Harvard Forest

Data Archive

HF002

Vegetation Response in Simulated Hurricane Experiment at Harvard Forest since 1990

Related Publications

Data

• hf002-01: trees in control plot (preview)
• hf002-02: trees in experimental plot (preview)
• hf002-03: tree damage in experimental plot (preview)
• hf002-04: tree damage in control plot (preview)
• hf002-05: pit and mound dimensions in experimental plot (preview)
• hf002-06: tree regeneration (preview)
• hf002-07: shrub cover (preview)
• hf002-08: shrub height (preview)
• hf002-09: herbs (preview)
• hf002-10: recruitment (preview)
• hf002-11: regeneration notes (preview)

Overview

• Lead: David Foster, Audrey Barker Plotkin
• Investigators: Sarah Cooper-Ellis, Ann Lezberg
• Contact: Information Manager
• Start date: 1990
• End date: 2020
• Status: ongoing
• Location: Tom Swamp Tract (Harvard Forest)
• Latitude: +42.49 degrees
• Longitude: -72.20 degrees
• Elevation: 310 meter
• Datum: WGS84
• Taxa: Acer rubrum (red maple), Betula lenta (black birch), Quercus rubra (red oak)
• Release date: 2023
• Language: English
• EML file: knb-lter-hfr.2.25
• DOI: digital object identifier
• EDI: data package
• DataONE: data package
• Related links:
• Litterfall in Simulated Hurricane Experiment at Harvard Forest since 1989
• Trace Gas Fluxes and Soil N Dynamics in Simulated Hurricane Experiment at Harvard Forest 1989-1991
• Fuel Loading in Simulated Hurricane Experiment at Harvard Forest since 1993
• Study type: long-term measurement
• Research topic: large experiments and permanent plot studies; physiological ecology, population dynamics and species interactions
• LTER core area: disturbance patterns
• Keywords: hurricane damage, tree maps, tree mortality, vegetation dynamics, wind
• Abstract:

  Wind disturbance profoundly shapes temperate forests but few studies have evaluated patterns and mechanisms of long-term forest dynamics following major windthrows. In 1990, we initiated a large hurricane simulation experiment in a 0.8 ha manipulation (pulldown) and 0.6 ha control area of a maturing Quercus rubra-Acer rubrum forest in New England. We toppled 276 trees in the pulldown, using a winch and cable, in the northwesterly direction of natural treefall from major hurricanes. Eighty percent of canopy trees and two-thirds of all trees greater than 5 cm dbh suffered direct and indirect damage. We used twenty years of measurements to evaluate the trajectory and mechanisms of forest response after intense disturbance. Based on the patch size and disturbance magnitude, we expected pioneer tree and understory species to drive succession.

  The first decade of analyses emphasized tree seedling establishment and sprouting by damaged trees as the dominant mechanisms of forest recovery in this extensive damaged area. However, despite 80% canopy damage and 8000 m2 patch size, surviving overstory and advance regeneration controlled longer-term forest development. Residual oaks make up 42% of stand basal area after 20 years. The new cohort of trees, dominated by black birch advance regeneration, contributes 30% of stand basal area. There were shifts in understory vegetation composition and cover, but few species were gained or lost after 20 years. Stand productivity rebounded quickly (litterfall recovered to pre-disturbance levels in six years), but we predict that basal area in the pulldown will lag behind the control (which gained 6 m2/ha over 20 years) for decades to come. This controlled experiment showed that although the scale and intensity of damage were great, abundant advance regeneration, understory vegetation, and damaged trees remained, allowing the forest to resist changes in ecosystem processes and invasion by new species.

• Methods:

  A. Methods for manipulation and tree damage and mortality assessment

  The Tom Swamp Hurricane Experiment was initiated in 1990 in order to study long-term vegetation and ecosystem response to wind disturbance. The 0.8 ha experimental and 0.6 ha control (untreated) areas were surveyed and marked at 10m by 10m intervals prior to the manipulation to form grids with long axes (experiment: 160m; control: 120m) running 85.5 degrees. Half of each area was surrounded by electrical fencing to exclude deer; the electricity was discontinued after a few years, and the fence was taken down in 2009. Untreated red oak-red maple forest of similar age and structure occupied the 30 m buffer between and around the manipulation and control areas.

  In both areas, all trees of diameter greater than or equal to 5 cm dbh (experimental: 888 trees; control: 776 trees) were mapped prior to the manipulation using a mapping technique in which inter-tree distances were measured to the nearest centimeter (Boose, E.R., E.F. Boose and A.L. Lezberg. 1998. A practical method for mapping trees using distance measurements. Ecology 79:819-827). For each tree, species, canopy position, health, existing damage and diameter were recorded. Trees with multiple stems originating from a single base were measured as separate individuals.

  In the first week of October, during peak hurricane season, 276 dominant and codominant trees (76.5% of all live canopy trees) in the experimental area were individually pulled over toward the northwest to approximate the direction of hurricane winds. A choker wrapped around the main trunk at heights of 2.5m to 4.5m was fastened to a cable from a winch on a logging skidder, and pulling force was applied until the weight of the crown pulled the tree over. Trees closest to the operating site but just beyond the 30m buffer of intact forest were pulled first and trees farther away were pulled onto previously felled trees. The skidder operated from a clearcut 10-m strip to the north of the manipulation creating swaths of damage less than 15m wide and moving westward. Trees damaged by other trees were left where they fell and no effort was made to pull trees beyond their final point of repose if they were caught in other standing trees, fallen crowns, mounds, or other fallen boles.

  Tree Damage Assessment: During the winter of 1990 to 1991, all 888 trees in the experimental area were relocated and classified into one of eight primary damage classes. Details of damage were recorded, and pits and mounds measured and mapped. Damage was also assessed for the 776 trees in the control plot. New damage occurring in subsequent years of the study was occasionally recorded in both the experiment and control plots.

  Leafout and Sprouting Assessment: In the experimental and control areas all trees were assessed in mid-summer for degree of crown survival and for presence (1991), numbers (1992, 1993, 1994, 1995, 1997, 2000, 2005), and location (basal, trunk, or branch) of sprouts. Trees with no leafout of residual crowns were designated as "dead" and any sprouts from these trees were counted as new individuals.

  Leafout categories include: L4 = mostly leafed out or more than 90% branches leafed out; L3 = more than 50% but less than 90% leafed out; L2 = less than 50% but more than a single branch leafed out; L1 = only a few leaves or small branches leafed out, or 1 large branch; less than 10% leafout. F = false, no leafing out.

  Sprout types include: BASP = new growth (dating to damage) emerging from immediately below ground, from base or root collar; TRSP = new growth (epicormic shoots) from major stem; BRSP = new growth from branch (not just buds).

  For basal sprouts, count individual sprouts for individuals less than 15. For trees with sprouts greater or equal to 15, give a stem class with 15-24=15+, 25-34=25+, etc. Branch sprouts and trunk sprouts are generally only tallied for presence/absence because they are too difficult to count on standing trees. Count branch sprouts below the major crown only on standing undamaged trees. If there is unusually prolific sprouting please add to comments an estimate of abundance. In 1991, basal sprouts were not counted and only presence/absence is indicated. In 1992, trunk sprouts were counted in the same way as basal sprouts. Count leafed out sprouts originating after the manipulations only. Branch sprout assessment was discontinued after 1996, and was never recorded in the control plot.

  B. Sapling and sprout regeneration survey

  In the hurricane manipulation experiment, twenty-four 2-m x 5-m plots were randomly established on each of three transects running parallel to the long axis in the experimental area (~west to east) and on one transect running parallel to the long axis in the control, for a total of 96 plots.

