Project Overview


The FRED Initiative began as an international collaboration of root ecologists with an overarching goal of improving our understanding and model representation of fine-root traits and processes. To meet this goal, we looked to the long and rich history of observations of belowground plant traits, with a specific focus on fine roots, to serve as a solid foundation for our current understanding and as fuel for the next generation of measurements. The Fine-Root Ecology Database (FRED) was born (Iversen et al., 2017). In the years since, FRED has been used to understand and model root trait variation across the world. 


  • The first version of FRED (FRED 1.0) was released to the broader public in February 2017 (data citation: Iversen et al., 2016). FRED 1.0 housed more than 70,000 root trait observations from more than 800 data sources. It represented more than 300 root traits, along with associated ancillary data related to site, vegetation, edaphic, and climatic conditions from across the globe.

    FRED has been popular; over the course of 1 year, FRED 1.0 was downloaded more than 200 times to address a number of questions related to modeling, local site or species measurements, and broad trait relationships across species or sites. A pre-release of FRED (FRED 0.0) that was incorporated into the fourth version of the TRY database (TRY 4.0) has also been quite popular; the FRED-TRY synergy increases the representation of belowground plant traits in TRY and facilitates above- and belowground trait linkages. Over the time period from July 2017 to February 2018, observations from FRED 0.0 were requested from TRY 175 times; half of these queries were focused on root traits, while the rest were for ancillary data only.

    FRED 1.0 Downloads
    When users downloaded FRED 1.0, they were asked to select the primary data use they had planned for the database (a). Over a period of 1 year from its initial release in February 2017, FRED 1.0 was downloaded 208 times for use in five main categories: Assess broad trait relationships across species or sites (38%); Identify trait observations to combine with local site or species measurements (31%); Modeling (15%); Educational (8%); and Other (landscape design, data exploration, etc.; 7%). (Downloads of FRED 0.0 from TRY are not shown here.) More detailed data use plans were also requested from each user to assess the utility of FRED for multiple different types of projects, and to help steer future data collation. The details of these plans are not made public, but we illustrate some of the most frequently-used words in a word cloud (b) (this cloud includes plans submitted both to FRED and to TRY).
  • Map of FRED 1.0 downloads

    Downloads of FRED 0.0 (filled white circles) and FRED 1.0 (filled red circles) span the world, including 42 countries across six continents, but were mainly focused in the United States, Europe, and China.

  • A new version of FRED is now available. FRED 2.0 is an improved version of his older brother (data citation: Iversen et al., 2018), with 50% more root trait observations, particularly in the categories of root anatomy, architecture, chemistry, and morphology. FRED 2.0 has more than 105,000 observations of more than 300 root traits, with data collected from more than 1200 data sources. The ancillary data available have increased concurrently with increased root trait observations. FRED 2.0 is now freely available to the broader community of root and rhizosphere ecologists. FRED 2.0 will also be submitted to the next version of TRY upon its release. The observation numbers associated with individual root traits and ancillary data can be found here and here. Changes made to the database between FRED 1.0 and FRED 2.0 can be found here.

  • Map of locations of root observations in FRED.
    Map of the locations of root trait observations included in FRED 2.0. Only ~61% of the observations in FRED 2.0 were reported with geo-referenced locations. To facilitate spatial analyses and visualization, we include two additional variables in the FRED 2.0 database (‘Latitude_main’ and ‘Longitude_main’). FRED 2.0 houses data from 2285 distinct locations, more than double that of FRED 1.0.
  • FRED 3.0 will become available in February 2021. FRED 3.0 has more than 150,000 observations of more than 330 root traits, with data collected from more than 1400 data sources. FRED 3.0 has 45% more root trait observations than FRED 2.0, particularly in the categories of root anatomy, morphology, and microbial associations; ancillary data on associated site, vegetation, edaphic, and climatic conditions from across the globe have also increased concurrently. 

    This newest version of FRED is has been encoded into database form (Microsoft Azure), and we have developed a User Interface (programmed using Vue.js for the user interface and Node.js for interface with the data) that allows users to filter the observations in FRED according to their scientific needs. However, users will still be able to download the entire FRED flat file containing all ~150,000 root trait observations along with associated ancillary data.

    The newest version of FRED will be submitted to TRY, and will likely be available through TRY version 7.0. The observation numbers associated with individual root traits and ancillary data will be found here and here. Changes made to the database between FRED 2.0 and FRED 3.0 will be found here. Please cite FRED 3.0 as well as the original data source where possible. 

  • Map of root trait observations.
    a) FRED 3.0 observations are distributed unevenly across the globe (map from Iversen & McCormack 2021, New Phytologist, in press). For the purposes of this map, land cover within a Köppen-Geiger climate classification zone was aggregated into hex bins that are extruded in three-dimensional space based on the number of root trait samples collected in each bin. Map courtesy of Chris DeRolph. (b) The number of root trait samples in FRED 3.0 that were collected from each Köppen-Geiger climate subclass, summed within each climate class. (c) The distribution of observations in FRED 3.0 across broad categories of root traits.


  • We thank A. Shafer Powell and J. Katie Baer for their assistance with FRED data harvesting, Chris DeRolph for his assistance with GIS mapping, Les Hook for his assistance with best data management practices, and Dave Connerth and Derek Brownlee for their assistance with FRED database development and programming as well as this website.

  • This work is supported by the Biological and Environmental Research program within the Department of Energy's Office of Science.