uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/4818d2cd40661a8f189a0eca93db4bbd John Drake Adrien Finzi https://orcid.org/0000-0003-2220-4533 Marc-Andre Giasson Researcher 2023 English

We evaluated possible seasonal variation in the temperature sensitivity of microbially mediated soil fluxes related to decomposition (net N mineralization, net nitrification, proteolysis, the maximum velocity (Vmax) of proteolysis, microbial respiration, and the Vmax of four soil exo-enzymes) across forests dominated by eastern hemlock (Tsuga canadensis), white ash (Fraxinus americana), and red oak (Quercus rubra) in Harvard Forest. We asked two simple questions: (1) do temperature sensitivities vary across forest types or different steps of the decomposition process, and (2) do temperature sensitivities display plasticity on a seasonal time frame?We observed substantial variation in temperature sensitivities (Q10 and R10 values) across the different fluxes and forest types. The ash soils exhibited the strongest temperature sensitivities and the mineral-N fluxes exhibited higher temperature sensitivities relative to the proteolytic fluxes or microbial respiration. The Vmax of soil exo-enzymes varied considerably in an interactive manner across forests and time, and the response of some enzymes was consistent with the thermal plasticity. The enzymatic kinetic properties Vmax and Km (half-saturation constant) were strongly correlated with slopes that differed across enzymes, reflecting an enzyme-specific tradeoff between maximum catalytic rate and substrate-binding efficiency. Generally, Q10 values were largely constant, but R10 values varied in a manner consistent with distinct seasonal plasticity. There was a consistent seasonal shift in R10 values coincident with snowmelt, suggesting that the time following snowmelt is a particularly interesting and dynamic period of microbial activity in these temperate forests.

biogeochemistry carbon hemlock microbes nitrogen mineralization oak soil respiration 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=hf256 Prospect Hill Tract (Harvard Forest). Coordinates based on WGS84 datum. -72.335288 -72.172284 +42.545576 +42.347058 2010 2011 genus Fraxinus species americana white ash genus Quercus species rubra red oak genus Tsuga species canadensis eastern hemlock 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

For detailed methods, please see: Drake, J. E., M.-A. Giasson, K. J. Spiller, and A. C. Finzi. 2013. Seasonal plasticity in the temperature sensitivity of microbial activity in three temperate forest soils. Ecosphere 4(6):77. http://dx.doi.org/10.1890/ES13-00020.1.

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. hf256-01-micro-exo-enz-act.csv microbial exo-enzyme activity hf256-01-micro-exo-enz-act.csv 144276 7561a87f0739b23384fce0c6e3e413b1 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p25/hf256/hf256-01-micro-exo-enz-act.csv year year of sampling YYYY 1 year NA missing value month month of sampling month of sampling NA missing value day day of sampling day of sampling NA missing value date date of sampling YYYY-MM-DD 1 day NA missing value species dominant tree species in the plot FRAM white ash QURU red oak TSCA eastern hemlock NA missing value plot plot number plot number NA missing value substrate enzyme substrate used AP acid phosphatase BG b-1,4-glucosidase CBH cellobiohydrolase NAG b-N-acetylglucosaminidase NA missing value substrate.conc enzyme substrate concentration micromole 1 natural NA missing value activity microbial exo-enzyme activity measured (μmol substrate converted/g soil/hour) micromolePerGramPerHour 0.00001 real NA missing value 3240 hf256-02-exo-enz-kin.csv exo-enzymes kinetics hf256-02-exo-enz-kin.csv 17604 2c0a4f2652699bbafb72efe4964bd8c0 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p25/hf256/hf256-02-exo-enz-kin.csv year year of sampling YYYY 1 year NA missing value month month of sampling month of sampling NA missing value day day of sampling day of sampling NA missing value date date of sampling YYYY-MM-DD 1 day NA missing value species dominant tree species in the plot FRAM white ash QURU red oak TSCA eastern hemlock NA missing value plot plot number plot number NA missing value substrate enzyme substrate used AP acid phosphatase BG b-1,4-glucosidase CBH cellobiohydrolase NAG b-N-acetylglucosaminidase NA missing value v.max maximum exo-enzyme activity at saturating substrate concentrations micromolePerGramPerHour 0.00001 real NA missing value km half-saturation constant, or the substrate concentration at which the exo-enzyme activity is half the v.max value micromole 0.0001 real NA missing value 360 hf256-03-soil-cn.csv soil carbon and nitrogen hf256-03-soil-cn.csv 4784 0d222fb02ffd48ca4dcc8e51d371eed6 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p25/hf256/hf256-03-soil-cn.csv year year of sampling YYYY 1 year NA missing value month month of sampling month of sampling NA missing value day day of sampling day of sampling NA missing value date date of sampling YYYY-MM-DD 1 day NA missing value species dominant tree species in the plot FRAM white ash QURU red oak TSCA eastern hemlock NA missing value plot plot number plot number NA missing value n soil percent nitrogen dimensionless 0.000000001 real NA missing value c soil percent carbon dimensionless 0.000000001 real NA missing value 90 hf256-04-soil-proc.csv soil processes hf256-04-soil-proc.csv 66523 791e57cb34591e61cf1ce33b3d7e250e 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p25/hf256/hf256-04-soil-proc.csv year year of sampling YYYY 1 year NA missing value month month of sampling month of sampling NA missing value day day of sampling day of sampling NA missing value date date of sampling YYYY-MM-DD 1 day NA missing value doy julian day of sampling nominalDay 1 natural NA missing value species dominant tree species in the plot FRAM white ash QURU red oak TSCA eastern hemlock NA missing value plot plot number plot number NA missing value season sampling season sampling season NA missing value dry.wet soil dry mass:wet mass ratio dimensionless 0.000000001 real NA missing value temp incubation temperature celsius 1 natural NA missing value net.n.min net N mineralization (μg N/g dry soil/day) microgramPerGramPerDay 0.000000001 real NA missing value net.n.nit net N nitrification(μg N/g dry soil/day) microgramPerGramPerDay 0.000000001 real NA missing value proteolysis proteolysis, the rate of protein depolymerization into free amino acids (μg N/g dry soil/hour) microgramPerGramPerHour 0.000000001 real NA missing value proteolysis.c proteolysis under saturating protein substrate, 0.6% casein in soil solution (μg N/g dry soil/hour) microgramPerGramPerHour 0.000000001 real NA missing value rsoil soil respiration (μg C/g dry soil/hr) microgramPerGramPerHour 0.000000001 real NA missing value 648 soil short-term measurement micromole