  Individual saplings and sprouts were measured and tagged in these plots in 1990 (before the manipulation), 1991, 1993, 1996 and 1999. All stems greater than 0.3m total height were included in this survey. Previously tagged saplings and sprouts may exceed 5cm in diameter and should still be measured. Tags should be moved if they are girdling the tree and this damage to the tree should be noted. The 1999 sampling was the final measurement of regeneration; future work will focus on regeneration that has grown above a 5 cm dbh threshold (see methods in part D, below).

  For each stem, several variables are measured, and are described below:

  LOCATION. C = center of plot; E = eastern section of plot; EC = east central section of plot; N = northern section of plot; NC = north central section of plot; NE = northeastern section of plot; NW = northwestern section of plot; S = southern section of plot; SC = south central section of plot; SE = southeastern section of plot; SW = southwestern section of plot; W = western section of plot; WC = west central section of plot. Saplings/sprouts on the edge of the plot are labeled "*" in the location column.

  SPECIES. The first two letters of the genus and species names of the tree are used. Black birch and yellow birch were lumped together until old enough to distinguish with certainty.

  AGE. If the age of a sapling or sprout cannot be determined (because of age, browsing, etc.), this will be noted in the comments and the age column will be left blank. Stems that are residual (present before the pulldown) are given an age of "R". Others are recorded as N91 (new in 91), N92 (new in 92), etc. Often the age determination was somewhat uncertain; in these cases the age is enclosed in brackets (e.g., [N91]).

  STEM TYPE. SAP = sapling; BASP = basal sprout; TRSP = trunk sprout; RTSP = root sprout; BRRT = rooted branch.

  HEIGHT. Height is the vertical distance from the ground to the highest leaf-tip. If a stem is taller than 3 m, height is measured to the nearest 0.5m (0.1m if possible), using a telescoping height pole. If less than 3m tall, measure height to nearest 0.1m, using a folding meter stick. If a stem originates from a mound, or in a pit, the height should be adjusted to be the distance to the GROUND (this may have to be estimated somewhat). In general, the height should measure the position in the canopy of the crown of the tree.

  STEM LENGTH. Stem length is length of the stem up to, but not including, the new growth. It is often different from the height, as stems are sometimes bent or originate above or below ground level. Stem length is recorded only for smaller stems.

  Diameters are taken with calipers at the point indicated with paint on the "old" stems when it can be relocated. If the old paint cannot be relocated, new spots are painted and it is noted in the comments section. To relocate an old bole diameter, we looked at 1993 data sheets and measured at one half of the 1993 stem length. Measurements are taken with the paint spot aligned between the forks of the calipers, showing on the open side where possible. Old spots were repainted. "New" stems were marked where measured.

  BASAL DIAMETER. Measure above basal swelling or 1cm from the ground, whichever is greater (should be marked on tree). Recorded in cm. Some of these are becoming quite hard to reach as the trees grow. Diameter tape is sometimes easier to use. Any unusual basal swelling or scars are also noted in the comments. Some basal diameter markings are really buried and should be relocated and marked above ground. If a new basal diameter is marked, this is noted in the comments.

  BOLE DIAMETER. If a tree is less than 2m, measure half way up the stem length. If tree is more than 2 m, measure at 1.33m (dbh). Measure to nearest 0.1mm Recorded in cm. If we could not find paint from the previous years, we relocated the bole by taking half of the 1993 stem length (or height if no SL is noted). In comments, "new BOLE @____" was noted.

  DBH. Measure only if stem is longer than 2 m. Recorded in cm. If the last measurements for a stem were basal and bole diameters, but the stem is now long enough to get a DBH, we will take all three measurements. The height of DBH is measured from the base of the stem, not from the ground, even on trunk sprouts. This makes it too high to reach on many sprouts with an elevation.

  In deciding whether to give a stem a bole diameter or a dbh, refer to the previous year's data set. If the stem had a bole diameter and no dbh previously, but is now large enough for a dbh, both bole diameter and dbh should be recorded. If a bole diameter and a dbh were recorded previously, only a dbh is needed. If the basal diameter is inaccessible, both bole diameter and dbh should be recorded if possible.

  STEM OF ORIGIN. For sprouts and rooted branches only. Examples: SAP? for unidentified sapling , TR0820, or SAP0240 (Include PULLDAM in comments: type of damage to stem of origin: BENT, UPRT, CRSN, RTBR, TPSN, LEAN, STND) . We relied on the previous years' designations of PULLDAM to stems of origin unless the damage clearly occurred since the pulldown.

  HEIGHT OF EMERGENCE. Location along originating stem from which sprouts emerge. RC= root collar, 0013 = 13 cm along bole, 2412 = 24 meters or 2412 cm along bole. BG = below ground. Measure from root crown (where bole connects to roots). For previously tagged trunk sprouts that are a long way from the base of the tree, we will rely on previous years' data.

  ELEVATION. Height from ground to the base of sprout or sapling (which is not necessarily the lowest point on the tree). For basal sprouts, this is 0, and for most saplings, this is also 0, but if a sapling is on mound or in a pit, it may have elevation. Measure in m, to the nearest 0.01m (cm). If the stem is growing in a pit, the elevation may be negative. For some TRSPs, elevation and height of emergence are equal (if the stem of origin is standing). For others, they may be different (if the stem of origin is bent, leaning, etc.). Both elevation and height of emergence should be recorded where appropriate, even if they are equal.

  #SPROUTS. Number of sprouts in a clump (not always the number of sprouts on the tree). Only for sprouts. Clumps emerge from the same point on the root collar.

  SUBSTRATE. See the diagram for details. GR = ground; ST = stump; MT = mound top; RP = root plate; MO = mound; MB = mound base or mound edge; RO = rock; PT = pit; TR = tree; PE = pit edge.

  COMMENTS. Include damage, if there are multiple sprouts from same tree, browsing, and whether the stem is dead, down, broken, bent, leaning, buried, leader dead, new leader, or gone. In the data file, columns D1991, D1993, and D1996 record whether a stem is dead, living or gone in each of these years of measurement. If damage was detailed in previous years, it will not be repeated, likewise on shared stems (unless there are additional saplings/sprouts). New basal markings will be noted, as will new bole markings (and location of the new bole).

  Leaning stems were classified as follows in 1996 and 1999: Class 1 Lean = 0 - 44 degrees from vertical. Class 2 Lean = 45-90 degrees from vertical (including those "around 45 degrees" and those "around 90"). Class 3 Lean more than 90 degrees from vertical.

  C. Understory vegetation methods

  Twenty-four 2-m x 5-m plots were randomly established on each of three transects running parallel to the long axis in the experimental area (~west to east) and on one transect running parallel to the long axis in the control, for a total of 96 plots.

  Composition and structure of understory vegetation were assessed before (1990) and after (1991, 1992, 1995, 2000, 2005, 2010, 2015) the manipulation in the 96 plots described above (shrubs) and in 1-m2 plots nested within the 2-m x 5-m plots (herbs).

  Herbs: At each 1m2 subplot plot a circular plastic Delvin frame divided into 8 pie shaped divisions was centered around the center flag to facilitate judgments of cover percentages. The plot frame lies parallel to the ground (vertical on uproots). Cover is defined as the projection (on the ground within the sampling frame) of all above-ground portions of each species, whether that species individual is rooted within the plot or not. Cover estimates were made to the nearest 0.01 percent (for cover less than 0.15 or the nearest 0.1% for individual species; cover estimated only to the nearest 0.1% in 2000 and thereafter). Plastic cutouts of known size were used to estimate cover. Fruits and large flowers were not included in cover estimates. Total subgroup cover was estimated for the following at each plot: 1) Seedlings less than 0.3 m tall; 2) Shrubs less than 1 m tall; 3) Herbs/graminoids; 4) Ferns; 5) Moss; 6) Clubmoss. Shrubs more than 1 m tall, saplings/sprouts more than 0.3 m but less than 5 cm dbh, and overhanging materials were given a cover class between 1 and 4 (1 = less than 16%; 2 = 17-49%; 3 = 50-83%; 4 = 84-100%).

