.0001 21.500 0.328
Clay% 0.018 0.003 5.231 < 0.0001
Silt% 0.027 0.004 6.114 < 0.0001
Intercept -4.937 0.239 -20.660 < 0.0001 9.178 0.089
pH 0.112 0.037 3.030 0.003
Pasture lands
Intercept -3.045 0.829 -3.674 < 0.0001 0.833 -0.001
MAT -0.031 0.034 -0.913 0.363
Intercept -3.670 0.201 -18.227 < 0.0001 0.438 -0.004
MAP 0.000 0.000 -0.662 0.509
Intercept -5.222 0.167 -31.203 < 0.0001 38.090 0.320
Clay% 0.018 0.002 8.005 < 0.0001
Silt% 0.017 0.002 7.227 < 0.0001
Intercept -4.735 0.226 -20.920 < 0.0001 17.840 0.096
pH 0.157 0.037 4.224 < 0.0001
Forest lands
Intercept 0.606 0.588 1.029 0.304 49.500 0.142
MAT -0.177 0.025 -7.036 < 0.0001
Intercept -4.578 0.176 -25.967 < 0.0001 37.900 0.112
MAP 0.001 0.000 6.157 < 0.0001
Intercept -5.194 0.205 -25.345 < 0.0001 34.670 0.187
Clay% 0.019 0.003 7.172 < 0.0001
Silt% 0.023 0.003 7.799 < 0.0001
Intercept -3.689 0.208 -17.738 < 0.0001 0.566 -0.001
pH 0.028 0.037 0.752 0.453
SOC: Soil organic carbon; MAT: mean annual temperature; MAP: mean annual precipitation.

Table 5. Stepwise model results for best model for SOC on each land use type and the whole region of Puerto Rico
R 2 F value P-value
Agricultural lands SOC = o β0 + β 1 (Soil Oder) + β 2 (Silt+Clay) + β 3 (Annual Temperature) + β 4 (pH) + e 0.60 15.09 < 0.0001
Pasture lands SOC = β0 + β 1 (Soil Suborder) + β 2 (Silt+Clay) + β 3 (pH) + e 0.45 7.674 < 0.0001
Forest lands SOC = β0 + β 1 (Soil Suborder) + β 2 (Texture Classification) + β 3 (Annual Temperature) + e 0.598 17.66 < 0.0001
SOC = β0 + β 1 (Soil Suborder) + β 2 (Land use type) + β 3 (Texture Classification) + β 4 (pH) +
Whole region 0.55 18.34 < 0.0001
β 5 (Annual Temperature) + e
SOC: Soil organic carbon.

frameworks that account for land-use history, soil properties, and climatic heterogeneity.