Table 1. Parameter estimates for “full” ANCOVA models of DM ~ D2, with parameters for root-deformation (Not or Yes) levels
La variable respuesta: pesos secos (DM) Variable categorica: deformacion (yes/no) Covariable: diametro (D2)
library(readxl)
ancova <- read_excel("C:/Users/La Enana/Desktop/I semestre 2021/Biosta/FASE-6-ANCOVA_2.xlsx")
## Registered S3 methods overwritten by 'tibble':
## method from
## format.tbl pillar
## print.tbl pillar
set.seed(2021)
n <- nrow(ancova)
mu <- sample(n, n * 0.80) #muestra aleatoria del 80%
ancova.train <- ancova[mu, ]
ancova.test <- ancova[-mu, ]
¿La relacion de los pesos secos (DM) con respecto al diametro (D2) difiere entre las deformaciones de las raices (yes/no)?
Parámetro 1. LDM (Peso seco foliar)
mon<-lm(LDM ~ Deformation + D2, data = ancova.train)
shapiro.test(mon$residuals)
##
## Shapiro-Wilk normality test
##
## data: mon$residuals
## W = 0.93991, p-value = 0.0009524
#Los datos no cumplen normalidad.
library(car)
## Warning: package 'car' was built under R version 4.0.3
## Loading required package: carData
moH<-lm(LDM ~ Deformation, data = ancova.train)
leveneTest(moH)
## Warning in leveneTest.default(y = y, group = group, ...): group coerced to
## factor.
## Levene's Test for Homogeneity of Variance (center = median)
## Df F value Pr(>F)
## group 1 0.7643 0.3847
## 78
#Existe homogeneidad entre las varianzas.
mol<-lm(LDM ~ D2, data = ancova.train)
summary(mol)
##
## Call:
## lm(formula = LDM ~ D2, data = ancova.train)
##
## Residuals:
## Min 1Q Median 3Q Max
## -2.51021 -0.46795 -0.07718 0.29440 2.88742
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 0.256207 0.206841 1.239 0.219
## D2 0.067809 0.003331 20.359 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.9867 on 78 degrees of freedom
## Multiple R-squared: 0.8416, Adjusted R-squared: 0.8396
## F-statistic: 414.5 on 1 and 78 DF, p-value: < 2.2e-16
#El modelo es significativo.
moi<-lm(LDM ~ Deformation * D2, data = ancova.train)
anova(moi)
## Analysis of Variance Table
##
## Response: LDM
## Df Sum Sq Mean Sq F value Pr(>F)
## Deformation 1 8.62 8.62 8.6291 0.004377 **
## D2 1 394.93 394.93 395.3538 < 2.2e-16 ***
## Deformation:D2 1 0.01 0.01 0.0056 0.940585
## Residuals 76 75.92 1.00
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#No existe interacción
moa<-lm(LDM ~ Deformation * D2, data = ancova.train)
summary(moa)
##
## Call:
## lm(formula = LDM ~ Deformation * D2, data = ancova.train)
##
## Residuals:
## Min 1Q Median 3Q Max
## -2.53083 -0.46717 -0.08022 0.30631 2.87361
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) 0.2602733 0.3042009 0.856 0.395
## DeformationYes -0.0010296 0.4222119 -0.002 0.998
## D2 0.0679758 0.0045465 14.951 <2e-16 ***
## DeformationYes:D2 -0.0005135 0.0068672 -0.075 0.941
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.9995 on 76 degrees of freedom
## Multiple R-squared: 0.8417, Adjusted R-squared: 0.8354
## F-statistic: 134.7 on 3 and 76 DF, p-value: < 2.2e-16
moa
##
## Call:
## lm(formula = LDM ~ Deformation * D2, data = ancova.train)
##
## Coefficients:
## (Intercept) DeformationYes D2 DeformationYes:D2
## 0.2602733 -0.0010296 0.0679758 -0.0005135
library(ggplot2)
p <- ggplot(ancova.train, (aes(x=D2, y=LDM, color=Deformation, shape=Deformation))) + ylab("Peso seco foliar (g)") + xlab("Diametro (cm)") + theme_classic()
p + geom_point() + geom_smooth(method=lm, se=FALSE, fullrange=TRUE)
## `geom_smooth()` using formula 'y ~ x'
Parámetro 2. SDM (Peso seco del vástago)
modn<-lm(SDM ~ Deformation + D2, data = ancova.train)
shapiro.test(modn$residuals)
##
## Shapiro-Wilk normality test
##
## data: modn$residuals
## W = 0.94801, p-value = 0.002658
#No son normales
library(car)
modh<-lm(SDM ~ Deformation, data = ancova.train)
leveneTest(modh)