  Substrates were also given a cover class in the following categories: 1) Leaf litter; 2) Disturbed soil on mound; 3) Bare (exposed) soil on flat ground; 4) Bare soil in pit; 5) Vertical intact ground on mound top; 6) Vertical exposed ground-organic soil; 7) Exposed rocks/stones; 8) Woody debris -- large boles, stumps, other fragments; 9) Tree base or exposed roots of live and dead trees. Substrates should add up to 100%.

  Shrubs: Cover of shrub species was estimated in the same way as herb species cover inside 10m2 rectangular plots (2m wide by 5m long). Maximum heights for each species present on each plot were taken in meters to the nearest 0.1m. Shrubs taller than 3m were recorded as greater than 3m. Beginning in 1991, microsite characteristics were estimated in cover classes as follows: 5 = more than 75%; 4 = 50-75%; 3 = 25-50%, 2 = 5-25%; 1 = 1-5%; + = less than 1% for the following: prostrate branches and crowns up to 3 m high, boles, mound/pit complexes, large rocks more than 0.5m diameter, and tree stumps.

  D. Recruitment survey

  Prior to 2000, recruitment of new trees (stems growing greater than 5cm dbh) can be estimated from the sapling and sprout regeneration survey. Beginning in 2000, recruitment of trees greater than 5cm dbh across the entire experimental and control plots was done. Beginning in 2010, we tagged and mapped individuals in the new cohort.

  2000-2009: Live stems that have grown into the greater than 5cm dbh class since the original survey in 1989 or 1990 were measured. Location (by 10m x 10m grid cell), species, diameter at breast height (1.37m), stem type (sapling or sprout), stem of origin if a sprout (e.g., sapling less than 5cm dbh, Tree #356), notes (such as forked stems, dead leader, basal sprouts, damage) were recorded for each stem. Beginning in 2003, substrate (e.g. mound, ground) was also recorded.

  The following species are considered trees: Acer rubrum, A. saccharum, Betula allegheniensis, B. lenta, B. papyrifera, Castanea dentata, Carya glabra, C. ovata, Fagus grandifolia, Fraxinus Americana, Ostrya virginiana, Pinus strobus, Populus tremuloides, Prunus pensylvanica, P. serotina, Quercus rubra, Sorbus americana, and Tsuga canadensis. Species including Corylus sp., Amelanchier sp., Viburnum sp. are shrubs.

  Methodological details: (1) Live stems only. (2) Trunk sprouts are included if: a) on a prostrate bole, or b) are less than 1.37m up the stem of a standing/leaning/bent tree. (3) Bent or leaning stems counted if stem is more than 5cm at 1.37m from ground, not 1.37m along the stem. (4) Height to measure diameter is 1.37 from ground (for example, a tree growing on a mound or stump would be measured at 1.37m from level ground, not 1.37m up the stem). (5) Diameter measurements are to the nearest 0.1cm. (6) Some stems may have originated as sprouts, but if stem of origin cannot be seen, the stem will be noted as a sapling (e.g., most Castanea dentata look like saplings, but obviously are old basal sprouts.

  2010 and ongoing: Tag numbers began with #1001. New recruits in 2015 were tagged with numbers beginning with 2001. Large-format (~15mm:10m) gridded maps of each 10m by 10m grid cell of the sites were used to map in new stems relative to tapes (laid from grid post to grid post on the ground) and existing mapped trees. Note that recruits are listed in both the ‘trees’ files (hf002-01 and hf002-02) and the recruitment file (hf002-10) from 2010 onward, but that the recruitment file (hf002-10) includes only live trees.

  To calculate total density, basal area, etc. for all trees greater than 5cm dbh at any year: 1990 – use hf002-01 and hf002-02; 1991-1999 – use hf002-01 and hf002-02, combined with an area-adjusted estimate from hf002-04 (subset stems greater than 5cm); 2000-2009 – use hf002-01 and hf002-02, combined with hf002-07; 2010 and ongoing – use hf002-01 and hf002-02; these files include all tagged stems including recruits, starting with the 2010 census.

• Organization: Harvard Forest. 324 North Main Street, Petersham, MA 01366, USA. Phone (978) 724-3302. Fax (978) 724-3595.

• Project: 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. (ROR).

• Funding: National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210.

• Use: 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.

• License: Creative Commons Zero v1.0 Universal (CC0-1.0)

• Citation: Foster D, Barker Plotkin A. 2023. Vegetation Response in Simulated Hurricane Experiment at Harvard Forest since 1990. Harvard Forest Data Archive: HF002 (v.25). Environmental Data Initiative: https://doi.org/10.6073/pasta/71582f1bb1b348c47d4498436ad513e0.

Detailed Metadata

hf002-01: trees in control plot

1. year: year of measurement
2. tree: tree number
3. species: species name
   • ACRU: Acer rubrum
   • ACSA: Acer saccharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betula papyrifera
   • CAGL: Carya glabra
   • CAOV: Carya ovata
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • PIST: Pinus strobus
   • QURU: Quercus rubra
   • TIAM: Tilia americana
   • TSCA: Tsuga canadensis
   • UNK: unknown
4. x: cartesian coordinate identifying location within the plot along its 50 m axis (note: 0,0 is at northwest corner) (unit: number / missing value: NA)
5. y: cartesian coordinate identifying location within the plot along its 120 m axis (note: 0,0 is at northwest corner) (unit: number / missing value: NA)
6. can.90: canopy class recorded in 1990
   • D: dominant
   • C: codominant
   • I: intermediate
   • S: suppressed (or lower stratum)
   • NA: most dead trees
7. old.basp: basal sprouts present prior to manipulation
   • F: tree had no basal sprouts before 1990
   • T: tree had basal sprouts before 1990
8. dbh: diameter at breast height in cm (to 0.1 cm). For dead trees, dbh typically measured once, then not measured thereafter. (unit: centimeter / missing value: NA)
9. cond: tree condition
   • D: dead
   • L: living
   • M: moribund
10. leaf: crown vigor visual assessment
    • F: false, no leafing out
    • L1: only a few leaves or small branches leafed out, or one large branch; less than10% leafout
    • L2: less than 50% but more than a single branch leafed out
    • L3: more than 50% but less than 90% leafed out
    • L4: more than 90% crown leafed out
11. basp: number of basal sprouts
    • 0: no sprouts
    • 1-15: actual number of sprouts with green leaves that have arisen from base of main stem since experiment began
    • 19: 15-24
    • 29: 25-34
12. trsp: trunk sprouts. Number of trunk sprouts recorded in 1991, 1992 and 1993. From 1994 onward, T = trunk sprouts present, F = no trunk sprouts present
13. damage: damage from natural causes (this is the control site)
    • BENT: bole deviates from a straight line
    • CRSN: bole broken at more than 50% height
    • DEAD: tree dead (standing or otherwise)
    • GONE: dead tree decomposed and not discernable
    • LEAN: bole deviates from vertical
    • RTBR: rootbreak: tree pulled up with roots but soil not significantly displaced
    • SNAP: bole broken at less than 50% height
    • STND: no notable damage
    • TPSN: tip snap: tip of leader snapped, other parts of crown not damaged
    • UPRT: uproot: tree pulled up with roots creating mound
14. notes: text description adding information

