DOI: 10.5061/dryad.612jm64gs
title: Data from: Restoration of riparian forest cover increases carbon stocks in the Pacific Northwest

description: Reforestation of degraded riparian areas provides climate mitigation
 benefits through increased carbon storage. In recent decades, riparian
 reforestation has accelerated in the Pacific Northwest (PNW) of the United
 States, primarily aiming to restore ecosystem functions and associated
 benefits, but few studies have evaluated riparian planting C sequestration
 and storage, particularly in highly productive wet riparian ecosystems
 like the PNW.  Using these plantings as a ‘natural experiment’,
 we assessed C storage in woody vegetation (trees and shrubs) and soils
 across a chronosequence of PNW riparian reforestation sites, and
 non-forested riparian baseline sites, representing the pre-planting
 condition. These data were used to evaluate changes in C storage with
 planting age and identify key covariates affecting C storage in plants and
 soils and their relationship with planting age across a ~430 km
 latitudinal gradient in western Oregon, USA.   
 Sites were distributed across 3 ecoregions, the Willamette Valley, the
 Pacific Northwest Coast, and the Klamath Mountains. The 43 studies sites
 were either non-forested or planted 5 -27 years before field data
 collection. The dataset includes biophysical properties of each site, as
 well as measurements of trees, shrubs, and soils which were used to
 calculate C storage at each plot and site. Sites stored between 38.3 –
 511.1 Mg C per hectare, and carbon storage generally increased with
 planting age. The majority of site carbon was stored in soils; however, C
 storage differed more across planting ages for trees and the understory
 than for soil. 
description: # Data from: Restoration of riparian forest cover increases carbon stocks
 in the Pacific Northwest [Access this dataset on
 Dryad](http:///doi.org/10.5061/dryad.612jm64gs) This dataset contains
 carbon storage and other relevant properties in the woody vegetation and
 soils of non-forested baseline and reforested riparian areas in western
 Oregon. Detailed methods for these data are available in the associated
 open-access article. ## Description of the data and file structure In
 recent decades, riparian reforestation has accelerated in the Pacific
 Northwest (PNW) of the United States, primarily aiming to restore
 ecosystem functions and associated benefits. Reforestation of degraded
 riparian areas provides climate mitigation benefits through increased
 carbon (C) storage, but the magnitude of this benefit is uncertain. Using
 these plantings as a ‘natural experiment’, we assessed C storage in woody
 vegetation (trees and shrubs) and soils across a chronosequence of PNW
 riparian reforestation sites, and non-forested baseline sites,
 representing the pre-planting condition. This dataset contains C storage
 across planting ages (years since planted) and biophysical properties
 hypothesized to affect C storage in woody vegetation and soils and their
 relationship with planting age across a ~430 km latitudinal gradient in
 western Oregon, USA. Site coordinates are not made available, to preserve
 landowner privacy. Inventory files (ending in "inv.csv") contain
 clean woody C survey data used for biomass C estimations and the estimated
 biomass and biomass C for the smallest unit calculated. Allometric
 equations for shrubs biomass estimation are found in shrub_index.csv. Soil
 properties and carbon contents are provided by depth on an
 non-mass-corrected fixed-depth basis and a corrected, equal soil mass
 basis. Final plot level results used for the analyses presented in the
 associated article are given in
 [final_plot_results.csv](#final_plot_results.csv) ### File Structure
 RipRefCarb.zip \| - ReadMe.MD \| - ReadMe.html \| - pred.csv \| -
