uid=HFR,o=lter,dc=ecoinformatics,dc=org all public read doi:10.6073/pasta/d8d6cdabff930d396e2c474e8595ce3c David Foster https://orcid.org/0000-0003-1171-3762 Audrey Barker Plotkin https://orcid.org/0000-0002-4473-9785 Walter Lyford Ann Lezberg Researcher 2023 English

Permanent forest plots provide an empirical understanding of forest change over time, and are an invaluable part of forestry and ecological research. Walter Lyford began measurements of a 2.88 ha red oak-red maple forest on the Prospect Hill Tract of Harvard Forest in 1969. All trees over 2 inches (5 cm) were mapped on very large-scale (1 inch = 5 feet) hand-drawn maps, and included live and dead trees, stumps, windthrows and other features such as stone walls, boulders, soil moisture and a damage boundary from the 1938 hurricane. All living and dead trees have been re-located and measured (diameter at breast height, canopy class for live trees; condition, decay class, diameter, bole length and stem orientation for fallen dead trees) in 1969, 1975, 1987-1992, 2001, and 2011. In 2001, the original, hand-drawn maps were digitized using ArcView GIS. From 1969 to 2011, red oak (Quercus rubra) increased its dominance of the stand’s total basal area from 52% to 60%; however, red maple (Acer rubrum) has become relatively less abundant, decreasing from 30% to 23%. While red oak and red maple continue to account for the majority of the basal area in the stand, the secondary species experienced a dramatic increase in relative abundance of individuals in the stand; yellow birch (Betula alleghaniensis), black birch (Betula lenta), American chestnut (Castanea dentata), American beech (Fagus grandifolia), witch hazel (Hamamelis virginiana), eastern white pine (Pinus strobus), and eastern hemlock (Tsuga canadensis) have increased from comprising 25% of the individuals in the stand in 1969 to comprising 52% in 2011. The total biomass of living individuals is increasing linearly (R2=0.99, p=0.0002), which implies that the stand has not yet experienced an age-induced decrease in biomass accumulation.

maple oak permanent plots soil tree maps vegetation dynamics LTER controlled vocabulary populations 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=hf032 Prospect Hill Tract (Harvard Forest). Coordinates based on WGS84 datum. -72.18 -72.18 +42.53 +42.53 345 345 meter 1969 2021 genus Acer species rubrum red maple genus Quercus species rubra red oak 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

Detailed tree maps were prepared by Walter Lyford over this 2.88 ha area between 1962-1969. Map accuracy is within 1-2 feet. Maps cover 32, 100x100 ft. blocks; each block is marked in the field with labeled wooden stakes. The entire site was censused in 1969 and 1975, between 1987 and 1992, 2001, and 2011. Blocks censused in 1987: SE61, SW60, SW61, SW62, SW70, SW71. Blocks censused in 1991: SE11, SE21, SE31, SE41, SE51, SW10, SW11, SW20, SW22, SW30, SW40, SW50, SW51. Blocks censused in 1992: SW00, SW01, SW21, SW31, SW32, SW33, SW34, SW41, SW42, SW43, SW44, SW52, SW53.