hf002-02: trees in experimental plot

1. year: year of measurement
2. tree: tree number
3. species: species name
   • ACRU: Acer rubrum
   • ACSA: Acer saccharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betula papyrifera
   • CADE: Castanea dentata
   • CAGL: Carya glabra
   • CAOV: Carya ovata
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • PIST: Pinus strobus
   • POGR: Populus grandidentata
   • PRPE: Prunus pensylvanica
   • PRSE: Prunus serotina
   • QURU: Quercus rubra
   • TSCA: Tsuga canadensis
4. x: cartesian coordinate identifying location within the plot along its 50 m axis (note: 0,0 is at northwest corner) (unit: number / missing value: NA)
5. y: cartesian coordinate identifying location within the plot along its 160 m axis (note: 0,0 is at northwest corner) (unit: number / missing value: NA)
6. can.90: canopy class recorded in 1990
   • C: codominant
   • D: dominant
   • I: intermediate
   • S: suppressed (or lower stratum)
   • NA: most dead trees
7. manip.dam: damage from the manipulation (1990)
   • BENT: bole deviates from a straight line
   • CRSN: bole broken at more than 50% height
   • GONE: gone
   • LEAN: bole deviates from vertical
   • RTBR: rootbreak: tree pulled up with roots but soil not significantly displaced
   • SNAP: bole broken at less than 50% height
   • STND: standing: no notable damage
   • STSN: stem snap: one tagged stem of a multiple-stemmed tree snapped
   • TPSN: tip snap: tip of leader snapped, other parts of crown not damaged
   • UPRT: uproot: tree pulled up with roots creating mound
8. dbh: diameter at breast height in cm (to 0.1 cm). For dead trees, dbh typically measured once, then not measured thereafter. (unit: centimeter / missing value: NA)
9. cond: tree condition
   • D: dead
   • L: living
   • M: moribund
10. leaf: crown vigor visual assessment
    • F: false, no leafing out
    • L1: only a few leaves or small branches leafed out, or one large branch; less than10% leafout
    • L1W1: only a few leaves or small branches leafed out, or one large branch; less than10% leafout; only a few leaves or small branches leafed out, or one large branch; less than10% leafout, and now withered and dead
    • L1W2: only a few leaves or small branches leafed out, or one large branch; less than10% leafout ; less than 50% but more than a single branch leafed out but now withered and dead
    • L1W3: only a few leaves or small branches leafed out, or one large branch; less than10% leafout ; more than 50% but less than 90% leafed out, but now withered and dead
    • L1W4: only a few leaves or small branches leafed out, or one large branch; less than10% leafout; greater than 90% crown leafed out but now withered and dead
    • L2: less than 50% but more than a single branch leafed out
    • L2W1: less than 50% but more than a single branch leafed out; only a few leaves or small branches leafed out, or one large branch; less than10% leafout, and now withered and dead
    • L2W2: less than 50% but more than a single branch leafed out; less than 50% but more than a single branch leafed out but now withered and dead
    • L3: more than 50% but less than 90% leafed out
    • L3W1: more than 50% but less than 90% leafed out : only a few leaves or small branches leafed out, or one large branch; less than10% leafout, and now withered and dead
    • L3W2: more than 50% but less than 90% leafed out: less than 50% but more than a single branch leafed out but now withered and dead
    • L4: less than 90% crown leafed out
    • L4W1: less than 90% crown leafed out : only a few leaves or small branches leafed out, or one large branch; less than10% leafout, and now withered and dead
    • W1: only a few leaves or small branches leafed out, or one large branch; less than10% leafout, and now withered and dead
    • W2: less than 50% but more than a single branch leafed out but now withered and dead
    • W3: more than 50% but less than 90% leafed out, but now withered and dead
11. basp: number of basal sprouts
    • F: absent
    • T: present
    • 0: no sprouts
    • 1-15: actual number of sprouts with green leaves that have arisen from base of main stem since experiment began
    • 19: 15-24
    • 29: 25-34
12. trsp: trunk sprouts presence or absence recorded in 1991
    • F: absent
    • T: present
13. brsp: sprouts from major branches presence or absence (1991-1996)
    • F: absent
    • T: present
14. current.dam: subsequent damage (1994) or current damage status (2010 onward)
    • BENT: bole deviates from a straight line
    • CRSN: bole broken at more than 50% height
    • GONE: unable to find, presumably very decomposed
    • LEAN: bole deviates from vertical
    • RTBR: rootbreak; tree pulled up with roots but soil not significantly displaced
    • SNAP: bole broken at less than 50% height
    • STND: no notable damage
    • STSN: stem snap: one tagged stem of a multiple-stemmed tree snapped
    • TPSN: snap of tip or top of leader
    • UPRT: uproot: tree pulled up with roots creating mound
15. notes: text description adding information

hf002-03: tree damage in experimental plot

1. year: year of measurement
2. tree: tree tag number
3. species: species name
   • ACRU: Acer rubrum
   • ACSA: Acer saccharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betula papyrifera
   • CADE: Castanea dentata
   • CAGL: Carya glabra
   • CAOV: Carya ovata
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • PIST: Pinus strobus
   • POGR: Populus grandidentata
   • PRSE: Prunus serotina
   • QURU: Quercus rubra
   • TSCA: Tsuga canadensis
4. dam.90: Major category describing the state of tree immediately following the pulldown manipulation. Includes preexisting damage if no new damage so we can follow chronic damage to trees in the site.
   • BENT: bole deviates from a straight line
   • CRSN: bole broken at more than 50% height
   • GONE: cannot relocate the tree
   • LEAN: bole deviates from vertical
   • RTBR: rootbreak: tree pulled up with roots but soil not significantly displaced
   • SNAP: bole broken at less than 50% height
   • STND: standing: no notable damage
   • STSN: stem snap: one tagged stem of a multiple-stemmed tree snapped
   • TPSN: tip snap: tip of leader snapped, other parts of crown not damaged
   • UPRT: uproot: tree pulled up with roots creating mound
5. sec.dam.90: minor/secondary damage (1990 only)
   • BENT: if tree is bent in addition to snap or uproot
   • CASC: gash or scar or scrape from cable pulling across tree
   • CHSC: choker scar around tree diameter
   • CRSN: bole broken at more than 50% height
   • LEAN: if tree is leaning in addition to snap
   • MASN: snap of major branch (branch originates from bole) where bole forks
   • MISN: snap of minor branches or multiple stems less than 5 cm dbh or tips of trees
   • NONE: none
   • SHAT: if tree that was uprooted or snapped is also shattered into 3+ pieces
   • TPSN: snap of tip or top of leader
   • TRSC: gash, scar or scrape from falling tree
6. cause: cause of damage (1990 only)
   • D: all trees with choker scares are directly pulled
   • F: tree knocked over by another falling tree, even if the tree did not fall directly on the bole but tangled the canopy or somehow tore up the root mound, causing a fall
   • M: stem pulled down because connected at base (multiple-stemmed tree) to stem actually pulled
   • I: incidental, indirectly pulled down with root mat of another tree pulled
   • O: pre-existing damage (should apply only to snaps, bends and leans)
   • ?: cause unclear – used if a tree had a pink ribbon but no choker scar so we weren't sure if it was knocked over by other trees before being pulled or if the choker didn't dig into the bark
7. rot: evidence of rot
   • FALSE: no evidence of rot
   • TRUE: evidence of rot
8. bend.ht: bend in stem (unit: meter / missing value: NA)
9. uprt.ang: uproot angle given as degrees deviating from vertical using a clinometer on Suunto compass (unit: degree / missing value: NA)
10. dam.current: current damage status of tree
    • BENT: bole deviates from a straight line
    • CRSN: bole broken at more than 50% height
    • GONE: cannot relocate the treE
    • LEAN: bole deviates from vertical
    • RTBR: rootbreak: tree pulled up with roots but soil not significantly displaced
    • SNAP: bole broken at less than 50% height
    • STND: standing: no notable damage
    • STSN: stem snap: one tagged stem of a multiple-stemmed tree snapped
    • TPSN: tip snap: tip of leader snapped, other parts of crown not damaged
    • UPRT: uproot: tree pulled up with roots creating mound
11. orient.mag: orientation in nearest degrees (unit: degree / missing value: NA)
12. bole.elev: height above ground at dbh of the elevated bole for uproots and snaps (unit: meter / missing value: NA)
13. snap.ht: snap height (unit: meter / missing value: NA)
14. ht.length: length of prostrate stem (unit: meter / missing value: NA)
15. d.bot: diameter of fallen stem at the bottom end of the stem, recorded starting in 2010 (unit: centimeter / missing value: NA)
16. d.top: diameter of fallen stem at the top end of the stem, recorded starting in 2010 (unit: centimeter / missing value: NA)
17. decay: decay class for dead trees (starting in 2010)
    • 1: solid wood, recently fallen, bark and twigs present
    • 2: solid wood, significant weathering, branches present
    • 3: wood not solid, bark may be sloughing but nail still must be pounded into wood
    • 4: wood sloughing and/or friable, nail may be forcibly pushed into wood
    • 5: wood friable, barely holding shape, nail may be easily pushed into wood
18. comments: comments

