Root Trait Inventory

In total, the observations in FRED 2.0 encompass 328 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 2.0 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
Root System Allocation within plant Aboveground/belowground net primary production ratio F00841 Annual aboveground net primary production (NPP) divided by belowground NPP. 118 30 148
Root System Standing crop Belowground biomass per ground area F00885 Root mass per square meter for the specified depth increment. 4350 7028 11378
Root System Standing crop Belowground biomass per plant F00898 Total root mass for the entire plant. 7211 127 7338
Root System Standing crop Belowground biomass per soil volume F00896 Kilograms of root mass per cubic meter of soil. 897 230 1127
Root System Standing crop Belowground necromass per ground area F00917 Dead root mass per square meter for the specified depth increment. 448 795 1243
Root System Allocation within plant Belowground/aboveground mass ratio F00838 Ratio of belowground biomass (g m-2) to aboveground biomass (g m-2). 677 67 744
Root System Allocation within root system Coarse root/fine root mass ratio F00854 Ratio of coarse root biomass to fine root biomass. 1636 9 1645
Root System Allocation within plant Fine root C/leaf C ratio F00844 Ratio of fine root carbon to leaf carbon. 40 30 70
Root System Allocation within plant Fine root mass/leaf mass ratio F00843 Ratio of fine-root mass to leaf mass. 1831 27 1858
Microbial associations Other rhizosphere microbes Mycoheterotrophy F01288 “x” denotes the presence of mycoheterotrophy. Blank indicates the data are not related to mycoheterotrophy or that mycoheterotrophy data were not available. 3 0 3
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction contact exploration mycorrhizae F00609 Percentage of mycorrhizal tips that are of the contact exploration type. 12 0 12
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction long-distance exploration mycorrhizae F00611 Percentage of mycorrhizal tips that are of the long-distance exploration type. 12 0 12
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction medium-distance exploration mycorrhizae F00613 Percentage of mycorrhizal tips that are of the medium-distance exploration type. 12 0 12
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction mycorrhizal root tips that are living F00617 Percentage of mycorrhizal tips that are living. 12 0 12
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction of root length F00638 Percentage of root length colonized by mycorrhizal fungi, identified by the presence of mycorrhizal hyphae, arbuscules, or vesicles. This column contains information from both AM and EM colonization reported in columns F00622 and F00626, and additional data when mycorrhizal type was unspecified or both colonization types were present. 602 62 664
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction root length colonized by AM mycorrhizae F00622 Percentage of root length which shows colonization by arbuscular mycorrhizal fungi. These data may also be contained in column F00638. 547 48 595
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction root length colonized by EM mycorrhizae F00626 Percentage of root length which shows colonization by ectomycorrhizal fungi. These data may also be contained in column F00638. 14 4 18
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction root tips colonized by mycorrhizae F00619 Percentage of root tips that are colonized by mycorrhizal fungi. 279 4 283
Microbial associations Mycorrhizal fungi Mycorrhiza_Fraction short-distance exploration mycorrhizae F00615 Percentage of mycorrhizal tips that are of the short-distance exploration type. 12 0 12
Microbial associations Mycorrhizal fungi Mycorrhiza_Length of AM hyphae per soil mass F00606 Millimeters of arbuscular mycorrhizal hyphae per gram of soil, determined by dispersing soils in sodium metaphosphate solution, passing through a series of sieves, collecting hyphae on filters, and examining hyphae through a microscope. 0 31 31
Microbial associations Mycorrhizal fungi Mycorrhiza_Number of AM spores per soil mass F00641 Number of arbuscular mycorrhizae spores per gram of soil, determined by isolating the spores using the wet-sieving technique and counting them under a microscope. 2 4 6
Microbial associations Mycorrhizal fungi Mycorrhiza_Number of root tips per root length colonized by mycorrhizae F00635 Number of tips per cm of root on root branch that contains mycorrhizal fungi. 16 0 16
Microbial associations Mycorrhizal fungi Mycorrhiza_PLFA proxy for EM mass per ground area F00607 Grams of external ectomycorrhizal mycelium biomass in soil per square meter of ground area for a given sampling depth, estimated based on PLFA with a conversion factor of 2 nmol 18:2omega6.9 per milligram of fungal biomass. 12 0 12
Microbial associations Mycorrhizal fungi Mycorrhiza_PLFA proxy for mycorrhizal hyphal C per soil mass F01333 Milligrams of mycorrhizal hyphal carbon per kilogram of soil mass, estimated from PLFA biomarkers as specified in Chen et al 2016 (DOI: 10.1073/pnas.1601006113). 26 0 26
Anatomy Internal mycological structures Mycorrhiza_Root length fraction that contains arbuscules F00111 Percentage of root length that contains arbuscules, determined using a random intercept method. 0 4 4
Anatomy Internal mycological structures Mycorrhiza_Root length fraction that contains vesicles F00113 Percentage of root length that contains fungal vesicles, determined using a random intercept method. 0 4 4
Microbial associations Mycorrhizal fungi Mycorrhiza_Type_Data source F00645 Type of mycorrhizae formed. "AbtM" = arbutoid mycorrhizae; “AM” = arbuscular mycorrhizae; “DS” = dark septate endophyte mycorrhizae; “EeM” = ectendomycorrhizae; “EM” = ectomycorrhizae; “ErM” = ericoid mycorrhizae”;, "OrM" = orchid mycorrhizae; “mycorrhizal” means mycorrhizae are present but type is unknown; “NM” = non-mycorrhizal. 9577 194 9771
Microbial associations Mycorrhizal fungi Mycorrhiza_Visual estimate of root colonization intensity F00631 Intensity of mycorrhizal colonization based on five categories of mycorrhizal intensity, estimated visually and averaged across samples examined. 5554 0 5554
Physiology Nutrient uptake Plant N uptake rate_Annual N uptake per ground area F00780 Total amount of nitrogen taken up by plants per hectare over the course of a year. 174 81 255
Physiology Nutrient uptake Plant N uptake_Daily uptake of molar 15N-Glycine per shoot dry mass F01396 Uptake of 15N-Glycine tracer over the course of 24 hours per shoot dry mass, estimated with the equation F = [T(AS-AB)]/AF, where T is the plant N concentration AS is the atom percent excess 15N in the sample, AB is the atom percent excess 15N in the natural sample, and AF is the atom percent excess 15N in the tracer. 10 0 10
