Madison M. Laughlin Liliana K. Rangel-Parra Jenna E. Morris Daniel C. Donato Joshua S. Halofsky Brian J. Harvey 20240130 v1.1.0 tabular digital data Laughlin, M.M., Rangel-Parra, L.K., Jenna E. Morris, J.E., Donato, D.C., Halofsky, J.S., and Harvey, B.J., 2024, Patterns and drivers of early conifer regeneration following stand-replacing wildfire in Pacific Northwest (USA) temperate maritime forests: Zenodo, https://zenodo.org/doi/10.5281/zenodo.10595208. https://zenodo.org/doi/10.5281/zenodo.10595208 https://github.com/Harvey-Lab-UW/Laughlin_etal_2023_FEM Madison M. Laughlin Liliana K. Rangel-Parra Jenna E. Morris Daniel C. Donato Joshua S. Halofsky Brian J. Harvey 202312 publication Forest Ecology and Management vol. 549 n/a Elsevier BV ppg. 121491 Data accompanying the manuscript 'Patterns and drivers of early conifer regeneration following stand-replacing wildfire in Pacific Northwest (USA) temperate maritime forests' by Laughlin, Rangel-Parra, Morris, Donato, Halofsky and Harvey published in Forest Ecology and Management. Data include field measurements of post-fire seedling abundance and additional information about the forest stands where data were collected. See the main text of the manuscript for complete descriptions of how data were collected, and greater specifics on values and classifications. This research is part of a broad, collaborative effort across agencies and partners to better understand the drivers, characteristics, and indicators of post-fire resilience in northwestern Cascadia. The data here were collected to assess the patterns and potential drivers of conifer seedling regeneration and establishment following stand-replacing mortality in the western Cascades of Washington and Oregon. 20190601 20210920 observed Complete None planned Northwestern Cascadia -123.1964 -121.1762 48.7232 45.5438 ISO 19115 Topic Category biota none wildfire forest resilience recovery conifers USGS Thesaurus fires forest ecosystems ecosystem resilience USGS Metadata Identifier USGS:c32c2d90-316f-4086-8fa1-c1e5b226db4e None Washington Oregon western Cascades northwestern Cascadia Pacific Northwest None Pseudotsuga menziesii Abies amabilis Abies procera Thuja plicata Tsuga heterophylla Pinus monticola Pinus contorta Kingdom Plantae Subkingdom Viridiplantae Infrakingdom Streptophyta Superdivision Embryophyta Division Tracheophyta Subdivision Spermatophytina Class Pinopsida Subclass Pinidae Order Pinales Family Pinaceae Genus Pseudotsuga Species Pseudotsuga menziesii TSN: 183424 Genus Abies Species Abies amabilis TSN: 181824 Species Abies procera TSN: 181835 Genus Tsuga Species Tsuga heterophylla TSN: 183400 Genus Pinus Species Pinus monticola TSN: 183356 Species Pinus contorta TSN: 183327 Family Cupressaceae Genus Thuja Species Thuja plicata TSN: 18044 None. Please see 'Distribution Info' for details. This information is licensed under a Creative Commons Attribution 4.0 International License. Any user of these data ("User" hereafter) is required to cite it appropriately in any publication that results from its use. These data may be actively used by others for ongoing research, so coordination may be necessary to prevent duplicate publication. The User is urged to contact the authors of these data for questions about methodology or results. The User is encouraged to consider collaboration or co-authorship with authors where appropriate. Misinterpretation of data may occur if used out of context of the original study. Substantial efforts are made to ensure accuracy of the data and documentation, however complete accuracy of data sets cannot be guaranteed. All data are made available as is. Data may be updated periodically and it is the responsibility of the User to check for new versions of the data. The authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. Brian J. Harvey Associate Professor mailing

School of Environmental and Forest Sciences, University of Washington, 4000 15th Ave NE

