Wood construction more strongly shapes deadwood microbial communities than spatial location over 5 years of decay

Abstract

Summary Diverse communities of fungi and bacteria in deadwood mediate wood decay. While rates of decomposition vary greatly among woody species and spatially distinct habitats, the relative importance of these factors in structuring microbial communities and whether these shift over time remains largely unknown. We characterized fungal and bacterial diversity within pieces of deadwood that experienced 6.3–98.8% mass loss while decaying in common garden ‘rotplots’ in a temperate oak‐hickory forest in the Ozark Highlands, MO, USA. Communities were isolated from 21 woody species that had been decomposing for 1–5 years in spatially distinct habitats at the landscape scale (top and bottom of watersheds) and within stems (top and bottom of stems). Microbial community structure varied more strongly with wood traits than with spatial locations, mirroring the relative role of these factors on decay rates on the same pieces of wood even after 5 years. Co‐occurring fungal and bacterial communities persistently influenced one another independently from their shared environmental conditions. However, the relative influence of wood construction versus spatial locations differed between fungi and bacteria, suggesting that life history characteristics of these clades structure diversity differently across space and time in decomposing wood.

Microbial Diversity and Ecosystem Functioning in Deadwood of Black Pine of a Temperate Forest

“…Deadwood is a habitat for many specialised organisms, including microbes, invertebrates, bryophytes, lichens, and vascular plants [17]. Wood-inhabiting fungi and bacteria are the key decay agents, and from their perspective, deadwood represents both a habitat and a resource [18]. Saprophytic fungi, in particular Basidiomycota, produce arrays of extracellular enzymes and actively contribute to breaking down cellulose, hemicellulose, and lignin, supplying themselves with substrates for their growth [19].…”

“…Fungi and bacteria may develop intricate relationships of synergic, antagonistic, and/or neutral nature [25], influencing wood decay rates and community functions [18]. Bacteria may benefit from products released by the fungal decomposition processes [20,26] and, on the other side, may provide N, iron, and growth factors to stimulate fungal growth and accelerate the rate of wood decay [27][28][29].…”

“…Bacteria may benefit from products released by the fungal decomposition processes [20,26] and, on the other side, may provide N, iron, and growth factors to stimulate fungal growth and accelerate the rate of wood decay [27][28][29]. Both fungal and bacterial decay abilities are shaped by environmental conditions and biotic interactions [25] and the microbial community composition and function change as decomposition progresses [18].…”

Dead wood diversity promotes fungal diversity

“…Various abiotic and biotic factors influence the diversity of wood‐inhabiting fungi, shaping fungal community structure (Kahl et al 2017, Lee et al 2020). A larger contact area between wood and soil may increase fungal access to the log (Rajala et al 2012), while climate factors like relatively high temperature and humidity may facilitate fungal growth (Purahong et al 2017).…”

The Molecular Information About Deadwood Bacteriomes Partly Depends on the Targeted Environmental DNA

“…The role of bacterial communities in the deadwood habitat is still underexplored compared to fungi (Johnston et al, 2016(Johnston et al, , 2019Gómez-Brandón et al, 2020). Yet, the variations among bacterial communities within and between decay stages are poorly studied, as previously emphasized (Hoppe et al, 2015;Kielak et al, 2016b;Lee et al, 2020). Exploring such variations can increase our understanding about the dynamics of the deadwood ecosystem in terms of key players, functional redundant decomposers, and microbial succession.…”