Physiology Nutrient uptake Plant N uptake_Daily uptake of molar 15NH4+ per shoot dry mass F01392 Uptake of 15N-NH4+ tracer over the course of 24 hours per shoot dry mass, estimated with the equation F = [T(AS-AB)]/AF, where T is the plant N concentration AS is the atom percent excess 15N in the sample, AB is the atom percent excess 15N in the natural sample, and AF is the atom percent excess 15N in the tracer. 10 0 10
Physiology Nutrient uptake Plant N uptake_Daily uptake of molar 15NO3- per shoot dry mass F01394 Uptake of 15N-NO3- tracer over the course of 24 hours per shoot dry mass, estimated with the equation F = [T(AS-AB)]/AF, where T is the plant N concentration AS is the atom percent excess 15N in the sample, AB is the atom percent excess 15N in the natural sample, and AF is the atom percent excess 15N in the tracer. 10 0 10
Physiology Nutrient uptake Plant N uptake_Daily uptake of molar total 15N per shoot dry mass F01398 Combined uptake of 15N-NH4+, 15N-NO3-, and 15N-Glycine tracers over the course of 24 hours per shoot dry mass, estimated with the equation F = [T(AS-AB)]/AF, where T is the plant N concentration AS is the atom percent excess 15N in the sample, AB is the atom percent excess 15N in the natural sample, and AF is the atom percent excess 15N in the tracer. 10 0 10
Microbial associations Rhizosphere Rhizosphere soil_specific rhizosheath mass by FW F01453 Mass of soil left on root after all bulk soil is shaken off, divided by root fresh mass 58 0 58
Chemistry Secondary Compounds Root 12 phenol content per root C content F00380 Total concentration of twelve monophenols extracted from root per root C content. 35 0 35
Chemistry Macronutrients Root 15N content F00273 Concentration of nitrogen stable isotope in sampled roots, determined with a mass spectrometer. 5 0 5
Chemistry Stoichiometry Root 3,5-dihydroxybenzoic acid groups/vanillyl phenols ratio F00407 Percent of 3,5-dihydroxybenzoic acid to vanillyl phenols in root. Indicative of degradation status. 5 0 5
Chemistry Secondary Compounds Root acid hydrolyzable compounds content F00342 Concentration of acid soluble compounds in root. 156 3 159
Physiology Exudation Root acid phosphatase activity per root mass F00743 Acid phosphatase activity per unit root mass. 333 3 336
Chemistry Stoichiometry Root acid/aldehyde ratio for syringyl phenols F00403 Ratio of acid to aldehyde in root syringyl phenols. Indicative of diagenetic state of lignin. 5 0 5
Chemistry Stoichiometry Root acid/aldehyde ratio for vanillyl phenols F00405 Ratio of acid to aldehyde in root vanillyl phenols. Indicative of diagenetic state of lignin. 5 0 5
Anatomy Aerenchyma Root aerenchyma fraction of cross section F00100 Percentage of root cross-sectional area that consists of aerenchyma. 13 0 13
Anatomy Aerenchyma Root aerenchyma porosity fraction F00097 Percent porosity of root aerenchyma. 787 0 787
Anatomy Aerenchyma Root aerenchyma presence F00103 Whether aerenchyma are present in root. 12 0 12
Dynamics Lifespan Root age survivorship fraction F00476 Percentage of roots that live to the age presented in the “root age” column. 308 87 395
Chemistry Micronutrients Root Al content F00296 Mass of aluminum per root mass for sampled roots. 115 43 158
Chemistry Micronutrients Root Al content per root fresh mass F01304 Mass of root aluminum per fresh mass for sampled roots. 6 0 6
Chemistry Secondary Compounds Root alkyl C content per root C content F00431 Fraction of root carbon that is in alkyl groups. 8 0 8
Chemistry Secondary Compounds Root arabinans content F00346 Concentration of arabinans in root. 13 1 14
Chemistry Secondary Compounds Root aromatic C content per root C content F00437 Fraction of root carbon that is in aromatic groups. 4 0 4
Chemistry Micronutrients Root As content F00298 Mass of arsenic per root mass for sampled roots. 36 16 52
Chemistry Secondary Compounds Root ash C content per root C content F00340 Percentage of root carbon that is ash. 13 0 13
Chemistry Secondary Compounds Root ash content F00347 Concentration of ash in root. 32 1 33
Chemistry Micronutrients Root B content F00301 Mass of boron per root mass for sampled roots. 4 9 13
Chemistry Secondary Compounds Root bound phenol content per root C content F00348 Concentration of phenolic compounds that are bound to cell walls through ester/ether linkages per root carbon content. 35 0 35
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
Chemistry Macronutrients Root C content F00253 Mass of carbon per root mass for sampled roots. 2817 284 3101
Root System Standing crop Root C content per ground area F00909 Total mass of root carbon per ground area. 96 172 268
Root System Standing crop Root C content per soil mass F00906 Mass of root carbon per gram of soil. 236 0 236
Chemistry Stoichiometry Root C/N ratio F00413 Ratio of carbon to nitrogen in root by mass. 3686 499 4185
Chemistry Macronutrients Root Ca content F00249 Mass of calcium per root mass for sampled roots. 633 141 774
Chemistry Macronutrients Root Ca content per root fresh mass F01299 Mass of calcium per root fresh weight for sampled roots. 6 0 6
Chemistry Micronutrients Root Cd content F00305 Mass of cadmium per root mass for sampled roots. 36 3 39
Chemistry Cellulose Root cellulose and hemicellulose content per root mass F00245 Sum of concentrations of cellulose and all hemicelluloses in root. 15 0 15
Chemistry Cellulose Root cellulose content F00237 Concentration of cellulose in root. 246 72 318
Chemistry Cellulose Root cellulose content per root C content F00240 Percentage of root carbon that is cellulose. 7 0 7
Chemistry Secondary Compounds Root cinnamyl phenol content per root C content F00350 Concentration of cinnamyl phenols in root per root carbon content. 5 0 5
Chemistry Stoichiometry Root cinnamyl phenol/vanillyl phenol ratio F00417 Ratio of cinnamyl phenol to vanillyl phenol in root. Index for woody or nonwoody source. 5 0 5
Chemistry Micronutrients Root Cl- ion content F00308 Mass of Cl- ions per root mass for sampled roots, determined with flame photometer. 12 0 12
Morphology Root Color Root color_White or brown F00691 Whether observed roots are considered to be white or brown. 98 0 98
Chemistry Secondary Compounds Root condensed tannins F01330 Concentration of condensed tannins in root. 23 0 23
Anatomy Vessels or Tracheids Root conduit diameter F00142 D_h=[(1/n)sigma(n/i=1)d^4]^(1/4) where d is conduit lumen diameter and n is conduit number. 75 0 75
