uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/94fcd23751f04c1aa1eb0fee05df3180 David Orwig https://orcid.org/0000-0001-7822-3560 David Foster https://orcid.org/0000-0003-1171-3762 Laura Barbash Researcher Brian Hall Researcher Heidi Lux Researcher 2023 English

The recent unimpeded infestation of the hemlock woolly adelgid (HWA; Adelges tsugae) across the northeastern U.S. is driving large-scale hemlock decline and mortality. HWA has already infested over 40% of the towns in Massachusetts and, as a result, many landowners are considering pre-emptively harvesting their eastern hemlock (Tsuga canadensis) stands. To examine the local impacts of this cutting activity, we examined stand and ecosystem dynamics in 10 hemlock-dominated sites on public and private lands where hemlocks were harvested between 1 to12 years ago with nearby uncut forests. Forty-two to ninety-seven percent of hemlock stems and basal area were removed from the harvested sites. Sapling densities of 10,500 to 24,000 stems ha-1 dominated the vegetation at older cuts and consisted primarily of black birch (Betula lenta), red maple (Acer rubrum), and white pine (Pinus strobus). Seedling densities averaged 5 m-2 across sites, peaked at 20 m-2 at 6 to 9 year old sites, and consisted of hemlock, white pine, black birch, and red maple. Additional understory species that were common in cuts sites included various raspberry (Rubus) species, often averaging 30% cover, hay-scented fern (Dennstaedtia punctilobula), and various sedge (Carex) species. Harvesting resulted in soils that were 3 to 5 (deg C) warmer and tended to be drier in recent vs. older cuts. Net nitrogen mineralization rates in organic soils averaged just over 10 kg N ha-1yr-1 in recent cuts and approx. 5 kg N ha-1yr-1 in older cuts. Mineral soil net mineralization rates were lower among all cuts, ranging from 2.1 to 3.5 kg N ha-1yr-1. Nitrification rates were low in both soil horizons at all harvest ages. Recent cuts had much higher nitrogen capture (NH4- + NO3+) on resin bags averaging around 1200 μg N g resin-1 vs. 300 to 600 μg N g resin-1 captured in older cuts. Nitrification rates and nitrate capture on resin bags were lower in Massachusetts sites than those reported on sites with a long history of HWA that were then subsequently logged. Findings from this study corroborate past work, as more recent cuts also exhibited increased birch and maple establishment and higher N availability than older cuts. In contrast to prior studies, cutting in Massachusetts sites also led to abundant conifer regeneration of white pine and hemlock, suggesting that seed tree availability, seedbed characteristics, and lack of HWA at several of the MA sites contributed to the higher conifer seedling densities found in this study.

hemlock hemlock woolly adelgid nitrogen mineralization soil chemistry soil moisture soil temperature timber harvest vegetation dynamics LTER controlled vocabulary inorganic nutrients disturbance human-environment 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=hf128 Central Massachusetts. Coordinates based on WGS84 datum. -72.9 -71.7 +42.7 +42.0 2003 2009 genus Acer species rubrum red maple genus Adelges species tsugae hemlock woolly adelgid genus Betula species lenta black birch genus Carex species spp. sedge genus Dennstaedtia species punctilobula hayscented fern genus Pinus species strobus white pine genus Rubus species spp. brambles 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

Ten hemlock-dominated stands in central Massachusetts that experienced logging during the previous 12 years were selected to examine the compositional, structural, and microenvironmental changes associated with logging, and their impact on ecosystem processes including N- mineralization, nitrification, and N-availability. Results were compared with ongoing measurements in nearby uninfested hemlock forests. Vegetation was sampled in two 400 m2 plots systematically located in the central portion of each harvest area. All remaining trees (stems greater than 8 cm dbh) were tallied by species and dbh and assigned a canopy position based on the amount of intercepted light received by the tree crown. Pre-harvest basal area was reconstructed allometrically using the following regression equation relating stump diameter to dbh: hemlock (y = 0.884x + 0.0003; r2=0.995) from a sample of 215 stems (Kizlinski et al. 2002). For all other species, equations from Wharton (1984) were used. All saplings (less than 8 cm dbh and greater than 1.4 m tall) were tallied by species in each plot while herb and shrub cover and seedling (less than 1.5 cm dbh) densities were determined in ten, 1-m2 subplots located randomly within the plot grid. Nitrogen mineralization was measured at 6-week intervals during the growing season with one set of cores left over winter from May 2004 to May 2005, using a modified core method. Soil inorganic N concentrations were determined colorimetrically with a Lachat 8500 flow-injection autoanalyzer (Lachat Instruments, Inc., Milwaukee, Wisconsin, USA) An assessment of forest floor N availability and mobility was determined at each soil subplot from mixed-bed cation + anion resin bags (IONAC NM-60, Sybron Chemicals Inc., Birmingham, NJ). Soil temperature at 1 and 5 cm depths were measured every hour using small, buried data loggers (iButton, Dallas Semiconductor Corp.) at each soil-sampling plot. Soils collected during our initial sampling at each site were also analyzed for pH in a soil and CaCl2 slurry (1:10 organic soil:solution; 1:4 mineral soil:solution), and total C and N content by dry combustion with a Fisons CHN autoanalyzer. Texture was determined on mineral soils using the hydrometer method.

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. hf128-01-site.csv site descriptions hf128-01-site.csv 580 f6ac7f09187e51931cf7171c0eb1317a 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-01-site.csv site.name name of site name of site owner name of owner name of owner site.code site code site code site.description description of when site logged description of when site logged 10 hf128-02-soil-temp.csv soil temperature hf128-02-soil-temp.csv 512182 efa49787256d7bf4a7622da8bd30bdd6 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-02-soil-temp.csv datetime date and time YYYY-MM-DDThh:mm 1 minute NA missing value date date YYYY-MM-DD 1 day NA missing value year year YYYY month month month NA missing value day day of year day hour hour (24 hour time) hh:mm llsf.o average hourly organic soil temperature, PLOT 1 and 2 (LLSF) celsius 0.01 real NA missing value llsf.m average hourly mineral soil temperature, PLOT 2(LLSF) celsius 0.01 real NA missing value mgsf.m average hourly mineral soil temperature, PLOT 2(MGSF) celsius 0.01 real NA missing value mgsf.o average hourly organic soil temperature, PLOT 3(MGSF) celsius 0.01 real NA missing value nssf.o average hourly organic soil temperature, PLOT 3(NSSF) celsius 0.01 real NA missing value nssf.m average hourly mineral soil temperature, PLOT 4(NSSF) celsius 0.01 real NA missing value lero.o average hourly organic soil temperature, PLOT 4(LERO) celsius 0.01 real NA missing value lero.m average hourly mineral soil temperature, PLOT 5(LERO) celsius 0.01 real NA missing value heca.o average hourly organic soil temperature, PLOT 5(HECA) celsius 0.01 real NA missing value heca.m average hourly mineral soil temperature, PLOT 6(HECA) celsius 0.01 real NA missing value egbr.o average hourly organic soil temperature, PLOT 6(EGBR) celsius 0.01 real NA missing value egbr.m average hourly mineral soil temperature, PLOT 7(EGBR) celsius 0.01 real NA missing value swri.o average hourly organic soil temperature, PLOT 7(SWRI) celsius 0.01 real NA missing value swri.m average hourly mineral soil temperature, PLOT 8(SWRI) celsius 0.01 real NA missing value hahi.o average hourly organic soil temperature, PLOT 8(HAHI) celsius 0.01 real NA missing value hahi.m average hourly mineral soil temperature, PLOT 8(HAHI) celsius 0.01 real NA missing value atho.o average hourly organic soil temperature, PLOT 8(ATHO) celsius 0.01 real NA missing value atho.m average hourly mineral soil temperature, PLOT 8(ATHO) celsius 0.01 real NA missing value grla.o average hourly organic soil temperature, PLOT 8(GRLA) celsius 0.01 real NA missing value grla.m average hourly mineral soil temperature, PLOT 8(GRLA) celsius 0.01 real NA missing value 4419 hf128-03-soil-moisture.csv soil moisture hf128-03-soil-moisture.csv 17260 c25788f55325eddcc617466e12b4255d 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-03-soil-moisture.csv site site code (see site descriptions) site code age number of years since harvest at the time of the study (1-12) number of years since harvest at the time of the study (1-12) series series series month month soil sample was collected month soil sample was collected NA missing value subplot number of 1 x 1 m subplot within each plot ( n = 10) number of 1 x 1 m subplot within each plot ( n = 10) o.m soil horizon O organic M mineral moisture total evaporable moisture content of sample gram 0.01 real NA missing value 768 hf128-04-soil-chemistry.csv soil chemistry hf128-04-soil-chemistry.csv 5411 b7a53f78ba797ba17896d87f250a38f2 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-04-soil-chemistry.csv site site code (see site descriptions) site code plot number of 20 x 20 m plot in each site (n=2) number of 20 x 20 m plot in each site (n=2) subplot number of 1 x 1 m subplot within each plot ( n = 10) number of 1 x 1 m subplot within each plot ( n = 10) o.m soil horizon O organic M mineral ph soil pH dimensionless 0.01 real NA missing value n sample content percent nitrogen dimensionless 0.01 real NA missing value c sample content percent carbon dimensionless 0.01 real NA missing value c.n sample carbon:nitrogen ratio (C/N) dimensionless 0.01 real NA missing value 160 hf128-05-resin.csv resin bags hf128-05-resin.csv 5298 a20d6141b112b9f198b3d5bd303d0220 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-05-resin.csv gs.ow resin bags are deployed in the soil for the growing season (May-Oct) or over winter (Oct-May). GS growing season ow over winter site site code (see site descriptions) site code subplot number of 1 x 1 m subplot within each plot ( n = 10) number of 1 x 1 m subplot within each plot ( n = 10) nh4.n nitrogen in the form of ammonium in solution milligramsPerLiter 0.01 real NA missing value no3.n nitrogen in the form of nitrate in solution extract milligramsPerLiter 0.01 real NA missing value nh4.n.r nitrogen in the form of ammonium captured in resin (ug/g resin) microgramsPerGram 0.01 real NA missing value no3.n.r nitrogen in the form of nitrate captured in resin (ug/g resin) microgramsPerGram 0.01 real NA missing value 153 hf128-06-nitrogen.csv nitrogen mineralization hf128-06-nitrogen.csv 27466 df3ffc9c72e0ba12d8fc67bdc3a42640 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-06-nitrogen.csv site site code (see site descriptions) site code core.in date the core was placed in the study site YYYY-MM-DD core.out date the core was extracted from the study site YYYY-MM-DD subplot subplot where the core was located subplot where the core was located horizon soil horizon O organic M mineral net.nh4.n net ammonia kilogramsPerHectare 0.01 real NA missing value net.ho3.n net nitrate kilogramsPerHectare 0.01 real NA missing value 640 hf128-07-herb.csv herbs and ferns hf128-07-herb.csv 65508 276ba6745206374d63b777a435701dd5 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-07-herb.csv site site code (see site descriptions) site code (see site descriptions) plot number for 20 x 20 m plot within each site (n = 2) number for 20 x 20 m plot within each site (n = 2) subplot number of 1 x 1 m subplot within each plot ( n = 10) number of 1 x 1 m subplot within each plot ( n = 10) species species code, listed by 4 letter abbreviation (see species codes) species code cover percent herb cover to the nearest 0.5% within 1 x 1 m subplot for each species dimensionless 0.1 real NA missing value 3800 hf128-08-shrub.csv shrubs hf128-08-shrub.csv 37750 415ced7d13cfcbfafccaa653a18a788e 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-08-shrub.csv site site code (see site descriptions) site code (see site descriptions) plot number for 20 x 20 m plot within each site (n = 2) number for 20 x 20 m plot within each site (n = 2) subplot number of 1 x 1 m subplot within each plot ( n = 10) number of 1 x 1 m subplot within each plot ( n = 10) species species code, listed by 4 letter abbreviation (see species codes) species code cover percent shrub cover to the nearest 0.5 % within 1 x 1 m subplot for each species dimensionless 0.1 real NA missing value 2200 hf128-09-seedling-cov.csv seedling cover hf128-09-seedling-cov.csv 41303 338d37fd372d016b3191f408892ce39c 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-09-seedling-cov.csv site site code (see site descriptions) site code (see site descriptions) plot number for 20 x 20 m plot within each site (n = 2) number for 20 x 20 m plot within each site (n = 2) subplot number of 1 x 1 m subplot within each plot ( n = 10) number of 1 x 1 m subplot within each plot ( n = 10) species species code, listed by 4 letter abbreviation (see species codes) species code cover percent seedling cover to the nearest 0.5 % within 1 x 1 m subplot for each species dimensionless 0.1 real NA missing value 2400 hf128-10-seedling-den.csv seedling density hf128-10-seedling-den.csv 41114 b1865ae9db30b2edcfebdc16354e261b 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-10-seedling-den.csv site site code (see site descriptions) site code (see site descriptions) plot number for 20 x 20 m plot within each site (n = 2) number for 20 x 20 m plot within each site (n = 2) subplot number of 1 x 1 m subplot within each plot ( n = 10) number of 1 x 1 m subplot within each plot ( n = 10) species species code, listed by 4 letter abbreviation (see species codes) species code density seedling densities within 1 x 1 m subplot for each species numberPerMeterSquared 1 whole NA missing value 2400 hf128-11-stump.csv stumps hf128-11-stump.csv 7600 a7da26683de56f683a3c090b2985b31d 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-11-stump.csv site site code (see site descriptions) site code plot number of 20 x 20 m plot in each site (n=2) number of 20 x 20 m plot in each site (n=2) species 4 letter species code of tree cut 4 letter species code of tree cut diameter diameter of cut stump centimeter 0.1 real NA missing value 425 hf128-12-species-code.csv species codes hf128-12-species-code.csv 1027 85d1e6913ba6021217942e3ef92c489e 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p12/hf128/hf128-12-species-code.csv code species codes consist of first two letters of Latin genus and species species code name full Latin names according to Gleason and Cronquist full Latin names according to Gleason and Cronquist 43 conservation invasive regional short-term measurement 2 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf082