Tree species composition shapes the assembly of microbial decomposer communities during litter decomposition

Berlin

2022

457–472

Sonderdruck

13054S

40003582

Aims Litter decomposition is a complex process closely linked to terrestrial ecosystem dynamics. We examined how forest succession from Scots pine (Pinus sylvestris L.) to Pyrenean oak (Quercus pyrenaica Willd.) driven by global-change may influence litter decomposition in a Mediterranean ecotone forest. Methods We performed a reciprocal experiment using litterbags in pure Scots pine and Pyrenean oak forests to assess the litter decomposition process of pine (needles), oak (leaves) and a 1:1 mixture of needles and leaves over a two-year period. Results Home-field advantage was only found in the oak leaves, while needle decomposition rates were similar in both forests. There were synergistic effects of mixing litter that mainly increased the decomposition of needle litter. The litter mixing and the forest environment gained influence as drivers of litter decomposition over time by shaping the functional assembly of microbial communities and determining decomposition conditions. We found a staggered functional adjustment of the microbial community assembly driven by the litter type at early stages, followed by the convergence of colonizing microbial communities towards soil microbes and soil organic matter characteristics.Keywords: Litterbag, Litter mixing, Microbial community structure, Carbon cycling, Phyllosphere, Plant-soil-microorganism interactions