Anatomy Vessels or Tracheids Root conduit number per root stele area F00134 Number of conduits per stele cross-section area. 24 0 24
Anatomy Vessels or Tracheids Root conduit wall thickness F00154 Thickness of conduit wall from root scans. 69 0 69
Chemistry Construction cost Root construction cost F00246 Grams of glucose equivalent per gram of root dry weight. 28 0 28
Anatomy Cortex Root cortex thickness F00104 Thickness of root cortex. 353 0 353
Chemistry Micronutrients Root Cr content F00311 Mass of chromium per root mass for sampled roots. 36 8 44
Morphology Diameter Root cross-sectional area F01317 Cross-sectional area of root. 76 0 76
Chemistry Micronutrients Root Cu content F00314 Mass of copper per root mass for sampled roots. 67 27 94
Dynamics Decomposition Root decomposition_Annual k constant F00461 The K constant for the root in the exponential decay function Mt = M0 e-kt, where Mt is the mass of litter after time t, and M0 is the initial mass of litter. 613 184 797
Dynamics Decomposition Root decomposition_Annual N immobilized in decomposing roots F00466 Amount of nitrogen immobilized over the course of a year in decomposing roots. 4 0 4
Dynamics Decomposition Root decomposition_Annual necromass decomposition rate per ground area F00465 Amount of root necromass that decomposes over the course of a year. 0 15 15
Dynamics Decomposition Root decomposition_Estimated cumulative monthly mass loss F00457 Difference between cumulative growth rate and fine root biomass. 0 6 6
Dynamics Decomposition Root decomposition_Fraction C remaining F01364 For decomposition experiment, percentage of original root carbon remaining. 39 0 39
Dynamics Decomposition Root decomposition_Fraction mass remaining F00458 For decomposition experiment, percentage of original root mass remaining. 2007 1758 3765
Dynamics Decomposition Root decomposition_Fraction N remaining F00591 For decomposition experiment, percentage of original root nitrogen remaining. 716 136 852
Dynamics Decomposition Root decomposition_Monthly k constant F00463 K constant (decomposition constant, see F00461) for a single month. 0 12 12
Dynamics Decomposition Root decomposition_Monthly necromass decomposition rate per ground area F00464 Amount of root necromass that decomposes over the course of a month. 0 12 12
Morphology Diameter Root diameter F00679 Diameter of roots observed. 8729 487 9216
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
Morphology Dry matter content Root dry matter content (RDMC) F00689 Root dry mass divided by root fresh mass. 2102 159 2261
Chemistry Secondary Compounds Root ethanol soluble fraction F00352 Percentage of root tissue that is soluble in ethanol. 10 0 10
Anatomy Hypodermis Root exodermal wall thickness F00108 Thickness of exodermal wall from root scans. 27 0 27
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
Physiology Exudation Root exudation_C exudation rate per plant F01418 Total carbon exudation rate by fine roots per individual plant. 4 0 4
Physiology Exudation Root exudation_C exudation rate per root length F01416 Carbon exudation rate by length of fine roots. 4 0 4
Physiology Exudation Root exudation_C exudation rate per root mass F00754 Carbon exudation rate by mass of fine roots. 28 0 28
Physiology Exudation Root exudation_Concentration in soil F01430 Concentration of root exudates in the soil, estimated using 13C labelling. 6 0 6
Physiology Exudation Root exudation_Fraction estimated root mass F00751 Collected exudates scaled as proportion of estimated biomass accumulation. 4 0 4
Physiology Exudation Root exudation_molar C exudation rate per root area F01404 Root carbon exudation rate in terms of micromoles of Carbon exuded per root area. 32 0 32
Chemistry Micronutrients Root Fe content F00318 Mass of iron per root mass for sampled roots. 81 22 103
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
Chemistry Secondary Compounds Root free phenol content per root C content F00353 Concentration of phenolic compounds that are nonassociated forms in cell vacuoles per root carbon content. 35 0 35
Chemistry Secondary Compounds Root galactans fraction F00355 Concentration of galactans in root. 13 1 14
Dynamics Root Growth Root growth_Annual C production per ground area F00518 Amount of root carbon produced in one year. 10 193 203
Dynamics Root Growth Root growth_Annual length production per ground area F00546 Annual increase in total root length per unit ground area. 145 148 293
Dynamics Root Growth Root growth_Annual length production per minirhizotron surface area F00553 New root length observed per square centimeter of minirhizotron surface per year. 5 38 43
Dynamics Root Growth Root growth_Annual mass production per ground area F00521 Amount of root mass produced in one year. 778 503 1281
Dynamics Root Growth Root growth_Annual net new length production per ground area F00510 Live root length density appearance minus live root length density disappearance, adjusted to an annual value by subtracting net new length growth from the value for the previous sampling date, dividing by the number of days between sampling dates, and multiplying the result by the number of days in the year. 44 0 44
Dynamics Root Growth Root growth_Annual surface area production per ground area F00571 Root surface area produced per square meter of ground area per year. 24 18 42
Dynamics Root Growth Root growth_Bimonthly number of roots born per ingrowth screen area F00559 Inferred number of roots born per square centimeter of in-growth screen per two months. 0 16 16
Dynamics Root Growth Root growth_Cumulative length production per ground area F00543 Cumulative root length density appearance per unit ground area. 376 0 376
Dynamics Root Growth Root growth_Cumulative mass production per ground area F00527 Total root mass produced since the beginning of the study. 0 93 93
Dynamics Root Growth Root growth_Cumulative monthly mass ingrowth per screen area F00526 Cumulative rate of root growth into in-growth mesh, in kg per mesh cross-sectional area per month. 0 6 6
Dynamics Root Growth Root growth_Cumulative net length production per ground area F00507 Difference between cumulative live root appearance and cumulative live root disappearance. 46 0 46
Dynamics Root Growth Root growth_Daily elongation rate F00538 Rate at which elongation occurs for the roots where it does occur. 0 192 192
Dynamics Root Growth Root growth_Daily length production per coarse root length F00568 Total fine root length production per day per length of woody root. 12 0 12
Dynamics Root Growth Root growth_Daily length production per minirhizotron surface area F00551 New root length observed per square centimeter of minirhizotron surface per day. 108 164 272
Dynamics Root Growth Root growth_Daily mass production per coarse root length F00569 Total fine root mass produced per day per length of woody root. 12 0 12
Dynamics Root Growth Root growth_Daily mass production per ground area F00529 Amount of root mass produced in one day. 0 52 52
Dynamics Root Growth Root growth_Elongation fraction F00537 Percentage of roots that have elongated since the previous measurement. 0 196 196
Dynamics Root Growth Root growth_Fraction peak production F00513 The root production rate observed at a specific point divided by the maximum root production rate observed during the entire observation period. 126 0 126
Dynamics Root Growth Root growth_Length produced per P content F00286 Root length produced per unit mass of root phosphorus. 13 0 13
Dynamics Root Growth Root growth_Length production per ground area and exposition period F00556 Increase in root length per square meter of ground area during the observation period specified in the “[year/month/day] beginning data collection” and “[year/month/day] ending data collection” columns. 0 16 16
Dynamics Root Growth Root growth_Length production per minirhizotron frame F00540 Root length produced per minirhizotron frame. 32 0 32
Dynamics Root Growth Root growth_Length recovery from pruning F00566 Root length recovery from pruning. 56 4 60
Dynamics Root Growth Root growth_Mass production per ground area and exposition period F00534 Root biomass produced for the time interval specified in “main exposition period” and “production duration” or “in growth duration” (columns F01294 and F0076,F01283,F01284, or F01280). 82 74 156
Dynamics Root Growth Root growth_Mass production per plant per growing season F01276 Increase in belowground biomass per plant (by dry weight) over the course of one growing season. 8 0 8
Dynamics Root Growth Root growth_Monthly mass ingrowth per screen area F00531 Monthly rate of root growth into in-growth mesh, in kg per mesh cross sectional area per month. 0 6 6
Dynamics Root Growth Root growth_Monthly mass production per ground area F00532 Amount of root mass produced in one month. 123 0 123
Dynamics Root Growth Root growth_Monthly mass production per soil volume F00533 Root mass produced per cubic centimeter of soil each month. 108 0 108
Dynamics Root Growth Root growth_Number of roots per area of ingrowth screen F00903 Number of roots per square cm of in-growth screen. 0 89 89
Dynamics Root Growth Root growth_Predicted amplitude of monthly net root production F00561 Log of predicted amplitude of monthly net root production if it occurs (ie if mRLQ>0), based on negative binomial distribution. See Mao et al. 2013 (DOI: 10.1007/s11104-012-1324-2)for further details. 0 26 26
Dynamics Root Growth Root growth_Surface area production per ground area and exposition period F00574 Increase in root surface area per square meter of ground area during the observation period specified in the “Exposition period_main” column [F01294]. 0 16 16
Morphology Root Hairs Root hair density F00733 Number of root hairs per root surface area. 25 0 25
Morphology Root Hairs Root hair diameter F00736 Diameter of root hairs. 25 0 25
Morphology Root Hairs Root hair incidence F00692 Percentage of fine roots that contain root hairs, by the gridline method. 2 60 62
Morphology Root Hairs Root hair length F00696 Length of root hairs. 231 60 291
Morphology Root Hairs Root hair volume per root mass F00700 Volume of root hairs per gram of root mass, estimated using specific root length. 28 0 28
Chemistry Cellulose Root hemicellulose content per root C content F00242 Percentage of root carbon that is hemicellulose. 2 0 2
Chemistry Cellulose Root hemicellulose content per root mass F00243 Percentage of root mass that is hemicellulose. 174 2 176
Root System Standing crop Root intact branch length F00196 Total root length contained within an intact root branch. 4 0 4
Chemistry Macronutrients Root K content F00289 Mass of potassium per root mass for sampled roots. 561 223 784
Chemistry Macronutrients Root K content per root fresh mass F01302 Mass of root potassium per fresh mass for sampled roots. 6 0 6
Physiology Nutrient uptake Root K uptake_Fraction K uptake capacity per soil depth interval F00766 Estimated potassium uptake capacity of roots at the depth interval specified in Soil depth_Upper sampling depth (F00068) and Soil depth_Lower sampling depth (F00069) relative to the plant’s total uptake capacity. 15 0 15
Root System Standing crop Root length density (RLD)_Root length per ground area F00934 Root length divided by soil core cross-sectional area. 3224 409 3633
Root System Standing crop Root length density (RLD)_Root length per soil volume F00938 Root length divided by the sampled soil volume. 647 152 799
Root System Allocation within root system Root length fraction per root diameter class F00864 Percentage of root length composed of a specific root diameter class. 137 24 161
Root System Allocation within root system Root length fraction per root order class F00867 Percentage of root length composed of a specific root order. 204 3 207
Root System Standing crop Root length fraction per species F00933 Percentage of total root length belonging to an individual species. 18 0 18
Morphology Root Length Root length from base to tip F00703 Distance from root base to tip. 1034 28 1062
Root System Standing crop Root length per minirhizotron frame F00930 Total root length observed per minirhizotron frame. 32 0 32
Root System Standing crop Root length per minirhizotron surface area F00944 Meters of root length visible per square meter of minirhizotron surface. 170 137 307
Root System Standing crop Root length per plant F00942 Total length of all roots for an entire plant. 1907 127 2034
Root System Standing crop Root length ratio (RLR) F00927 Root length per gram of plant mass. 68 0 68
Physiology Nutrient uptake Root Li uptake_Daily uptake of molar Li per root length F01427 Daily uptake rate of lithium by roots, reported in terms of micrograms taken up per meter of root length. 16 0 16
Chemistry Secondary Compounds Root lignin content F00358 Concentration of lignin in root. 553 208 761
Chemistry Secondary Compounds Root lignin content per root C content F00361 Percentage of root carbon that exists as lignin. 7 0 7
Chemistry Secondary Compounds Root lignin phenol content per root C content F00356 Total concentration of monophenols that constitute lignin in root per root carbon content. 35 0 35
Chemistry Secondary Compounds Root lignin phenol vegetation index (LPVI) F00338 [S%(S% + 1)/(V% + 1) + 1] * [C%(C% + 1)/(V% + 1) + 1], where V%, S%, and C% are the respective percentages of vanillyl phenol, syringyl phenol, and cinnamyl phenol in root lignin. Indicator for taxonomic source identification. 5 0 5
