Root Trait Inventory

In total, the observations in FRED 3.0 encompass more than 330 root traits. To better understand the breadth and depth of these traits, we have grouped them into eight categories: root anatomy, architecture, chemistry, dynamics, morphology, physiology, and the whole-root system, as well as microbial associations. These root trait categories, along with others, are described and mapped in relation to one-another here.

Each observation in FRED is based on a single trait measurement made by an investigator on fine roots taken from a defined species or plant community at a specific location, date, and time. Many observations are plot or treatment means, and we include measures of variation and sample size where available (statistical data are not shown here). In some cases, multiple trait observations were taken from one collection of fine roots, but no sample has observations of all fine-root traits (most samples are associated with one or a few traits).

Use the search box to see whether FRED 3.0 has a particular root trait of interest, or choose combinations from the Trait Category and Trait Type boxes below and click the "Filter" button to view subsets of the data.

Trait Category Trait Type Traits Column ID Description Single-species Observations Multi-species Observations Total observations
Architecture Topology Root branching architecture_Root length per higher order root length F00187 Root length for a given order divided by the length of the roots in the higher order. 232 0 232
Architecture Topology Root branching intensity (branching ratio)_Number of roots per higher order root F00179 Number of roots in a given order divided by the number of roots in the higher order. 497 6 503
Architecture Topology Root branching intensity_root tips per higher order root length F00182 Number of lower-order roots per centimeter length of higher-order root. 79 0 79
Architecture Topology Root branching intensity_root tips per total root length F01339 Number of lower-order roots per total root length in category. 1504 8 1512
Architecture Topology Root dichotomous branching index F00210 Determined by formula [Pe – min(Pe)] / [max(Pe) – min(Pe)]. DBI of 1 indicates a completely herringbone topology, while DBI of 0 indicates a completely dichotomous topology. 4 0 4
Architecture Topology Root external path length (Pe) F00213 Sum of the number of links in all paths from each external link (root segment between two nodes) to the base link (the link from which all other links descend). (Definition from Beidler et al. 2015, DOI: 10.1111/nph.13123). 878 127 1005
Architecture Topology Root forks per root length F01414 Number of root forks per cm of root length. 0 24 24
Architecture Topology Root fractal dimension F00199 Fractal dimension of scanned roots. 908 238 1146
Architecture Topology Root link branching angle F00170 Mean angle between a link (segments of roots between two nodes or a node and a tip) and the extension of the link before it. 878 238 1116
Architecture Topology Root link length F00203 Length of root links (segments of roots between two nodes or a node and a tip). 1138 238 1376
Architecture Topology Root links per root branch F00173 Number of links (segments of roots between two nodes or a node and a tip) per root branch. 4 0 4
Architecture Topology Root tips per ground area F00219 Total number of root tips per square meter of ground area (sampled from a given depth increment). 76 16 92
Architecture Topology Root tips per minirhizotron frame F00216 Number of root tips observed per minirhizotron frame. 36 0 36
Architecture Topology Root tips per plant F00222 Total number of root tips for an entire plant. 896 127 1023
Architecture Topology Root tips per root branch F00176 Number of root tips and root endings per root branch. 4 0 4
Architecture Topology Root tips per soil volume F00224 Number of root tips per liter of soil. 38 0 38
Architecture Topology Root topological index (TI) F00226 Slope of the linear regression of log10(Pe) against log10µ, in which Pe is external path length and µ represents magnitude (number of root tips in the system). A greater TI indicates a more “herringbone” branching system. 878 238 1116
Architecture Topology Specific root forks density (SRFD) F00207 Number of root bifurcations per gram of root mass. 3 9 12
Architecture Topology Specific root tip abundance (SRTA) F00192 Number of root tips per milligram of root mass. 1232 255 1487