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Harvard Forest Data Archive

HF050

Long-Term Decomposition Plots at Harvard Forest 1990-2009

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Data

Overview

  • Lead: Charles McClaugherty
  • Investigators:
  • Contact: Charles McClaugherty
  • Start date: 1990
  • End date: 2009
  • Status: completed
  • Location: Prospect Hill Tract (Harvard Forest)
  • Latitude: +42.531 to +42.534
  • Longitude: -72.183 to -72.181
  • Elevation: 360 to 390 meter
  • Taxa: Acer rubrum (red maple), Pinus resinosa (red pine)
  • Release date: 2009
  • Revisions:
  • EML file: knb-lter-hfr.50.20
  • DOI: digital object identifier
  • Related links:
  • Study type: long-term measurement
  • Research topic: large experiments and permanent plot studies
  • LTER core area: organic matter
  • Keywords: decomposition, nitrogen, phosphorus, wood
  • Abstract:

    Mass loss (estimated by decreases in density) and total nitrogen content (TKN) is measured in decaying logs (1.2 m long and diameter range: 6-50 cm) and sticks (10-30 cm long and diameter less than 5 cm) of red pine (Pinus resinosa Ait.) and red maple (Acer rubrum L.) Logs and sticks were collected from freshly cut trees and placed on the forest floor in a red pine plantation (pine only) or a nearby red maple dominated deciduous forest (maple only) in the Prospect Hill tract. Maple logs and sticks lost density faster than did pine.

    Total Kjeldahl Nitrogen is measured as a percent of organic matter in red pine and red maple logs. N content differed significantly according to state of decay (p=0.002) but not between species. Total organic phosphorus in Kjeldahl digests is measured as a percent of organic matter in red pine and red maple logs. P content differed significantly according to state of decay (p=0.0008) but not between species.

  • Methods:

    Mass loss was measured directly for sticks and by density (saran coated samples weighed in and out of water) for logs. Nitrogen was determined by Kjeldahl digestion and determination of ammonia in the digestate using flow injection.

    Nitrogen and phosphorus was measured in decayed red pine and red maple logs collected from the forest after 17 years of decay. Due to fragmentation and infiltration by roots mass loss and density could not be determined. Wood fell into two distinct decay classes. Samples from logs were analyzed for total kjeldahl nitrogen and phosphorus (TKN and TKP) and related to species and decay state.

  • 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:

    McClaugherty C. 2009. Long-Term Decomposition Plots at Harvard Forest 1990-2009. Harvard Forest Data Archive: HF050.

Detailed Metadata

HF050-01: mass loss

  1. species: species of wood incubated
    • rm: red maple
    • rp: red pine
  2. type: type of wood incubated
    • L: log
    • S: stick
  3. months: number of months since initial placement in field (unit: number / missing value: NA)
  4. n: number of samples used to estimate density (unit: number / missing value: NA)
  5. density.per: percentage of density in samples relative to density of fresh sample (unit: dimensionless / missing value: NA)
  6. stddev: standard deviation of density.per values (unit: dimensionless / missing value: NA)
  7. tkn.per: total Kjeldahl nitrogen as a percent of dry matter (unit: dimensionless / missing value: NA)

hf050-02: nitrogen and phosphorus

  1. species: species of decayed log from which sample was taken
    • rp: red pine
    • rm: red maple
  2. decay: decay class
    • less decayed: firm with structural integrity
    • more decayed: friable, flexible
  3. tkn: total Kjeldahl nitrogen (% of ash-free dry mass) (unit: dimensionless / missing value: NA)
  4. tkp: total Kjeldahl phosphorus (% of ash-free dry mass) (unit: dimensionless / missing value: NA)