Alteration of Surface Soil Characteristics by Four Tree Species

Abstract

Changes in soil proprties were studied in a 30—year—old mixed plot plantation of Norway spruce (Picea abies (L.) Karst.), red oak (Quercus rubra L.), white pine (Pinus strobus L.), and red pine (P. resinosa Ait.). The species plots were arranged in a Latin square. The surface 5 inches (12.8 cm) of soil below Norway spruce contained the highest percentage of organic matter and the greatest pore volume of the four species. However, it had a slower inflitration rate than the soil supporting the other two conifers, but not as slow as that below oak. Organic matter content in the soil below all species decreased rapidly with depth. Differences in the nitrogen, postassium and calcium content of the soil below the four species were concentrated in the surface 2 inches of soil and generally disappeared below that level. Soil below Norway spruce had the highest concentrations of the three aforementioned elements at the surface inch and that of white pine the least. The amount and quality of litter—derived organic matter in the soil was evidently the key factor in determining differences in the nutrient content of the soil in which these four tree species were growing.