## Warning in leveneTest.default(y = y, group = group, ...): group coerced to
## factor.
## Levene's Test for Homogeneity of Variance (center = median)
## Df F value Pr(>F)
## group 1 2.0177 0.1595
## 78
#Las varianzas son homogeneas
modl<-lm(SDM ~ D2, data = ancova.train)
summary(modl)
##
## Call:
## lm(formula = SDM ~ D2, data = ancova.train)
##
## Residuals:
## Min 1Q Median 3Q Max
## -1.03262 -0.29316 -0.04105 0.23185 2.16830
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -0.462962 0.112910 -4.10 1e-04 ***
## D2 0.036475 0.001818 20.06 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.5386 on 78 degrees of freedom
## Multiple R-squared: 0.8377, Adjusted R-squared: 0.8356
## F-statistic: 402.5 on 1 and 78 DF, p-value: < 2.2e-16
#El modelo es significativo
modi<-lm(SDM ~ Deformation * D2, data = ancova.train)
anova(modi)
## Analysis of Variance Table
##
## Response: SDM
## Df Sum Sq Mean Sq F value Pr(>F)
## Deformation 1 4.554 4.554 16.6798 0.0001085 ***
## D2 1 112.599 112.599 412.3811 < 2.2e-16 ***
## Deformation:D2 1 1.485 1.485 5.4379 0.0223553 *
## Residuals 76 20.751 0.273
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#Se viola el supuesto de no interacción
moda<-lm(SDM ~ Deformation * D2, data = ancova.train)
summary(moda)
##
## Call:
## lm(formula = SDM ~ Deformation * D2, data = ancova.train)
##
## Residuals:
## Min 1Q Median 3Q Max
## -1.13881 -0.21032 -0.03857 0.18749 1.95663
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -0.586328 0.159041 -3.687 0.000424 ***
## DeformationYes 0.293565 0.220740 1.330 0.187524
## D2 0.039846 0.002377 16.763 < 2e-16 ***
## DeformationYes:D2 -0.008372 0.003590 -2.332 0.022355 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.5225 on 76 degrees of freedom
## Multiple R-squared: 0.8511, Adjusted R-squared: 0.8452
## F-statistic: 144.8 on 3 and 76 DF, p-value: < 2.2e-16
moda
##
## Call:
## lm(formula = SDM ~ Deformation * D2, data = ancova.train)
##
## Coefficients:
## (Intercept) DeformationYes D2 DeformationYes:D2
## -0.586328 0.293565 0.039846 -0.008372
library(ggplot2)
p <- ggplot(ancova.train, (aes(x=D2, y=SDM, color=Deformation, shape=Deformation))) + ylab("Peso seco del vastago (g)") + xlab("Diametro (cm)") + theme_classic()
p + geom_point() + geom_smooth(method=lm, se=FALSE, fullrange=TRUE)
## `geom_smooth()` using formula 'y ~ x'
Parámetro 3. RDM (Peso seco de la raíz)
nmo<-lm(RDM ~ Deformation + D2, data = ancova.train)
shapiro.test(nmo$residuals)
##
## Shapiro-Wilk normality test
##
## data: nmo$residuals
## W = 0.97303, p-value = 0.08855
#Son normales
library(car)
hmo<-lm(RDM ~ Deformation, data = ancova.train)
leveneTest(hmo)
