uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/c9649f14260def9e9a540979983fd6e4 Kristen DeAngelis https://orcid.org/0000-0002-5585-4551 Jerry Melillo Grace Pold https://orcid.org/0000-0003-4418-4246 2023 English

As Earth’s climate warms, the massive stores of carbon found in soil are predicted to become depleted, and leave behind a smaller carbon pool that is less accessible to microbes. At a long-term forest soil-warming experiment in central Massachusetts, soil respiration and bacterial diversity have increased, while fungal biomass and microbially-accessible soil carbon have decreased. Here, we evaluate how warming has affected the microbial community’s capability to degrade chemically-complex soil carbon using lignin-amended BioSep beads. We profiled the bacterial and fungal communities using PCR-based methods and completed extracellular enzyme assays as a proxy for potential community function. We found that lignin-amended beads selected for a distinct community containing bacterial taxa closely related to known lignin degraders, as well as members of many genera not previously noted as capable of degrading lignin. Warming tended to drive bacterial community structure more strongly in the lignin beads, while the effect on the fungal community was limited to unamended beads. Of those bacterial operational taxonomic units (OTUs) enriched by the warming treatment, many were enriched uniquely on lignin-amended beads. These taxa may be contributing to enhanced soil respiration under warming despite reduced readily available C availability. In aggregate, these results suggest that there is genetic potential for chemically complex soil carbon degradation that may lead to extended elevated soil respiration with long-term warming.

climate change community dynamics decomposition microbes soil warming LTER controlled vocabulary populations organic matter LTER core area Harvard Forest HFR LTER USA HFR default

This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.

Creative Commons Zero v1.0 Universal https://spdx.org/licenses/CC0-1.0.html CC0-1.0 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf304 Prospect Hill Tract (Harvard Forest). Coordinates based on WGS84 datum. -72.18 -72.18 +42.54 +42.54 365 365 meter 2013 2013 complete Information Manager Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 hf-im@lists.fas.harvard.edu Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu

A full description of the methods is found in the published manuscript. Briefly, to each of four replicate heated and four replicate disturbance control plots, we horizontally deployed separate pouches containing lignin-amended (Sigma no. 471003) or unamended Bio-Sep bead (Microbial Insights, Knoxville TN) pouches (details in next section). Pouches were deployed as either “surface” bags, or as “subsurface” bags. Surface bags were placed on the surface of the soil under the leaf litter layer. Subsurface bead bags were buried in the soil between the organic horizon and the mineral soil. Bags were deployed for 11 weeks, after which amended and unamended beads were assayed for oxidative enzyme activity (with activities measured on a per gram bead basis as well as a per cell basis), as well as community composition by sequencing. The sequences were then quantitatively compared to known lignin-degrading species. Sequence data available under BioProject ID PRJNA242968.

Harvard Forest

324 North Main Street Petersham MA 01366 USA

(978) 724-3302 (978) 724-3595 https://harvardforest.fas.harvard.edu https://ror.org/059cpzx98 pointOfContact The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210. hf304-01-biosep-oxidative-sum.csv biosep oxidative summary hf304-01-biosep-oxidative-sum.csv 5399 163262b967a96c5852fa244a7af413f4 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p30/hf304/hf304-01-biosep-oxidative-sum.csv bag bag identification number bag identification number NA missing value horizon location of bag deployment subsurface bags incubated between organic horizon and mineral soil surface bags deployed on surface of organic horizon below litter layer NA missing value amendment whether or not beads were amended with lignin Unamended not amended Lignin amended NA missing value plot plot ID for deployment in long-term warming plots plot ID for deployment in long-term warming plots NA missing value treatment plot warming treatment Heated 5C heated treatment Control disturbance control plots NA missing value bag.id bag identification number bag identification number NA missing value bead.wt mass of beads used in assay slurry in 40 ml buffer gram 0.001 real NA missing value po phenol oxidase activity as change in A460nm of 50ul enzyme assay supernatant over the first three hours of the assay (ie it is a slope), assuming the initial absorbance was zero number 0.000000001 real NA missing value hpo peroxidase activity calculated using the change in A460nm of 50ul enzyme assay supernatant over the first three hours of the assay (ie it is a slope), assuming the initial absorbance was zero. The greatest changes occurred in the first 20 minutes, however these these initial values cannot be used due to the large variablity in blanks. number 0.000000001 real NA missing value net.hpo net peroxidase activity, calculated as plates with H2O2 minus plates without number 0.000000001 real NA missing value po.activity calculated using the formula Activity = (slope)*volume of buffer used (40ml)/(extinction coefficient (7.9umol)* volume plated (0.05ml)*g beads), where slope is the phenol oxidase slope micromolePerGramPerHour 0.000000001 real NA missing value oxi.beads activity = (slope)*volume of buffer used (40ml)/(extinction coefficient (7.9umol)* volume plated (0.05ml)*g beads), using the peroxidase (ie +H2O2 wells) slope gram 0.000000001 real NA missing value net.peroxidase difference between OXI.beads and PO activity, since phenol oxidases are active under the addition of H2O2, along with other activities micromolePerGram 0.000000001 real NA missing value cells.bead direct counts of cells detected per gram bead number 0.01 real NA missing value po.sa phenol oxidase specific activity (substrate converted per hour per 1e9 cells) dimensionless 0.000000001 real NA missing value oxi.cells total oxidative specific activity (substrate converted per hour per 1e9 cells) dimensionless 0.000000001 real NA missing value net.perox net phenol oxidase specific activity (substrate converted per hour per 1e9 cells) dimensionless 0.000000001 real NA missing value 32 plot community soil short-term measurement https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf005