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Harvard Forest Data Archive

HF048

Hemlock Understory Vegetation Plots at Harvard Forest since 2002

Related Publications

Data

Overview

  • Lead: David Foster, David Orwig
  • Investigators: Audrey Barker Plotkin
  • Contact: Audrey Barker Plotkin
  • Start date: 2002
  • End date: 2016
  • Status: ongoing
  • Location: Prospect Hill Tract (Harvard Forest), Slab City Tract (Harvard Forest)
  • Latitude: +42.45 to +42.55
  • Longitude: -72.22 to -72.18
  • Elevation: 250 to 350 meter
  • Taxa: Tsuga canadensis (eastern hemlock)
  • Release date: 2016
  • Revisions:
  • EML file: knb-lter-hfr.48.19
  • 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: hemlock woolly adelgid, hemlock, understory vegetation, vegetation dynamics
  • Abstract:

    Hemlock (Tsuga canadensis) forests in New England are changing rapidly with the invasion of the hemlock woolly adelgid (HWA, Adelges tsugae), an exotic insect pest that kills hemlock trees. As the adelgid invades hemlock stands at Harvard Forest, we are monitoring how forest structure and function changes. We surveyed community vegetation structure and composition prior to adelgid infestation, and are repeating this survey as infestation progresses. These measurements will allow us to link the long-term history of these hemlock stands to other current studies of hemlock response to adelgid infestation.

  • Methods:

    In 2002, we surveyed understory vegetation in existing hemlock-dominated plots at the Harvard Forest. Three plots were in or adjacent to the Hemlock Mapped Tree Plot (HF031), three were plots established in 1996 by Jennifer Jenkins (Jenkins, J. C., Aber, J. D., Canham, C. 1999. Hemlock woolly adelgid impacts on community structure and N cycling rates in eastern hemlock forest. Canadian Journal of Forest Research 29: 630-645.), and four were plots established in 1995 by Jason McLachlan (HF029 and HF053).

    In each plot, we established two transects running north-south. Five 1 m2 subplots were spaced evenly along each transect. We labeled the NW corner, unless otherwise noted. Transects are marked with string and yellow tent stakes (no string at Jenkins plots), and plots are marked with pink flags.

    Within each sub-plot, we estimated percent cover for herbs, shrubs, and seedlings to the nearest one percent. We counted the number of seedlings by species. A seedling is a tree less than 1.3m tall. If rocks or coarse woody debris covered a significant portion of the plot, their percent cover was recorded. In addition, the depth of the organic soil layer was measured to the nearest 0.5 cm at the NW corner of each subplot. We searched each plot and compiled a species list for the entire 20m x 20m or 30m x 30m area.

    Saplings were tallied by species across the plot. A sapling is a tree greater than 1.3m tall but less than 8cm in diameter. They were noted live or dead.

    In 2012, we resampled the understory vegetation (seedlings, saplings, herbs, shrubs, species list, substrates) only in the four plots established by Jason McLachlan. Organic layer depth was not measured in 2012. In 2016, we resampled understory vegetation and organic layer depth in the three plots associated with the Hemlock Mapped Tree Plot, and the four McLachlan plots. We discontinued measurements in the three Jenkins plots because these had less long-term ecological data, and are located nearby and in very similar forest to one of the McLachlan plots.

  • 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, Orwig D. 2016. Hemlock Understory Vegetation Plots at Harvard Forest since 2002. Harvard Forest Data Archive: HF048.

Detailed Metadata

hf048-01: o-layer

  1. plot: plot code
    • HG1: 20m x 20m plot within hemlock woodlot mapped plot on Prospect Hill Tract, Compartment 2 (the one with the huge O layer closest to BG swamp)
    • HG2: 20m x 20m plot within hemlock woodlot mapped plot (has lots of hemlock seedlings)
    • HG3: 20m x 20m plot just outside hemlock woodlot
    • PH2: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 2
    • PH7: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 7
    • SC1: 20m x 20m plot hemlock plot on Slab City Tract, Compartment 9
    • SC2: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC3: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC9: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 9
    • SC10: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 10
  2. subplot: number of 1m2 subplot
  3. year: year of measurement
  4. o.layer: depth of organic soil layer to the nearest 0.5 cm (unit: centimeter / missing value: NA)

