TY - JOUR

T1 - Soil organic matter mobilization by re-compaction of old forest skid trails

AU - Nazari, Meisam

AU - Horvat, Malte

AU - Joergensen, Rainer Georg

AU - Peth, Stephan

N1 - Funding Information: The authors thank the German Federal Ministry of Food and Agriculture (BMEL) for funding the “Bodmech” project with the funding code 22028715 . We are grateful to Gabriele Dormann, Markus Hammer-Weis, Margit Rode and Pouria Sadeghianfar for providing skillful technical assistance.

PY - 2020/6

Y1 - 2020/6

N2 - Wood harvesting is restricted to a system of permanent skid trails in order to minimize the soil disturbance and damage. Therefore, it is not the compaction of previously undisturbed forest soil, but the re-compaction of already existing skid trails that is of practical relevance when investigating machinery-induced wood harvest effects on soil properties. This study investigated the effects of machinery-induced re-compaction on soil physical, chemical, and microbiological properties of an old skid trail in a spruce forest by wheeling 8 times with a maximum total load of 32.2 Mg, using a genuine old skid trail as a control. Re-compaction significantly increased the bulk density and reduced the porosity, whereas the soil organic carbon (SOC) and total nitrogen (N) contents were not significantly affected. However, re-compaction reduced the SOC/total N ratio by 10%, suggesting considerable SOC mineralization after re-compaction. K 2SO 4 extractable C contents were increased by 94% at 0–3 cm and 67% at 7–10 cm depth after re-compaction. This led to 20% and 90% increased microbial biomass C/soil organic C (MBC/SOC) ratios at 0–3 cm and at 7–10 cm depth, respectively. In contrast, the ergosterol/MBC ratio was significantly decreased by 10% at 0–3 cm and by about 30% at 7–10 cm depth by re-compaction, apparently due to the promotion of bacteria and mobilization of soil organic matter.

AB - Wood harvesting is restricted to a system of permanent skid trails in order to minimize the soil disturbance and damage. Therefore, it is not the compaction of previously undisturbed forest soil, but the re-compaction of already existing skid trails that is of practical relevance when investigating machinery-induced wood harvest effects on soil properties. This study investigated the effects of machinery-induced re-compaction on soil physical, chemical, and microbiological properties of an old skid trail in a spruce forest by wheeling 8 times with a maximum total load of 32.2 Mg, using a genuine old skid trail as a control. Re-compaction significantly increased the bulk density and reduced the porosity, whereas the soil organic carbon (SOC) and total nitrogen (N) contents were not significantly affected. However, re-compaction reduced the SOC/total N ratio by 10%, suggesting considerable SOC mineralization after re-compaction. K 2SO 4 extractable C contents were increased by 94% at 0–3 cm and 67% at 7–10 cm depth after re-compaction. This led to 20% and 90% increased microbial biomass C/soil organic C (MBC/SOC) ratios at 0–3 cm and at 7–10 cm depth, respectively. In contrast, the ergosterol/MBC ratio was significantly decreased by 10% at 0–3 cm and by about 30% at 7–10 cm depth by re-compaction, apparently due to the promotion of bacteria and mobilization of soil organic matter.

KW - Soil compaction

KW - Porosity

KW - Extractable C

KW - Microbial biomass

KW - Ergosterol

KW - Skid trail

UR - http://www.scopus.com/inward/record.url?scp=85081645364&partnerID=8YFLogxK

U2 - 10.1016/j.ejsobi.2020.103173

DO - 10.1016/j.ejsobi.2020.103173

M3 - Article

VL - 98

JO - European journal of soil biology

JF - European journal of soil biology

SN - 1164-5563

M1 - 103173

ER -