hf002-04: tree damage in control plot

1. year: year of measurement
2. tree: tree tag number
3. species: species name
   • ACRU: Acer rubrum
   • ACSA: Acer saccharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betula papyrifera
   • CADE: Castanea dentata
   • CAGL: Carya glabra
   • CAOV: Carya ovata
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • PIST: Pinus strobus
   • QURU: Quercus rubra
   • TIAM: Tilia americana
   • TSCA: Tsuga canadensis
   • UNK: species not identified (1 tree)
4. dam.current: current damage status of tree
   • BENT: bole deviates from a straight line
   • CRSN: bole broken at more than 50% height
   • GONE: cannot relocate the treE
   • LEAN: bole deviates from vertical
   • RTBR: rootbreak: tree pulled up with roots but soil not significantly displaced
   • SNAP: bole broken at less than 50% height
   • STND: standing: no notable damage
   • STSN: stem snap: one tagged stem of a multiple-stemmed tree snapped
   • TPSN: tip snap: tip of leader snapped, other parts of crown not damaged
   • UPRT: uproot: tree pulled up with roots creating mound
5. orient.mag: orientation of fallen bole in nearest degrees (unit: degree / missing value: NA)
6. bole.elev: height above ground at dbh of the elevated bole for uproots and snaps (unit: meter / missing value: NA)
7. snap.ht: snap height (unit: meter / missing value: NA)
8. ht.length: length of prostrate stem (unit: meter / missing value: NA)
9. d.bot: diameter of fallen stem at the bottom end of the stem, recorded starting in 2010 (unit: centimeter / missing value: NA)
10. d.top: diameter of fallen stem at the top end of the stem, recorded starting in 2010 (unit: centimeter / missing value: NA)
11. decay: decay class for dead trees; not recorded in 1990
    • 1: solid wood, recently fallen, bark and twigs present
    • 2: solid wood, significant weathering, branches present
    • 3: wood not solid, bark may be sloughing but nail still must be pounded into wood
    • 4: wood sloughing and/or friable, nail may be forcibly pushed into wood
    • 5: wood friable, barely holding shape, nail may be easily pushed into wood
12. comments: comments

hf002-05: pit and mound dimensions in experimental plot

1. year: year of measurement
2. tree: tree number (corresponds with numbers in hf002-02)
3. species: species name
   • ACRU: Acer rubrum
   • ACSA: Acer saccharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betula papyrifera
   • CAGL: Carya glabra
   • CAOV: Carya ovata
   • FRAM: Fraxinus americana
   • OSVI: Ostrya virginiana
   • PIST: Pinus strobus
   • QURU: Quercus rubra
4. damage: major category describing state of tree immediately after the manipulation in 1990
   • LEAN: bole deviates from vertical
   • RTBR: rootbreak: tree pulled up with roots but soil not significantly displaced
   • UPRT: uproot: tree pulled up with roots creating mound
5. remeas100: pit/mound complexes remeasured
   • yes: one of 100 pit/mound complexes whose dimensions were remeasured in 2005 and 2015
   • no: measured in 1990 only
6. no.stems: number of stems (tagged trees only) on the tipup mound (mostly 1; some doubles and triples) (unit: number / missing value: NA)
7. mound.no: mound number
8. mound.wdth: the long axis of a mound (unit: meter / missing value: NA)
9. mound.ht: highest point of mound, not including bare roots extending beyond mound, measured perpendicular to intact ground (unit: meter / missing value: NA)
10. mound.thck: thickness of mound or roots exposed (unit: meter / missing value: NA)
11. pit.dpth: pit depth (unit: meter / missing value: NA)
12. pit.wdth: pit width (unit: meter / missing value: NA)
13. pit.thck: pit thickness (unit: meter / missing value: NA)
14. no.saps: number of tree saplings (greater than 30cm tall) on pit-mound (unit: number / missing value: NA)
15. comments: comments recorded 1990 and 2015

