This metadata is the documentation for the field soil observations, ecological site identification, and geomorphology characteristics collected by the Assessment, Inventory, and Monitoring (AIM) terrestrial program between 2012 and 2021 in 14 states of the western United States. The AIM program is conducted by the Bureau of Land Management (BLM)’s and provides information to guide site-specific management of ecosystem functions and services. There are 31,267 monitoring plots (79% of plots) with identified ecological sites and 29,228 plots (74% of plots) containing soil morphology descriptions of soil horizons examined in excavated pits. While soil texture class is observed in most soil horizons (98%), rock fragment volume is the soil property with the least data availability (75%). The consistency of soil data (e.g., clay content observations within the ranges of texture classes) increases as a function of time following guidance in soil profile description training for AIM data collectors. Nearly 47% of AIM plots are found on gentle slopes of 0-5% steepness and on Flat/Plain and Hill/Mountain landscape types. The AIM database is a source of georeferenced soil and geomorphology information that can be used for land management and research on land potential, soil geography, and assessment of soil health indicators across the western United States.

Resources in this dataset:

• Resource title: Plot characteristics
  File name: PlotCharacteristics.csv
  Resource description: Plot characteristics table contains information on GPS coordinates, ecological site ID, and geomorphological settings, such as slope, aspect, landscape type, etc.

• Resource title: Soil horizon
  File name: SoilHorizon.csv
  Resource description: The soil horizon table has information on soil morphology attributes, such as color, texture class, effervescence, soil structure, etc.

• Resource title: Plot characteristics data dictionary
  File name: PlotCharacteristicsDataDictionary.csv

• Resource title: Soil horizon data dictionary
  File name: SoilHorizonDataDictionary.csv

• Resource title: Methods
  File name: Methods.txt