Nitrogen and Carbon Reallocation in Fungal Mycelia during Decomposition of Boreal Forest Litter

• DOI: 10.1371/journal.pone.0092897
• Publication Date: 2014-03-20T21:14:41Z
• Authors: Johanna B. Boberg; Roger D. Finlay; Jan Stenlid; Alf Ekblad; Björn D. Lindahl
• Keywords: Decomposer; Scots pine; Microcosm; Plant litter; Litter; Nutrient cycle

Boreal forests are characterized by spatially heterogeneous soils with low N availability. The decomposition of coniferous litter in these systems is primarily performed basidiomycete fungi, which often form large mycelia a well-developed capacity to reallocate resources spatially- an advantageous trait environments. In axenic microcosm we tested whether fungi increase their biomass production reallocating between Pinus sylvestris (Scots pine) needles at different stages decomposition. We estimated fungal analysing the accumulation cell wall compound chitin. Monospecific were compared interspecific interactions. found that reallocated assimilated and mycelial growth away from well-degraded towards fresh components. This redistribution was accompanied reduced older litter. Interconnection substrates increased over-all C use efficiency (i.e. allocation rather than respiration), presumably enabling translocation growth-limiting higher quality. Fungal connection also restricted N-mineralization dissolved organic N, suggesting saprotrophs boreal forest ecosystems act redistribute release N. spatial integration resource qualities hindered interactions, litters contrasting quality colonised two species. experiments provide detailed picture how reallocation decomposer leads more efficient utilisation separated under N-limitation. From ecosystem point view, such economic behaviour could potentially contribute matter layers forests.