 final_plot_results.csv \| - Woody/ |    | - shrub_index.csv |    | -
 Inventories/ |        | - tree_inv.csv |        | - shrub_inv.csv
 |        | - seedling_inv.csv |        | - cwd_inv.csv \| - Soil_Depth/
 |    | - soil_fd.csv |    | - soil_esm.csv ### Data Dictionary The
 following tables provide definitions of variables contained in the 9 csv
 files. | File | Description | |
 :-------------------------------------------------- |
 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------: | | [final\_plot\_results.csv](#final_plot_results.csv) | Final plot level carbon storage. | | [tree\_inv.csv](#tree_inv.csv) | Tree biomass C storage by individual, based on NSVB (National-Scale Volume Biomass) method. (Westfall et al. 2024) | | [shrub\_inv.csv](#shrub_inv.csv) | Shrub biomass C storage by individual | | [seedling\_inv.csv](#seedling_inv.csv) | Seedling biomass by species. | | [cwd\_inv.csv](#cwd_inv.csv) | Coarse woody debris (CWD) biomass and C by individual CWD piece | | [soil\_fd.csv](#soil_fd.csv) | Soil organic C concentration and other properties on fixed depth (non-mass corrected) basis. | | [soil\_esm.csv](#soil_esm.csv) | Mass-corrected soil organic carbon storage and other properties by depth layer. Data were mass-corrected (i.e. corrected to equal soil mass (ESM) basis) using a previously published tool (von Haden, Yang, and DeLucia 2020) | | [shrub\_index.csv](#shrub_index.csv) | Index of shrub species appearing in the dataset by name, allometric equations, and USDA plant codes linking species to equations. | | [pred.csv](#pred.csv) | Dataset of tested biophysical predictors. | #### final\_plot\_results.csv Final plot level data for carbon storage, woody vegetation, coarse woody debris, and soil properties. Soil properties are expressed on a mass normalized basis for the profile (i.e. summed for soil and soil carbon stock, and mass-weighted averages for sand, silt, clay, and pH). | Variable | Type | label | units | | :------------------ | :-------- | ---------------------------------------------------------------------------------: | --------: | | site | character | Site ID | | | plot | integer | Plot ID within site | | | tot\_MgC\_ha | numeric | Total (tree + understory + CWD + soil) C stock | Mg C ha⁻¹ | | tree\_MgC\_ha | numeric | Tree C stock | Mg C ha⁻¹ | | shrub\_MgC\_ha | numeric | Shrub C stock | Mg C ha⁻¹ | | understory\_MgC\_ha | numeric | Shrub + Seedling C stock | Mg C ha⁻¹ | | seedling\_MgC\_ha | numeric | Seedling C stock | Mg C ha⁻¹ | | cwd\_MgC\_ha | numeric | Coarse woody debris C stock | Mg C ha⁻¹ | | soil\_MgC\_ha | numeric | Soil C stock, equal-mass-normalized, by profile. | Mg C ha⁻¹ | | soil\_Mg\_ha | numeric | Soil mass per land area | Mg ha⁻¹ | | sand | numeric | Sand sized (0.063 - 2 mm) particle content, equal-mass-normalized, by profile. | % | | silt | numeric | Silt sized (0.002 - 0.063 mm) particle content, equal-mass-normalized, by profile. | % | | clay | numeric | Clay sized (&lt; 0.002 mm) particle content, equal-mass-normalized, by profile. | % | | pH | numeric | Soil pH in 1:1 water | | #### tree\_inv.csv Inventory of tree dimensions, species, measurement conditions, and biomass C storage by tree stem, including stems within multi-stemmed individuals (see tree_number variable). | Variable | Type | label | units | | :------------- | :-------- | -----------------------------------------------------------------------: | ----------: | | site | character | Site ID | | | plot | integer | Plot ID within site | | | tree\_number | numeric | Sequential tree x stem ID within plot | Tree#.Stem# | | height\_method | character | Height measurement method: meter stick/tape (T) or laser rangefinder (L) | | | live\_status | character | Tree live (L) or dead (D) | | | broken\_intact | character | Tree stem broken (B) or intact (I) | | | dbh | numeric | Diameter of stem at 1.3 m above ground | cm | | height | numeric | Tree height | m | | USDA\_Code | character | USDA Plants 3 - 6 character species code | | | SPCD | integer | Numerical species code for NSVB calculations | | | genus | character | Tree genus | | | species | character | Tree species, if known | | | tree\_MgC | numeric | Tree C content, by stem. | Mg C | #### shrub\_inv.csv Inventory of shrub dimensions, species, and biomass C storage by individual shrubs. | Variable | Type | label | units | | :------------ | :-------- | ----------------------------------------------: | ----: | | site | character | Site ID | | | plot | integer | Plot ID within site | | | shrub\_number | integer | Sequential shrub ID within plot | | | genus | character | Genus of shrub | | | species | character | Species of shrub | | | USDA\_Code | character | USDA Plants 3 - 6 character species code | | | length | numeric | Maximum shrub length | m | | width | numeric | Width of shrub, perpendicular to maximum length | m | | height | numeric | Maximum height of shrub | m | | shrub\_MgC | numeric | C content of shrub | Mg C | #### seedling\_inv.csv Inventory of tree seedling and sapling count by species, and their stem density and biomass by plot. Final biomass C by plot is in [final_plot_results.csv](#final_plot_results.csv). | Variable | Type | label | units | | :------------- | :-------- | -----------------------: | ------: | | site | character | Site ID | | | plot | integer | Plot ID within site | | | seed\_count | integer | Seeds plot | Count | | ABGR | integer | n Abies grandis | Count | | ACMA3 | integer | n Acer macrophyllum | Count | | ALRH | integer | n Alnus rhombifolia | Count | | ALRU2 | integer | n Alnus rubra | Count | | CADE | integer | n Calocedrus decurrens | Count | | CRDO2 | integer | n Crataegus douglasii | Count | | FRLA | integer | n Fraxinus latifolia | Count | | JUNI | integer | n Juglans nigra | Count | | PIJE | integer | n Pinus jeffreyi | Count | | PIPO | integer | n Pinus ponderosa | Count | | POBA2 | integer | n Populus trichocarpa | Count | | PSME | integer | n Pseudotsuga menziesii | Count | | QUGA | integer | n Quercus garryana | Count | | QUKE | integer | n Quercus kelloggii | Count | | SAHO | integer | n Salix hookeriana | Count | | THPL | integer | n Thuja plicata | Count | | seedling\_nha | integer | Seedling density by plot | ha⁻¹ | | seedling\_Mgha | numeric | Seedling biomass by plot | Mg ha⁻¹ | #### cwd\_inv.csv CWD biomass and C density by individual CWD piece. Numerical species codes (SPCD) match the numerical species code in tree_inv.csv. Density decay reduction factors and decay class descriptions: (Harmon et al. 2011) Downed-wood carbon content: (Harmon et al. 2013) | Variable | Type | label | units | | :-------------- | :-------- | -----------------------------------------------------------------------------------: | -------: | | site | character | Site ID | | | plot | integer | Plot ID within site | | | cwd\_number | integer | Sequential ID for CWD piece within plot | | | decay\_class | integer | Decay classes used by the U.S. Forest Service and as described in Harmon et al. 2011 | | | diameter\_cm | numeric | Diameter of CWD piece | cm | | USDA\_Code | character | USDA Plants 3 - 6 character species code | | | SPCD | integer | Numerical code for CWD piece species | | | spg | numeric | Species-based biomass density coefficient | g cm⁻³ | | dcrf | numeric | Density decay reduction factor, based on Harmon et al. 2011 | | | dwcc | numeric | Downed-wood carbon content, from Harmon et al. 2013 | % | | length\_m | numeric | Length of CWD piece | m | | biomasskgm2\_i | numeric | Biomass density of individual piece | kg m⁻² | | cwd\_C\_kgm2\_i | numeric | Carbon density of individual piece | kg C m⁻² | #### soil\_fd.csv