## Warning in leveneTest.default(y = y, group = group, ...): group coerced to
## factor.
## Levene's Test for Homogeneity of Variance (center = median)
## Df F value Pr(>F)
## group 1 0.0065 0.936
## 78
#Las varianzas son homogéneas
lmo<-lm(RDM ~ D2, data = ancova.train)
summary(lmo)
##
## Call:
## lm(formula = RDM ~ D2, data = ancova.train)
##
## Residuals:
## Min 1Q Median 3Q Max
## -2.9712 -0.9829 -0.0301 0.7542 4.6328
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -0.803990 0.291599 -2.757 0.00726 **
## D2 0.105687 0.004696 22.508 < 2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 1.391 on 78 degrees of freedom
## Multiple R-squared: 0.8666, Adjusted R-squared: 0.8649
## F-statistic: 506.6 on 1 and 78 DF, p-value: < 2.2e-16
#El modelo es significativo
imo<-lm(RDM ~ Deformation * D2, data = ancova.train)
anova(imo)
## Analysis of Variance Table
##
## Response: RDM
## Df Sum Sq Mean Sq F value Pr(>F)
## Deformation 1 0.21 0.21 0.1188 0.7313
## D2 1 995.82 995.82 568.0682 <2e-16 ***
## Deformation:D2 1 1.95 1.95 1.1097 0.2955
## Residuals 76 133.23 1.75
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#La variable respuesta y la covariable no interaccionan
amo<-lm(RDM ~ Deformation * D2, data = ancova.train)
summary(amo)
##
## Call:
## lm(formula = RDM ~ Deformation * D2, data = ancova.train)
##
## Residuals:
## Min 1Q Median 3Q Max
## -2.6190 -0.8771 -0.0611 0.6187 3.8996
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -1.111639 0.402978 -2.759 0.00727 **
## DeformationYes 0.398477 0.559309 0.712 0.47837
## D2 0.103382 0.006023 17.165 < 2e-16 ***
## DeformationYes:D2 0.009583 0.009097 1.053 0.29548
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 1.324 on 76 degrees of freedom
## Multiple R-squared: 0.8822, Adjusted R-squared: 0.8776
## F-statistic: 189.8 on 3 and 76 DF, p-value: < 2.2e-16
amo
##
## Call:
## lm(formula = RDM ~ Deformation * D2, data = ancova.train)
##
## Coefficients:
## (Intercept) DeformationYes D2 DeformationYes:D2
## -1.111639 0.398477 0.103382 0.009583
p <- ggplot(ancova.train, (aes(x=D2, y=RDM, color=Deformation, shape=Deformation))) + ylab("Peso seco de la raiz (g)") + xlab("Diametro (cm)") + theme_classic()
p + geom_point() + geom_smooth(method=lm, se=FALSE, fullrange=TRUE)
## `geom_smooth()` using formula 'y ~ x'
Parámetro 4. TDM (Peso seco total)
nmod<-lm(TDM ~ Deformation + D2, data = ancova.train)
shapiro.test(nmod$residuals)
##
## Shapiro-Wilk normality test
##
## data: nmod$residuals
## W = 0.96848, p-value = 0.04543
#Son normales
library(car)
hmod<-lm(TDM ~ Deformation, data = ancova.train)
leveneTest(hmod)
## Warning in leveneTest.default(y = y, group = group, ...): group coerced to
## factor.
## Levene's Test for Homogeneity of Variance (center = median)
## Df F value Pr(>F)
## group 1 0.2369 0.6278
## 78
#Son homogéneas las varianzas
lmod<-lm(TDM ~ D2, data = ancova.train)
summary(lmod)
##
## Call:
## lm(formula = TDM ~ D2, data = ancova.train)
##
## Residuals:
## Min 1Q Median 3Q Max
## -4.5169 -1.5956 -0.1005 1.1195 6.9438
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -1.010746 0.481723 -2.098 0.0391 *
## D2 0.209971 0.007757 27.068 <2e-16 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.298 on 78 degrees of freedom
## Multiple R-squared: 0.9038, Adjusted R-squared: 0.9026
## F-statistic: 732.7 on 1 and 78 DF, p-value: < 2.2e-16
#El modelo es significativo
imod<-lm(TDM ~ Deformation * D2, data = ancova.train)
anova(imod)
## Analysis of Variance Table
##
## Response: TDM
## Df Sum Sq Mean Sq F value Pr(>F)
## Deformation 1 30.5 30.5 5.7810 0.01864 *
## D2 1 3849.1 3849.1 728.5526 < 2e-16 ***
## Deformation:D2 1 0.0 0.0 0.0019 0.96490
## Residuals 76 401.5 5.3
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#No hay interacción
amod<-lm(TDM ~ Deformation * D2, data = ancova.train)
summary(amod)