Seattle Washington 98195 United States of America (206) 685-9929 bjharvey@uw.edu This research is part of a broad, collaborative effort across agencies and partners to better understand the drivers, characteristics, and indicators of post-fire resilience in northwestern Cascadia and was supported by the United States Department of Agriculture (USDA) Forest Service – Pacific Northwest Research Station under award 20-JV-11261927-060 as part of the Westside Fire and Climate Adaptation Research Initiative. The project described in this publication was also supported by Grant / Cooperative Agreement G20AC00115 from the United States Geological Survey Northwest Climate Adaptation Science Center. Its contents are solely the responsibility of the authors and do not necessarily represent the views of the Northwest Climate Adaptation Science Center or the USGS. This manuscript is submitted for publication with the understanding that the United States Government is authorized to reproduce and distribute reprints for Governmental purposes. Additional support was provided by the Good Neighbor Authority between the USDA Forest Service and Washington Department of Natural Resources. Burn severity, forest zone, and pre-fire stand age were consistent within each 1-ha (56.5 m radius) plot. Plots of the same strata (i.e., same forest zone and pre-fire stand age) were separated by at least 400 m to reduce spatial autocorrelation. Plot centers were established at least 100 m away from a road or trail when possible to limit the influence of human activities or edge effects. We did not establish plots within areas that were salvage logged or planted post-fire, and avoided placing plots near streams, wetlands, or ephemeral creeks. Data were assessed to ensure that attribute values fall within expected bounds. We focused our sampling on western hemlock or Pacific silver fir forest zones since they occupy most of the forested land in the study region and are most relevant to forest land management. We excluded the Douglas-fir zone since these forests occur at warmer sites and are associated with a historically more frequent, mixed-severity fire regime relative to northwestern Cascadia. This dataset is considered complete, please refer to the complete metadata record and companion primary publication, Laughlin et al 2023. We established 39 1-ha long-term monitoring plots across four recent wildfires in northwestern Cascadia to measure post-fire conifer abundance and species composition. All plots were established June through September 2019–2021 within stand-replacing patches of wildfire (i.e., areas where overstory tree mortality exceeded 90 %) stratified across two axes of interest: forest zone (lower elevation western hemlock zone and higher elevation Pacific silver fir zone) and pre-fire stand age (young, mid-seral, and late-seral). Potential plot locations were first identified remotely using spatial layers related to burn severity, forest zone, and stand-age with all accessible locations considered equally. Potential plot locations were ground validated by keying out forest zone, pre-fire stand age, and burn severity and then randomized locally using a random distance and azimuth to establish plot center. 2021 At each plot (hereafter referred to as ‘stand’), post-fire conifer regeneration surveys occurred within twelve circular subplots evenly distributed along four 24.5 m sub-cardinal transects (i.e., transects situated along azimuths of 45, 135, 225, and 315 degrees from plot center, with three subplots per transect). Within each subplot, post-fire conifer regeneration less than 10 cm tall of each species were tallied within a 0.5 m radius circle from subplot center and regeneration ≥10 cm tall of each species were tallied within a 3.5 m radius circle from subplot center. 2022 Based on established general ecological understanding of the system, we measured six factors relevant to seedling establishment and survival: pre-fire stand structure, seed source availability, macroclimate setting, post-fire climatic conditions, topo-climatic conditions, and competition/microsite conditions. Our final eight explanatory variables related to these factors included: pre-fire stand age (young, mid-seral, late-seral), distance to the nearest live seed source (i.e., the nearest living clump of mature trees at least 1 ha in area), forest zone (western hemlock versus Pacific silver fir), standardized precipitation evapotranspiration index (SPEI), heat load index (HLI), topographic wetness index (TWI), average vegetation percent cover, and average bryophyte percent cover. Pre-fire stand age, forest zone, vegetation percent cover, bryophyte percent cover, and the variables to calculate HLI were collected in the field. Distance to the nearest live seed source, TWI, and SPEI were derived from publicly available geospatial datasets and are described in more detail in our related primary publication (Laughlin et al 2023). 