Abstract Detail

Ecology

Malik, Rondy J [1], Trexler, Ryan [2], Eissenstat, David [3], Bell, Terrence H [4].

Regardless of the ‘home’ soil, bark decomposition can promote environmental filtration of microbes at a local scale.

Although nutrient cycling is pivotal to ecosystem function and sustainability, bark decomposition may be a key factor in determining rates of carbon storage. Bark and its underlying chemical properties may act as environmental filters for microbial assemblages. Increase in decomposer efficiency may be attained through co-localized adaptation, where bark litter traits have adapted to the local environment, and microbial decomposers have adapted to bark litter traits. To test for co-localized adaptations, a full factorial design featuring 2 species * 2 soil communities * 25 tree replicates was used in this study. The experiment was conducted at a temperate mixed hardwood forest, in central Pennsylvania. It featured 2 species, or bark types (eastern hemlock and white oak), and 2 soil communities (eastern hemlock and white oak). When bark type matched the soil environment of its parent tree, this was denoted as "home" soil environment. When bark type did not match the soil environment of its parent tree, this was denoted as "away" soil environment. These combinations allowed the examination of the main effect of both bark type and soil communities on decomposition. Bark microbial assemblages were characterized through sequencing of 16S rRNA and fungal ITS gene fragments, as were assemblages in the adherent soil after 12 months of bark decomposition (mass loss). Results showed that bark decomposition rates varied at the local scale, as decomposition was suppressed in soil communities beneath the canopy of eastern hemlock, but at the same time, enhanced in soil communities beneath the canopy of white oak. Thus, white oak bark tissue was readily degraded in its "home" soil, suggesting a 'home-field advantage' for white oak, but a "home-field advantage" was not detected for eastern hemlock. Among species, a significant positive correlation was detected between remainder bark mass and bacterial diversity. This may suggest that decomposer liberation of bark chemical compounds, including tannins and soluble polyphenolics, might act as environmental filters affecting overall microbial diversity. Taken together, these findings suggest recalcitrant litter decomposition may shift microbial assemblages, and therefore provide additional insight into ecosystem function.

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1 - Penn State University, Ecosystem Science and Management, 223 Forest Resources bldg, University Park, Pennsylvania, 16802
2 - Penn State University, Plant Pathology and Environmental Microbiology, 113 Buckhout, University Park, Pennsylvania, 16802
3 - Penn State University, Ecosystem Science And Managment, 201 Forest Resources Building, University Park, PA, 16802, United States
4 - Penn State University, Plant Pathology and Environmental Microbiology, 317 Buckhout, University Park, Pennsylvania, 16802

Keywords:
Bark
Decomposition
Microbiome
Eastern Forest.

Presentation Type: Poster
Session: P, Ecology Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PEC032
Abstract ID:1013
Candidate for Awards:None