Microbial and environmental controls on wood decomposition in deciduous forests of different ages

Abstract

Wood decomposition is regulated by microbial community and soil conditions and plays an important role in global carbon cycling. Among many factors, local conditions, associated with forest age and the leaf litter adjacent to decaying wood may directly and indirectly influence microbial colonization and rate of decay. In this study, wood sticks with and without leaf litter were buried in young (50–70 years), old (120–150 years) and uncut (over 200 years) forests at the Smithsonian Environmental Research Center (SERC), Maryland, USA to test hypotheses about woody and foliar litter interaction during decomposition and whether decay rates are associated with differences in microbial community and soil properties. At the early stages of decomposition, wood mass loss in the young forests was significantly higher than that in other two forests but was not different between old and uncut forests. Adjacent foliar litter increased functional diversity of wood colonizing fungi, and enhanced decay in old and uncut stands. Factors, significantly correlated with decomposition, included fungal community composition, soil moisture, pH and C:N ratio. This study highlights the importance of local factors, such as land use and forest age affecting wood decomposition rates.