Soil Development and Vegetation Succession in Glacial Fiords of Southcentraland Southeast Alaska

Most Alaskan Little Ice Age (LIA) tidewater glaciers reached their maximums from 100 to 250 years ago. More than 90% have been retreating since then, in many cases opening up bays as much as 100 km long. Accelerated melting of these glaciers under current climate conditions has created opportunities for examining the soil and plant development on recently-deglacierized surfaces of known date. We used a releve method to examine linkages between soil and vegetation in a chronosequence in three glacial fjords in Kenai Fjords National Park. Releves representative of five different vegetation succession patterns were chosen for study. Soil pits were dug at each releve. Thirty soils were examined in the field for horizonation, texture, presence of rock fragments, structure, and moisture content. These soils were sampled at sites within lateral and recessional glacial moraine deposits ranging from meters to several kilometers from modern glacier termini and in an old growth forest unaffected by LIA glacial advance. The data show an increase in soil profile development with distance from termini and as vegetation moves through successional stages from bare ground to mature forest. These findings related to similar results for other soil/plant chronosequences examined at several Southeastern Alaska fiord locations. No spodosols were found in any recently deglacierized areas. However, they were found in soil in the old growth forest.