uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/3df68d6d84a5fd5b357363ac706ba50f Audrey Barker Plotkin https://orcid.org/0000-0002-4473-9785 Meghan Blumstein https://orcid.org/0000-0003-0905-6265 Danelle Laflower Researcher Greta VanScoy Researcher 2023 English

During the mid-late growing season of 2018, we established two study sites. We established plots in the Quabbin Watershed Forest (‘Forest’). Plots had varying defoliation severity, as classified by a published Landsat timeseries analysis (Pasquarella, V.J., Bradley, B.A, and Woodcock, C.E. 2017 Near-real-time monitoring of insect defoliation using Landsat time series. Forests 8(8), 275; doi:10.3390/f8080275.). Within plots, defoliation of oaks also varied. That is, even in lightly defoliated areas we observed a few oaks that were severely defoliated. We also tagged 85 individual oak trees from roadsides and hedgerows in and within 15 km of the mid-sized town of Amherst, Massachusetts (‘Town’). For each tree, we recorded diameter at breast height (DBH), species, and canopy position (1 = full sun; 2 = partially shaded; 3 = mostly/fully shaded). In the Forest plots, we recorded defoliation class (1 = 0-25% defoliated; 2 = 25-50% defoliated; 3 = 50-75% defoliated; 4 = 75-100% defoliated). For the Town trees, we estimated defoliation to the nearest 5%. These two sites were established independently and came together in Winter 2018-2019 for this study. From these sites, we selected 34 Forest trees (from four plots) and 47 Town trees for NSC sampling, representing a range of defoliation severity in 2018. Note: we did not use the data collected from Quabbin Plot 6, because these trees likely died prior to autumn 2018, nor did we use the ‘Harvard Forest’ site in our analyses. All selected trees were alive in late summer 2018, although some were predicted to die within a year based on a visual assessment of crown dieback. Secondary selection criteria included sampling a range of tree size and species. Diameter of the sample trees ranged from 15-69 cm at the Forest site (mean 49 cm) and from 12-66 cm at the Town site (mean 35 cm). Most of the oaks at the two sites were red oak (Quercus rubra L., n = 66) but we included white oak (Q. alba L., n = 15) to the extent it was available.

We sampled NSCs in February 2019, and again in February 2020. From each sample tree, we collected a 2 cm (under bark) sample of wood from: 1) the stem, at ~1.3 m height; and 2) a coarse root, at ~20 cm from the base of the tree. Samples were collected using a standard 4.3 mm diameter increment borer, stored on ice in the field, and then stored in a −80o C freezer until processing.

We assessed defoliation and/or dieback four times over the course of the study. At the initial defoliation assessment in late summer 2018, some of the Forest trees exhibited branch dieback and browning leaves. We recorded crown dieback and mortality status at leaf-out in May 2019, during June – August 2019 and in July – August 2020. A tree was presumed dead if it did not produce leaves; no tree that failed to leaf out in May 2019 produced leaves later that season or in 2020. Crown dieback was rated visually on a five-point scale (1 = 0-25 dieback; 2 = 25-50% dieback; 3 = 50-75% dieback; 4 = 75-99% dieback; 5 = dead). In 2019, we recorded defoliation by Lymantria dispar during their larval period from late May – early July. Despite high egg-mass counts in Fall 2018, high larval mortality in 2019 led to very low defoliation (Brown, 2019). There were few Lymantria dispar larvae and minimal defoliation in 2020.

Total NSC reserves were extracted from freeze-dried and ground woody tissue samples following the protocol of Landhäusser et al. (Landhäusser SM, Chow PS, Dickman LT, Furze ME, Kuhlman I, Schmid S, Wiesenbauer J, Wild B, Gleixner G, Hartmann H, et al. 2018. Standardized protocols and procedures can precisely and accurately quantify non-structural carbohydrates. Tree physiology 38: 1764–1778.). In brief, after grinding the wood samples using a Wiley mill and then a ball grinder, we extracted sugars from 30 mg of dried tissue using 80% hot ethanol, then read them using a phenolic colorimetric assay and a spectrophotometer at 490 nm (ThermoFisher Scientific Genesys 180 UV-Vis Spectrophotometer). The methodology extracted and quantified all soluble sugars in the samples, including glucose, sucrose, fructose, and other oligosaccharides and glucans. We included two internal laboratory standards (Q. rubra stem-wood) with each set of samples, with sets within 10% of the laboratory estimate (42 mg g-1) accepted. Starch was extracted from the tissue remaining after sugar extraction. We solubilized the tissue in NaOH, then incubated it with alpha-amylase and amyloglucosidase digestive enzymes, which digest starch into glucose. Solutions were assayed using a PGO-color reagent solution (Sigma Chemicals) and read on the spectrophotometer at 525 nm. Starch concentrations of mg glucose-starch-equivalent per g dry wood were calculated based on a glucose standard curve (Sigma Chemicals).

