我的数据集 (sp.abd) 有 4 个物种。每行代表一个跨越四个季节的站点。我还有每个站点温度、湿度和 pH 值的环境数据。但是，我不知道如何使用ggplot2覆盖环境dbRDA。有 other examples 使用 baseplot，但不确定如何使用 autoplot。同样，我可以将相同的内容添加到聚类图中吗？

#Environemnt Data
temp <- rnorm(72,mean = 12,sd = 5)
moist <- rnorm(72,mean = 20,sd = 20)
ph <- rnorm(72,mean = 4,sd = 2)
season <- rep(c("Summer","Autumn","Winter","Spring"),each = 18)

envvar <- data.frame(temp,moist,ph,season)

#Species Abundance Data
sp1 <- rnorm(72,1)
sp2 <- rnorm(72,mean = 2,1)
sp3 <- rnorm(72,mean = 3,1)
sp4 <- rnorm(72,mean = 9,1)

sp.abd <- data.frame(sp1,sp2,sp3,sp4,season)

env.dbrda <- dbrda(dp.abd[,-5] ~ .,as.data.frame(envvar[,-4]))

#Plotting PCA
library(ggfortify)
df <- sp.abd [1:4]
pca_res <- prcomp(df,scale. = TRUE)
screeplot(pca_res)

autoplot(pca_res,data = sp.abd,colour = 'season',loadings = TRUE,loadings.colour = 'blue',loadings.label = TRUE,loadings.label.size = 3) 

#Plotting Clusters
library(cluster)
library(ggfortify)
autoplot(pam(df,4),frame = TRUE,frame.type = 'norm') + theme_classic()