2022 plot_level_data_by_species.csv Comma Separated Value (CSV) file containing data. Producer Defined plotID unique plot identifier in the format fire_plot. Fire is the wildfire where the plot is located and Plot a unique plot number identifier. Producer Defined unique plot identifier in the format fire_plot. Fire is the wildfire where the plot is located and Plot a unique plot number identifier. species four letter code indicating the species of each measured conifer seedling. Producer Defined abpr Abies procera (Noble fir) Producer defined psme Pseudotsuga menziesii (Douglas-fir) Producer defined abam Abies amabilis (Pacific silver fir) Producer defined pico Pinus contorta (lodgepole pine) Producer defined pimo Pinus monticola (western white pine) Producer defined tshe Tsuga heterophylla (western hemlock) Producer defined thpl Thuja plicata (western red-cedar) Producer defined abla Abies lasiocarpa (subalpine fir) Producer defined pien Picea engelmannii (Engelmann spruce) Producer defined regen_per_ha_yr Regeneration rate of seedlings (i.e., seedlings per hectare per year) for a species within a plot (includes post-fire seedlings of all heights). Producer Defined 4 86168 shade_tolerance conifer species classification of shade tolerance, binned into two groups: shade intolerant ("intolerant") and shade tolerant ("tolerant"). Producer Defined intolerant species is classified as shade intolerant Producer defined tolerant species is classified as shade tolerant Producer defined plot_level_data.csv Comma Separated Value (CSV) file containing data. Producer Defined plotID unique plot identifier in the format Fire_Plot. Fire is the wildfire where the plot is located and Plot is a unique plot number identifier. Producer Defined unique plot identifier in the format Fire_Plot. Fire is the wildfire where the plot is located and Plot is a unique plot number identifier. fire the wildfire where the plot is located Producer Defined eagl Eagle Creek Producer defined good Goodell Creek Producer defined mapl Maple Producer defined nors Norse Peak Producer defined seedling_count Raw count of established seedlings >= 10 cm tall within a plot. Producer Defined 1 2376 seedlings_per_ha Established seedling density (i.e., seedlings per hectare) >=10 cm tall within a plot Producer Defined 21.65373375 51449.2714 seedlings_per_ha_yr Establishment rate of seedlings (i.e., seedlings per hectare per year) >=10 cm tall within a plot Producer Defined 5 10290 regen_count Raw count of all seedlings within a plot (includes post-fire seedlings of all heights). Producer Defined 1 2439 regen_per_ha Seedling density (i.e., seedlings per hectare) within a plot (includes post-fire seedlings of all heights) Producer Defined 21.65373375 264067.2831 regen_per_ha_yr Regeneration rate of seedlings (i.e., seedlings per hectare per year) within a plot (includes post-fire seedlings of all heights) Producer Defined 5 88022 stand_age pre-fire stand age classification of plot Producer Defined mature mid-seral Producer defined old late-seral Producer defined young early-seral Producer defined forest_zone forest zone classification of plot Producer Defined abam Pacific silver fir zone Producer defined tshe Western hemlock zone Producer defined seedwall_dist_m_sat distance in meters to the nearest clump of living mature trees at least 1 ha in area, measured from plot center using 2-3 year post-fire NAIP imagery. Producer Defined 22.97 1610.11 veg_pc average percent cover of herbs and shrubs, measured in the field. Producer Defined 0.620454545 57.54884058 hli plot-level heat load index. An index of incident solar radiation calculated using slope, aspect, and latitude. Values range from 0 (cooler topo-climatic conditions) to 1 (warmer topo-climatic conditions). Producer Defined 0.37864762 0.995808376 twi plot-level topographic wetness index. Index of topographic controls on hydrologic processes, including soil moisture. Lower values indicate drier conditions; higher values indicate wetter conditions. Producer Defined 4.2288899 8.1405296 bryo_pc average percent cover of bryophytes (i.e., non-vascular plants), measured in the field. Producer Defined 0.1 64.09090909 avg_spei_3yr Index of growing season drought anomalies over a 180-day window. Values between -1 and 1 indicate relatively ‘normal’ conditions; values < -1 indicate drought; values > 1 indicate a wetter than normal growing season. Range -1.07 - 0.19 Producer Defined -1.07 0.186666667 spp_richness number of conifer species present within a plot. Producer Defined 1 6 sdi plot-level Shannon diversity index of conifer species. