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Harvard Forest Data Archive

HF054

Community and Ecosystem Impacts in Hemlock Removal Experiment at Harvard Forest since 2003

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Data

Overview

  • Lead: David Orwig, David Foster
  • Investigators: Heidi Lux
  • Contact: David Orwig
  • Start date: 2003
  • End date: 2015
  • Status: ongoing
  • Location: Simes Tract (Harvard Forest)
  • Latitude: +42.47 to +42.48
  • Longitude: -72.22 to -72.21
  • Elevation: 200 to 240 meter
  • Taxa: Adelges tsugae (hemlock woolly adelgid), Betula lenta (black birch), Tsuga canadensis (eastern hemlock)
  • Release date: 2017
  • Revisions:
  • EML file: knb-lter-hfr.54.23
  • 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: air temperature, hemlock, hemlock woolly adelgid, nitrogen mineralization, soil chemistry, soil temperature, successional dynamics, timber harvest, tree mortality
  • 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 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:

    Orwig D, Foster D. 2017. Community and Ecosystem Impacts in Hemlock Removal Experiment at Harvard Forest since 2003. Harvard Forest Data Archive: HF054.

Detailed Metadata

hf054-01: air temperature

  1. date: date
  2. year: year
  3. month: month
  4. day: day of month
  5. time: time
  6. am.pm: am or pm
  7. airt.7: air temperature plot 7 (unit: celsius / missing value: NA)
  8. airt.8: air temperature plot 8 (unit: celsius / missing value: NA)

hf054-02: soil temperature

  1. date: date
  2. year: year
  3. month: month
  4. day: day of month
  5. time: time
  6. am.pm: am or pm
  7. m.1: hourly mineral soil temperature, PLOT 1(GIRDLE) (unit: celsius / missing value: NA)
  8. o.1: hourly organic soil temperature, PLOT 1(GIRDLE) (unit: celsius / missing value: NA)
  9. m.2: hourly mineral soil temperature, PLOT 2(GIRDLE) (unit: celsius / missing value: NA)
  10. o.2: hourly organic soil temperature, PLOT 2(GIRDLE) (unit: celsius / missing value: NA)
  11. m.3: hourly mineral soil temperature, PLOT 3(GIRDLE) (unit: celsius / missing value: NA)
  12. o.3: hourly organic soil temperature, PLOT 3(GIRDLE) (unit: celsius / missing value: NA)
  13. m.4: hourly mineral soil temperature, PLOT 4(GIRDLE) (unit: celsius / missing value: NA)
  14. o.4: hourly organic soil temperature, PLOT 4(GIRDLE) (unit: celsius / missing value: NA)
  15. m.5: hourly mineral soil temperature, PLOT 5(GIRDLE) (unit: celsius / missing value: NA)
  16. o.5: hourly organic soil temperature, PLOT 5(GIRDLE) (unit: celsius / missing value: NA)
  17. m.6: hourly mineral soil temperature, PLOT 6(GIRDLE) (unit: celsius / missing value: NA)
  18. o.6: hourly organic soil temperature, PLOT 6(GIRDLE) (unit: celsius / missing value: NA)
  19. m.7: hourly mineral soil temperature, PLOT 7(GIRDLE) (unit: celsius / missing value: NA)
  20. o.7: hourly organic soil temperature, PLOT 7(GIRDLE) (unit: celsius / missing value: NA)
  21. m.8: hourly mineral soil temperature, PLOT 8(GIRDLE) (unit: celsius / missing value: NA)
  22. o.8: hourly organic soil temperature, PLOT 8(GIRDLE) (unit: celsius / missing value: NA)

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
  3. core.out: date soil care incubation ended
  4. incubation: number of days core was in the soil (unit: number / missing value: NA)
  5. year: year
  6. horizon: soil horizon
    • O: organic horizon
    • M: mineral horizon
  7. block: block type
    • valley: valley
    • ridge: ridge
  8. treatment: experimental treatment
    • girdle: girdle
    • log: logged
    • control: control
    • hw control: hardwood control
  9. plot: experimental plot number (1-8)
  10. subplot: subplot number (1-32), there are 4 subplots in each plot
  11. net.nh4.n: final core – initial core extracted Nitrogen in the form of ammonium (unit: milligramPerKilogram / missing value: NA)
  12. net.no3.n: final core – initial core extracted Nitrogen in the form of nitrate (unit: milligramPerKilogram / missing value: NA)
  13. core.wgt: soil core weight (unit: gram / missing value: NA)
  14. core.area: area (unit: hectare / missing value: NA)
  15. net2.nh4.n: final core – initial core extracted Nitrogen in the form of ammonium (unit: kilogramsPerHectare / missing value: NA)
  16. net2.no3.n: final core – initial core extracted Nitrogen in the form of nitrate (unit: milligramPerKilogram / missing value: NA)
  17. moisture: total evaporable moisture content of sample ([g moist soil)-(g dry soil)]/(g dry soil) (unit: gram / missing value: NA)

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
  3. end.date: end date
  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 (unit: milligramsPerLiter / missing value: NA)
  9. no3.n: Nitrogen in the form of nitrate in solution extract (unit: milligramsPerLiter / missing value: NA)
  10. nh4.n.r: Nitrogen in the form of ammonium captured in resin (unit: microgramsPerGram / missing value: NA)
  11. no3.n.r: Nitrogen in the form of nitrate captured in resin (unit: microgramsPerGram / missing value: NA)

hf054-05: soil chemistry

  1. site: research site
    • ST: Simes Tract
  2. year: year
  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 (unit: number / missing value: NA)
  8. n.per: sample content percent nitrogen (unit: dimensionless / missing value: NA)
  9. c.per: sample content percent carbon (unit: dimensionless / missing value: NA)
  10. c.n: sample carbon:nitrogen ratio (unit: dimensionless / missing value: NA)