Chemistry Stoichiometry Root lignin/N ratio F00419 Ratio of lignin concentration to N concentration in root. 118 15 133
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
Chemistry Secondary Compounds Root lipid content F00362 Concentration of lipids in root. 18 0 18
Chemistry Secondary Compounds Root mannans content F00364 Concentration of mannans in root. 13 1 14
Root System Allocation within plant Root mass fraction (RMF) F00846 Root biomass divided by total plant biomass. 6003 8 6011
Root System Allocation within root system Root mass fraction per root diameter class F00855 Percentage of root biomass contributed by a particular diameter class. 210 16 226
Root System Allocation within root system Root mass fraction per root order class F00858 Percentage of root biomass contributed by a particular root order. 297 0 297
Root System Allocation within root system Root mass fraction per species F00884 Percentage of total root mass composed of a particular species in a community. 48 12 60
Dynamics Lifespan Root mean lifespan_d F00469 Mean lifespan of roots observed, expressed in days. 203 45 248
Dynamics Lifespan Root mean lifespan_Main_d F01295 Mean lifespan in days. This column combines data from both “Root mean lifespan_d” (F00470) and “Root mean lifespan_yr” (F01292) columns. If source originally presents lifespan in years or months, lifespan is converted to days for this value. 256 45 301
Dynamics Lifespan Root mean lifespan_yr F01292 Mean lifespan of roots observed, expressed in years. 53 0 53
Dynamics Lifespan Root median lifespan_d F00470 Median lifespan of roots observed, expressed in days. 232 10 242
Dynamics Lifespan Root median lifespan_Main_d F01296 Median lifespan in days. This column combines data from both “Root median lifespan_d” (F00470) and “Root median lifespan_yr” (F01293) columns. If source originally presents lifespan in years or months, lifespan is converted to days for this value. 243 10 253
Dynamics Lifespan Root median lifespan_yr F01293 Median lifespan of roots observed, expressed in years. 11 0 11
Anatomy Vessels or Tracheids Root metaxylem cell wall thickness F00150 Thickness of the cell wall in the root metaxylem. 4 0 4
Anatomy Vessels or Tracheids Root metaxylem cell wall thickness/vessel diameter ratio F00128 Percentage of metaxylem vessel diameter that consists of cell wall thickness. 4 0 4
Anatomy Vessels or Tracheids Root metaxylem vessel diameter F00140 Vessel diameter of root metaxylem. 4 0 4
Chemistry Macronutrients Root Mg content F00257 Mass of magnesium per root mass for sampled roots. 525 133 658
Chemistry Macronutrients Root Mg content per root fresh mass F01300 Mass of magnesium per root fresh weight for sampled roots. 6 0 6
Microbial associations Other rhizosphere microbes Root microbes_Bacterial biomass C content per root mass F00659 Concentration of bacterial carbon in root material, estimated based on calculated average conversion factor of muramic acid to fungal carbon. 15 1 16
Microbial associations Other rhizosphere microbes Root microbes_Fungal biomass C content per root mass F00658 Concentration of fungal carbon in root material, estimated based on calculated average conversion factor of glucosamine to fungal carbon. 15 1 16
Microbial associations Other rhizosphere microbes Root microbes_Fungal C/bacterial C ratio F00660 Ratio of root fungal carbon to root bacterial carbon. 15 1 16
Microbial associations Other rhizosphere microbes Root microbes_Microbial biomass C content per root mass F00656 Carbon from microbial biomass in roots, calculated from root ergosterol and the ergosterol/microbial biomass carbon ratio of the rhizosphere soil. 17 1 18
Microbial associations Other rhizosphere microbes Root microbes_Microbial biomass N content per root mass F00657 Nitrogen from microbial biomass in roots, calculated from root ergosterol and microbial biomass C/N ratio of the rhizosphere soil. 14 1 15
Microbial associations Other rhizosphere microbes Root microbes_Root glucosamine content per root mass F00652 Concentration of glucosamine measured in root material. 18 1 19
Microbial associations Other rhizosphere microbes Root microbes_Root length hyphal fraction F00629 Percentage of root length that contains fungal hyphae, determined using a random intercept method. 0 4 4
Chemistry Micronutrients Root Mn content F00322 Mass of manganese per root mass for sampled roots. 247 30 277
Chemistry Micronutrients Root Mn content per root fresh mass F01305 Mass of root manganese per fresh mass for sampled roots. 6 0 6
Dynamics Root Mortality Root mortality_Annual root length mortality per ground area F00500 Annual mortality of root length density. 112 30 142
Dynamics Root Mortality Root mortality_Annual root length mortality per minirhizotron surface area F00498 Observed length of roots which dies per minirhizotron surface per year. 5 13 18
Dynamics Root Mortality Root mortality_Annual root mass mortality per ground area F00490 Amount of root biomass that dies in one year per square meter of ground area. 44 44 88
Dynamics Root Mortality Root mortality_Cumulative root length disappearance per ground area F00487 Cumulative root length density disappearance observed per ground area. 374 0 374
Dynamics Root Mortality Root mortality_Cumulative root length mortality per minirhizotron frame F00493 Root length mortality observed per minirhizotron frame since the beginning of observation. 28 0 28
Dynamics Root Mortality Root mortality_Daily root length mortality per minirhizotron surface area F00496 Observed length of roots which dies per minirhizotron surface per day. 104 130 234
Dynamics Root Mortality Root mortality_Fraction initial intersections with ingrowth screen lost F00505 For in-growth screen, percentage of root-screen contacts lost after installation. 0 28 28
Dynamics Root Mortality Root mortality_Monthly mass disappearance per soil volume F00485 Mass of root biomass that disappears per cubic centimeter of soil per month. Calculated based on loss of mass. 72 0 72
Dynamics Root Mortality Root mortality_Monthly necromass increase per soil volume F00486 Amount of root biomass that dies per cubic centimeter of soil per month. Calculated based on change in necromass. 102 0 102
Dynamics Root Mortality Root mortality_Monthly number of roots lost per ingrowth screen area F00503 Inferred number of roots to die per square centimeter of in-growth screen per two months. 0 16 16
Dynamics Root Turnover Root mortality_Root N loss per annual plant N uptake F00577 Nitrogen lost through fine root mortality as a percentage of annual whole-plant nitrogen uptake. 5 0 5
Dynamics Root Turnover Root mortality_Root N loss per plant N content per ground area F00578 Nitrogen lost through fine root mortality as a percentage of whole-plant N storage (root nitrogen per ground area). 5 3 8
Microbial associations Other rhizosphere microbes Root muramic acid content F00653 Concentration of muramic acid measured in root material. 18 1 19
Chemistry Macronutrients Root N content F00261 Mass of nitrogen per root mass for sampled roots. 5717 1047 6764
Root System Standing crop Root N content per ground area F00921 Total mass of root nitrogen per ground area for the specified depth increment. 166 382 548
Chemistry Macronutrients Root N content per root length F00270 Root nitrogen mass per meter of root length. 249 0 249
Root System Standing crop Root N mass per soil mass F00924 Mass of root nitrogen per gram of soil. 236 0 236
Physiology Nutrient uptake Root N uptake_Cumulative N uptake F00770 Total root nitrogen uptake since the first observation per meter square of ground area. 20 0 20
Physiology Nutrient uptake Root N uptake_Hourly NO3- uptake per root mass F01459 Hourly maximum uptake capacity of NO3- per root mass, determined by colorometric methods. 0 0 0
Physiology Nutrient uptake Root N uptake_Hourly uptake of 15NH4+ per root fresh mass F00773 Hourly uptake of nitrogen by roots per root fresh mass, as determined by a root bioassay using 15NH4+. Reported in terms of nanograms of NH4+. 4 0 4
Physiology Nutrient uptake Root N uptake_Hourly uptake of molar NH4+ per root fresh mass F00775 Hourly uptake of nitrogen by roots per root fresh mass, as determined by a root bioassay using 15NH4+.  Reported in terms of nmol of NH4+. 22 0 22
Physiology Nutrient uptake Root N uptake_Hourly uptake of molar NH4+ per root mass F01457 Hourly maximum uptake capacity of NH4+ per root mass, determined by colorometric methods. 0 0 0
Physiology Nutrient uptake Root N uptake_Hourly uptake per unit root mass F00777 Amount of nitrogen taken up per unit root mass per hour. 24 0 24
Physiology Nutrient uptake Root N uptake_Molar inorganic N uptak?e per root area F01405 Hourly uptake of inorganic nitrogen in terms of micromoles of nitrogen per root area. 8 0 8
Physiology Nutrient uptake Root N uptake_Molar NH4+ uptake per root area F01406 Hourly uptake of nitrogen by roots per root surface area, as determined by a root bioassay using 15NH4+. Reported in terms of umol of NH4+. 8 0 8
Physiology Nutrient uptake Root N uptake_Molar NO3- uptake per root area F01407 Hourly uptake of nitrogen by roots per root surface area, as determined by a root bioassay using 15NO3-. Reported in terms of umol of NO3-. 8 0 8
Physiology Nutrient uptake Root N uptake_Molar organic N uptake per root area F01408 Hourly uptake of organic nitrogen in terms of micromoles of nitrogen per root area. 8 0 8
Chemistry Micronutrients Root Na content F00334 Mass of sodium per root mass for sampled roots. 51 42 93
Chemistry Micronutrients Root Na+ content F00331 Mass of Na+ ions per root mass, determined by silver ion titration. 32 0 32
Chemistry Stoichiometry Root NAH/root N ratio F00409 Ratio of non-acid hydrolysable compounds to nitrogen in root tissue. 102 3 105
Root System Allocation within root system Root necromass/biomass ratio F00870 Dead root mass divided by live root mass. 751 882 1633
Chemistry Secondary Compounds Root neutral detergent soluble fraction F00365 Percentage of root mass that is soluble in neutral detergent. 7 0 7
Chemistry Micronutrients Root Ni content F00326 Mass of nickel per root mass for sampled roots. 40 12 52
Microbial associations Nitrogen fixers Root nodules_Nodule mass on dead roots per ground area F00649 Total dry weight of all root nodules collected from dead roots in soil cores. 25 0 25
Microbial associations Nitrogen fixers Root nodules_Nodule mass on living roots per ground area F00646 Total dry weight of all root nodules collected from living roots in soil cores. 3 0 3
Chemistry Secondary Compounds Root non-acid hydrolyzable compounds content (NAH) F00366 Concentration of compounds in root that are not acid soluble. Also known as Root acid insoluble fraction (AIF). 310 10 320
Chemistry Total non-structural carbohydrates Root non-structural C content per root C content F00427 Percentage of root carbon that is non-structural 2 0 2
Chemistry Secondary Compounds Root nonpolar compounds content F00374 Concentration of nonpolar compounds in root. 146 11 157
Anatomy Vessels or Tracheids Root number of tracheary elements F00132 Number of tracheary elements present in root, with secondary cell-wall thickening counted per xylem pole. 5 0 5
Anatomy Vessels or Tracheids Root number of vessels F01313 Number of vessels per root cross-section. 202 0 202
Physiology Nutrient uptake Root N_Annual turnover per ground area F00769 Annual root nitrogen turnover per meter square of ground area. 26 0 26
Chemistry Macronutrients Root N_Molar organic N content F00276 Millimoles of organic nitrogen in root per gram of root mass. 20 0 20
Chemistry Secondary Compounds Root O-alkyl C content per root C content F00434 Fraction of root carbon that is in O-alkyl groups. 4 0 4
Chemistry Stoichiometry Root organic N/root total N ratio F00421 Root organic N concentration divided by total root N concentration. 20 0 20
Chemistry Macronutrients Root P content F00277 Mass of phosphorous per root mass for sampled roots. 1603 310 1913
Chemistry Macronutrients Root P content per root fresh mass F01301 Mass of root phosphorus per fresh mass for sampled roots. 6 0 6
Physiology Nutrient uptake Root P uptake_Fraction maximum P uptake rate F00763 Fraction of maximum phosphorus uptake rate achieved by age group  specified in F00062 and F00063. 22 0 22
Physiology Nutrient uptake Root P uptake_Hourly uptake of H2PO4- F00784 Hourly uptake of H2PO4, as determined by a root bioassay. 4 0 4
Physiology Nutrient uptake Root P uptake_Rate per root mass F00786 Rate of phosphorus uptake per gram of root per second. 12 0 12
Physiology Nutrient uptake Root P uptake_Rate per root surface area per second F00788 Phosphorus uptake per unit root area, determined with tissue cassettes. 18 0 18
Chemistry Secondary Compounds Root p-hydroxy phenol content per root C content F00378 Concentration of p-hydroxybenzoic acid, p-hydroxyacetophenon, and p-hydroxybenzaldehyde phenols in root per root C content. 5 0 5
Anatomy Hypodermis Root passage cell number in exodermis F00109 Number of passage cells in exodermis. 27 0 27
Anatomy Hypodermis Root passage cell number per root circumference F00110 Number of passage cells per mm root circumference. 27 0 27
Chemistry Micronutrients Root Pb content F00319 Mass of lead per root mass for sampled roots. 41 11 52
Anatomy Phellem Root phellem F00157 Number of phellem layers in root. 187 0 187
Chemistry Secondary Compounds Root phenols content F00382 Concentration of phenols per unit root dry mass. 45 0 45
Chemistry Secondary Compounds Root phenols_chlorogenic acid molarity per root mass F01328 Micromoles of chlorogenic acid yielded per root mass from ethanol boiling extraction and Folin-Ciocalteu’s phenol reagent. See page 1221 of Zadworny et al. 2017, DOI: 10.1111/gcb.13514, for further information. 212 0 212
Physiology Exudation Root phosphatase activity per root length F00760 Phosphatase activity of roots, based on release of p-nitrophenol from a solution of p-nitrophenyl phosphate per meter of root length per hour. 13 0 13
Physiology Exudation Root phosphatase activity per root mass F00757 Hydrolysis of p-nitrophenyl phosphatase to p-nitrophenol after incubation at 37°C for 1 hour. 14 0 14
Chemistry pH Root pH_Water F01461 pH of root powder, measured in water. 48 0 48
Chemistry Secondary Compounds Root polar compounds content F00384 Concentration of polar compounds in root. 142 3 145
Chemistry Secondary Compounds Root polyphenol content F00388 Concentration of polyphenols in root. 20 0 20
Chemistry Stoichiometry Root polyphenol/root N ratio F00422 Ratio of root polyphenol concentration to root N concentration. 6 0 6
Physiology Nutrient uptake Root preferred N form F00791 Form or forms of nitrogen preferentially taken up by roots. NH4-N is NH4, NO3-N is NO3, and ON is organic nitrogen. If multiple forms are preferred, their relative preference to each other is shown with >=, 37 0 37
Anatomy Vessels or Tracheids Root protoxylem cell wall thickness F00152 Thickness of the cell wall in the root protoxylem. 4 0 4
Anatomy Vessels or Tracheids Root protoxylem cell wall thickness per protoxylem diameter F00130 Percentage of protoxylem vessel diameter that consists of cell wall thickness. 4 0 4
Anatomy Vessels or Tracheids Root protoxylem diameter F00148 Vessel diameter of root protoxylem. 4 0 4
Dynamics Root Growth Root pruning recovery F00570 Percentage pruned woody roots that recovered by proliferating fine roots. 6 0 6
Physiology Nutrient uptake Root Rb uptake_Daily uptake of molar Rb+ per root length F01425 Daily uptake rate of rubidium by roots, reported in terms of nanograms taken up per meter of root length. 0 0 0
Physiology Nutrient uptake Root Rb uptake_Hourly Rb uptake per root mass F00796 Hourly uptake rate of rubidium by roots, as determined by a root bioassay using 86Rb+, reported in terms of nanograms taken up per fresh weight of roots per hour. 19 0 19
Physiology Nutrient uptake Root Rb uptake_Hourly uptake of molar Rb+ per root fresh mass F00792 Hourly uptake rate of rubidium by roots per root fresh mass, as determined by a root bioassay using 86Rb+, reported in nmol taken up per fresh weight of roots per hour. 19 0 19
Dynamics Root Growth Root relative growth rate (RGR)_Root length F00515 [In (each growth response at 30, 60 and 90 days of the treatments) - In (each growth response at 0, 30 and 60 days of the treatments, respectively)]/30 days; see Imada et al. 2008 (DOI: 10.1111/j.1365-2435.2008.01454.x) for more details. 68 0 68
Physiology Respiration Root respiration rate per root dry mass_CO2 release F00802 Root respiration rate of CO2 per g root dry mass per second. 278 59 337
Physiology Respiration Root respiration rate per root dry mass_O2 uptake F00799 Root respiration rate of O2 per root dry mass, as measured in a respiration chamber. 1448 162 1610
Physiology Respiration Root respiration rate per root length_CO2 release F00807 Root respiration rate of CO2 per meter of root length, as measured in a respiration chamber. 43 0 43
Physiology Respiration Root respiration rate per root mass_C release F00805 Root respiration rate, converted from terms of nmol O2 g-1 s-1,converted to µg C g-1 s-1using a respiratory quotient of 1.25. See Matamala & Schlesinger 2000 (DOI: 10.1046/j.1365-2486.2000.00374.x) for further details. 20 0 20
Chemistry Secondary Compounds Root rhamnan content F00391 Concentration of rhamnans in root. 10 0 10
Chemistry Macronutrients Root S content F00293 Mass of sulfur per root mass for sampled roots. 111 41 152
Chemistry Macronutrients Root S content per root fresh mass F01303 Mass of root sulfur per fresh mass for sampled roots. 6 0 6
Chemistry Micronutrients Root Si content F00329 Mass of silicon per root mass for sampled roots. 29 0 29
Chemistry Secondary Compounds Root starch fraction F01329 Percentage of root mass consisting of starches. 274 21 295
Anatomy Vessels or Tracheids Root stele cross-sectional area F01324 Cross-sectional area of root stele. 9 0 9
Anatomy Stele Root stele cross-sectional fraction F00122 Percentage of root cross-sectional area that is occupied by the stele. 120 0 120
Anatomy Stele Root stele diameter F00118 Diameter of root stele. 417 0 417
Anatomy Stele Root stele diameter/root diameter ratio F00115 Stele diameter divided by root diameter. 343 0 343
Anatomy Stele Root stele/root cortex ratio F00125 Proportion of root cross sectional area occupied by the stele divided by proportion of root cross sectional area occupied by the cortex. 93 0 93
Chemistry Secondary Compounds Root structural C content per root C content F00392 Percentage of root carbon that is structural. 2 0 2
Root System Allocation within root system Root surface area fraction per root order class F00872 Percentage of total root surface area that a specific root order comprises. 41 0 41
Root System Standing crop Root surface area per ground area F00878 Total surface area of roots per square meter of ground area. 126 99 225
Dynamics Lifespan Root survivorship_Fraction of root tips surviving after one year F00483 Percentage of root tips that survive after one year. 62 9 71
Dynamics Lifespan Root survivorship_Fraction roots surviving for exposition period F00480 Percentage of roots which survive for the time interval represented in the row (i.e., the time period between the dates in the “[date] beginning collection” and “[date] ending collection” columns). 24 0 24
Dynamics Lifespan Root survivorship_Fraction roots surviving for growing season F00479 Percentage of roots which survive over the course of a growing season. 28 0 28
Chemistry Secondary Compounds Root syringyl phenol content per root C content F00393 Concentration of syringyl phenols in root per root carbon. 5 0 5
Chemistry Stoichiometry Root syringyl/vanillyl phenol ratio F00423 Ratio of syringyl phenol to vanillyl phenol in root. Index for taxonomic level (angiosperm or gymnosperm) of plant from which phenol was derived. 5 0 5
Root System Allocation within root system Root tip fraction per root diameter class F00953 Proportion of total number of root tips comprised by a particular diameter class. 354 0 354
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
Morphology Root tissue density Root tissue density (RTD) F00709 Weight of roots sampled divided by volume of roots. 6432 268 6700
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
Chemistry Total non-structural carbohydrates Root total non-structural carbohydrate content (TNC) F00428 Glucose equivalents per dry weight of roots, determined colorimetrically. 717 26 743
Dynamics Root Turnover Root turnover_Annual biomass turnover per ground area F00579 Root mass multiplied by turnover rate. 18 25 43
Dynamics Root Turnover Root turnover_Annual root system replacement F00582 Turnover as the inverse of belowground net primary productivity. 652 268 920
Dynamics Root Turnover Root turnover_Estimated rate per growing season F00589 Number of days in growing season divided by median lifespan of roots. 16 0 16
Dynamics Root Turnover Root turnover_Mass per dry season F00585 Turnover during dry season as defined in original data source. 0 8 8
Dynamics Root Turnover Root turnover_Mass per wet season F00587 Turnover during wet season as defined in original data source. 0 8 8
Chemistry Secondary Compounds Root vanillyl phenol content per root C content F00395 Concentration of vanillyl phenols in root per root carbon. 5 0 5
Chemistry Stoichiometry Root vanillyl phenol/lignin phenol ratio F00425 Ratio of vanillyl phenol to lignin phenol in root. Indicative of lignin quality. 5 0 5
Anatomy Vessels or Tracheids Root vessel cross-sectional area F01319 Cross-sectional area per root vessel. 76 0 76
Anatomy Vessels or Tracheids Root vessel diameter F00145 Diameter of root vessels. 209 0 209
Anatomy Vessels or Tracheids Root vessel number per root cross-sectional area F01321 Number of vessels in root per root cross-sectional area. 97 0 97
Root System Standing crop Root volume per ground area F00946 Total volume of roots per square meter of ground area for the specified depth increment. 86 74 160
Chemistry Secondary Compounds Root water or ethanol soluble compounds fraction F00397 Percentage of root tissue that is soluble in water or ethanol. 29 7 36
Chemistry Secondary Compounds Root water soluble compounds fraction F00399 Percentage of root tissue that is soluble in water. 178 71 249
Chemistry Secondary Compounds Root water soluble compounds per root mass F00401 Percentage of root tissue that consist of water-soluble sugars, as determined by a phenol–sulfuric acid assay. 44 7 51
Chemistry Secondary Compounds Root water soluble phenol compounds per root mass F01281 Percentage of root tissue that consists of water-soluble phenols. 10 0 10
Physiology Water uptake Root water uptake per root length F00819 Daily water uptake in milliliters, per centimeter of root length. 52 0 52
Physiology Water uptake Root water uptake per root surface area F00815 Water absorption rate per surface area of root. 9 0 9
Physiology Water uptake Root water uptake_Hourly uptake rate per soil volume F00822 Rate of water uptake by roots, divided by the volume of soil from which roots take up water. 149 0 149
Physiology Water uptake Root water uptake_Hydraulic conductivity (Lp) F00812 Hydraulic conductivity of roots. 140 0 140
Chemistry Secondary Compounds Root xylan content F00402 Concentration of xylans in root. 10 0 10
Anatomy Vessels or Tracheids Root xylem cross-sectional area F01311 Cross-sectional area of root xylem. 67 0 67
Anatomy Vessels or Tracheids Root xylem cross-sectional fraction F01315 Percentage of root cross-sectional area occupied by xylem. 67 0 67
Anatomy Vessels or Tracheids Root xylem vessel number per root stele area F00137 Number of xylem vessels per root stele cross-sectional area. 129 0 129
Chemistry Micronutrients Root Zn content F00335 Mass of zinc per root mass for sampled roots. 94 29 123
Root System Allocation within plant Root/shoot ratio F00851 Ratio of root tissue mass to shoot mass, where rhizomes are counted as shoot mass. 341 34 375
Root System Depth distribution Rooting depth F00954 Depth which includes all observed roots. 2554 514 3068
Root System Depth distribution Rooting depth_Active F00956 Depth where most of the root activity of interest occurs. 0 201 201
Root System Depth distribution Rooting depth_Extrapolated 50 percent rooting depth F00959 Depth which includes 50 percent of total roots in profile, extrapolated from logistic dose-response model described in Schenk & Jackson 2003, DOI: 10.3334/ORNLDAAC/659 176 388 564
Root System Depth distribution Rooting depth_Extrapolated 95 percent rooting depth F00960 Depth which includes 95 percent of total roots in profile, extrapolated from logistic dose-response model described in Schenk & Jackson 2003, 10.3334/ORNLDAAC/659 199 388 587
Root System Depth distribution Rooting depth_Fraction roots in soil depth increment F00963 Proportion of observed roots (quantified by column F00961, “Notes_Rooting depth measurement”) contained in depth interval. 248 180 428
Root System Depth distribution Rooting depth_Interpolated 50 percent rooting depth F00957 Depth which includes 50 percent of all observed roots in profile, calculated by fitting logistic dose-response curve to cumulative root profile and interpolating to maximum sampling depth, using the equation D_S50=D_50*([R_max/0.5R_Smax]-1)^(1/c) where Rmax is the estimated total amount of roots, RSmax is the total amount of roots in sampled profile, and C is a dimensionless shape parameter. 176 388 564
Root System Depth distribution Rooting depth_Interpolated 95 percent rooting depth F00958 Depth which includes 95 percent of roots in profile, calculated by fitting logistic dose-response curve to cumulative root profile and interpolating to maximum sampling depth, using the equation D_S95=D_50*([R_max/0.95R_Smax]-1)^(1/c). 204 388 592
Root System Depth distribution Rooting depth_min F01409 Minimum depth which includes all observed roots. 131 20 151
Morphology Specific root length Specific root area (SRA) F00718 Root surface area divided by root mass. 1829 365 2194
Architecture Topology Specific root forks density (SRFD) F00207 Number of root bifurcations per gram of root mass. 3 9 12
Morphology Specific root length Specific root length (SRL) F00727 Length of roots divided by root mass. 8336 607 8943
Architecture Topology Specific root tip abundance (SRTA) F00192 Number of root tips per milligram of root mass. 1232 255 1487
Root System Allocation within root system Taproot mass fraction F00875 Percentage of root mass that consists of the taproot. 13 0 13