hf048-02: substrate

  1. plot: plot code
    • HG1: : 20m x 20m plot within hemlock woodlot mapped plot on Prospect Hill Tract, Compartment 2 (the one with the huge O layer closest to BG swamp)
    • HG2: 20m x 20m plot within hemlock woodlot mapped plot (has lots of hemlock seedlings)
    • HG3: 20m x 20m plot just outside hemlock woodlot
    • PH2: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 2
    • PH7: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 7
    • SC1: 20m x 20m plot hemlock plot on Slab City Tract, Compartment 9
    • SC2: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC3: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC9: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 9
    • SC10: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 10
  2. subplot: number of 1m2 subplot
  3. year: year of measurement
  4. rock: percent cover of rocks (except for 2002, estimated to the nearest 5%) (unit: dimensionless / missing value: NA)
  5. tree: percent cover of tree stem (except for 2002, estimated to the nearest 5%) (unit: dimensionless / missing value: NA)
  6. down.wood: percent cover of down wood (except for 2002, estimated to the nearest 5%) (unit: dimensionless / missing value: NA)

hf048-03: herb

  1. year: year of measurement
  2. plot: plot code
    • HG1: 20m x 20m plot within hemlock woodlot mapped plot on Prospect Hill Tract, Compartment 2 (the one with the huge O layer closest to BG swamp)
    • HG2: 20m x 20m plot within hemlock woodlot mapped plot (has lots of hemlock seedlings)
    • HG3: 20m x 20m plot just outside hemlock woodlot
    • PH2: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 2
    • PH7: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 7
    • SC1: 20m x 20m plot hemlock plot on Slab City Tract, Compartment 9
    • SC2: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC3: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC9: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 9
    • SC10: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 10
  3. subplot: number of 1m2 subplot
  4. aranud: percent cover of Aralia nudicaulis. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  5. aritri: percent cover of Arisaema triphyllum. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  6. clibor: percent cover of Clintonia borealis. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  7. copgro: percent cover of Coptis groenlandica. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  8. denpun: percent cover of Dennstaedtia punctilobula. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  9. dryspi: percent cover of Dryopteris spinulosa. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  10. epirep: percent cover of Epigaea repens. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  11. galspe: percent cover of Galium species. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  12. lycluc: percent cover of Lycopodium lucidulum. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  13. maican: percent cover of Maianthemum canadense. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  14. medvir: percent cover of Medeola virginiana. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  15. monuni: percent cover of Monotropa uniflora. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  16. osmcin: percent cover of Osmunda cinnamomea. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  17. oxaspe: percent cover of Oxalis species. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  18. tribor: percent cover of Trientalis borealis. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  19. triund: percent cover of Trillium undulatum. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  20. uvuses: percent cover of Uvularia sessilifolia. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  21. unk: percent cover of unknown species. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)

hf048-04: shrub

  1. year: year of measurement
  2. plot: plot code
    • HG1: 20m x 20m plot within hemlock woodlot mapped plot on Prospect Hill Tract, Compartment 2 (the one with the huge O layer closest to BG swamp)
    • HG2: 20m x 20m plot within hemlock woodlot mapped plot (has lots of hemlock seedlings)
    • HG3: 20m x 20m plot just outside hemlock woodlot
    • PH2: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 2
    • PH7: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 7
    • SC1: 20m x 20m plot hemlock plot on Slab City Tract, Compartment 9
    • SC2: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC3: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC9: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 9
    • SC10: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 10
  3. subplot: number of 1m2 subplot
  4. gaupro: percent cover of Gaultheria procumbens. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  5. mitrep: percent cover of Mitchella repens. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  6. ilemuc: percent cover of Ilex mucronata. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  7. rhonud: percent cover of Rhododendron nudiflorum. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  8. vacang: percent cover of Vaccinium angustifolium. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  9. viblan: percent cover of Viburnum lantanoides. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)

hf048-05: seedling density

  1. year: year of measurement
  2. plot: plot code
    • HG1: 20m x 20m plot within hemlock woodlot mapped plot on Prospect Hill Tract, Compartment 2 (the one with the huge O layer closest to BG swamp)
    • HG2: 20m x 20m plot within hemlock woodlot mapped plot on Prospect Hill Tract, Compartment 2 (the one with the huge O layer closest to BG swamp)
    • HG3: 20m x 20m plot just outside hemlock woodlot
    • PH2: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 2
    • PH7: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 7
    • SC1: 20m x 20m plot hemlock plot on Slab City Tract, Compartment 9
    • SC2: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC3: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC9: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 9
    • SC10: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 10
  3. subplot: number of 1m2 subplot
  4. acru: number of Acer rubrum seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  5. bele.beal: number of Betula lenta or Betula alleghaniensis (difficult to distinguish as seedlings) seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  6. bepa: number of Betula papyrifera seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  7. fagr: number of Fagus grandifolis seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  8. nysy: number of Nyssa sylvatica seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  9. piru: number of Picea rubens seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  10. pist: number of Pinus strobus seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  11. prse: number of Prunus serotina seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  12. quru: number of Quercus rubra seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  13. tsca: number of Tsuga canadensis seedlings observed in the 1m2 plot (unit: number / missing value: NA)
  14. unk: number of seedlings of unknown species observed in the 1m2 plot (unit: dimensionless / missing value: NA)

