#Download and install the following packages.
install(esc)
install(tidyverse) 
install(dmetar)
install(meta)
install(PerformanceAnalytics)
install(metafor)

library(esc)
library(tidyverse) 
library(dmetar)
library(meta)
library(PerformanceAnalytics)
library(metafor)

#Load the database
co<-read.table("dataset.txt",h=T)
co

#Perform meta-analysis

m.gen<- metagen(TE = TE,seTE = seTE,studlab = Author,data = co,sm = "SMD",fixed = FALSE,random = TRUE,method.tau = "ML",hakn = TRUE)
summary(m.gen)
forest(m.gen)

#Subgroup meta-analysis
species<-update.meta(m.gen,subgroup=Group,tau.common=FALSE)
species


weather<-update.meta(m.gen,subgroup=Weather,tau.common=FALSE)
weather

activity<-update.meta(m.gen,subgroup=Anthropogenic_activity,tau.common=FALSE)
activity


continent<-update.meta(m.gen,subgroup=Continent,tau.common=FALSE)
continent

#Meta-regression
model1<- rma(yi = TE,
              sei = seTE,
              data = si,
              method = "ML",
              mods = ~ Coverage,
              test = "knha")