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. hf369-01-trees.csv trees hf369-01-trees.csv 9181 0ee2b78a27935483b7439c8f6510076f 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p36/hf369/hf369-01-trees.csv site site Amherst Town Harvard Forest Simes Quabbin Forest NA missing value plot plot name plot name NA missing value tree tree number. Unique identifier is combination of plot and tree tree number NA missing value tag tag number for Quabbin plot trees that are part of related permanent plot study tag number for Quabbin plot trees NA missing value point one of 3 variable-radius plot centers established in 2018 in the Quabbin plots one of 3 variable-radius plot centers established in 2018 in the Quabbin plots NA missing value species species Q. alba white oak Q. rubra northern red oak NA missing value dbh.cm diameter at breast height centimeter 0.1 real NA missing value can.exp canopy exposure 1 full sun 2 partially shaded 3 mostly/fully shaded NA missing value ref.class.18 defoliation class in 2018. Based on def.per.18 for the Amherst trees 1 0-25% defoliated 2 25-50% defoliated 3 50-75% defoliated 4 75-100% defoliated NA missing value def.per.18 percent defoliation in 2018; to nearest 5% for Amherst and mid-point of ref.class.18 for Quabbin dimensionless 0.1 real NA missing value n.egg.masses.18 number of Lymantria dispar egg masses counted in summer-fall 2018; 30 means more than 30 and 100 means WAY more than 30 number 1 whole NA missing value cond.19 condition D dead L live in 2019 NA missing value defol.2019 defoliation class in 2019 1 0-25% defoliated 2 25-50% defoliated 5 dead NA missing value dieback.2019 dieback classes 1 0-25% dieback 2 25-50% dieback 3 50-75% dieback 4 75-99% dieback 5 dead NA missing value notes.18 notes about the tree in 2018 notes about the tree in 2018 NA missing value notes.19 notes about the tree in 2019 notes about the tree in 2019 NA missing value ind_leaf_defoliation_S19 average herbivory percent based on a sample of 30 individual leaves from that tree; summer 2019; Amherst trees only dimensionless 0.00000001 real NA missing value defoliation_canopy_pct_F19 estimated percent defoliation; Amherst trees dimensionless 0.1 real NA missing value ind_leaf_defoliation_F19 average herbivory percent based on a sample of 30 individual leaves from that tree; fall 2019; Amherst trees only dimensionless 0.00000001 real NA missing value new_eggmasses_below2m_19 number of new Lymantria dispar egg masses counted in fall 2019 below 2 m on the tree dimensionless 1 whole NA missing value cond.20 condition in 2020 D dead L live NA missing value dieback.20 percent dieback in 2020 1 0-25% dieback 2 25-50% dieback 3 50-75% dieback 4 75-99% dieback 5 dead NA missing value note.20 notes about the tree in 2020 notes about the tree in 2020 NA missing value 94 hf369-02-nsc.csv nonstructural carbohydrates hf369-02-nsc.csv 35247 53564bf29ef81265aecde8100ebf205e 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p36/hf369/hf369-02-nsc.csv vial.id identifier for sample vial identifier for sample vial NA missing value site site Amherst Town Quabbin Forest Simes Harvard Forest NA missing value plot plot name plot name NA missing value tree_id unique identifier is combination of plot and tree unique identifier is combination of plot and tree NA missing value tissue root or stem root root stem stem NA missing value weight.mg sample weight milligram 0.01 real NA missing value sugar.perc.dw sugars in percent dry weight dimensionless 0.000000001 real NA missing value starch.perc.dw starch in percent dry weight dimensionless 0.000000001 real NA missing value tnc.perc.dw total nonstructural carbohydrates (sugars and starches) in percent dry weight dimensionless 0.000000001 real NA missing value date date that the sample was collected in the field YYYY-MM-DD 1 day NA missing value month month that the sample was collected in the field month that the sample was collected in the field NA missing value year year that the sample was collected in the field YYYY 1 year NA missing value note note about the sample note about the sample NA missing value 360 invasive community short-term measurement https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf344 https://harvardforest.fas.harvard.edu/exist/apps/datasets/showData.html?id=hf424