##
## Call:
## lm(formula = TDM ~ Deformation * D2, data = ancova.train)
##
## Residuals:
## Min 1Q Median 3Q Max
## -4.9773 -1.5883 -0.2934 1.1806 6.5094
##
## Coefficients:
## Estimate Std. Error t value Pr(>|t|)
## (Intercept) -1.4376934 0.6995822 -2.055 0.0433 *
## DeformationYes 0.6910122 0.9709766 0.712 0.4788
## D2 0.2112037 0.0104558 20.200 <2e-16 ***
## DeformationYes:D2 0.0006972 0.0157928 0.044 0.9649
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.299 on 76 degrees of freedom
## Multiple R-squared: 0.9062, Adjusted R-squared: 0.9025
## F-statistic: 244.8 on 3 and 76 DF, p-value: < 2.2e-16
amod
##
## Call:
## lm(formula = TDM ~ Deformation * D2, data = ancova.train)
##
## Coefficients:
## (Intercept) DeformationYes D2 DeformationYes:D2
## -1.4376934 0.6910122 0.2112037 0.0006972
p <- ggplot(ancova.train, (aes(x=D2, y=TDM, color=Deformation, shape=Deformation))) + ylab("Peso seco total (g)") + xlab("Diametro (cm)") + theme_classic()
p + geom_point() + geom_smooth(method=lm, se=FALSE, fullrange=TRUE)
## `geom_smooth()` using formula 'y ~ x'
Table 2. Relative prediction error (RPE, % mean ± standard deviation) from validation data (n = 40) (Eq. 3)
Parámetro 1. LDM (Peso seco foliar)
modancova<-lm(ancova.train$LDM ~ ancova.train$Deformation*ancova.train$D2)
summary(modancova)
##
## Call:
## lm(formula = ancova.train$LDM ~ ancova.train$Deformation * ancova.train$D2)
##
## Residuals:
## Min 1Q Median 3Q Max
## -2.53083 -0.46717 -0.08022 0.30631 2.87361
##
## Coefficients:
## Estimate Std. Error t value
## (Intercept) 0.2602733 0.3042009 0.856
## ancova.train$DeformationYes -0.0010296 0.4222119 -0.002
## ancova.train$D2 0.0679758 0.0045465 14.951
## ancova.train$DeformationYes:ancova.train$D2 -0.0005135 0.0068672 -0.075
## Pr(>|t|)
## (Intercept) 0.395
## ancova.train$DeformationYes 0.998
## ancova.train$D2 <2e-16 ***
## ancova.train$DeformationYes:ancova.train$D2 0.941
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.9995 on 76 degrees of freedom
## Multiple R-squared: 0.8417, Adjusted R-squared: 0.8354
## F-statistic: 134.7 on 3 and 76 DF, p-value: < 2.2e-16
s<-summary(modancova)
pv<-predict(modancova, newdata=data.frame(ancova.test$LDM, ancova.test$Deformation, ancova.test$D2), interval="prediction")
## Warning: 'newdata' had 20 rows but variables found have 80 rows
RPE_mean=mean(((pv[,1]-ancova.test$LDM)/ancova.test$LDM)*100)
RPE_sd= sd(((pv[,1]-ancova.test$LDM)/ancova.test$LDM)*100)
RPE_mean
## [1] 107.3573
RPE_sd
## [1] 364.0816
Parámetro 2. SDM (Peso seco del vástago)
modancova2<-lm(ancova.train$SDM ~ ancova.train$Deformation*ancova.train$D2)
summary(modancova2)
##
## Call:
## lm(formula = ancova.train$SDM ~ ancova.train$Deformation * ancova.train$D2)
##
## Residuals:
## Min 1Q Median 3Q Max
## -1.13881 -0.21032 -0.03857 0.18749 1.95663
##
## Coefficients:
## Estimate Std. Error t value
## (Intercept) -0.586328 0.159041 -3.687
## ancova.train$DeformationYes 0.293565 0.220740 1.330
## ancova.train$D2 0.039846 0.002377 16.763
## ancova.train$DeformationYes:ancova.train$D2 -0.008372 0.003590 -2.332
## Pr(>|t|)
## (Intercept) 0.000424 ***
## ancova.train$DeformationYes 0.187524
## ancova.train$D2 < 2e-16 ***
## ancova.train$DeformationYes:ancova.train$D2 0.022355 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 0.5225 on 76 degrees of freedom
## Multiple R-squared: 0.8511, Adjusted R-squared: 0.8452
## F-statistic: 144.8 on 3 and 76 DF, p-value: < 2.2e-16
m<-summary(modancova2)
mp<-predict(modancova, newdata=data.frame(ancova.test$SDM, ancova.test$Deformation, ancova.test$D2), interval="prediction")
## Warning: 'newdata' had 20 rows but variables found have 80 rows
RPE_mean=mean(((mp[,1]-ancova.test$SDM)/ancova.test$SDM)*100)
RPE_sd= sd(((mp[,1]-ancova.test$SDM)/ancova.test$SDM)*100)
RPE_mean
## [1] 1005.321
RPE_sd
## [1] 2132.889
Parámetro 3. RDM (Peso seco de la raíz)
modancova3<-lm(ancova.train$RDM ~ ancova.train$Deformation*ancova.train$D2)
summary(modancova3)