Each grid block was temporarily flagged around its boundaries with measuring tapes. It helped to use ones that had both feet and meters on it. We did not find it necessary to mark out 10ft. intervals with staked flags or divide the blocks into subsections. To locate individual trees, we used the ArcView maps created in 2001. We matched individuals in the field to the entries on the datasheets based on their coordinates, species, and historical measurements. We were able to successfully navigate through the blocks using these GIS maps, although it would be easier to see the numbers on the maps if they were shifted slightly, to avoid having overlapping numbers in instances where trees share a base. For each tree, data on dbh, canopy position (dominant, codominant, intermediate, or suppressed), and condition (living, dead, snapped, stump, rootbreak, windthrown, or windthrown and cut) were recorded. Diameter was measured with a diameter tape to the nearest 0.1cm, and was recorded in centimeters. Diameters of some dead and all fallen trees were recorded with calipers. When it was necessary to measure living trees with calipers, this was noted on the datasheets. A condition of "dead" was applied to all individuals with at least 4.5ft of stem still standing. For any length of standing bole less than 4.5ft, the tree was scored as snapped. For fallen stems (and the tops of standing dead trees, when the crown was easily evident on the ground), length in feet, orientation in degrees true north, and diameters were taken when possible. Both dead standing and fallen stems were assigned a decay class. A 3 tiered decay scale was used: D1=firm/solid, fresh, small twigs or stubs intact D2= partial decay, bark may be partially missing, bole may be broken but shape is still evident D3= decaying into ground/soil, crumbled, often fully or partially buried If the tree was cut by a beaver, it was listed as snapped for the condition, and the note "beaver" in the comments section. If a tree could not be located (almost always previously dead trees that had rotted away, and in a handful of instances, missing trees), the tree was scored as "gone." If a tree had been scored as "gone" previously, we did not attempt to relocate it. Comments included the orientation of leaning, living stems, the presence of basal and or trunk sprouts, and the presence of dead branches, top snaps, and dead leaders as necessary. Trees were marked with chalk to track progress. New trees (stems that had grown above 5cm dbh since the last census) were added to the dataset; diameter, canopy class, species, and condition were noted. Stems greater than 5 cm dbh that were fused to another individual, or growing as a vertical branch of a fallen prostrate tree were scored as new individuals. New individuals were marked with flagging. Coordinates were determined by measuring from a very nearby tree with known coordinates (within 1 ft), or by measuring the distance from the boundary tape to the individual. When these methods were not possible, the "INTERPNT method" of triangulation (Boose et al. 1998, Ecology 79:819-827) was used. Distances from the new tree to three nearby reference points (trees with known coordinates) were measured in the field in feet and later converted to meters. We checked approximately 26 trees in the field that either failed the first or second tolerance levels (0.3 meters and 1 meter, respectively) or returned a result of an open triangle. After one round of remeasurement, only three trees exceeded the 0.3m tolerance level, and a field check confirmed that the coordinates appeared to be accurate. Coordinates generated by INTERPNT were converted to the nearest half foot.

For downed dead trees, we added measurements of base and top diameter, to allow more accurate volume and mass estimates for these trees. For most of the new recruits, we measured the distance and angle (using a compass) from a known tree and calculated the XY coordinates of the new tree using trigonometry.

Our objective was to translate most of the information on Lyford's hand-drawn maps to digital format. We used ArcView 3.2 software, and spatial information from the original 22x22 inch maps was digitized using a digitizing tablet (Summagraphics Microgrid II). Most themes are polygons, including stonewalls and roads, since the map scale is so large. The following themes were created: Block corners (just the coordinates where the grid posts are located - a point theme); block polygons were created by connecting the dots and modifying SW01 (incompletely surveyed) and SW44 (incomplete as part of block is in swamp and was not surveyed). Trees (point theme derived from coordinates in data table). Footpath (line theme). Intermittent streams (line theme). Soil moisture type (polygon). Area damaged by 1938 hurricane (polygon). Road (polygon). Woods road (polygon - not very evident on ground anymore). Stonewalls (polygon). Manipulations (polygon). Some experimental sites are still evident on the ground. Nitrogen fertilization treatments done by Lyford in separate theme. Rocks (patchy coverage - Lyford drew in boulders only on some maps (greater than 2ft. diam.) and both boulders and rocks (1-2ft. diam.) on others). Fallen stems (line). Endpoints of each fallen stem were calculated from length and bearing measurements, using an extension called "bearing.avx" written by Yingming Zhou. A line theme was created from these points using an ArcView extension called "drawline2.ave" written by Rodrigo Nobrega. In some cases, we noted that the bole was displaced from the tree base - the X,Y coordinates were adjusted accordingly only if both amount and direction of displacement were noted.

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. hf032-01-tree.csv tree data hf032-01-tree.csv 1155739 8e8c23210be892c23d980c42b68d994c 1 \r\n column , https://harvardforest.fas.harvard.edu/data/p03/hf032/hf032-01-tree.csv block Lyford block ID. See plot map for layout of 100x100 ft. subdivisions of the plot Lyford block ID meas3y trees in the ‘1991’ census were actually measured in 1987, 1991 or 1992. The exact measurement year is indicated here. YYYY NA missing value treeid assigned in database; trees not tagged in field but identified by location and species. tree ID xsite location within site. These are Cartesian coordinates based on N-S and E-W baselines. foot 0.1 real NA missing value ysite location within site. These are Cartesian coordinates based on N-S and E-W baselines. foot 0.1 real NA missing value species tree species ACPE Acer pensylvanicum ACRU Acer rubrum ACSA Acer saccharum ALIN Alnus incana AMSP Amelanchier sp. BEAL Betula alleghaniensis BELE Betula lenta BEPA Betula papyrifera BEPO Betula populifolia CADE Castanea dentata FAGR Fagus grandifolia FRAM Fraxinus americana HAVI Hamamelis virginiana NYSY Nyssa sylvatica PIRU Picea rubens PIST Pinus strobus POGR Populus grandidentata PRSE Prunus serotina QUAL Quercus alba QURU Quercus rubra QUVE Quercus velutina TSCA Tsuga canadensis ULSP Ulmus sp. UNK Unknown dbh69 Diameter at breast height (4.5ft.) in 1969 centimeter 0.1 real NA missing value can69 canopy class in 1969 D dominant CD codominant I intermediate S suppressed (or lower stratum) cond69 condition in 1969 D dead L living SN snapped (at less than 50% total height) ST cut stump W windthrown WC windthrown and cut dbh75 diameter at breast height (4.5ft.) in 1975, converted from inches centimeter 0.1 real NA missing value can75 canopy class in 1975 D dominant CD codominant I intermediate S suppressed (or lower stratum) cond75 condition in 1975 D dead L living SN snapped (at less than 50% total height) ST cut stump W windthrown WC windthrown and cut dbh91 diameter at breast height (4.5ft.) in 1987-1992, converted from inches centimeter 0.1 real NA missing value can91 canopy class in 1987-1992 D dominant CD codominant I intermediate S suppressed (or lower stratum) cond91 condition in 1987-1992 D dead G gone L living RB root break SN snapped (at less than 50% total height) ST cut stump W windthrown WC windthrown and cut dbh01 diameter at breast height (4.5ft.) in 2001 centimeter 0.1 real NA missing value can01 canopy class in 2001 D dominant CD codominant I intermediate S suppressed (or lower stratum) cond01 condition in 2001 D dead G gone L living RB root break SN snapped (at less than 50% total height) ST cut stump W windthrown WC windthrown and cut orient1969 orientation in 1969 N north NE northeast E east SE southeast S south SW southwest W west NW northwest dbh11 diameter at breast height (4.5ft.) in 2011 centimeter 0.1 real NA missing value can11 canopy class in 2011 D dominant CD codominant I intermediate S suppressed (or lower stratum) cond11 condition in 2011 D dead G gone L living RB root break SN snapped (at less than 50% total height) ST cut stump W windthrown WC windthrown and cut length11 length of downed bole in 2011 (feet to the nearest tenth of foot) foot 0.1 real NA missing value angle11 direction of downed bole in 2011 (degrees, 0 is true N) degree 1 whole NA missing value decay11 decay class in 2011 D1 firm/solid, fresh, small twigs or stubs intact D2 partial decay, bark may be partially missing, bole may be broken but shape is still evident D3 decaying into ground/soil, crumbled, often fully or partially buried dbh21 diameter at breast height (4.5ft.) in 2021 centimeter 0.1 real NA missing value can21 canopy class in 2021 D dominant CD codominant I intermediate S suppressed (or lower stratum) cond21 condition in 2021 D dead G gone L living RB root break SN snapped (at less than 50% total height) ST cut stump W windthrown WC windthrown and cut length21 length of downed bole in 2021 (feet to the nearest tenth of foot) foot 0.1 real NA missing value angle21 direction of downed bole in 2021 (degrees, 0 is true N) degree 1 whole NA missing value decay21 decay class in 2021 D1 firm/solid, fresh, small twigs or stubs intact D2 partial decay, bark may be partially missing, bole may be broken but shape is still evident D3 decaying into ground/soil, crumbled, often fully or partially buried dbot21 diameter at the base of a downed dead tree in 2021 centimeter 0.1 real NA missing value dtop21 diameter at the top end of a downed dead tree in 2021 centimeter 0.1 real NA missing value comments comments, identified by year comments soilmoist soil moisture from Lyford’s hand-drawn maps Dry dry Moist moist Muck muck Water water Wet wet hurrdam damage from 1938 hurricane based on Lyford’s hand-drawn maps and corroborated by Rowlands’ maps of hurricane damage across the Harvard Forest low low damage moderate moderate damage severe severe damage edge10m tree location relative to the edge of the plot 0 tree is more than 10m from the plot edge 1 tree is less than 10m from the plot edge can62 canopy class in 1962 D dominant CD codominant I intermediate S suppressed (or lower stratum) cond62 condition in 1962 D dead L living ST cut stump W windthrown WC windthrown and cut dbh62 diameter at breast height (4.5ft.) in 1962 centimeter 0.1 real NA missing value 6315 hf032-02-map.jpg Lyford plot map hf032-02-map.jpg 48344 4d67a532819e487d39e3695039cb0f66 none jpeg https://harvardforest.fas.harvard.edu/data/p03/hf032/hf032-02-map.jpg image plot community long-term measurement