The effects of mulching on nitrogen availability translated directly into effects on nutrient
uptake and growth of river birch. Foliar nitrogen concentration was higher in the composted
yard waste treatment than in the ground wood pallet or bare soil control (Figure 4). Fertilization
increased the foliar N levels of trees growing in the wood pallet and bare soil treatments, but had
no effect on foliar N of plants mulched with composted yard waste (Figure 4).