hf002-06: tree regeneration

1. grid: grid location
   • TSIBD: located in pulldown site
   • TSICT: located in control site
2. plot: plot location
3. trans: transect
4. st.no: sapling and sprout number (unit: number / missing value: NA)
5. year: year of measurement
6. loc: location within plot
   • C: center of plot
   • E: eastern section of plot
   • E*: eastern section of plot, edge of plot
   • EC: east central section of plot
   • EC*: east central section of plot, edge of plot
   • N: northern section of plot
   • N*: northern section of plot, edge of plot
   • NC: north central section of plot
   • NC*: north central section of plot, edge of plot
   • NE: northeastern section of plot
   • NE*: northeastern section of plot, edge of plot
   • NW: northwestern section of plot
   • NW*: northwestern section of plot, edge of plot
   • S: southern section of plot
   • S*: southern section of plot, edge of plot
   • SC: south central section of plot
   • SC*: south central section of plot, edge of plot
   • SW: southwestern section of plot
   • SW*: southwestern section of plot, edge of plot
   • W: western section of plot
   • W*: western section of plot, edge of plot
   • WC: west central section of plot
   • WC*: west central section of plot, edge of plot
7. species: species
   • ACRU: Acer rubrum
   • ACSA: Acer saccharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BELE?: probabaly Betula lenta, but too small to be sure yet
   • BEPA: Betula papyrifera
   • BEPO: Betula populifolia
   • BESP: either B. lenta or B. alleghaniensis, but too small to be sure yet
   • CADE: Castanea dentata
   • CAGL: Carya glabra
   • CAOV: Carya ovata
   • COAL: Cornus alternifolia
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • OSVI: Ostrya virginiana
   • PIST: Pinus strobus
   • POTR: Populus tremuloides
   • PRPE: Prunus pensylvanica
   • PRSE: Prunus serotina
   • QUAL: Quercus alba
   • QURU: Quercus rubra
   • SALIX?: Salix sp.
   • SOAM: Sorbus americana
   • TSCA: Tsuga canadensis
8. age: total age of the sapling or sprout (not the year the stem reached greater than or equal to 0.3m)
   • N90: seedling or sprout established in 1990
   • [N90]: probably established in 1990, but age cannot be determined with certainty
   • N91: seedling or sprout established in 1991
   • [N91]: probably established in 1991, but age cannot be determined with certainty
   • N92: seedling or sprout established in 1992
   • [N92]: probably established in 1992, but age cannot be determined with certainty
   • N93: seedling or sprout established in 1993
   • [N93]: probably established in 1993, but age cannot be determined with certainty
   • N94: seedling or sprout established in 1994
   • [N94]: probably established in 1994, but age cannot be determined with certainty
   • N95: seedling or sprout established in 1995
   • [N95]: probably established in 1995, but age cannot be determined with certainty
   • N96: seedling or sprout established in 1996
   • [N96]: probably established in 1996, but age cannot be determined with certainty
   • N97: seedling or sprout established in 1997
   • [N97]: probably established in 1997, but age cannot be determined with certainty
   • N98: seedling or sprout established in 1998
   • [N98]: probably established in 1998, but age cannot be determined with certainty
   • N99: seedling or sprout established in 1999
   • [N99]: probably established in 1999, but age cannot be determined with certainty
   • R: residual (present before 1990)
   • [R]: probably residual, but age cannot be determined with certainty
   • R-9: residual but overlooked in previous surveys
   • [?]: cannot determine age
9. type: defines stems as saplings or different types of sprouts
   • BASP: basal sprout
   • BRRT: rooted branch
   • RTSP: root sprout
   • SAP: sapling
   • SAP?: sapling?
   • TRSP: trunk sprout
10. ht: vertical distance from the ground to the highest leaf-tip (unit: meter / missing value: NA)
11. length: length of the stem up to, but not including, current year growth (unit: meter / missing value: NA)
12. basaldiam: stem diameter measured above basal swelling or 1cm from the ground, whichever is greater (unit: centimeter / missing value: NA)
13. bolediam: if a tree is less than 2m, measure half way up the stem length. If tree greater than 2 m, measure at 1.33m (dbh) (unit: centimeter / missing value: NA)
14. dbh: stem diameter at 1.33m (unit: centimeter / missing value: NA)
15. origin: for sprouts and rooted branches, this identifies the stem from which the sprout originates
16. regen.type: type of regeneration
    • ADVREG: advance regeneration - stem present before the manipulation
    • NEWSAP: tree germinated after the manipulation
    • SEEDSPR: seedling sprout
    • SPRSPR: sprout from an older sprout
    • TREESPR: sprout from tree-sized (5cm diameter or greater) stem. Includes basal sprouts and trunk sprouts.
    • ?: unknown
17. emerg: location along originating stem from which sprouts emerge
    • RC: root collar
    • BG: below ground
    • ?: unknown
    • #: distance (cm) from base along originating stem from which sprouts emerge
18. elev: height from ground to the base of sprout or sapling (unit: centimeter / missing value: NA)
19. nospr: number of sprouts in a clump (not always the number of sprouts on the tree) (unit: number / missing value: NA)
20. subst: substate on which the stem is growing
    • GR: ground
    • GR?: ground?
    • MB: mound base or mound edge
    • MO: mound
    • MT: mound top
    • PE: pit edge
    • PT: pit
    • RO: rock
    • RP: root plate
    • ST: stump
    • TR: tree
21. pulldam: damage to the stem of origin (not the sprout itself)
    • BENT: bole deviates from a straight line
    • CRSN: bole broken at greater than 50% height
    • DEAD: stem of origin dead
    • LEAN: bole deviates from vertical
    • RTBR: rootbreak: tree pulled up with roots but soil not significantly displaced
    • SNAP: bole broken at less than 50% height
    • STND: no notable damage
    • TPSN: tip of tree snapped above most of crown
    • UPRT: uproot: tree pulled up with roots creating mound
22. d.1991: whether a stem is dead, living or gone
    • F: false - the stem is living in 1991
    • G: gone - the stem cannot be relocated in 1991
    • T: true - the stem is dead in 1991
23. d.1993: whether a stem is dead, living or gone
    • F: false - the stem is living in 1993
    • G: gone - the stem cannot be relocated in 1993
    • T: true - the stem is dead in 1993
24. d.1996: whether a stem is dead, living or gone
    • F: false - the stem is living in 1996
    • G: gone - the stem cannot be relocated in 1996
    • T: true - the stem is dead in 1996
25. d.1999: whether a stem is dead, living or gone
    • F: false - the stem is living in 1999
    • G: gone - the stem cannot be relocated in 1999
    • T: true - the stem is dead in 1999
26. comments: comments

hf002-07: shrub cover

1. plot: location by transect and plot. T1 - T4 refer to the transect location. T1 is furthest north, and T4 is furthest south. T1 - T3 are in the pulldown site; T4 is in the control site. P1 - P24 refer to plot number. Each transect has 24 plots, arranged from west to east.
2. year: year of measurement
3. transect: location by transect. 1 - 4 refer to the transect location. Transect 1 is furthest north, and transect 4 is furthest south. Transects 1-3 are in the pulldown site; transect 4 is in the control site.
4. amecan: Amelanchier sp. cover (unit: dimensionless / missing value: NA)
5. berthu: Berberis thunbergii cover (unit: dimensionless / missing value: NA)
6. celorb: Celastrus orbiculatus cover (unit: dimensionless / missing value: NA)
7. chimac: Chimaphila maculata cover (unit: dimensionless / missing value: NA)
8. corcon: Corylus cornuta cover (unit: dimensionless / missing value: NA)
9. craspe: Crataegus sp. cover (unit: dimensionless / missing value: NA)
10. dielon: Diervilla lonicera cover (unit: dimensionless / missing value: NA)
11. euoalt: Euonymous alatus cover (unit: dimensionless / missing value: NA)
12. gaupro: Gaultheria procumbens cover (unit: dimensionless / missing value: NA)
13. ilever: Ilex verticillata cover (unit: dimensionless / missing value: NA)
14. kallat: Kalmia latifolia cover (unit: dimensionless / missing value: NA)
15. loncan: Lonicera canadensis cover (unit: dimensionless / missing value: NA)
16. lonmor: Lonicera morrowii cover (unit: dimensionless / missing value: NA)
17. mitrep: Mitchella repens cover (unit: dimensionless / missing value: NA)
18. rhonud: Rhododendron nudiflorum cover (unit: dimensionless / missing value: NA)
19. rhurad: Rhus radicans cover (unit: dimensionless / missing value: NA)
20. rhutyp: Rhus typhina cover (unit: dimensionless / missing value: NA)
21. ruball: Rubus allegheniensis cover (unit: dimensionless / missing value: NA)
22. rubida: Rubus idaeus cover (unit: dimensionless / missing value: NA)
23. rubhis: Rubus hispidus cover (unit: dimensionless / missing value: NA)
24. rubodo: Rubus odoratus cover (unit: dimensionless / missing value: NA)
25. rubspe: Unknown Rubus sp. cover (unit: dimensionless / missing value: NA)
26. rosspe: Rosa sp. cover (unit: dimensionless / missing value: NA)
27. sampub: Sambucus pubens cover (unit: dimensionless / missing value: NA)
28. smiher: Smilax herbacea cover (unit: dimensionless / missing value: NA)
29. sorame: Sorbus americana cover (unit: dimensionless / missing value: NA)
30. vacang: Vaccinium angustifolium cover (unit: dimensionless / missing value: NA)
31. vaccor: Vaccinium corymbosum cover (unit: dimensionless / missing value: NA)
32. vacspe: Vaccinium species cover (unit: dimensionless / missing value: NA)
33. vacvac: Vaccinium vacillans cover (unit: dimensionless / missing value: NA)
34. vaccmb: Vaccinium all species combined cover (unit: dimensionless / missing value: NA)
35. vibace: Viburnum acerifolium cover (unit: dimensionless / missing value: NA)
36. vibcas: Viburnum cassinoides cover (unit: dimensionless / missing value: NA)
37. vibden: Viburnum dentatum cover (unit: dimensionless / missing value: NA)
38. vitspe: Vitis sp. cover (unit: dimensionless / missing value: NA)
39. prostrate: prostrate branches and crowns covering the plot. In 1991, these were lumped with boles.
    • 5: more than 75%
    • 4: 50-75%
    • 3: 25-50%
    • 2: 5-25%
    • 1: 1-5%
    • x: less than 1%
40. boles: downed tree boles. In 1991, these were lumped with prostrate branches and crowns.
    • 5: more than 75%
    • 4: 50-75%
    • 3: 25-50%
    • 2: 5-25%
    • 1: 1-5%
    • x: less than 1%
41. tree: cover of prostrate branches and crowns together with boles (1991 only)
    • 5: more than 75%
    • 4: 50-75%
    • 3: 25-50%
    • 2: 5-25%
    • 1: 1-5%
    • x: less than 1%
42. mound: cover class of mounds in the plot. In 1991 and 1992, these were lumped with pits.
    • 5: more than 75%
    • 4: 50-75%
    • 3: 25-50%
    • 2: 5-25%
    • 1: 1-5%
    • x: less than 1%
43. pit: cover class of pits in the plot. In 1991 and 1992, these were lumped with mounds.
    • 5: more than 75%
    • 4: 50-75%
    • 3: 25-50%
    • 2: 5-25%
    • 1: 1-5%
    • x: less than 1%
44. moundpit: pit and mound (1991 and 1992)
    • 5: more than 75%
    • 4: 50-75%
    • 3: 25-50%
    • 2: 5-25%
    • 1: 1-5%
    • x: less than 1%
45. rock: rocks greater than 0.5m diameter
    • 5: more than 75%
    • 4: 50-75%
    • 3: 25-50%
    • 2: 5-25%
    • 1: 1-5%
    • x: less than 1%
46. stump: stump
    • 5: more than 75%
    • 4: 50-75%
    • 3: 25-50%
    • 2: 5-25%
    • 1: 1-5%
    • x: less than 1%

