| The forest soils of southeast Alaska are distributed in a complex pattern with respect to microrelief. This microrelief is primarily caused by the soil disturbance associated with the blowdown of trees; treethrow.;Young mound and pit soils have very little horizon development until they are about 100 to 200 years old. The young pits and mounds are morphologically similar, but their chemistry reveals important differences. Pits are affected by a soil genetic regime dominated by wet conditions. Podzolization is the active soil process on the well drained mounds.;Old mound and pit soils are morphologically quite different. Mound soils are well drained Spodosols (Cryorthods), and pit soils are formed under an aquic regime, hence they become either Cryaquods or Histosols. Spatial analyses of soil morphological features on an area basis reveals that pit microsites tend to have more poorly drained soils and mound microsites tend to be better drained. The older the site, the more poorly drained and organic the soils tend to be. The magnitude of variability suggests that soils are distributed in a complex arrangement, with individual soil bodies occupying contiguous areas less than 20 square meters.;Microrelief consists of pits and mounds. Some mounds and pits are young, and immature soils have formed on them. Other surfaces are older and more mature soils formed on them. The result is a mosaic of old and young surfaces and pits and mounds on the landscape. Soils form differently in these different microsites. |
