DOI: 10.5061/dryad.z612jm6jw
title: Data from: Enhanced woody biomass production in a mature temperate forest under elevated CO2

description: This data set reports tree growth and net primary productivity in response
 to experimentally elevated atmospheric CO2 concentration in the free-air
 CO2 enrichment (FACE) of the Birmingham Institute of Forest Research
 (BIFoR FACE). Data ae reported for a pre-treatment period (2010-2016) and
 from the onset of CO2 treatment (2017-2023). The BIFoR FACE experiment is
 located in central England (52.801°N, 2.301°W, 107 m above sea level)
 within a deciduous forest dominated by 180-year old Quercus robur L.
 trees, which represent 92% of the forest’s basal area. There are six
 experimental arrays of approximately 30 m diameter. Tree ring analysis was
 used to determine growth patterns within the arrays prior to the onset of
 CO2 treatment. The trees in three of the arrays have been exposed to
 elevated CO2 (ambient concentration + 150 ppm) during the growing seasons
 since 2017. Tree diameter was measured with manual dendrometers, and dry
 mass of oak trees was calculated using an allometric equation determined
 by terrestrial laser scan of the trees within the arrays. Dry matter
 production of understory species and coarse roots was calculated using
 allometric equations from the literature. Leaf production was calculated
 from mass of leaf litter collected in litter baskets. Fine-root production
 was measured in ingrowth cores and scaled to 1-meter depth based on
 fine-root biomass in deep cores. Exudation rates were scaled up to a full
 growing season and total fine-root mass.
description: All methods associated with the collection and processing of
 these data are described in: Norby RJ et al. 2024. Enhanced woody biomass
 production in a mature temperate forest under elevated
 CO<sub>2</sub>. <em>Nature Climate
 Change</em>.
description: # Data from: Enhanced woody biomass production in a mature temperate
 forest under elevated CO2
 [https://doi.org/10.5061/dryad.z612jm6jw](https://doi.org/10.5061/dryad.z612jm6jw) These data are internally consistent data products that have been subjected to quality checks and data management procedures. The provided data files are in comma separate format (csv): BIFoR_tree_ring.csv BIFoR_DMI.csv BIFoR_litter.csv BIFoR_NPP.csv BIFoR_root_production.csv BIFoR_TLS.csv ## Description of the data and file structure **Data Dictionary: BIFoR_tree_ring.csv** | Column number | Column name | Units | Description | | :------------ | :------------------- | :------ | :----------------------------------------------------------------------------------------------------------------- | | 1 | array |   | Arrays 2, 3, and 5 are in ambient CO2; arrays 1, 4, and 6 are elevated CO2 | | 2 | CO2 treatment |   | Ambient CO2: average 420 ppm; elevated CO2: 554 ppm | | 3 | Tree number |   | Unique 4-digit number | | 4 | Year |   | 2010-2020 | | 5 | Ring width | 0.01 mm | Cores were collected in June 2021 and August 2022. | | 6 | Tree diameter | mm | Initial diameter (1.3 m height) was measured in 2020, and previous diameters were calculated based on ring widths. | | 7 | Basal area | cm2 | Calculated from diameter | | 8 | Basal area increment | cm2 | Increase in basal area during the year |   **Data Dictionary: BIFoR_DMI.csv** | Column number | Column name | Units | Description | | :------------ | :------------ | :---- | :--------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 1 | Array |   | Arrays 2, 3, and 5 are in ambient CO2; arrays 1, 4, and 6 are elevated CO2 | | 2 | CO2 treatment |   | Ambient CO2: average 420 ppm; elevated CO2: 554 ppm | | 3 | Year |   | 2016-2023 | | 4 | Species |   | Oak, *Quercus robur*; Ash, *Fraxinus* *excelsior*; Elm, *Ulmus glabra*; Hawthorn, \*Crataegus monogyna; \*Hazel, \*Corylus avellana; \*Sycamore, *Acer pseudoplatanus* | | 5 | Tree number |   | Unique 4-digit number of trees with dbh &gt; 10 cm | | 6 | Diameter | cm | Diameter at 1.3 m height (dbh) | | 7 | Biomass | kg | Dry mass of aboveground wood, calculated from allometric equation | | 8 | DMI | cm2 | Dry matter increment, change in aboveground biomass during the year |   **Data Dictionary: BIFoR_litter.csv** | Column number | Column name | Units | Description | | :------------ | :----------------- | :---- | :-------------------------------------------------------------------------------- | | 1 | Array |   | Arrays 2, 3, and 5 are in ambient CO2; arrays 1, 4, and 6 are elevated CO2 | | 2 | CO2 treatment |   | Ambient CO2: average 420 ppm; elevated CO2: 554 ppm | | 3 | Calendar year |   | 2019-2023 | | 4 | Leaf year |   | Leaf year starts April 1 of calendar year and ends March 31 of next calendar year | | 5 | Date |   | Date litter was collected from trap | | 6 | Litter trap number |   | Trap number within array (1-6) | | 7 | Trap area | m2 | Diameter at 1.3 m height | | 8 | Mass\_oak | g | Dry mass of oak leaves in trap | | 9 | Mass\_understory | g | Dry mass of leaves of understory species in trap | | 10 | Mass\_reprod | g | Dry mass of reproductive tissue in trap |   **Data Dictionary: BIFoR_root_production.csv** | Column number | Column name | Units | Description | | :------------ | :------------------- | :---- | :----------------------------------------------------------------------------------------------------- | | 1 | Array |   | Arrays 2, 3, and 5 are in ambient CO2; arrays 1, 4, and 6 are elevated CO2 | | 2 | CO2 treatment |   | Ambient CO2: average 420 ppm; elevated CO2: 554 ppm | | 3 | Install\_date |   | Date in 2021 or 2022 that in-growth core was installed | | 4 | Collection\_date |   | Date in 2021 or 2022 that in-growth core was retrieved | | 5 | Duration | d | Number of days between install and collection dates | | 6 | Fine-root production | g m-2 | Production of fine-root (&lt; 2 mm diameter) dry matter divided by cross sectional area of ingrowth core. | | 7 | Fraction\_top 30 |   | Fraction of fine roots in top 30 cm of soil in 1-m deep soil cores |   **Data Dictionary: BIFoR_NPP.csv** | Column number | Column name | Units | Description | | :------------ | :------------------- | :---- | :------------------------------------------------------------------------------------------------------------------------------------------------- | | 1 | Array |   | Arrays 2, 3, and 5 are in ambient CO2; arrays 1, 4, and 6 are elevated CO2 | | 2 | CO2 treatment |   | Ambient CO2: average 420 ppm; elevated CO2: 554 ppm | | 3 | Year |   | 2021 or 2022 | | 4 | Oak stem wood | g m-2 | Dry matter production of oak stem wood during year per unit land area | | 5 | Understory wood | g m-2 | Dry matter production of stem and coarse root wood of understory species during year per unit land area | | 6 | Oak coarse root | g m-2 | Dry matter production of oak coarse woody root during year per unit land area | | 7 | Fine-root production | g m-2 | Dry matter production of fine-roots (&lt; 2 mm diameter) during year per unit land area | | 8 | Reproduction | g m-2 | Dry matter production of reproductive tissue during year per unit land area | | 9 | Oak leaves | g m-2 | Dry mass of oak leaves produced during year per unit land area | | 10 | Understory leaves | g m-2 | Dry mass of leaves of understory species produced during year per unit land area | | 11 | Exudation | g m-2 | Exudation of carbon per day per g fine root, converted to dry matter equivalent and scaled to a 247-day growing season and total fine root biomass | | 12 | Total | g m-2 | Total net primary productivity during year per unit land area (sum of column 4-10) |   **Data Dictionary: BIFoR_TLS.csv**   | Column number | Column name | Units | Description | | :------------ | :------------ | :---- | :---------------------------------------------------------------------------------------------- | | 1 | Array |   | Arrays 2, 3, and 5 are in ambient CO2; arrays 1, 4, and 6 are elevated CO2 | | 2 | CO2 treatment |   | Ambient CO2: average 420 ppm; elevated CO2: 554 ppm | | 3 | Tree number |   | Unique 4-digit number of trees with dbh &gt; 10 cm | | 4 | Diameter | cm | Tree diameter at 1.3 m height measured in December 2021 | | 5 | Tree volume | m3 | Tree volume (bole and branches) calculated from terrestrial laser scan in January-February 2022 | | 6 | Tree biomass | kg | Tree biomass calculated as tree volume multiplied by specific gravity of 0.58 | ## Version Changes **22 July 2025** 2024 data for oak added to BIFoR_DMI.csv File name BIFoR_TLS.csv corrected