Year

• Label: Year
• Definition: The year in which the sample was taken.
• Type: Date/time
• Date format: YYYY
• Missing values: None specified

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Block

• Label: Block
• Definition: A given block has to do with the location of the chambers in the field. There were 10 chambers of each treatment and it is a blocked experiment which means that the site was divided into 10 blocks and each block contains one chamber of each treatment. This helps us statistically account for possible variations in light, moisture, etc. across the entire site.
• Type: Nominal
• Missing values: None specified

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ID

• Label: Tree ID
• Definition: Unique identifier to distinguish individuals of the same species within the same root box.
• Type: Nominal
• Missing values: None specified

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NO2

• Label: Nitrogen Dioxide Treatment Level
• Definition: Indicates whether the associated plants were grown in at elevated (40 ppb) or ambient NO2 levels.
• Type: Code list
• Codes:
  • N = Elevated NO2 treatment levels
  • A = Ambient NO2 treatment levels
• Missing values:
  • NA =

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CO2

• Label: Carbon Dioxide Treatment Level
• Definition: Indicates whether the associated plants were grown in at elevated (760 ppm) or ambient (380 ppm) CO2 levels.
• Type: Code list
• Codes:
  • C = Elevated Carbon Dioxide Treatment
  • A = Ambient Carbon Dioxide Treatment
• Missing values: None specified

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NO3

• Label: Nitrate Treatment Level
• Definition: Indicates whether the associated plants were grown in soils with increased nitrate (NO3-) levels (30 kg N ha-1 yr-1) or at untreated nitrate levels.
• Type: Code list
• Codes:
  • F = Elevated NO3- treatment levels
  • A = Ambient NO3- levels
• Missing values: None specified

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percent_N

• Label: Percent Nitrogen
• Definition: Weight percent nitrogen in the sample.
• Type: Physical quantity
• Unit: percent
• Maximum: Not specified
• Minimum: Not specified
• Precision: 0.001
• Missing values:
  • NA =

,
percent_C

• Label: Percent Carbon
• Definition: Weight percent carbon in the sample.
• Type: Physical quantity
• Unit: percent
• Maximum: Not specified
• Minimum: Not specified
• Precision: 0.01
• Missing values:
  • NA =

,
CN_ratio

• Label: Carbon Nitrogen Ratio
• Definition: Mass ratio of C:N in the sample of interest. Calculated as follows: C/N = %C / %N.
• Type: Nominal
• Missing values: None specified