The depth-dependent relationship present in the Broadleaf–Conifer plots but not in the Pasture–Broadleaf plots, while unusual, may have to do with the fact that on average the forest stands in Broadleaf–Conifer plots were older (mean Broadleaf age = 27 years,mean Conifer age = 28 years), whereas the mean age of Broadleaf stands in the Pasture–Broadleaf plantations was 18 years