ylab and xlab title not showing up in a panel plot 5 rows 2column

Question

I have a panel plot shown below. The main problem is ylab and xlab titles are not showing up. How can I set it or reduce the graphics to have all within the window?

Below the command used to make the plot:

par(mar=rep(2,4))
par(mfrow=c(4,2))

 plot(me.ts,las=1,
  main=" ",     # Main title for t`enter code here`he plot  
 xlab="Time",                 # Label for the x-axis  
 ylab="rainfall (mm/day)",   # Label for the y-axis  
 font.lab=1,                  # Font to use for the axis labels: 1=plain 
 ylim=c(0, 4), # Range for the y-axis; "x
 xaxp=c(2071,2095,4), # X-axis min, max and
 bty="l", lwd=2)  
 me.time = time(me.ts)
 abline(reg=lm(me.ts ~ me.time),col="blue", lwd=2, asp=1)
  m=lm(me.ts ~ me.time)