Pseudoreplication issue in the analysis - a simple simulation example

# Pseudoreplication issue

# 1600 quadrats sampled in 8 grids (each grid 200 quadrats)
# what happens if we consider quadrats as independent units?

DEP <- rnorm (1600)
EXP <- rnorm (1600)
GRID <- rep (1:8, each = 200)
boxplot (DEP ~ GRID)


solution <- sapply (0:10, FUN = function (x) 
  replicate (100, expr = {
    RAND1 <- runif (n = 8, min = 0, max = x)
    RAND2 <- runif (n = 8, min = 0, max = x)
    DEP_recoded <- DEP + RAND1[GRID]
    EXP_recoded <- EXP + RAND2[GRID]
    cor.test (DEP_recoded, EXP_recoded)$p.value
  })
)
boxplot (solution, xlab = 'Value of Grid level environment', ylab = 'P-values')