hf002-08: shrub height

1. plot: location by transect and plot. T1 - T4 refer to the transect location. T1 is furthest north, and T4 is furthest south. T1 - T3 are in the pulldown site; T4 is in the control site. P1 - P24 refer to plot number. Each transect has 24 plots, arranged from west to east.
2. year: year of measurement
3. transect: location by transect. 1 - 4 refer to the transect location. Transect 1 is furthest north, and transect 4 is furthest south. Transects 1-3 are in the pulldown site; transect 4 is in the control site.
4. species: species and genus code
   • amecan: Amelanchier sp.
   • berthu: Berberis thunbergii
   • celorb: Celastrus orbiculatus
   • corcon: Corylus cornuta
   • craspe: Crataegus sp.
   • dielon: Diervilla lonicera
   • euoalt: Euonymous alatus
   • gaupro: Gaultheria procumbens
   • ilever: Ilex verticillata
   • kallat: Kalmia latifolia
   • loncan: Lonicera canadensis
   • lonmor: Lonicera morrowii
   • mitrep: Mitchella repens
   • rhonub: Rhododendron nudiflorum
   • rhurad: Rhus radicans
   • rhutyp: Rhus typhina
   • ruball: Rubus allegheniensis
   • rubida: Rubus idaeus
   • rubhis: Rubus hispidus
   • rubodo: Rubus odoratus
   • rubspe: Unknown Rubus sp.
   • rosspe: Rosa sp.
   • sampub: Sambucus pubens
   • smiher: Smilax herbacea
   • sorame: Sorbus americana
   • vacang: Vaccinium angustifolium
   • vaccor: Vaccinium corymbosum
   • vacspe: Vaccinium species
   • vacvac: Vaccinium vacillans
   • vaccmb: Vaccinium all species combined
   • vibace: Viburnum acerifolium
   • vibcas: Viburnum cassinoides
   • vibden: Viburnum dentatum
   • vitspe: Vitis sp.
5. height: height (tallest stem of that species in the plot, meters). Note: If a shrub was greater than or equal to 3m, the height was recorded simply as 3m (30 cases out of 2309 total shrub occurrences 1990-2015), except for one shrub in 1990 (4.0), and one shrub in 2010 (3.3m). 95% of the shrub heights are less than 2m. (unit: meter / missing value: NA)

