uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/8970317b0c4cf48463801e57c9ccbc71 Eric Davidson https://orcid.org/0000-0002-8525-8697 Kathleen Savage https://orcid.org/0000-0002-1649-5314 2023 English

We have been making long-term soil respiration measurements at our transect sites since the summer of 1995. The rainfall exclusion experiment began in May of 2001 and autochamber measurements began in 2003. A root exclusion experiment (trenching) was conducted from 2012-2014.

precipitation soil moisture soil respiration soil temperature litterfall roots LTER controlled vocabulary inorganic nutrients 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=hf006 Prospect Hill Tract (Harvard Forest). Coordinates based on WGS84 datum. -72.17 -72.17 +42.54 +42.54 340 365 meter 1995 2014 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

There are 6 sites located along a northwest and southwest transect from the EMS tower on the Prospect Hill tract of the Harvard forest. Sites ranged from very poorly drained swamp to well drained uplands. Measurements were collected at approximately weekly intervals during the summer and biweekly for the remainder of the season. Soil respiration was measured using a dynamic chamber system. Soil CO2 flux is measured by placing a chamber over fixed collars in the soil. The change in CO2 concentration within the chamber headspace is recorded every 12s for 4.5 min. A linear regression of the increasing chamber headspace concentration is used to calculate a flux rate and converted to units of mg C m-2 hr-1. Soil temperature and volumetric soil moisture were collected concurrent with soil respiration measurements. Soil temperature is taken using a 10cm probe inserted vertically from the surface. Volumetric water content is determined with 15 cm TDR probes inserted vertically in the soil. Soil profile CO2 concentrations are also measured at the same time scale as soil respiration rates.

We selected 3 well drained upland sites (20m x 20m) approximately 400 ft southwest of the EMS tower. Within each site we selected a treatment (n=3) and control plot (n=3). Corrugated plastic roof panels (5m x 5m) were used to construct a roof at each of the treatment plots. Control plot were located adjacent to each treatment plot. Four soil respiration collars were placed in each of the treatment and control plots and measured at weekly intervals during the summer and biweekly to monthly for the rest of the season. Fluxes were calculated using the same method as for our long term soil respiration sites. Quantative pits were dug at each of the 3 sites. Each pit was located between a control and treatment plot such that when we instrumented the pits one side was within the control plot and one side was within the treatment plot. The pits were instrumented with soil temperature, tdr moisture probes and soil CO2 concentration sampling probes. Litter layer water content was measured using DC-halfbridge sensors (see Borken et al. 2003 for description).

Soil CO2 Flux (mg C m-2 h-1) is measured by an automated soil respiration system which automatically places a chamber over collars (that are left in place) in the soil. Air from the chamber headspace is pumped into an Infrared Gas Analyzer (LICOR 6252) at a rate of 0.7L/min for a 5 minute period. The change in headspace CO2 concentration is recorded every 12s for 4.5 minutes a Campbell Scientific CR10X logger. A linear regression on the change in headspace concentration over time, along with air temperature, atmospheric pressure and chamber surface area are used to convert these measurements to units of mg C m-2 hr-1. For more details of the automated system see: Savage et al. 2008. A conceptual and practical approach to data quality and analysis procedures for high-frequency soil respiration. Functional Ecology 22: 1000-1007.

In the late fall of 2012, a trench was dug (to 1m depth) around a 5x5m area, severing all roots leading into the treatment plot. Plastic tarp was placed along the walls of the trenched plot to prevent new root in-growth and then backfilled. All under-story vegetation within the trenched plot was clipped in the early spring in 2013 and 2014. Four automated chambers were placed within the trenched plot and four in an adjacent control plot area. Given the constrained space and the disturbance due to the trenching method, we chose to use one large trenched plot with four replicate chambers within it as opposed to four separate trenched plots. We recognize that this setup would be considered “pseudo-replication”, however in our experience spatial heterogeneity in soil respiration within 5 m can be as great as between 25 m. Automated soil respiration chambers were utilized in conjunction with the trenching method to partition Rt into its components, Rh and Ra. Soil respiration was measured for each chamber at 90 minute intervals from early spring through late fall of both 2012 (pre trenching period), 2013 and 2014. Respiration was not measured from late fall of 2012 (after trenching) to the early spring of 2013 (5 months) to remove the potential influence of CO2 efflux from dying roots and any potential CO2 “pulse” from trenching. Fluxes, along with soil temperature and moisture (at 10cm depth, Campbell Scientific CS650 WC probes), were measured at 90 minute intervals from early spring through late fall of 2013 and 2014. All data were measured and stored using a Campbell Scientific CR1000 datalogger. Measurements from the non-trenched plot (control) represent the combined Rh and Ra components, Rt. Fluxes from the trenched plot represent, Rh and the difference (Rt-Rh) represents Ra.

Leaf litterfall was collected from 6 baskets at each of the sampling sites. Twigs and sticks are not included. Leaf litter samples were dried at 60oC for 48 hrs and weighed. Data were converted to units of g C m-2 yr-1. NA signifies no data collected that year.

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. hf006-01-soil-respiration.csv soil respiration hf006-01-soil-respiration.csv 291202 eb28227d9b220808ffb83ee96dba09d6 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p00/hf006/hf006-01-soil-respiration.csv datetime date and time YYYY-MM-DDThh:mm NA missing value date date YYYY-MM-DD jd Julian date nominalDay 1 natural doy sequential day of year over multiple years nominalDay 1 natural NA missing value flux CO2 flux milligramPerMeterSquaredPerHour 0.01 real NA missing value se standard error of CO2 flux milligramPerMeterSquaredPerHour 0.01 real NA missing value soilt soil temperature at 10cm depth celsius 0.1 real NA missing value vsm volumetric soil moisture over the top 15cm of soil gramsPerGram 0.01 real NA missing value time time of sampling hh:mm NA missing value site site name site name NA missing value drainage drainage class drainage class NA missing value 4281 hf006-02-rain-exclusion.csv rainfall exclusion hf006-02-rain-exclusion.csv 4033 41ca12d246b2165c547b932fe0695837 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p00/hf006/hf006-02-rain-exclusion.csv date date YYYY-MM-DD jd Julian date nominalDay 1 natural mean.flux CO2 flux milligramPerMeterSquaredPerHour 0.01 real NA missing value se standard error milligramPerMeterSquaredPerHour 0.01 real NA missing value control.mean.flux mean CO2 flux milligramPerMeterSquaredPerHour 0.01 real NA missing value control.se standard errorof mean flux milligramPerMeterSquaredPerHour 0.01 real NA missing value soilt.flux soil temperature at 10cm depth celsius 0.1 real NA missing value soilt.mean mean soil temperature at 10cm depth celsius 0.1 real NA missing value 83 hf006-03-autochamber.csv autochamber hf006-03-autochamber.csv 1123075 f7da3973325e823d7dc1714e83a0afe8 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p00/hf006/hf006-03-autochamber.csv datetime date and time YYYY-MM-DDThh:mm NA missing value date date YYYY-MM-DD NA missing value year year YYYY NA missing value doy day of year nominalDay 1 natural NA missing value time time of sampling hh:mm NA missing value flux1 soil respiration measured at collar 1 milligramPerMeterSquaredPerHour 0.01 real NA missing value flux2 soil respiration measured at collar 2 milligramPerMeterSquaredPerHour 0.01 real NA missing value flux3 soil respiration measured at collar 3 milligramPerMeterSquaredPerHour 0.01 real NA missing value flux4 soil respiration measured at collar 4 milligramPerMeterSquaredPerHour 0.01 real NA missing value flux5 soil respiration measured at collar 5 milligramPerMeterSquaredPerHour 0.01 real NA missing value flux6 soil respiration measured at collar 6 milligramPerMeterSquaredPerHour 0.01 real NA missing value temp.ll soil temperature measured in leaf litter celsius 0.01 real NA missing value temp3 soil temperature measured at 3 cm celsius 0.01 real NA missing value temp4.5 soil temperature measured at 4.5 cm celsius 0.01 real NA missing value temp7 soil temperature measured at 7 cm celsius 0.01 real NA missing value temp8.5 soil temperature measured at 8.5 cm celsius 0.01 real NA missing value temp12 soil temperature measured at 12 cm celsius 0.01 real NA missing value temp14 soil temperature measured at 14 cm celsius 0.01 real NA missing value temp36 soil temperature measured at 36 cm celsius 0.01 real NA missing value mois5 soil moisture measured at 5cm depth (volumetric) number 0.01 real NA missing value 8562 hf006-04-litterfall.csv litterfall hf006-04-litterfall.csv 769 c1f44a1f93dede4e3dbe1b8a0b622243 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p00/hf006/hf006-04-litterfall.csv site site name site name NA missing value lf.1996 total litterfall for 1996 gramsPerSquareMeter 0.1 real NA missing value lf.1997 total litterfall for 1997 gramsPerSquareMeter 0.1 real NA missing value lf.1998 total litterfall for 1998 gramsPerSquareMeter 0.1 real NA missing value lf.1999 total litterfall for 1999 gramsPerSquareMeter 0.1 real NA missing value lf.2000 total litterfall for 2000 gramsPerSquareMeter 0.1 real NA missing value lf.2001 total litterfall for 2001 gramsPerSquareMeter 0.1 real NA missing value lf.2002 total litterfall for 2002 gramsPerSquareMeter 0.1 real NA missing value lf.2003 total litterfall for 2003 gramsPerSquareMeter 0.1 real NA missing value lf.2004 total litterfall for 2004 gramsPerSquareMeter 0.1 real NA missing value lf.2005 total litterfall for 2005 gramsPerSquareMeter 0.1 real NA missing value lf.2006 total litterfall for 2006 gramsPerSquareMeter 0.1 real NA missing value lf.2007 total litterfall for 2007 gramsPerSquareMeter 0.1 real NA missing value lf.2008 total litterfall for 2008 gramsPerSquareMeter 0.1 real NA missing value lf.2009 total litterfall for 2009 gramsPerSquareMeter 0.1 real NA missing value lf.2010 total litterfall for 2010 gramsPerSquareMeter 0.1 real NA missing value 9 hf006-05-root-exclusion.csv root exclusion (trenching) hf006-05-root-exclusion.csv 10164693 86b98dd502331dd2dfc28f6bc74505f3 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p00/hf006/hf006-05-root-exclusion.csv datetime date and time YYYY-MM-DDThh:mm NA missing value year year YYYY date date YYYY-MM-DD time time hh:mm chamber.id chamber number chamber number NA missing value flux soil respiration milligramPerMeterSquaredPerHour 0.01 real NA missing value soilt.t soil temperature at 10cm depth, trenched plot celsius 0.1 real NA missing value soilt.c soil temperature at 10cm depth, control plot celsius 0.1 real NA missing value vsm.t volumetric soil moisture, trenched plot cubicCentimetersPerCubicCentimeters 0.01 real NA missing value vsm.c volumetric soil moisture, control plot cubicCentimetersPerCubicCentimeters 0.01 real NA missing value treatment treatment PT pre-trenched T trenched C control NA missing value 146680 soil long-term measurement 3 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf004 milligramPerMeterSquaredPerHour