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Harvard Forest Data Archive

HF047

Regeneration Following Clearcutting Study at Harvard Forest since 1991

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Data

Overview

  • Lead: John O'Keefe
  • Investigators:
  • Contact: John O'Keefe
  • Start date: 1991
  • End date: 2000
  • Status: ongoing
  • Location: Prospect Hill Tract (Harvard Forest)
  • Latitude: +42.53178
  • Longitude: -72.18676
  • Elevation: 335 meter
  • Taxa:
  • Release date: 2007
  • Revisions:
  • EML file: knb-lter-hfr.47.18
  • DOI: digital object identifier
  • Related links:
  • Study type: long-term measurement
  • Research topic: large experiments and permanent plot studies; physiological ecology, population dynamics and species interactions
  • LTER core area: disturbance
  • Keywords: browsing, regeneration, timber harvest, vegetation dynamics
  • Abstract:

    Measurements of regeneration following removal in 1990 of a 64-year old red pine plantation on the Prospect Hill tract were continued for the twelfth year in 2001.

    Browsing in 2001 remained at very low levels (less than 2% of stems). As mean tree height continues to increase both the amount of browsing and the impact of browsing on future stand characteristics should remain low. Overall, our observations show that browsing has had little long-term impact during the regeneration of this stand. White ash, the most heavily browsed species, remains the most common species in the plots.

    After remaining quite stable over the past five years, in 2001 the overall stem density of tree species declined to 17,883 stems/ha, compared with 19,464 stems/ha in 2000, 19,414 stems/ha in 1999, 19,958 stems/ha in 1998, 19,414 stems/ha in 1997, and 20,696 stems/ha in 1996. The relative importance of major species has remained the same over the past six years. In 2001, white ash (36.5%) remained the most numerous tree species, followed by red maple (26.9%), sugar maple (14.4%) and black cherry (9.4%). These percentages changed little from 2000. After a slight decrease in 2000, red oak increased slightly to 7.5% of tree stems in 2001, the majority of which were small seedlings. Overall, the percentage of stems that originated as seedlings rather than sprouts decreased to 19.3%, down from 23.1% in 2000, 23.4% in 1999, 25.4% in 1998, and 23.7% in 1997. The majority of these seedlings (55.7%) were white ash, most less than 0.5 m tall.

    Mean stem height rose to 3.46 m, compared to 3.20 m in 2000, 3.24 m in 1999, 3.01 m in 1998, 2.92 m in 1997, 2.87 m in 1996 and 2.67 m in 1995. The resumption in mean height growth over the past year probably reflects low seedling establishment and mortality of seedlings and young sprouts less than 0.5 m tall along with continued growth of the taller stems. The tallest stems were 20 white ash, 15 red maples, 15 sugar maples, 6 black cherries, 5 pin cherries, 3 paper birches, and 1 trembling aspen greater than 7 m tall. Diameter at breast height (dbh) is now being recorded for all stems taller than seven meters. Of the five most common species, sugar maple had the tallest mean height (4.75 m), followed by red maple (3.98 m), black cherry (3.69m), and white ash (2.99 m). Because of the preponderance of small seedlings, red oak mean height was only 0.67 m. It remains to be seen how many seedlings will survive to play a role in the developing stand. Our next sampling will be done in year 15.

  • Methods:

    Species, height, origin and evidence of browsing were recorded for all woody stems on 50 milacre (1.13 m radius) plots established on a five-meter grid within the clearcut. A fenced exclosure was initially erected around half of the plots. The exclosure fence has not been maintained since year 5 because no evidence of significant differences in regeneration between the exclosure and the open area was found. Extensive mixed hardwood regeneration (generally less than 7 m tall) was cut back to the ground during harvest, ensuring at least initial dominance by sprouts.

  • Use:

    This dataset is released to the public under Creative Commons license CC BY (Attribution). 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.

  • Citation:

    O'Keefe J. 2007. Regeneration Following Clearcutting Study at Harvard Forest since 1991. Harvard Forest Data Archive: HF047.

Detailed Metadata

HF047-01: regeneration data

  1. plot: plot number, composed of the row (1-10) followed by the plot (1-5), ranging from 11 to 105
  2. year: year of sampling
  3. species: species code, composed of the first two letters of the Latin genus followed by the first two letters of the Latin species. If only two letters are used they represent the genus.
    • ACRU: Acer Rubrum red maple
    • ACSA: A. saccharum sugar maple
    • AM: Amelanchier sp. shadbush
    • BEAL: Betula alleghaniensis yellow birchB
    • BEPA: B. papyrifera paper birch
    • COAL: Cornus alternifolia alternate-leaved dogwood
    • FAGR: Fagu grandifolia beech
    • FRAM: Fraxinus Americana white ash
    • ILVE: Ilex verticillata winterberry
    • LO: Lonicera sp. honeysuckle
    • NEMU: Nemopanthus mucronata mountain holly
    • PIRE: Pinus resinosa red pine
    • PIST: P. strobus white pine
    • POTR: Populus tremuloides trembling aspen
    • PRPE: Prunus pensylvanica pin cherry
    • PRSE: P. serotina black cherry
    • QUAL: Quercus alba white oak
    • QURU: Q. rubra red oak
    • VI: Vitis sp. grape
    • VICA: Viburnum cassinoides withered
    • VIDE: V. dentatutm arrowwood
  4. clump: clump identifier. These are not tagged or consistent from year to year, but indicate that stems in different height classes are part of the same clump. Stems of seedling origin represent a single stem clump.
  5. origin: origin of stem
    • SE: seedling
    • SP: sprout
  6. browse: whether the stem appears browsed
    • 0: none
    • 1: lightly
    • 2: moderately/heavily
  7. stem: number of stems in the clump within a given height class (unit: number / missing value: NA)
  8. height: height class of the stem(s)
    • 1: 0.1 - 0.5 m
    • 2: 0.5 - 1.0 m
    • 3: 1.0 - 2.0 m
    • 4: 2.0 - 3.0 m
    • 5: 3.0 - 5.0 m
    • 6: 5.0 - 7.0 m
    • 7: >7.0 m
  9. stem.id: unique tag number given to each stem taller than 7 meters, consisting of the plot number followed by the assigned stem number
  10. dbh: diameter at breast height (1.3 m) (unit: centimeter / missing value: NA)
  11. comments: comments