uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read Joshua Rapp https://orcid.org/0000-0002-7767-5837 Elizabeth Crone Kristina Stinson Iris Le Ronce Researcher 2025 English

Seed production assures the persistence of tree populations and forest cover over the long-term, and so has long interested plant demographers and foresters. Many forest tree species produce seeds synchronously and at irregular intervals across large areas, a phenomenon known as masting. Initiated in spring 2011, this study addresses the mechanisms of mast seeding in sugar maple (Acer saccharum), and its impact on pollinators, seed consumers, and forest carbon dynamics at the Harvard Forest. We monitor seed production (via counts of seeds on trees), flower production, and resource status (via sap collection) on 20 trees. Pollinator dynamics and seed predation (by weevils) are also monitored. In 2015, we added sap and seed monitoring of red maple (Acer rubrum) trees to explore the hypothesis that this non-masting species would have muted dynamics compared to its masting congener.

primary production populations LTER core area flowering leaves maple masting seed production LTER controlled vocabulary 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=hf285 Prospect Hill Tract (Harvard Forest). Coordinates based on WGS84 datum. -72.19 -72.19 +42.53 +42.53 340 340 meter 2011 2024 genus Acer species rubrum red maple species saccharum sugar maple ongoing 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

We have monitored reproductive effort since 2011 and NSC in xylem sap since 2012 at Harvard Forest. We monitor nonstructural carbohydrates in xylem sap by tapping 20 trees using traditional gravity tapping methods, following accepted guidelines (Heiligmann et al. 2006). In late February when temperatures rise above freezing during the day, 5/16 inch diameter holes are drilled into trees and 5/16” spiles inserted into the holes. Trees greater than 20 inches in diameter are fitted with two spiles, located on opposite sides of the tree. Xylem sap is collected from February through early April, on all days when there is sap flow (generally when temperatures during the day rise above the freezing point of water). At each collection, sap is weighed and the sugar content measured for each tap hole.

Reproductive effort is evaluated are both flowering and fruiting stages. During flowering (late-April through early May) we qualitatively evaluate flowering effort of each tree (low - fewer than 1,000 flowering buds; medium – 1000-10000 flowering buds; high - more than 10,000 flowering buds) and evaluate whether trees have only male flowers or have both male and female flowers, and if so, which sex is mature first on the tree. From 2011-2014 we also sampled 9 branches from each tree (3 from upper canopy, 3 from mid-canopy, and 3 from lower-canopy) and counted the number of male and female flowers in each bud originating from the last two year’s growth of the main twig. We also counted the number of leaves originating from each bud. For these collections we also measured the length in millimeters of the last two year’s growth of the main twig. In the spring of 2011-2014 we also marked branches with and without flowers that we returned to in the fall. When seeds were mature, we collected these branches and counted the number of leaves on the terminal twig, the total leaf area, the length of twig growth, and the number of samaras for flowering twigs. We also examined the status of the samaras collected and seed predation by evaluating whether they were empty, or contained a filled seed, grub, exit hole, or a non-viable seed that was wrinkled, small, or moldy. We examine pollination by insects (mainly andrenid bees) by installing pollinator exclusion bags on 3 branches of 3-5 trees each spring during flowering. In the fall, we collect the bagged twigs, as well as nearby control twigs (marked in the spring) and evaluate samaras as above. To evaluate whole tree seed production, we make timed counts of seeds across the canopy using binoculars in late summer (Koenig et al. 1994). Crone and Rapp each count the number of seeds they observe in 15 seconds. The two counts are summed and used as a metric of seed production for that tree.

