Pisgah Forest Permanent Plots

Data

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

Overview

• Lead: David Foster, Peter Schoonmaker
• Investigators: Audrey Barker-Plotkin, Jesse DeNormandie, Russell Stafford
• Contact: David Foster
• Start date: 1984-01-01
• End date: ongoing
• Location: Pisgah State Forest (Winchester NH)
• Latitude: +42.83
• Longitude: -72.44
• Elevation:
• Taxa:
• Research topic: plot, community, regional
• Study type: long-term measurement
• LTER core area: disturbance
• Keywords: forest dynamics, hurricane, old growth, regeneration
• Release date: 2000
• EML version: knb-lter-hfr.41.9
• Revisions: data updated 2009-05-20
• Related links:
• 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 2000, 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.

• Use:

  This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement. For more information on LTER Network data access and use policies, please see: http://www.lternet.edu/data/netpolicy.html.

• Citation:

  Foster D, Schoonmaker P. 2000. Pisgah Forest Permanent Plots. Harvard Forest Data Archive: HF041.

Detailed Metadata

hf041-01: trees

1. YEAR: year of measurement (YYYY)
2. PLOT: plot number. One of 14 20x20m plots.
3. SPECIES: species code
   • ACPE: Acer pennsylvanicum
   • ACRU: Acer rubrum
   • ACSA: Acer sachharum
   • BEAL: Betula alleghaniensis
   • BELE: Betula lenta
   • BEPA: Betual papyrifera
   • FAGR: Fagus grandifolia
   • FRAM: Fraxinus americana
   • PIRU: Picea rubens
   • QUBO: Quercus borealis (same as Quercus rubra)
   • TSCA: Tsuga canadensis
4. COND: condition
   • L: living
   • D: dead
5. DBH: Tree diameter measured at breast height (1.37m). In 1984 and 1990, measurements are to the nearest cm. In 1995, 2000 and 2006, measurements are to the nearest 0.1 cm. (centimeter )
6. 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 (YYYY)
2. SPEC.STEM: species code and stem type. Saplings = stems 20 cm height to 2 cm diameter at breast height. Seedlings = stems less than 20 cm tall. Sprouts = stems originating from dead tree bases or root sprouts.
3. PLOT: plot number. One of 14 20x20m plots.
4. COUNT: abundance. 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 sproutswere collected in 1984 and 1990 (sprouts were not counted in 1984). (number )

hf041-03: understory

1. YEAR: year of measurement (YYYY)
2. SPEC: species code and unknowns 1-14.
   • ARANUD: Aralia nudicaulis
   • ASTACU: Aster acuminatus
   • ASTSPP: Aster spp.
   • CLIBOR: Clintonia borealis
   • DENPUN: Dennstaedtia punctilobula
   • DRYMAR: Dryopteris marginalis
   • DRYSPI: Drypoteris spinulosa
   • EPIVIR: Epifagus virginiana
   • GAUPRO: Gaultheria procumbens
   • LONCAN: Lonicera canadensis
   • LONSPP: Lonicera spp.
   • LYCLUC: Lycopodium lucidulum
   • LYCOBS: Lycopodium obscurum
   • MAICAN: Maianthemum canadense
   • MEDVIR: Medeola virginiana
   • MITREP: Mitchella repens
   • MONUNI: Monotropa uniflora
   • POLVUL: Polypodium vulgare
   • SAMCAN: Sambucus canadensis
   • TRIBOR: Trientalis borealis
   • TRIUND: Trillium undulatum
   • TRISPP: Trillium spp.
   • UVUSES: Uvularia sessifolia
   • VACcfVAC: Vaccinium cf. vacillans
   • VACSPP: Vaccinium spp.
   • VIBACE: Viburnum acerifolium
   • VIBALN: Viburnum alnifolium
3. PLOT: plot number (1-14)
4. COUNT: abundance of each understory species per plot, using the following 10-point scale:
   • *: 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%

hf041-04: windthrow

1. PLOT#: plot number. One of 14 20x20m plots.
2. STEM#: stems are numbered starting at #1 in each plot
3. ANGLE: the orientation of the downed trees is recorded in degrees, based on magnetic (not true) north (degree )
4. DIA#1: diameter at the bottom end of the downed tree. Because of rot, this may be an approximate measurement. (centimeter )
5. DIA#2: diameter at the top end of the downed tree. Because of rot, this may be an approximate measurement. (centimeter )
6. LENGTH: length of the downed tree within the plot (meter )
7. COND: condition of tree
   • 1: solid
   • 2: partially decayed, broken
   • 3: decomposed into soil
   • NA: no data
8. ORIGIN: origin of tree
   • W: windthrow
   • S: snap
   • NA: no data