• Address:
  705 Spear Street
  South Burlington, Vermont 05403
  United States of America
  
  Phone: (802) 391-4135
  Email: femc@uvm.edu
  Website: www.uvm.edu/femc

Measure foliar nitrogen of sugar maple to determine relationships between leaf nitrogen content and resorption efficiency during autumn leaf senescence. To examine the variability in resorption efficiency among and within sugar maple trees. To establish a baseline for long-term nutrient cycling research. To examine the variability in resorption efficiency and foliar N content among and within sugar maple trees. To determine the relationship between resorption efficiency and foliar N content.

• Label: Tree #

• Description: Number of the tree sampled

• Storage Type: int

• Measurment Type: ordinal

• Label: Green Foliar N

• Description: Nitrogen from live leaf samples

• Storage Type: decimal

• Measurment Type: ratio
• Standard Unit: customMicrogramsPerSquareCentimeter
• Precision: 0.01
• Unit: MicrogramsPerSquareCentimeter
• Number Type: real

• Label: Green Foliar N Southeast

• Description: Nitrogen from live leaf samples in the Southeast

• Storage Type: decimal

• Measurment Type: ratio
• Standard Unit: customMicrogramsPerSquareCentimeter
• Precision: 0.01
• Unit: MicrogramsPerSquareCentimeter
• Number Type: real

• Label: Green Foliar N Weight

• Description: Nitrogen from live leaf sample measured by the percent of dry weight

• Storage Type: decimal

• Measurment Type: ratio
• Standard Unit: percent
• Precision: 0.01
• Unit: percent
• Number Type: real

• Label: Green Foliar N Weight

• Description: Nitrogen from live leaf sample measured by the percent of dry weight (southeast)

• Storage Type: decimal

• Measurment Type: ratio
• Standard Unit: percent
• Precision: 0.01
• Unit: percent
• Number Type: real

• Label: Leaf litter N

• Description: Nitrogen from leaf litter samples

• Storage Type: decimal

• Measurment Type: ratio
• Standard Unit: customMicrogramsPerSquareCentimeter
• Precision: 0.01
• Unit: MicrogramsPerSquareCentimeter
• Number Type: real

• Label: Leaf litter N SE

• Description: Nitrogen from leaf litter samples (southeast)

• Storage Type: decimal

• Measurment Type: ratio
• Standard Unit: customMicrogramsPerSquareCentimeter
• Precision: 0.01
• Unit: MicrogramsPerSquareCentimeter
• Number Type: real

• Label: Percent Resorption

• Description: Percent nitrogen resorbed is calculated as 100* (maximum N mass/leaf area)-(leaf litter N mass/ leaf area)

• Storage Type: decimal

• Measurment Type: ratio
• Standard Unit: percent
• Precision: 0.01
• Unit: percent
• Number Type: real
• Bounds:
• Minimum: 0
• Maximum: 100

• Label: Percent Resorption SE

• Description: Percent nitrogen resorbed is calculated as 100* (maximum N mass/leaf area)-(leaf litter N mass/ leaf area) (southeast)

• Storage Type: decimal

• Measurment Type: ratio
• Standard Unit: percent
• Precision: 0.01
• Unit: percent
• Number Type: real
• Bounds:
• Minimum: 0
• Maximum: 100

• Study specimens
  • Started: 1993-05-01
    
  • Method Description: Twenty sugar maple trees used for foliage sampling.

• Plot description
  • Method Description: One 75 X 50 m plot used for soil, litter, throughfall and precipitation collections.

• Leaf samples
  • Method Description: Leaf samples collected from north and south sides of tree; from lower, middle and upper canopy. Samples of leaves were collected once in mid-July and once in mid-August to obtain a measure of the maximum nitrogen pool. Foliar nutrient concentrations are most stable in this time frame.

• Leaf litter
  • Started: 1993-09-20
    
  • Method Description: Leaf litter traps collected twice weekly. One litter trap was placed under each tree, positioned so that minimal litter would fall in from surrounding trees. Leaf litter was collected throughout the leaf drop period (September 20-October 22).

• Throughfall collection
  • Method Description: Throughfall collections consisted of two funnel collectors under each of five trees, on north and south sides of tree. Plus two collectors in an open area in close proximity to the site to collect rain as a control.

• Leaf tissue analysis
  • Method Description: After each sampling, leaf tissue was run through a leaf area meter, assigned a thrips damage index number, oven dried at 70 degrees C to a constant weight and ground in a Wiley mill.

• Chromatograph
• Sampling Description: Dionex Ion Chromatograph Model 2010i was used to analyze nitrate.

• Flow injection analysis
• Sampling Description: Lachat Quick Chem AE flow injection analysis was used to test ammonium colorimetrically.

• Elemental Analyzer
• Started: 1993-05-01
  
• Sampling Description: Leeman Laboratories CHN CE440 Elemental Analyzer was used to determine total nitrogen.

• Leaf litter traps, funnel precipitation colle
• Started: 1993-05-01
  
• Sampling Description: Leaf litter traps. Funnel precipitation collectors.

• Pole pruners, ladders and rope climbing equip
• Started: 1993-05-01
  
• Sampling Description: Pole pruners, ladders and rope climbing equipment.