Dataset: Plot Condition Groups Defined By Forest Inventory and Analysis Program

Methods

The methods followed in the creation of the dataset, including description of field, laboratory and processing steps, and quality control procedures

Current Methods

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  See FIA Manual in the Documents tab for full details

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  See FIA Manual in the Documents tab for full details

• Plot establishment
  
  

  Plots to be visited are selected based on stratification of remote sensing interpretation

• Plot establishment
  
  

  Plots to be visited are selected based on stratification of remote sensing interpretation

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  Plots are designed to cover a 1-acre sample area, though not all trees in the plot are measured. Recent surveys use standard fixed-radius plot, while earlier inventories used mixtures of fixed-radius and variable-radius (prism) plot design

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  Plots are designed to cover a 1-acre sample area, though not all trees in the plot are measured. Recent surveys use standard fixed-radius plot, while earlier inventories used mixtures of fixed-radius and variable-radius (prism) plot design

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  Plot locations are 'fuzzed and swapped' to protect privacy and plot integrity in accordance with Federal laws. 'Fuzzed' plots are generally within 0.5 miles of original plot center, and plots where data was 'swapped' are generally similar in nature. See FIA manual for full details

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  Plot locations are 'fuzzed and swapped' to protect privacy and plot integrity in accordance with Federal laws. 'Fuzzed' plots are generally within 0.5 miles of original plot center, and plots where data was 'swapped' are generally similar in nature. See FIA manual for full details

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  The standard plot consists of four 24.0-foot radius subplots (approximately 0.0415 or 1/24 acre), on which trees 5.0 inches and greater in diameter are measured. Within each of these subplots is nested a 6.8-foot radius microplot (approximately 1/300th acre) on which trees smaller than 5.0 inches in diameter are measured

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  The standard plot consists of four 24.0-foot radius subplots (approximately 0.0415 or 1/24 acre), on which trees 5.0 inches and greater in diameter are measured. Within each of these subplots is nested a 6.8-foot radius microplot (approximately 1/300th acre) on which trees smaller than 5.0 inches in diameter are measured

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  Conditions are defined by changes in land use or changes in vegetation that occur along more-or-less distinct boundaries. Reserved status, owner group, forest type, stand-size class, regeneration status, and stand density are used to define forest conditions. In older plot designs, plot center or subplots locations were rearranged such that the entire plot sampled a single condition, while in the current design, different conditions are “mapped” on the same plot.

• 
  
  

  Conditions are defined by changes in land use or changes in vegetation that occur along more-or-less distinct boundaries. Reserved status, owner group, forest type, stand-size class, regeneration status, and stand density are used to define forest conditions. In older plot designs, plot center or subplots locations were rearranged such that the entire plot sampled a single condition, while in the current design, different conditions are “mapped” on the same plot.

• Field attributes
  
  

  In addition to attributes that are collected in the field, FIADB includes attributes that are populated in the office. Examples of field attributes include tree diameter and height, and slope and aspect of the plot and subplot. Attributes that are populated in the office include assigned attributes, such as county and owner group codes, or computed attributes, such as tree and area expansion factors, and tree volumes

• Field attributes
  
  

  In addition to attributes that are collected in the field, FIADB includes attributes that are populated in the office. Examples of field attributes include tree diameter and height, and slope and aspect of the plot and subplot. Attributes that are populated in the office include assigned attributes, such as county and owner group codes, or computed attributes, such as tree and area expansion factors, and tree volumes

• Standards and guidelines
  
  

  Forest inventory plans are designed to meet sampling error standards for area, volume, growth, and removals provided in the Forest Service directive (FSH 4809.11) known as the Forest Survey Handbook (U.S. Department of Agriculture 2008). These standards, along with other guidelines, are aimed at obtaining comprehensive and comparable information on timber resources for all parts of the country

• Standards and guidelines
  
  

  Forest inventory plans are designed to meet sampling error standards for area, volume, growth, and removals provided in the Forest Service directive (FSH 4809.11) known as the Forest Survey Handbook (U.S. Department of Agriculture 2008). These standards, along with other guidelines, are aimed at obtaining comprehensive and comparable information on timber resources for all parts of the country

Dataset Fields

Detailed documentation of the fields comprising the dataset, including the type of measurement, units where applicable, and any controlled vocabularies or code lists present in the data

Sampling Equipment

Equipment and software used to collect data, including how that equipment was used.

Site Characteristics

The spatial extent of the dataset site coverage, and descriptions of the spatial extent and context for the data collection