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Hemlock Removal Experiment - Community and Ecosystem Impacts

HF054 EML Publications Archive

Data

Overview

  • Lead: David Orwig, David Foster
  • Investigators: Heidi Lux
  • Contact: David Orwig
  • Start date: 2003-08-05
  • End date: ongoing
  • Location: Simes Tract (Harvard Forest)
  • Latitude: +42.47 to +42.48
  • Longitude: -72.22 to -72.21
  • Elevation: 200 to 240 meters
  • Taxa: Adelgis tsugae (hemlock woolly adelgid), Betula lenta (black birch), Tsuga canadensis (eastern hemlock)
  • Research topic: plot, community
  • Study type: long-term measurement
  • LTER core area: disturbance
  • Keywords: pest infestation, salvage logging, successional dynamics, tree mortality, Tsuga canadensis
  • Release date: 2009
  • EML version: knb-lter-hfr.54.7
  • Revisions:
  • Related links:
  • Abstract:

    Hemlock decline in New England is caused by direct and indirect effects of invasion of the hemlock woolly adelgid. Direct damage from the insect is causing gradual mortality of hemlock, and widespread harvesting of hemlock in advance of mortality creates a contrasting disturbance. Although both processes affect thousands of acres of forest annually, we have only a limited understanding of their effects on forest ecosystem function and productivity and the nature of the subsequent forest community. We anticipate that harvesting will yield different consequences than gradual mortality from the insect. Therefore we have designed an experiment to simulate the impact of both in order to contrast them. To simulate some of the effects of the adelgid (e.g., progressive mortality, retention of the wood on the site) we are girdling all hemlocks in a hemlock-dominated stand. In the adjacent area we are conducting a commercial harvesting of hemlock. Results from both experimental treatments will be compared to the changes observed in forests that are being infested by the adelgid, and can also be included in integrated analyses of a suite of large experiments that form a core component of the Harvard Forest LTER program.

  • Methods:

    Nitrogen mineralization was measured using 4 closed-topped cores at each of eight 30 x 30 m plots. Sampling occurred at 5-week intervals during each growing season with one set of cores left over winter. An additional assessment of forest floor N availability and mobility was determined from mixed-bed cation + anion resin bags that were buried for 6-month intervals at the organic layer-mineral layer interface (ca. 5 cm) in each sampling plot. Soil temperature at 1 and 5 cm depths were measured at each soil sampling plot every 30 minutes throughout the growing season using iButton temperature data loggers.

    Soil samples were returned to the laboratory on ice and processed the next day. Organic and mineral soils were passed through a 5.0 mm mesh screen, weighed for total mass, and subsampled for gravimetric moisture and inorganic N. NH4-N and NO3-N were extracted from all soils using 1M KCl and from resin bags using 2M KCl and concentrations were determined colorimetrically with a Lachat flow-injection 8500 autoanalyzer.

    We determined the following properties of soils collected during our initial sampling at each site: organic matter by loss on ignition (5.5 hrs at 550 oC), pH in a soil and CaCl2 slurry (1:10 organic soil:solution; 1:4 mineral soil:solution), and total C and N content by dry combustion with our Fisons CHN autoanalyzer. Remaining organic and mineral soils were air-dried and stored in our sample archive.

  • 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:

    Orwig D, Foster D. 2009. Hemlock Removal Experiment - Community and Ecosystem Impacts. Harvard Forest Data Archive: HF054.

Detailed Metadata

hf054-01: air temperature

  1. year: year (YYYY)
  2. month: month
  3. day: day of month (DD)
  4. time: time (hh:mm)
  5. am_pm: am or pm
  6. airt_7: air temperature plot 7 (celsius )
  7. airt_8: air temperature plot 8 (celsius )

hf054-02: soil temperature

  1. year: year (YYYY)
  2. month: month
  3. day: day of month (DD)
  4. time: time (hh:mm)
  5. am_pm: am or pm
  6. 1 M: hourly mineral soil temperature, PLOT 1(GIRDLE) (celsius )
  7. 1 O: hourly organic soil temperature, PLOT 1(GIRDLE) (celsius )
  8. 2 M: hourly mineral soil temperature, PLOT 2(GIRDLE) (celsius )
  9. 2 O: hourly organic soil temperature, PLOT 2(GIRDLE) (celsius )
  10. 3 M: hourly mineral soil temperature, PLOT 3(GIRDLE) (celsius )
  11. 3 O: hourly organic soil temperature, PLOT 3(GIRDLE) (celsius )
  12. 4 M: hourly mineral soil temperature, PLOT 4(GIRDLE) (celsius )
  13. 4 O: hourly organic soil temperature, PLOT 4(GIRDLE) (celsius )
  14. 5 M: hourly mineral soil temperature, PLOT 5(GIRDLE) (celsius )
  15. 5 O: hourly organic soil temperature, PLOT 5(GIRDLE) (celsius )
  16. 6 M: hourly mineral soil temperature, PLOT 6(GIRDLE) (celsius )
  17. 6 O: hourly organic soil temperature, PLOT 6(GIRDLE) (celsius )
  18. 7 M: hourly mineral soil temperature, PLOT 7(GIRDLE) (celsius )
  19. 7 O: hourly organic soil temperature, PLOT 7(GIRDLE) (celsius )
  20. 8 M: hourly mineral soil temperature, PLOT 8(GIRDLE) (celsius )
  21. 8 O: hourly organic soil temperature, PLOT 8(GIRDLE) (celsius )

hf054-03: nitrogen mineralization

  1. series: incubation series. Even number represents the initial core # for each series, starting with series 2. The net mineralization value is core 1minus core 2, then core 4- core 3, etc.
  2. core in: date soil incubation began , in situ (YYYY-MM-DD)
  3. core out: date soil care incubation ended (YYYY-MM-DD)
  4. Incubation: number of days core was in the soil (number )
  5. year: year (YYYY)
  6. horizon: soil horizon
    • O: organic horizon
    • M: mineral horizon
  7. treatment: experimental treatment
    • girdle: girdle
    • log: logged
    • control: control
    • hw control: hardwood control
  8. plot: experimental plot number (1-8)
  9. sub plot: subplot number (1-32), there are 4 subplots in each plot
  10. net NH4-N: final core – initial core extracted Nitrogen in the form of ammonium (milligramsPerKilogram )
  11. net NO3-N: final core – initial core extracted Nitrogen in the form of nitrate (milligramsPerKilogram )
  12. core wgt: soil core weight (gram )
  13. core area: area (hectare )
  14. net NH4-N: final core – initial core extracted Nitrogen in the form of ammonium (kilogramsPerHectare )
  15. net NO3-N: final core – initial core extracted Nitrogen in the form of nitrate (milligramsPerKilogram )
  16. moisture: total evaporable moisture content of sample ([g moist soil)-(g dry soil)]/(g dry soil) (gram )

hf054-04: resin data

  1. gs/ow: resin bags are deployed in the soil for the growing season (May-Oct) or over winter (Oct-May)
    • OW: over winter
    • GS: growing season
  2. start-date: start date (YYYY)
  3. end-date: end date (YYYY)
  4. site: research site
    • ST: Simes Tract
  5. treatment: experimental treatment
    • girdle: girdled
    • log: logged
    • control: control
    • HW control: hardwood control
  6. plot: experimental plot (1-8)
  7. subplot: subplot (1-32), there are 4 subplots in each plot
  8. NH4-N: Nitrogen in the form of ammonium in solution extract (milligramsPerLiter )
  9. NO3-N: Nitrogen in the form of nitrate in solution extract (milligramsPerLiter )
  10. NH4-N: Nitrogen in the form of ammonium captured in resin (microgramsPerGram )
  11. NO3-N: Nitrogen in the form of nitrate captured in resin (microgramsPerGram )

hf054-05: soil chemistry

  1. Site: research site
    • ST: Simes Tract
  2. Year: year (YYYY)
  3. plot: experimental plot (1-8)
  4. trmt: experimental treatment
    • girdle: girdled
    • log: logged
    • control: control
    • hw control: hardwood control
  5. subplot: experimental subplot (1-32), there are 4 subplots per plot
  6. horizon: soil horizon
    • O: organic horizon
    • M: minteral horizon
  7. pH: soil pH (number )
  8. % N: sample content percent nitrogen (dimensionless )
  9. % C: sample content percent carbon (dimensionless )
  10. C:N: sample carbon:nitrogen ratio (dimensionless )
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