hf002-09: herbs

1. plot: location by transect and plot
2. year: year of measurement
3. transect: location by transect. 1 - 4 refer to the transect location. Transect 1 is furthest north, and transect 4 is furthest south. Transects 1-3 are in the pulldown site; transect 4 is in the control site.
4. lyccla: Lycopodium clavatum cover (unit: dimensionless / missing value: NA)
5. lycluc: Lycopodium lucidulum cover (unit: dimensionless / missing value: NA)
6. lycobs: Lycopodium obscurum cover (unit: dimensionless / missing value: NA)
7. athfel: Athyrium felix-femina cover (unit: dimensionless / missing value: NA)
8. denpun: Dennstaedtia punctilobula cover (unit: dimensionless / missing value: NA)
9. dryspi: Dryopteris spinulosa (intermedia and carthusiana) cover (unit: dimensionless / missing value: NA)
10. onosen: Onoclea sensibilis cover (unit: dimensionless / missing value: NA)
11. osmcin: Osmunda cinnamomea cover (unit: dimensionless / missing value: NA)
12. osmcla: Osmunda claytoniana cover (unit: dimensionless / missing value: NA)
13. ptraqu: Pteridium aquilinum cover (unit: dimensionless / missing value: NA)
14. thenov: Thelypteris nova-boracensis cover (unit: dimensionless / missing value: NA)
15. thepal: Thelypteris palustris cover (unit: dimensionless / missing value: NA)
16. ampbra: Amphicarpa bracteata cover (unit: dimensionless / missing value: NA)
17. anequi: Anemone quinquefolia cover (unit: dimensionless / missing value: NA)
18. apoand: Apocynum androsaemifolim cover (unit: dimensionless / missing value: NA)
19. aranud: Aralia nudicaulis cover (unit: dimensionless / missing value: NA)
20. ariatr: Arisaema atrorubens cover (unit: dimensionless / missing value: NA)
21. astacu: Aster acuminatus cover (unit: dimensionless / missing value: NA)
22. astdiv: Aster divaricatus cover (unit: dimensionless / missing value: NA)
23. aqucan: Aquilegia canadensis cover (unit: dimensionless / missing value: NA)
24. ciralt: Cirsium sp. cover (unit: dimensionless / missing value: NA)
25. clibor: Clintonia borealis cover (unit: dimensionless / missing value: NA)
26. epispe: Epilobium sp.(coloratum/ciliatum) cover (unit: dimensionless / missing value: NA)
27. erehie: Erechtites hieracifolia cover (unit: dimensionless / missing value: NA)
28. eupspe: Eupatorium sp. cover (unit: dimensionless / missing value: NA)
29. goopub: Goodyera pubescens cover (unit: dimensionless / missing value: NA)
30. houcae: Houstonia caerulea cover (unit: dimensionless / missing value: NA)
31. hydame: Hydrocotyle americana cover (unit: dimensionless / missing value: NA)
32. hyppun: Hypericum punctatum cover (unit: dimensionless / missing value: NA)
33. lobinf: Lobelia inflata cover (unit: dimensionless / missing value: NA)
34. lysqua: Lysimachia quadrifolia cover (unit: dimensionless / missing value: NA)
35. maican: Maianthemum canadense cover (unit: dimensionless / missing value: NA)
36. medvir: Medeola virginiana cover (unit: dimensionless / missing value: NA)
37. monuni: Monotropa uniflora cover (unit: dimensionless / missing value: NA)
38. polpub: Polygonatum pubescens cover (unit: dimensionless / missing value: NA)
39. potsim: Potentilla simplex cover (unit: dimensionless / missing value: NA)
40. prespe: Prenanthes sp. cover (unit: dimensionless / missing value: NA)
41. smirac: Smilacina racemosa cover (unit: dimensionless / missing value: NA)
42. solcae: Solidago caesia cover (unit: dimensionless / missing value: NA)
43. solrug: Solidago rugosa cover (unit: dimensionless / missing value: NA)
44. tribor: Trientalis borealis cover (unit: dimensionless / missing value: NA)
45. uvuses: Uvularia sessilifolia cover (unit: dimensionless / missing value: NA)
46. viobla: Viola blanda cover (unit: dimensionless / missing value: NA)
47. viospe: Viola sp. cover (unit: dimensionless / missing value: NA)
48. luzmul: Luzula multiflora cover (unit: dimensionless / missing value: NA)
49. juneff: Juncus effusus cover (unit: dimensionless / missing value: NA)
50. braere: Brachyelytrum erectum cover (unit: dimensionless / missing value: NA)
51. agrspe: Agrostis sp. cover (unit: dimensionless / missing value: NA)
52. danspi: Danthonia spicata cover (unit: dimensionless / missing value: NA)
53. fesrub: Festuca rubra cover (unit: dimensionless / missing value: NA)
54. carspe: cover for all Carex species (unit: dimensionless / missing value: NA)
55. unkhrb: unknown herb cover (unit: dimensionless / missing value: NA)
56. unkgra: unknown graminoid cover (unit: dimensionless / missing value: NA)
57. unkfer: unknown fern cover (unit: dimensionless / missing value: NA)
58. leaf: litter cover (unit: dimensionless / missing value: NA)
59. soil: bare (exposed) soil on flat ground (unit: dimensionless / missing value: NA)
60. pit: bare soil in pit (unit: dimensionless / missing value: NA)
61. mound: combines vertical intact ground on mound top, disturbed soil on mound (unit: dimensionless / missing value: NA)
62. rock: exposed rocks/stones (unit: dimensionless / missing value: NA)
63. wood: woody debris cover class (large downed boles, stumps, other woody fragments) (unit: dimensionless / missing value: NA)
64. treebase: base of standing live treee in plot cover (unit: dimensionless / missing value: NA)
65. ovrroot: overhanging roots or rootplates
    • 0: no cover
    • 1: less than 17% cover
    • 2: 17-49%
    • 3: 50-83% cover
    • 4: 84-100% cover
66. ovrbrnc: overhanging branches from displaced trees and saplings
    • 0: no cover
    • 1: less than 17% cover
    • 2: 17-49%
    • 3: 50-83% cover
    • 4: 84-100% cover
67. ovrbole: overhanging boles
    • 0: no cover
    • 1: less than 17% cover
    • 2: 17-49%
    • 3: 50-83% cover
    • 4: 84-100% cover
68. ovrdeb: suspended woody debris overhanging the plot
    • 0: no cover
    • 1: less than 17% cover
    • 2: 17-49%
    • 3: 50-83% cover
    • 4: 84-100% cover
69. ovrveg: vegetation overhanging the plot other than vegetation already counted as cover
    • 0: no cover
    • 1: less than 17% cover
    • 2: 17-49%
    • 3: 50-83% cover
    • 4: 84-100% cover
70. seedling: total cover seedlings less than 0.3 m tall (unit: dimensionless / missing value: NA)
71. saplings: total cover of saplings/sprouts greater than 0.3m height but less than 5 cm dbh. Actual percent cover was recorded in 1990, but translated to a cover class to match the subsequent years.
    • 0: no cover
    • 1: less than 17% cover
    • 2: 17-49%
    • 3: 50-83% cover
    • 4: 84-100% cover
72. shrubslo: total cover of shrubs less than 1m in height (unit: dimensionless / missing value: NA)
73. shrubshi: Total cover of shrubs greater than 1m in height. Percent cover in 1990; cover class 1-4 used 1991-2005. Cover class translated as 1=7.5%; 2=33.0%; 3=76.0%; 4=91.5%
    • 0: no cover
    • 1: less than 17% cover
    • 2: 17-49%
    • 3: 50-83% cover
    • 4: 84-100% cover
74. moss: total bryophyte (moss and liverwort) cover (unit: dimensionless / missing value: NA)
75. clubmoss: total lycopod (clubmoss) cover. Sum of each lycopod species cover. (unit: dimensionless / missing value: NA)
76. fern: total fern cover. Sum of each fernspecies cover. (unit: dimensionless / missing value: NA)
77. herb: total herb cover. Sum of each herb species cover. (unit: dimensionless / missing value: NA)
78. gram: total graminoid cover (grass, sedge, rush). Sum of each graminoid species cover (unit: dimensionless / missing value: NA)
79. notes: notes

hf002-10: recruitment

1. year: year (estimates of recruitment prior to 2000 can be estimated from the 10m2 sub-plots sampled 1990-1999, hf002-04; filter for dbh greater than or equal to 5cm)
2. plot: plot
   • CONTROL: control
   • PULLDOWN: pulldown (experimental)
3. gridcell: location within 10m x 10m grid cell in the experimental (160m x 50m) or control (120m x 50m) plot
4. tree: tag number (2010 onward; trees not tagged from 2000-2009)
5. x: cartesian coordinate identifying location within the plot along its 50 m axis (note: 0,0 is at northwest corner) (2010 onward; trees not mapped from 2000-2009) (unit: meter / missing value: NA)
6. y: cartesian coordinate identifying location within the plot along its 120 m (control) or 160 m (experimental) axis (note: 0,0 is at northwest corner) (2010 onward; trees not mapped from 2000-2009) (unit: meter / missing value: NA)
7. species: species names
   • ACPE: Acer pensylvanicum
   • ACRU: Acer rubrum
   • ACSA: Acer saccharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betula papyrifera
   • CADE: Castanea dentata
   • CAGL: Carya glabra
   • CAOV: Carya ovata
   • CASP: Carya spp.
   • COAL: Cornus alternifolia
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • OSVI: Ostrya virginiana
   • PIST: Pinus strobus
   • POGR: Papulus garndidentata
   • POTR: Populus tremuloides
   • PRPE: Prunus pensylvanica
   • PRSE: Prunus serotina
   • QURU: Quercus rubra
   • SOAM: Sorbus americana
   • TSCA: Tsuga canadensis
8. dbh: diameter at breast height (1.37) (unit: centimeter / missing value: NA)
9. st.type: stem type, categorized by regeneration method
   • BASP: basal sprout
   • SAP: sapling regenerated from seed (could be present before the manipulation or germinated after the manipulation)
   • TRSP: trunk sprout
10. st.origin: for basal sprouts and trunk sprouts, the tree from which it has sprouted
11. substrate: not recorded in 2000, this notes the substrate from which the stem emerges. Basal sprouts and trunk sprouts listed as having TR (tree) as their substrate.
    • G: ground
    • M: mound (not specified which part of mound)
    • MB: mound base
    • MO: mound
    • MT: mound top
    • PE: pit edge
    • PT: pit
    • R: rock
    • ST: stump
    • TR: tree
12. notes: descriptive information about whether the tree is multi-stemmed, is growing on a mound/pit (for 2000, not noted in all cases), or other comments

hf002-11: regeneration notes

1. grid: location
   • TSIBD: located in pulldown site
   • TSICT: located in control site
2. st.no: identifier. Every sapling and sprout is tagged in the field with its number. Tags are removed from dead saplings and sprouts, but numbers are not re-used. In 1996, new saplings were assigned numbers in the 3000s, new sprouts were assigned numbers in the 6000s; in 1999, new saplings were assigned numbers in the 4000s, new sprouts were assigned numbers in the 7000s.
3. year: year of measurement
4. comments: comments