Soil properties, fixed depth. | Variable | Type | label | units | | :------------- | :-------- | -----------------------------------------------------------: | -----: | | site | character | Site ID | | | plot | integer | Plot ID within site | | | layer | integer | Sequential depth layer, ordered top (1) to bottom (3) | | | FD\_Upper\_cm | integer | Top of field-based sample depth (cm) collection interval. | cm | | FD\_Lower\_cm | numeric | Bottom of field-based sample depth (cm) collection interval. | cm | | FD\_BD\_g\_cm3 | numeric | Soil bulk density (&lt;2mm, field-based). | g cm⁻³ | | FD\_SOC\_pct | numeric | Concentration of soil organic carbon in sample. | % | | FD\_sand | numeric | Sand sized (0.063 - 2 mm) particle content | % | | FD\_silt | numeric | Silt sized (0.002 - 0.063 mm) particle content | % | | FD\_clay | numeric | Clay sized (&lt; 0.002 mm) particle content | % | | FD\_pH | numeric | Soil pH in 1:1 water. | | #### soil\_esm.csv Soil properties, mass corrected using tool published by von Haden et al (2020) | Variable | Type | label | units | | :------------- | :-------- | -------------------------------------------------------------------: | --------: | | site | character | Site ID | | | plot | integer | Plot ID within site | | | Upper\_cm | integer | Top of equal-mass-normalized depth interval | cm | | Lower\_cm | integer | Bottom of equal-mass-normalized depth interval | cm | | soildens\_Mgha | numeric | Mass of soil per land area in depth interval. | Mg ha⁻¹ | | sand | numeric | Equal-mass-normalized sand sized (0.063 - 2 mm) particle content | % | | silt | numeric | Equal-mass-normalized silt sized (0.002 - 0.063 mm) particle content | % | | clay | numeric | Equal-mass-normalized clay sized (&lt; 0.002 mm) particle content | % | | pH | numeric | Equal-mass-normalized soil sized pH in 1:1 water | | | soil\_MgCha | numeric | Equal-mass-normalized soil organic carbon stock. | Mg C ha⁻¹ | #### shrub\_index.csv Shrub and sapling species codes, allometric equations and names. Allometric equations were derived from the following, as specified by “Source”: (Dickinson and Zenner 2010; Means et al. 1994; Huff, Ritchie, and Temesgen 2017; Verschuyl, Clark, and Loehle 2018; Smukler et al. 2010; Case 1995) | Variable | Type | label | | :------------------ | :-------- | -------------------------------------------------------------: | | genus | character | Shrub genus name | | species | character | Shrub species name | | CommonName | character | Common name | | USDA\_Code | character | USDA Plants 3 - 6 character species code | | ModelType | character | Model type: either shrub or sapling | | Equation | character | Name of allometric equation used for biomass calculation. | | EquationSpecificity | character | Taxonomic level used to specify equation. | | EQUATION | character | Allometric equation string that can be parsed for calculation. | | DPV\_UNIT | character | Density mass unit | | IV\_UNIT | character | Density volume unit | | Source | character | Source that allometric equation was derived from. | #### pred.csv Candidate predictors | Variable | Type | label | units | | :-------- | :-------- | ---------------------------------------------------------------------------: | -----------: | | site | character | Site ID | | | plot | integer | Plot ID within planting age | | | Age | integer | Planting age at time of sampling. Unplanted baseline sites have an age of 0. | years | | MAP | numeric | Mean annual precipitation, PRISM climate normal | mm | | MAT | numeric | Mean annual temperature, PRISM climate normal | °C | | MAR | numeric | Mean annual radiation, PRISM climate normal | MJ m⁻² day⁻¹ | | Elev | integer | Elevation at plot center | m | | Slop | numeric | Slope at plot center | % | | Asp | numeric | Aspect at plot center | ° | | FpW | numeric | Floodplain width | m | | StGr | numeric | Stream gradient | % | | Conf | numeric | Floodplain confinement ratio | Ratio | | Comp | numeric | Channel complexity ratio | Ratio | | Curv | numeric | Landscape curvature | m⁻¹ | | pH | numeric | Soil pH in 1:1 water | | | FnPt | numeric | Fine particle content (silt + clay sized particles) | % | | Rich\_tot | integer | Total species richness | Count | | Rich\_t | integer | Tree species richness | Count | | Rich\_u | integer | Understory species richness | Count | | Dens\_tot | integer | Total stem density | st ha ⁻¹ | | Dens\_t | integer | Tree stem density | st ha ⁻¹ | | Dens\_u | integer | Understory stem density | st ha ⁻¹ | # References Case, R. L. 1995. “The Ecology of Riparian Ecosystems of Northeast Oregon: Shrub Recovery at Meadow Creek and the Structure and Biomass of Headwater Upper Grande Ronde Ecosystems.” Master’s thesis, Corvallis, OR: Oregon State University. Dickinson, Yvette L., and Eric K. Zenner. 2010. “Allometric Equations for the Aboveground Biomass of Selected Common Eastern Hardwood Understory Species.” *Northern Journal of Applied Forestry* 27 (4):160–65. [https://doi.org/10.1093/njaf/27.4.160](https://doi.org/10.1093/njaf/27.4.160). Harmon, Mark E., Becky Fasth, Christopher W. Woodall, and Jay Sexton. 2013. “Carbon Concentration of Standing and Downed Woody Detritus: Effects of Tree Taxa, Decay Class, Position, and Tissue Type.” *Forest Ecology and Management* 291 (March): 259–67. [https://doi.org/10.1016/j.foreco.2012.11.046](https://doi.org/10.1016/j.foreco.2012.11.046). Harmon, Mark E., Christopher W. Woodall, Becky Fasth, Jay Sexton, and Misha. Yatkov. 2011. “Differences Between Standing and Downed Dead Tree Wood Density Reduction Factors: A Comparison Across Decay Classes and Tree Species.” NRS-RP-15. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. [https://doi.org/10.2737/NRS-RP-15](https://doi.org/10.2737/NRS-RP-15). Huff, Steve, Martin Ritchie, and H. Temesgen. 2017. “Allometric Equations for Estimating Aboveground Biomass for Common Shrubs in Northeastern California.” *Forest Ecology and Management* 398 (August): 48–63. [https://doi.org/10.1016/j.foreco.2017.04.027](https://doi.org/10.1016/j.foreco.2017.04.027). Means, Joseph E., Heather A. Hansen, Greg J. Koerper, Paul B Alaback, and Mark W. Klopsch. 1994. “Software for Computing Plant Biomass; BIOPAK Users Guide.” PNW-GTR-340. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. [https://doi.org/10.2737/PNW-GTR-340](https://doi.org/10.2737/PNW-GTR-340). Smukler, S. M., S. Sánchez-Moreno, S. J. Fonte, H. Ferris, K. Klonsky, A. T. O’Geen, K. M. Scow, K. L. Steenwerth, and L. E. Jackson. 2010. “Biodiversity and Multiple Ecosystem Functions in an Organic Farmscape.” *Agriculture, Ecosystems & Environment* 139 (1): 80–97.[https://doi.org/10.1016/j.agee.2010.07.004](https://doi.org/10.1016/j.agee.2010.07.004). Verschuyl, Jake, Laurie Clark, and Craig Loehle. 2018. “Predicting Shrub Biomass and Current Annual Growth from Field Measurements in the Oregon Coast Range.” *Northwest Science* 92 (1): 9.[https://doi.org/10.3955/046.092.0103](https://doi.org/10.3955/046.092.0103). von Haden, Adam C., Wendy H. Yang, and Evan H. DeLucia. 2020. “Soils’ Dirty Little Secret: Depth-Based Comparisons Can Be Inadequate for Quantifying Changes in Soil Organic Carbon and Other Mineral Soil Properties.” *Global Change Biology* 26 (7): 3759–70. [https://doi.org/10.1111/gcb.15124](https://doi.org/10.1111/gcb.15124). Westfall, James A., John W. Coulston, Andrew N. Gray, John D. Shaw, Philip J. Radtke, David M. Walker, Aaron R. Weiskittel, et al. 2024. “A National-Scale Tree Volume, Biomass, and Carbon Modeling System for the United States.” WO-GTR-104. Washington, DC: U.S. Department of Agriculture, Forest Service. [https://doi.org/10.2737/WO-GTR-104](https://doi.org/10.2737/WO-GTR-104).