Harvard Forest

Data Archive

HF041

Permanent Plots at Pisgah State Forest in Winchester NH since 1984

Related Publications

Data

• hf041-01: trees (preview)
• hf041-02: regeneration (preview)
• hf041-03: understory (preview)
• hf041-04: windthrow (preview)

Overview

• Lead: David Foster, Peter Schoonmaker
• Investigators: Audrey Barker Plotkin, Jesse DeNormandie, Russell Stafford
• Contact: Information Manager
• Start date: 1984
• End date: 2024
• Status: ongoing
• Location: Pisgah State Forest (NH)
• Latitude: +42.83 degrees
• Longitude: -72.44 degrees
• Elevation:
• Datum: WGS84
• Taxa:
• Release date: 2025
• Language: English
• EML file: knb-lter-hfr.41.25
• DOI: digital object identifier
• EDI: data package
• DataONE: data package
• Related links:
• Study type: long-term measurement
• Research topic: large experiments and permanent plot studies; physiological ecology, population dynamics and species interactions; regional studies
• LTER core area: disturbance patterns
• Keywords: hurricane damage, old growth forests, permanent plots, regeneration, vegetation dynamics
• Abstract:

  There are relatively few studies that have examined forest structure and composition both before and after a catastrophic wind disturbance has altered the forest. On a twenty acre parcel of old-growth forest located in the Pisgah State Forest in southwest New Hampshire, the collection of a long term data set from 1907-1995 has made it possible to consider how the hurricane of 1938 altered forest structure, species composition, and subsequent forest development in the stand. Various types of information were gathered throughout the century that allowed the quantification of forest structure and composition: species identification, diameter measurements, tree status (living or dead), tree cores, and individual tree growth and mortality have recently been tracked. The old-growth forest before 1938 was dominated by a Pinus-Tsuga-Hardwood mix. The hurricane left the forest devastated and incredibly altered. The total basal area of the forest was drastically reduced from approximately 70m2/ha to about 5m2/ha after the disturbance. White pine was effectively lost from the stand while many large Tsuga were also blown down. A large increase in density was subsequently recorded as many post-disturbance species took advantage of the resources that had been made available, especially light. Although there was a high level of destruction, a good amount of Tsuga and Fagus that had previously existed in the understory was released from suppression and grew to fill in parts of the overstory. Both the forest structure and the species composition changed from a relatively homogeneous state before the hurricane to an extremely heterogeneous one after the hurricane. The overall development of the stand followed the typical path of a recently disturbed area: after the initial increase in density in the few years after the storm, basal area has been steadily increasing while density has steadily decreased. It has also been possible to observe differences in the ability of individual species to react to the hurricane. Tsuga and Fagus are exhibiting a much-increased ability to remain in the stand while other post-disturbance species such as Betula and Acer are suffering much higher mortality. Although the forest already has very low tree species diversity, it will continue to drop with time as more and more of the post-disturbance hardwoods are lost to mortality.

• Methods:

  Data available on-line are from 14, 20m x 20m permanent plots established in 1984. Data collected include tree diameters, abundance of regeneration (saplings, seedlings and sprouts), understory flora abundance, and measurements of trees windthrown in 1938.

  Notes on tree measurements: There has been inconsistency in the methods used to record forked trees. The method used in 1984 is not known. In 1990 and from 2000 on, stems forking below breast height were listed as separate stems in the data files. However, in 1995, stems forking below breast height were lumped. In cases of forked trees, the diameter of each fork was measured and the sum of these was recorded as one diameter measurement on the field data sheet (e.g., in one case. a tagged birch in 1990 had a diameter of 12cm or so, in 1995 a diameter of 54cm and in 2000 of about 14cm. When the data sheet was checked, it just listed the diameter as 54 cm, stating in parentheses that this included 4 stems). Therefore, the stem counts in 1995 are not directly comparable to the other years, and the basal area calculations for 1995 are inflated.

  Original data sheets for 1995 and 2000 were examined closely and a revised version of the 1995 tree data was created. This revised file is the one included in the Web Data Catalog. In this revised file, diameters for all multiple-stemmed trees that could be found were split into separate diameter measurements, so that basal area calculations would be more accurate and data more comparable among sample years. However, since most trees are not tracked as individuals, it is likely that some problems still remain in the 1995 tree data file.