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. hf285-01-maple-tap.csv maple tapping data hf285-01-maple-tap.csv 13307 326060418f20310d885373bc7e40a189 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-01-maple-tap.csv date date of data collection YYYY-MM-DD 1 day NA missing value tree tree identification number; prefix is either HF (for sugar maples) or HFR (for red maples) tree identification number; prefix is either HF (for sugar maples) or HFR (for red maples) NA missing value tap A or B for trees with 2 taps; consistent within years but not between years A or B for trees with 2 taps; consistent within years but not between years NA missing value species tree species ACSA Acer saccharum ACRU Acer rubrum NA missing value dbh diameter at 1.4 m above ground centimeter 0.1 real NA missing value tap_bearing compass bearing of tap hole, facing into the tree degree 1 whole NA missing value tap_height tap height above ground centimeter 1 natural NA missing value 382 hf285-02-maple-sap.csv sap collection data hf285-02-maple-sap.csv 364956 e71a991c10ad3958f8ad2cdd2d4a16a5 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-02-maple-sap.csv date date of data collection YYYY-MM-DD 1 day NA missing value tree tree identification number; prefix is either HF (for sugar maples) or AR (for red maples) tree identification number; prefix is either HF (for sugar maples) or HFR (for red maples) NA missing value tap A or B for trees with 2 taps; consistent within years but not between years A or B for trees with 2 taps; consistent within years but not between years NA missing value time time of sap collection; recorded for each tap in 2012, at beginning and end of collection period thereafter hh:mm 1 minute NA missing value datetime date and time of sap collection; recorded for each tap in 2012, at beginning and end of collection period thereafter YYYY-MM-DDThh:mm 1 minute NA missing value sugar sugar concentration measured in Brixx (weight percent) with Misco digital refractometer of sap collected directly from tap dimensionless 0.1 real NA missing value species tree species ACSA Acer saccharum ACRU Acer rubrum NA missing value sap_wt weight of sap collected kilogram 0.01 real NA missing value 9022 hf285-03-maple-flower-qual.csv flowering data, whole tree hf285-03-maple-flower-qual.csv 5025 0d80a272ff8d904dd159ff85c9b94ded 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-03-maple-flower-qual.csv year year of observation YYYY 1 year NA missing value tree_num tree identification number tree identification number NA missing value first_sex first flower sex to mature on tree F female M male NF nonflowering MO male-only NA missing value flowering_intensity qualitative evaluation of whole-tree flowering low generally <1,000 flowering buds medium generally 1,000-10,000 flowering buds high generally >10,000 flowering buds none no flowering buds NA missing value 272 hf285-04-maple-flower.csv flowering data, twigs hf285-04-maple-flower.csv 188375 ea1ce613be8e2c7661d9f9f396091062 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-04-maple-flower.csv date data twig sample collected YYYY-MM-DD 1 day NA missing value tree tree identification number tree identification number NA missing value branch branch identification code (A-I) branch identification code (A-I) NA missing value canopy_strata location in the canopy (lower, middle, upper) location in the canopy (lower, middle, upper) NA missing value internode_year age of main twig internode from which the focal twig/bud originated number 1 natural NA missing value internode_num when 2 terminal twigs (i.e. a bifurcation), identification code to differentiate the two when 2 terminal twigs (i.e. a bifurcation), identification code to differentiate the two NA missing value bud_num bud identification number, ordered sequentially from terminal bud in bud identification number, ordered sequentially from terminal bud in NA missing value bud_pos position of bud on twig - terminal, sub-terminal, side (S# indicates number of side bud pair from terminal) T terminal ST sub-terminal Free text (unrestricted) .* NA missing value num_male count of male flowers in bud number 1 whole NA missing value num_female count of female flowers in bud number 1 whole NA missing value num_unknown count of flowers for which sex could not be determined number 1 whole NA missing value leaves whether or not leaves were present Y leaves present N leaves not present NA missing value num_leaves number of leaves originating in bud number 1 whole NA missing value 4026 hf285-05-maple-spring-branch.csv spring branch growth hf285-05-maple-spring-branch.csv 28157 f14ca3d0b194a980a853a1c996cf3eb6 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-05-maple-spring-branch.csv year year of observation YYYY 1 year NA missing value tree tree identification number tree identification number NA