uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/e4f2858e322293b5d45abb26eabdf558 David Orwig https://orcid.org/0000-0001-7822-3560 David Foster https://orcid.org/0000-0003-1171-3762 Richard Cobb Researcher Matthew Kizlinski Researcher Laura Barbash Researcher 2023 English

This study compares the magnitude and trajectory of vegetation and ecosystem function dynamics associated with the direct impact of hemlock woolly adelgid (Adelges tsugae; HWA) infestation versus the indirect consequences of HWA-induced damage in the form of salvage and pre-emptive logging of hemlock (Tsuga canadensis (L.) Carriere) forests. The study was conducted within an area extending from southern Connecticut up to and including the Connecticut River lowlands west to the Berkshire Plateauin central Massachusetts, USA. Overstory and understory vegetation and ecosystem function parameters such as decomposition and nitrogen cycling were examined in logged and unlogged portions of 10 hemlock stands varying in HWA damage intensity. Intensive hemlock logging generated more rapid and pronounced microenvironment and vegetation changes than chronic HWA damage. Black birch (Betula lenta L.) seedling densities and percent cover of brambles (Rubus L. spp.), sedges (Carex L. spp.) and hay-scented fern (Dennstaedtia punctilobula Michx.) were significantly higher in recent harvests versus HWA-damaged and undamaged sites. High black birch sapling densities (greater than 7000 ha –1) were common in the older harvests but not in adjacent, HWA-damaged portions of these sites. Undamaged sites had 20% more forest floor mass than HWA-damaged sites and double the mass of older cuts. Mass loss rates of cellulose paper suggest that conditions were more favorable for decomposition in the damaged and older logged sites. Recently cut sites had significantly larger inorganic N pools than undamaged forests, although total net nitrogen (N) mineralization rates were not significantly different among treatments. Nitrification rates of 0.2 kg ha-1 day-1 measured in the oldest cuts were three times greater than in HWA-damaged sites and over 200 times greater than in undamaged hemlock sites. However, resin bag capture in the older cuts was similar to amounts captured in undamaged and damaged forests, suggesting that excess nitrogen was being utilized in vegetative uptake. In contrast, relatively large amounts of ammonium and nitrate captured in recent harvests indicate higher N availability, less vegetative uptake, and a greater potential for N leaching. Results suggest that both the decline associated with HWA infestation and the indirect effects of HWA in the form of logging are generating profound changes in structure, composition, and ecosystem function in these forests, although at different spatial and temporal scales. Hemlock harvesting imposed more abrupt microenvironmental changes, and rapidly reduced vegetative cover while chronic HWA infestation led to gradually thinning canopies. Both disturbances led to black birch dominated forests, although logging resulted in greater amounts of shade-intolerant regeneration, higher soil pH and nitrification rates, and reduced forest floor mass. Preemptive cutting of undamaged forests may lead to greater N losses than those associated with HWA infestation or logging of deteriorated hemlock forests, due to reduced vegetative uptake. Silvicultural methods that allow for vegetation establishment prior to harvesting will likely lessen the ecological impacts of hemlock removal.

ammonium hemlock hemlock woolly adelgid nitrate nitrification nitrogen mineralization timber harvest LTER controlled vocabulary inorganic nutrients disturbance land use 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=hf082 Central Connecticut. Coordinates based on WGS84 datum. -73.2 -72.2 +41.9 +41.4 1999 2005 genus Adelges species tsugae hemlock woolly adelgid genus Betula species lenta black birch genus Carex spp. sedge genus Dennstaedtia species punctilobula hayscented fern genus Rubus 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

Transects were established in the most heavily cut area and in the nearest unlogged portion of each stand. Vegetation was sampled in 5 to 10 circular plots (78.5 m2) located every 20 m along these transects. Woody stems greater than or equal to 1.5 cm diameter at breast height (dbh; 1.37 m) were recorded by species, dbh, and crown position. Pre-harvest basal area was reconstructed allometrically using a regression equation relating stump diameter to dbh (y = 0.884x + 0.0003; r2=0.995) from a sample of 215 stems. Species, dbh, and probable mechanism of injury were noted for dead trees in harvest plots. Sapling (1.5 to 9.9 cm dbh) heights for each species were estimated in each plot. Herb and shrub cover was estimated in three, 1x1 m subplots located in random directions 3 m from each plot center. Seedling (less than 1.5 cm dbh) densities were also tallied in each subplot. Nitrogen (N) mineralization was measured with two consecutive 10-week incubations (May-July and July-September 2000) using an intact, closed-topped core method. Forest floor and mineral soil samples were homogenized by sieving (5.6 mm pore size), weighed for total mass, and sub sampled for gravimetric moisture content. Inorganic NH4-N and NO3-N concentrations were determined colorimetrically with a Lachat AE flow injection analyzer. Ion exchange resin bags were used to passively intercept inorganic N in soil solution. To characterize forest floor decomposition environment among sites, mass loss of a standard cellulose paper substrate was determined after 20 weeks.

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. hf082-01-sites.csv site descriptions hf082-01-sites.csv 1142 525527086eed7e7a4da41d39000da268 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-01-sites.csv site site code site code plot.nums range of plot numbers for each site range of plot numbers for each site site.name site description site description trans.desc transect description transect description 20 hf082-02-environ.csv environmental conditions hf082-02-environ.csv 1769 9cfa62bedf2eed29e945acbded67390c 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-02-environ.csv site site code (see site descriptions) site code plot number of plot where measurements were collected (10 sites x 10 plots/site =100 plots) number of plot where measurements were collected canopy.open percent open sky from hemispherical photographs analyzed with Gap Light Analyzer dimensionless 0.1 real NA missing value paper.loss percent mass loss of cellose filter paper (2 sheets Whatman No. 1, ~ 3 g) after 20 weeks of incubation in the field dimensionless 0.1 real NA missing value 100 hf082-03-soil.csv soil properties hf082-03-soil.csv 14948 b9316b5f35b4a9e1a1ac722c0d4d3299 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-03-soil.csv site site code (see site descriptions) site code treatment treatment type where sample was taken cut cut forest intact intact forest plot number of plot where measurements were collected (10 sites x 10 plots/site =100 plots) number of plot where measurements were collected horizon soil horizon M mineral soil O forest floor material excluding freshly fallen litter loi200 percent organic matter by weight, determined by 4 hours at 550C, with soil collected in the spring (200 series) dimensionless 0.01 real NA missing value loi400 percent organic matter by weight, determined by 4 hours at 550C, with soil collected in the summer (400 series). Loss on ignition was not done on the fall (600 series) collection. dimensionless 0.01 real NA missing value moisture200 gravimetric moisture of spring collection calculated as: (W-D)/D * 100 where W = mass of fresh soil sample, D= mass of soil sample dried at 105C for 48 h number 0.01 real NA missing value moisture400 gravimetric moisture of summer collection number 0.01 real NA missing value moisture600 gravimetric moisture of fall collection number 0.01 real NA missing value core200 dry mass of soil spring collection core after passed through No.3 ½ sieve gram 0.01 real NA missing value core400 dry mass of soil summer collection core after it passed through No.3 ½ sieve gram 0.01 real NA missing value core600 dry mass of soil fall collection core after it passed through No.3 ½ sieve gram 0.01 real NA missing value waterph pH of soil in water (1 g mineral soil: 4 mL water; 1 g forest floor:10 mL water) number 0.01 real NA missing value cacl2ph pH of soil in 0.01 M CaCl2 (1 g mineral soil: 4 mL CaCl2; 1 g forest floor:10 mL CaCl2) number 0.01 real NA missing value 200 hf082-04-resin.csv resin bags hf082-04-resin.csv 3723 6122068ce46524061fbd23c740678c92 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-04-resin.csv site site code (see site descriptions) site code treatment treatment type where sample was taken cut cut forest intact intact forest plot plot number. Each transect had 5-8 plot centers. Three additional bags per transect were installed between the plots. plot number nh4 mg ammonium nitrogen per g resin milligramPerGram 0.1 real NA missing value no3 mg nitrate nitrogen per g resin (mg g-1) milligramPerGram 0.1 real NA missing value 160 hf082-05-nitrogen.csv nitrogen mineralization hf082-05-nitrogen.csv 135080 70b34ad7cf724c3637207a6311dabf02 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-05-nitrogen.csv site site code (see site descriptions) site code treatment treatment type where sample was taken cut cut forest intact intact forest plot number of plot where measurements were collected (10 sites x 10 plots/site =100 plots) number of plot where measurements were collected horizon soil horizon m mineral soil o forest floor material excluding freshly fallen litter sample sample collected 200NH4KG/HA kg ha-1 ammonium nitrogen pool, spring collection 400NH4KG/HA kg ha-1 ammonium nitrogen pool, summer collection 600NH4KG/HA kg ha-1 ammonium nitrogen pool, fall collection >200NO3KG/HA kg ha-1 nitrate nitrogen pool, spring collection 400NO3KG/HA kg ha-1 nitrate nitrogen pool, summer collection 600NO3KG/HA kg ha-1 nitrate nitrogen pool, fall collection 200NH4MG/KG mg kg-1 ammonium nitrogen pool, spring collection 400NH4MG/KG mg kg -1 ammonium nitrogen pool, summer collection 600NH4MG/KG mg kg -1 ammonium nitrogen pool, fall collection 200NO3MG/KG mg kg -1 nitrate nitrogen pool, spring collection 400NO3MG/KG mg kg -1 nitrate nitrogen pool, summer collection 600NO3MG/KG mg kg -1 nitrate nitrogen pool, fall collection 100NH4KG/HA kg ha-1 ammonification, first 10-week incubation (May-July 2000) 100NO3KG/HA kg ha-1 nitrification, first 10-week incubation (May-July 2000 300NH4KG/HA kg ha-1 ammonification, second 10-week incubation (July-Oct 2000) 300NO3KG/HA kg ha-1 nitrification, second 10-week incubation (July-Oct 2000) 100NH4MG/KG mg kg -1 ammonification, first 10-week incubation (May-July 2000) 100NO3MG/KG mg kg -1 nitrification, first 10-week incubation (May-July 2000 300NH4MG/KG mg kg -1 ammonification, second 10-week incubation (July-Oct 2000) 300NO3MG/KG mg kg -1 nitrification, second 10-week incubation (July-Oct 2000) nmin Nmin, measurement and units defined in "Sample" dimensionless 0.01 real NA missing value 4000 hf082-06-carbon.csv carbon and nitrogen hf082-06-carbon.csv 969 1afffc9ca11c05882d5ef66df58bbdb0 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-06-carbon.csv site site code (see site descriptions) site code treatment treatment type where sample was taken cut cut forest intact intact forest horizon soil horizon m mineral soil below forest floor down to 15 cm (length of sample core) o forest floor excluding freshly fall leaves and twigs n percent nitrogen by weight dimensionless 0.01 real NA missing value c percent carbon by weight dimensionless 0.01 real NA missing value 40 hf082-07-decomp.csv lab decomposition hf082-07-decomp.csv 2181 49bfab7e0cf9d15c7f252d5e247a0fab 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-07-decomp.csv site site code (see site descriptions) site code treatment treatment type where sample was taken cut cut forest intact intact forest tray tray code. The material was split in half into two identical trays. tray code start percent organic matter at the beginning of the experiment dimensionless 1 whole NA missing value week5 percent organic matter remaining after 5 weeks dimensionless 0.01 real NA missing value week10 percent organic matter remaining after 10 weeks dimensionless 0.01 real NA missing value week15 percent organic matter remaining after 15 weeks dimensionless 0.01 real NA missing value week20 percent organic matter remaining after 20 weeks dimensionless 0.01 real NA missing value week25 percent organic matter remaining after 25 weeks dimensionless 0.01 real NA missing value week30 percent organic matter remaining after 30 weeks dimensionless 0.01 real NA missing value 40 hf082-08-herb.csv herb and shrub cover hf082-08-herb.csv 414592 309bac816b71920eb0d7b609ae10d40b 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-08-herb.csv site site code (see site descriptions) site code treatment treatment type where sample was taken cut cut forest intact intact forest plot plot number. Each transect had 5-8 plot centers plot number sub subplot code. Each plot had 3 randomly place subplots (A, B, C) subplot code cwd percent cover of coarse woody debris dimensionless 1 whole NA missing value cwd.height average height of CWD centimeter 1 whole NA missing value species species code species code cover percent cover of herbs and shrubs at each 1x1 m subplot to the nearest 1% dimensionless 1 whole NA missing value 15048 hf082-09-seed-cov.csv seedling cover hf082-09-seed-cov.csv 135909 f57debfc50daa3ccb604c4da7eda9028 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-09-seed-cov.csv site site code (see site descriptions) site code treatment treatment type where sample was taken cut cut forest intact intact forest plot plot number. Each transect had 5-8 plot centers plot number sub subplot code. Each plot had 3 randomly place subplots (A, B, C) subplot code species species code species code cover percent cover of seedlings for each 1x1 meter subplot. Individuals were considered seedlings if dbh was less than 1.5 cm. Individuals did not have to be growing in the subplot to be measured. dimensionless 1 whole NA missing value 6156 hf082-10-seed-dns.csv seedling density hf082-10-seed-dns.csv 135791 25fcf8134db8339ca49eca3d61a05f19 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p08/hf082/hf082-10-seed-dns.csv site site code (see site descriptions) site code treatment treatment type where sample was taken cut cut forest intact intact forest plot plot number. Each transect had 5-8 plot centers plot number sub subplot code. Each plot had 3 randomly place subplots (A, B, C) subplot code species species code species code count number of individuals growing in each 1x1 meter subplot. Individuals were considered seedlings if dbh was less than 1.5 cm number 1 whole NA missing value 6156 conservation invasive regional long-term measurement https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf128 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf021 milligramPerGram milligramPerKilogram