hf048-06: seedling cover

  1. year: year of measurement
  2. plot: plot code
    • HG1: 20m x 20m plot within hemlock woodlot mapped plot on Prospect Hill Tract, Compartment 2 (the one with the huge O layer closest to BG swamp)
    • HG2: 20m x 20m plot within hemlock woodlot mapped plot (has lots of hemlock seedlings)
    • HG3: 20m x 20m plot just outside hemlock woodlot
    • PH2: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 2
    • PH7: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 7
    • SC1: 20m x 20m plot hemlock plot on Slab City Tract, Compartment 9
    • SC2: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC3: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC9: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 9
    • SC10: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 10
  3. subplot: number of 1m2 subplot
  4. acru: percent cover of Acer rubrum. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  5. bele.beal: percent cover of Betula lenta or Betula alleghaniensis (difficult to distinguish as seedlings). Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  6. bepa: percent cover of Betula papyrifera. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  7. fagr: percent cover of Fagus grandifolis. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  8. nysy: percent cover of Nyssa sylvatica. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  9. piru: percent cover of Picea rubens. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  10. pist: percent cover of Pinus strobus. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  11. prse: percent cover of Prunus serotina. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  12. quru: percent cover of Quercus rubra. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  13. tsca: percent cover of Tsuga canadensis. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)
  14. unk: percent cover of unknown species. Cover was recorded to the nearest 1%. A cover % of 0.5% was assigned to species present within a subplot but with less than 1% cover. (unit: dimensionless / missing value: NA)

hf048-07: sapling

  1. year: year of measurement
  2. plot: plot code
    • HG1: 20m x 20m plot within hemlock woodlot mapped plot on Prospect Hill Tract, Compartment 2 (the one with the huge O layer closest to BG swamp)
    • HG2: 20m x 20m plot within hemlock woodlot mapped plot (has lots of hemlock seedlings)
    • HG3: 20m x 20m plot just outside hemlock woodlot
    • PH2: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 2
    • PH7: 30m x 30m hemlock history plot located on Prospect Hill Tract, Compartment 7
    • SC1: 20m x 20m plot hemlock plot on Slab City Tract, Compartment 9
    • SC10: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 10
    • SC2: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC3: 20m x 20m plot Jenkins plot on Slab City Tract, Compartment 9
    • SC9: 30m x 30m hemlock history plot located on Slab City Tract, Compartment 9
  3. species: species
    • ACPE: Acer pensylvanicum
    • ACRU: Acer rubrum
    • BELE: Betula lenta
    • CADE: Castanea dentata
    • FAGR: Fagus grandifolia
    • TSCA: Tsuga canadensis
  4. status: status
    • L: live
    • D: dead
  5. hwa: hemlock woolly adelgid (measured on TSCA only, based on visual inspection of branches within reach)
    • 1: present
    • 0: absent
  6. number: number of stems in the 20x20 or 30x30 m plot (unit: number / missing value: NA)
  7. plot.size: size of plot (unit: hectare / missing value: NA)
  8. num.ha: number of stems on a per hectare basis (unit: number / missing value: NA)
  9. note: note

hf048-08: species distribution

  1. type: vegetation type
    • F: ferns / lycopods
    • G: graminoids
    • H: herbs
    • S: shrubs
    • T: trees
  2. species: species name (Latin)
  3. common.name: common name of the plant
  4. hg1.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  5. hg2.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  6. hg3.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  7. ph2.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  8. ph7.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  9. sc9.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  10. sc10.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  11. sc1.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  12. sc2.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  13. sc3.02: presence or absence of each species in the plot in 2002
    • 0: absent
    • 1: present
  14. ph2.12: presence or absence of each species in the plot in 2012
    • 0: absent
    • 1: present
  15. ph7.12: presence or absence of each species in the plot in 2012
    • 0: absent
    • 1: present
  16. sc9.12: presence or absence of each species in the plot in 2012
    • 0: absent
    • 1: present
  17. sc10.12: presence or absence of each species in the plot in 2012
    • 0: absent
    • 1: present
  18. hg1.16: presence or absence of each species in the plot in 2016
    • 0: absent
    • 1: present
  19. hg2.16: presence or absence of each species in the plot in 2016
    • 0: absent
    • 1: present
  20. hg3.16: presence or absence of each species in the plot in 2016
    • 0: absent
    • 1: present
  21. ph2.16: presence or absence of each species in the plot in 2016
    • 0: absent
    • 1: present
  22. ph7.16: presence or absence of each species in the plot in 2016
    • 0: absent
    • 1: present
  23. sc9.16: presence or absence of each species in the plot in 2016
    • 0: absent
    • 1: present
  24. sc10.16: presence or absence of each species in the plot in 2016
    • 0: absent
    • 1: present