missing value branch branch identification code (A-I) branch identification code (A-I) NA missing value internode_year age of main twig internode from which the focal twig/bud originated number 1 natural NA missing value internode_num when 2 terminal twigs (i.e. a bifurcation), identification code to differentiate the two when 2 terminal twigs (i.e. a bifurcation), identification code to differentiate the two NA missing value internode_length length of main twig internode millimeter 0.1 real NA missing value num_buds number of buds originating from that internode number 1 whole NA missing value 1182 hf285-06-maple-fall-branch.csv fall leaf and twig growth and samara production hf285-06-maple-fall-branch.csv 132910 878b5eb1a6055ae462c936dc60c43d65 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-06-maple-fall-branch.csv date data branches collected YYYY-MM-DD NA missing value tree tree identification number tree identification number NA missing value branch branch identification code (A-I) branch identification code (A-I) NA missing value treatment treatment FL flowering NF non-flowering FR flowers removed, 2013 only NA missing value internode_year age of main twig internode from which the focal twig/bud originated number 1 whole NA missing value internode_num when 2 terminal twigs (i.e. a bifurcation), identification code to differentiate the two when 2 terminal twigs (i.e. a bifurcation), identification code to differentiate the two NA missing value internode_length length of main twig internode millimeter 1 natural NA missing value leaves number of leaves on terminal twig number 1 natural NA missing value leaves_missing number of pedicel scars indicating missing leaves number 1 natural NA missing value leaf_area total leaf area measured using a LI-3100 squareCentimeters 0.0000001 real NA missing value num_samaras number of samaras on terminal twig number 1 whole NA missing value 3082 hf285-07-maple-seedfilling.csv samara evaluation hf285-07-maple-seedfilling.csv 4703 3d5ed57f193ab3e843c0c25355533dde 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-07-maple-seedfilling.csv year year of observation YYYY 1 year NA missing value tree tree identification number tree identification number NA missing value branch branch identification code (A-I) branch identification code (A-I) NA missing value num_filled count of samaras with mature (or near-mature) seeds number 1 whole NA missing value num_empty count of empty samaras (no seeds) number 1 whole NA missing value num_grub count of samaras with grub present (likely had a seed that the grub ate; samara pair usually has frass) number 1 whole NA missing value num_wrinkle count of samaras with deformed seeds (likely still pollinated) number 1 whole NA missing value num_small count of samaras with small seeds (could be lumped with wrinkled) number 1 whole NA missing value num_moldy count of samaras that are moldy inside (likely because grub exited and frass colonized by mold) number 1 whole NA missing value num_exit count of samaras with evidence of weevils (frass, exit hole) but no weevil currently) number 1 whole NA missing value 172 hf285-08-maple-pollen-excl.csv samara evaluation, pollinator exclusion bag hf285-08-maple-pollen-excl.csv 6340 faa443dadbc687635083388041f42f5b 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-08-maple-pollen-excl.csv year year of observation YYYY 1 year NA missing value tree tree identification number tree identification number NA missing value branch branch identification code (A-I) branch identification code (A-I) NA missing value treatment treatment control open pollination exclusion pollinator exclusion bag installed during flowering NA missing value num_filled count of samaras with mature (or near-mature) seeds number 1 whole NA missing value num_empty count of empty samaras (no seeds) number 1 whole NA missing value num_grub count of samaras with grub present (likely had a seed that the grub ate; samara pair usually has frass) number 1 whole NA missing value num_wrinkle count of samaras with deformed seeds (likely still pollinated) number 1 whole NA missing value num_small count of samaras with small seeds (could be lumped with wrinkled) number 1 whole NA missing value num_moldy count of samaras that are moldy inside (likely because grubl exited and frass colonized by mold) number 1 whole NA missing value num_exit count of samaras with evidence of weevils (frass, exit hole) but no weevil currently) number 1 whole NA missing value num_missing in 2012, seeds were collected in late September, and some samaras were missing (i.e. only one of a pair present) number 1 whole NA missing value 159 hf285-09-maple-seed-count.csv samara pairs count hf285-09-maple-seed-count.csv 8360 6aac46b4f66d68b6417bdef263c6f25c 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-09-maple-seed-count.csv tree tree identification