##
## Call:
## lm(formula = ancova.train$RDM ~ ancova.train$Deformation * ancova.train$D2)
##
## Residuals:
## Min 1Q Median 3Q Max
## -2.6190 -0.8771 -0.0611 0.6187 3.8996
##
## Coefficients:
## Estimate Std. Error t value
## (Intercept) -1.111639 0.402978 -2.759
## ancova.train$DeformationYes 0.398477 0.559309 0.712
## ancova.train$D2 0.103382 0.006023 17.165
## ancova.train$DeformationYes:ancova.train$D2 0.009583 0.009097 1.053
## Pr(>|t|)
## (Intercept) 0.00727 **
## ancova.train$DeformationYes 0.47837
## ancova.train$D2 < 2e-16 ***
## ancova.train$DeformationYes:ancova.train$D2 0.29548
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 1.324 on 76 degrees of freedom
## Multiple R-squared: 0.8822, Adjusted R-squared: 0.8776
## F-statistic: 189.8 on 3 and 76 DF, p-value: < 2.2e-16
o<-summary(modancova3)
pv2<-predict(modancova3, newdata=data.frame(ancova.test$RDM, ancova.test$Deformation, ancova.test$D2), interval="prediction")
## Warning: 'newdata' had 20 rows but variables found have 80 rows
RPE_mean=mean(((pv2[,1]-ancova.test$RDM)/ancova.test$RDM)*100)
RPE_sd= sd(((pv2[,1]-ancova.test$RDM)/ancova.test$RDM)*100)
RPE_mean
## [1] 253.2045
RPE_sd
## [1] 797.2929
Parámetro 4. TDM (Peso seco total)
modancova4<-lm(ancova.train$TDM ~ ancova.train$Deformation*ancova.train$D2)
summary(modancova4)
##
## Call:
## lm(formula = ancova.train$TDM ~ ancova.train$Deformation * ancova.train$D2)
##
## Residuals:
## Min 1Q Median 3Q Max
## -4.9773 -1.5883 -0.2934 1.1806 6.5094
##
## Coefficients:
## Estimate Std. Error t value
## (Intercept) -1.4376934 0.6995822 -2.055
## ancova.train$DeformationYes 0.6910122 0.9709766 0.712
## ancova.train$D2 0.2112037 0.0104558 20.200
## ancova.train$DeformationYes:ancova.train$D2 0.0006972 0.0157928 0.044
## Pr(>|t|)
## (Intercept) 0.0433 *
## ancova.train$DeformationYes 0.4788
## ancova.train$D2 <2e-16 ***
## ancova.train$DeformationYes:ancova.train$D2 0.9649
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Residual standard error: 2.299 on 76 degrees of freedom
## Multiple R-squared: 0.9062, Adjusted R-squared: 0.9025
## F-statistic: 244.8 on 3 and 76 DF, p-value: < 2.2e-16
s<-summary(modancova4)
pv3<-predict(modancova4, newdata=data.frame(ancova.test$TDM, ancova.test$Deformation, ancova.test$D2), interval="prediction")
## Warning: 'newdata' had 20 rows but variables found have 80 rows
RPE_mean=mean(((pv3[,1]-ancova.test$TDM)/ancova.test$TDM)*100)
RPE_sd= sd(((pv3[,1]-ancova.test$TDM)/ancova.test$TDM)*100)
RPE_mean
## [1] 170.0881
RPE_sd
## [1] 553.2315
La relación que existe entre el peso seco foliar y el diámetro de la raíz al cuadrado es significativa (t (3, 76) = 14.951, p < 0.05), en adición, la deformación en la raíz no mostró efectos estadísticamente significativos sobre la biomasa foliar y el diámetro de la raíz al cuadrado (t (3, 76) = 0.856, p > 0.05). El modelo es significativo (F(3, 76) = 134.7, p < 0.05).
En el caso del peso seco del vástago, se encontró interacción entre las variables, por esto, se decidió no llevar a cabo la prueba de ANCOVA.
La relación entre el peso seco radicular y el diámetro de la raíz al cuadrado es significativa (t (3, 76) = 17.165, p < 0.05), también, la deformación en la raíz no mostró efectos estadísticamente significativos sobre la biomasa radicular y el diámetro de la raíz al cuadrado (t (3, 76) = 0.856, p > 0.05). El modelo es significativo (F (3, 76) = 190, p < 0.05).
Se encontró una relación estadísticamente significativa entre la biomasa total y el diámetro de la raíz al cuadrado (t (3, 76) = 20.200, p < 0.05)). No se encontró un efecto de la deformación de la raíz sobre biomasa total y el diámetro de la raíz al cuadrado (t (3,76) = -2.055, p > 0.05)). Por último, el modelo es significativo (F(3, 76) = 244.8, p < 0.05).
Las figuras están adjuntas en los resultados de la primera pregunta.
Modelo (LDM): y = (0.2603 + coeficiente) + (0.0680 + coeficiente) * x
y = (0.2603) + (0.0680) * x