• 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, Schoonmaker P. 2025. Permanent Plots at Pisgah State Forest in Winchester NH since 1984. Harvard Forest Data Archive: HF041 (v.25). Environmental Data Initiative: https://doi.org/10.6073/pasta/da73d72739e2243aa7e86fb793cff76e.

Detailed Metadata

hf041-01: trees

1. year: year of measurement
2. plot: plot number. One of 14 20x20m plots.
3. species: species code
   • ACPE: Acer pensylvanicum
   • ACRU: Acer rubrum
   • ACSA: Acer saccharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betual papyrifera
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • PIRU: Picea rubens
   • PIST: Pinus strobus
   • PRSE: Prunus serotina
   • QURU: Quercus rubra
   • TSCA: Tsuga canadensis
4. dbh: tree diameter measured at breast height (1.37m). In 1984 and 1990, measurements are to the nearest cm. Thereafter, measurements are to the nearest 0.1 cm. (unit: centimeter / missing value: NA)
5. cond: condition
   • L: living
   • D: dead
6. vigor: for hemlock trees only. Vigor rating is based on visual estimate of foliage loss.
   • 1: 0-25% foliar loss
   • 2: 25-50% foliar loss
   • 3: 50-75% foliar loss
   • 4: 75-99% foliar loss
   • 5: dead
7. tag: tag number for the subset of trees that have tags; recorded beginning with the 2006 census
8. notes: notes on individual trees (tag # for the subset of trees that have tags), tree health, etc.

hf041-02: regeneration

1. year: year of measurement
2. species: species code
   • ACPE: Acer pensylvanicum
   • ACRU: Acer rubrum
   • ACSP: Acer species or Acer spicatum?
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betula papyrifera
   • BESP: Betula species
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • NYSY: Nyssa sylvatica
   • PIRU: Picea rubens
   • PIST: Pinus strobus
   • PRSE: Prunus serotina
   • PRSP: Prunus species
   • QUAL: Quercus alba
   • QURU: Quercus rubra
   • TSCA: Tsuga canadensis
   • UNK: unknown tree species
3. size: size categories varied by sample year. In 1984 and 1990, Saplings = stems 20 cm height to 2 cm diameter at breast height. Seedlings = stems less than 20 cm tall. In 1990 only, Sprouts = stems originating from dead tree bases or root sprouts (but of no specific size range). From 2010 onward, all and only stems under 1m tall were included.
4. plot: plot number. One of 14 20x20m plots.
5. count: abundance, for 1984 and 1990. Abundances listed are generally the total number of stems counted in each plot. In some cases, a species was noted but no count was listed; in these cases, presence of the species is indicated by an asterisk (*). In some cases, the number of stems was very numerous and the abundance is qualitatively listed as "many." Abundance data for saplings, seedlings and sprouts were collected in 1984 and 1990 (sprouts were not counted in 1984).
6. cover: in 2010, cover classes rather than counts were recorded using the following 10-point scale
   • *: a single individual
   • 1: 1-2 individuals
   • 2: less than 1%
   • 3: B1-4%
   • 4: 4-10%
   • 5: 11-25%
   • 6: 26-33%
   • 7: 34-50%
   • 8: 51-75%
   • 9: 76-90%
   • 10: 91-100%
7. notes: notes

hf041-03: understory

1. year: year of measurement
2. species: species code and unknowns
   • ACTSPE: Actea cr. pachypodium
   • ARANUD: Aralia nudicaulis
   • ASTACU: Aster acuminatus
   • ASTDIV: Aster divaricatus
   • ASTSPP: Aster species
   • CARSPP: Carex species (CARSPP2, CARSPP3 etc. if more than one distinct Carex species identified within a plot)
   • CLIBOR: Clintonia borealis
   • CORALT: Cornus alternifolia
   • DENPUN: Dennstaedtia punctilobula
   • DIELON: Diervilla lonicera
   • DRYMAR: Dryopteris marginalis
   • DRYSPI: Dryopteris spinulosa
   • DRYSPP: Dryopteris species
   • EPIVIR: Epifagus virginiana
   • GAUPRO: Gaultheria procumbens
   • GOOSPE: Goodyera species (likely tesselata)
   • HAMVIR: Hamamelis virginiana
   • LONCAN: Lonicera canadensis
   • LONSPP: Lonicera spp.
   • LYCLUC: Lycopodium lucidulum
   • LYCOBS: Lycopodium obscurum
   • MAICAN: Maianthemum canadense
   • MEDVIR: Medeola virginiana
   • MITREP: Mitchella repens
   • MONUNI: Monotropa uniflora
   • POLACR: Polystichum acrostichoides
   • POLPUB: Polygonatum pubescens
   • POLVUL: Polypodium vulgare
   • RUBIDA: Rubus idaeus
   • RUBSPP: Rubus species
   • SAMCAN: Sambucus canadensis
   • TRIBOR: Trientalis borealis
   • TRIUND: Trillium undulatum
   • TRISPP: Trillium spp.
   • UVUSES: Uvularia sessilifolia
   • VACANG: Vaccinium angustifolium
   • VACcfVAC: Vaccinium cf. vacillans
   • VACSPP: Vaccinium spp.
   • VIBACE: Viburnum acerifolium
   • VIBALN: Viburnum alnifolium
   • VIBSPE: Viburnum species
3. plot: plot number (1-14)
4. cover: abundance of each understory species per plot, using the following 10-point scale (maximum cover observed was class 3)
   • *: a single individual
   • 1: 1-2 individuals
   • 2: less than 1%
   • 3: 1-4%
   • 4: 4-10%
   • 5: 11-25%
   • 6: 26-33%
   • 7: 34-50%
   • 8: 51-75%
   • 9: 76-90%
   • 10: 91-100%
5. notes: notes

hf041-04: windthrow

1. year: year of measurement
2. plot: plot number. One of 14 20x20m plots.
3. stem: stems are numbered starting at #1 in each plot. Stem numbers for 1984 and 2015 do not match, so change over time for individual pieces is not possible.
4. species: not recorded in 1984. In 2015, identity of the piece, to species of genus if possible, but sometimes listed simply as ‘conifer’, ‘deciduous’, or ‘unknown’
   • ACRU: Acer rubrum
   • BELE: Betula lenta
   • BEPA: Betula papyrifera
   • BETULA: Betula species
   • CONIFER: conifer
   • DECIDUOUS: deciduous
   • FAGR: Fagus grandifolia
   • PIST: Pinus strobus
   • TSCA: Tsuga canadensis
   • UNKNOWN: unknown
5. angle: the orientation of the downed trees is recorded in degrees, based on magnetic (not true) north (unit: degree / missing value: NA)
6. dia1: diameter at the bottom end of the downed tree in 1984. Because of rot, this may be an approximate measurement. If the bottom end of the tree is outside of the plot, the bottom diameter is measured at the plot boundary. (unit: centimeter / missing value: NA)
7. dia2: diameter at the top end of the downed tree in 1984. Because of rot, this may be an approximate measurement. If the top end of the tree is outside of the plot, the top diameter is measured at the plot boundary. (unit: centimeter / missing value: NA)
8. length: length of the downed tree within the plot, that is, if part of the downed tree is outside the plot boundary, it is not included in the measurement (unit: meter / missing value: NA)
9. cond1.3: condition of tree (recorded in 1984 and 2015)
   • 1: solid
   • 2: partially decayed, broken
   • 3: decomposed into soil
   • NA: no data
10. cond1.5: condition of tree on a 5-point decay scale (2015 only)
    • 1: Wood intact and hard. Bark intact. Fine twigs (possibly needles/leaves) present. Cross-sectional shape is round. Tree may be elevated by supporting branches. No invading roots.
    • 2: Wood intact and hard. Bark has begun to detach. Fine twigs and needles/leaves absent. Cross-sectional shape is round. Tree may be elevated but sagging slightly. No invading roots.
    • 3: Wood is hard to partially soft. Some bark may remain attached. Cross-sectional shape is round. Tree may be sagging near the ground. Roots invade sapwood.
    • 4: Wood substantially decayed and pieces easily slough off. Some bark may remain. Cross-sectional shape is elliptical. Tree on the ground. Roots invade the heartwood.
    • 5: Wood decayed throughout. May be in many soft portions or punky and resembling organic soil. Shape elliptical to flattened. Tree is on the ground, partially sunken into the organic layer.
11. origin: origin of tree
    • W: windthrow
    • S: snap
    • NA: no data
12. notes: notes