Estimation of Soil Organic Carbon Stock in the Midtre Lovénbreen Moraine, Svalbard

Abstract:

As a glacier retreats, land surface beneath the glacier is newly exposed, and changes in soil have initiated as well as microbial and plants species. Numerous studies have been done on soil development along the chronosequence in the glacier moraine, and mostly undisturbed areas were selected as sampling sites to represent soil age well. However, the surface of glacier moraine is remodeled by active flows, and terrain attributes are very diverse, thus soil organic carbon (SOC) accumulation is not always a linear function of soil age in the glacier moraine. Therefore, we examined the distribution of SOC in the Midtre Lovénbreen morain with a consideration of soil age, microtopography, and runoff activity in this study. Forty two soil sampling sites were selected among previously observed 300 points of plant species via the systematic random sampling method with a consideration of soil age, runoff activities, slope, aspect, and X, Y coordinates. Three close to the glacier terminus and nine sites outside of moraine were additionally sampled. Four different depths (0-5, 5-10, 10-20, and 20-30 cm) of soil were collected, and soil volume was measured by the excavation method in summer 2014. Currently, we are in a status of acquiring microtopographic information from digital elevation model, calculating bulk density, and preparing soil samples for SOC analysis. Once we gather all data, corresponding analysis and classification will be conducted to characterize sampling sites. Then, SOC distribution over the glacier moraine using microtopographic information will be estimated through modelling.