Title: The effects of degradation on selected soil parameters at the Sogn peatland site: A comparison of peatlands in different statuses

Type:
Final project
Year of publication:
2021
Keywords:
Sogn, degradation, peatland, hydrology, greenhouse-gases

Abstract

Peatland degradation has been a universal norm for centuries and has resulted in large amounts of CO2 being emitted into the atmosphere. Agriculture is the number one factor for peatland degradation in Lesotho and Iceland. Degradation influences hydrology of peatlands and increases oxidation of organic matter, contributing to greenhouse gas effects. However, natural peatlands represent large soil carbon reservoirs and groundwater storage. The study objectives were to evaluate groundwater levels and carbon stocks, and to quantify carbon dioxide fluxes in pristine, restored, and drained peatlands in the Sogn farm, South Iceland in order to adapt the evaluation approach to Lesotho circumstances. Data was collected randomly in three plots at 5-15 cm and 15-30 cm depths using a shovel. In addition, soil cores to measure carbon dioxide fluxes, water table depth, carbon content, soil organic matter, and bulk density were collected at 100 cm and 200 cm depth in the drained subsite using a soil auger. Soil organic matter was measured using Loss on ignition. A vario TOC cube was used to measure carbon content, and calibrated conduit PVC pipes were used to determine water level. The chamber method was used to determine carbon dioxide fluxes and bulk density was determined by the Bart method. The results showed that pristine and restored peatlands were statistically the same in terms of water table depth (p >0.59), CO2 fluxes (p >0.28), and soil organic matter (p >0.33), but there was a difference between pristine and drained sites, and restored and drained sites in WTD p <0.001), CO2 fluxes (p <0.001), and SOM (p <0.001). Carbon content (p <0.001) between pristine and restored, pristine and drained and restored and drained peatland was significantly different. This study showed the importance of valuing peatlands, to stop their degradation and to conserve them. The value of restoring degraded peatlands through the rewetting method is clear. Rewetting is a cost-effective method to revive the peatlands in a short period.

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