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Harvard Forest Data Archive

HF029

Long-term Stand Dynamics in Central Massachusetts 1500-2000

Related Publications

Data

Overview

  • Lead: David Foster, Jason McLachlan
  • Investigators:
  • Contact: David Foster
  • Start date: 1500
  • End date: 2000
  • Status: completed
  • Location: Prospect Hill Tract (Harvard Forest), Slab City Tract (Harvard Forest)
  • Latitude: +42.45 to +42.55
  • Longitude: -72.20 to -72.16
  • Elevation: 205 to 420 meter
  • Taxa: Betula (birch), Castanea (chestnut), Pinus (pine), Quercus (oak), Tsuga (hemlock)
  • Release date: 2013
  • Revisions:
  • EML file: knb-lter-hfr.29.19
  • DOI: digital object identifier
  • Related links:
  • Study type: paleological
  • Research topic: historical and retrospective studies; regional studies
  • LTER core area: disturbance
  • Keywords: dendrochronology, human disturbance, paleoecology, succession, vegetation dynamics
  • Abstract:

    The long-term impact of human land-use is among the most important factors influencing the development of vegetation in New England, a region which experienced extensive agricultural clearance in the 19th century and subsequent reforestation during this century. We employed stand-level pollen stratigraphies and tree-ring chronologies to examine the post-settlement dynamics of hemlock stands which have never been pastured or plowed, representing among the least disturbed parts of the central Massachusetts landscape. Although the sites are currently dominated by large Tsuga canadensis individuals and give the impression of great age and stability, our results indicate that they have dynamic developmental histories driven by exogenous disturbance factors, including logging, forest pathogens, catastrophic wind disturbance, and fire. Sites containing pre-settlement pollen assemblages indicate stand compositions at this time which were substantially different from each other and from modern assemblages. Pollen assemblages similar to those of modern stands were not established in any of our sites until the 20th century and the mechanisms by which these assemblages arose was considerably different in each stand, indicating great flexibility of forest response to a variety of disturbance types.

  • Methods:

    We recorded species, diameter at breast height, and crown class for all individuals greater than 2.5 cm in basal diameter in a 30 x30 m plot in each stand centered around the site of the humus monolith. General compositional records for each site since 1907 were obtained from Harvard Forest archival materials, and stem numbers and diameters measured in 1937 were available from 0.05-ha and 0.1-ha plots overlapping or adjacent to each of the current study sites. Disturbance histories for the town of Petersham and for the individual sites were compiled from a number of archival sources.

    We cored all stems greater than 2.5 cm dbh in each plot at the base and measured annual growth increments to the nearest 0.01 mm. A 30 x 30 cm humus monolith was removed from the center of each plot and was subsampled for pollen analysis at 1-2 cm intervals. Chronologies for the pollen records from Slab City IX and Slab City X were derived using parabolic curves fit through three pollen stratigraphic markers: European settlement (1730), marked by an increase in the agricultural weed species Ambrosia and Poaceae; the chestnut blight (1914), marked by a decline in Castanea pollen; and the uppermost assemblage (1995).

  • 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:

    Foster D, McLachlan J. 2013. Long-term Stand Dynamics in Central Massachusetts 1500-2000. Harvard Forest Data Archive: HF029.

Detailed Metadata

hf029-01: summary data

  1. plot: plot
    • PH2: Prospect Hill II
    • PH7: Prospect Hill VII
    • SC9: Slab City IX
    • SC10: Slab City X
  2. species: species name
    • Wp: Pinus strobes
    • hem: Tsuga
    • fg: Fagus grandifolia
    • rm: Acer rubrum
    • bb: Betula lenta
    • ro: Quercus rubra
    • yb: Betula alleghaniensis
    • fp: Fraxinus pennsylvanica
    • wa: Fraxinus Americana
    • pb: Betula papyrifera
  3. density: tree density (stems/ha) (unit: numberPerHectare / missing value: NA)
  4. basal.area: tree basal area (m2/ha) (unit: meterSquaredPerHectare / missing value: NA)

hf029-02: pollen

  1. plot: plot name
    • PH2: Prospect Hill II
    • PH7: Prospect Hill VII
    • SC9: Slab City IX
    • SC10: Slab City X
  2. depth: depth in centimeters in the sediment column (unit: centimeter / missing value: NA)
  3. taxa: individual taxa
  4. count: number of pollen grains of individual taxa identified (unit: number / missing value: NA)