number tree identification number date date counts occurred YYYY-MM-DD 1 day NA missing value ec_count Elizabeth Crone's samara pairs count for the tree number 1 whole NA missing value jr_count Josh Rapp's samara pairs count for the tree number 1 whole NA missing value total_count EC and JR samara pairs counts added together number 1 whole NA missing value note note note 280 hf285-10-leaf-removal.csv leaf removal data hf285-10-leaf-removal.csv 4579 56d6f9877ddc1f6fed2030721afcf3e5 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-10-leaf-removal.csv year year of measurements YYYY 1 year NA missing value tree tree identification number tree identification number NA missing value branch branch identification code (1-3) branch identification code (1-3) NA missing value treatment treatment control control leaf.removal leaf removal NA missing value num_flowering number of buds on twig without flowers (measured in spring) number 1 whole NA missing value num_notflowering number of buds on twig without flowers (measured in spring) number 1 whole NA missing value num_buds_w_samaras number of buds on twig with samaras (measured in fall) number 1 whole NA missing value num_samaras number of samaras on twig (measured in fall) number 1 whole NA missing value num_petioles number of samara petioles missing the samaras (measured in fall) number 1 whole NA missing value 126 hf285-11-leaf-removal-branches.csv leaf removal treatment, twig growth data hf285-11-leaf-removal-branches.csv 5026 eb4ae8848bbe24a86841510ab57b8c4d 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-11-leaf-removal-branches.csv tree tree identification number tree identification number NA missing value branch branch identification code (1-3) branch identification code (1-3) NA missing value treatment treatment control control leaf removal leaf removal NA missing value growth_year year of twig growth the length measurement corresponds to YYYY 1 year NA missing value internode_length length of the twig internode millimeter 0.1 real NA missing value 184 hf285-12-leaf-seed-removal.csv leaf and seed removal data hf285-12-leaf-seed-removal.csv 4016 19697b9463779d72d4760dac8bdfc2cb 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-12-leaf-seed-removal.csv year year of measurements YYYY 1 year NA missing value tree tree identification number tree identification number NA missing value branch branch identification code (1-3) branch identification code (1-3) NA missing value treatment treatment control control leaf removal leaf removal seed removal seed removal NA missing value num_flowering number of buds on twig with flowers (measured in spring) number 1 whole NA missing value num_notflowering number of buds on twig without flowers (measured in spring) number 1 whole NA missing value num_buds_w_samaras number of buds on twig with samaras (measured in fall) number 1 whole NA missing value num_samaras number of samaras on twig (measured in fall) number 1 whole NA missing value num_petioles number of samara petioles missing the samaras (measured in fall) number 1 whole NA missing value 108 hf285-13-leaf-seed-removal-branches.csv leaf and seed removal, branches data hf285-13-leaf-seed-removal-branches.csv 5915 6d869b27cf1bc1b0082917aba1be9147 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-13-leaf-seed-removal-branches.csv tree tree identification number tree identification number NA missing value branch branch identification code (1-3) branch identification code (1-3) NA missing value treatment treatment control control leaf removal leaf removal seed removal seed removal NA missing value growth_year year of twig growth the length measurement corresponds to YYYY 1 year NA missing value internode_length length of the twig internode millimeter 0.1 real NA missing value 214 hf285-14-perm-branches.csv branches data hf285-14-perm-branches.csv 3639 d488c46692c9dd3a1c00c3011e26ef82 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p28/hf285/hf285-14-perm-branches.csv year year of measurements YYYY 1 year NA missing value tree tree identification number tree identification number NA missing value branch branch identification code (A-C, new twigs to replace old twigs received new codes D-E) branch identification code (A-C, new twigs to replace old twigs received new codes D-E) NA missing value num_flowering number of buds on twig with flowers (measured in spring) number 1 whole NA missing value num_notflowering number of buds on twig without flowers (measured in spring) number 1 whole NA missing value num_buds_w_samaras number of buds on twig with samaras (measured in fall) number 1 whole NA missing value num_samaras number of samaras on twig (measured in fall) number 1 whole NA missing value num_petioles number of samara petioles missing the samaras (measured in fall) number 1 whole NA missing value 138 community long-term measurement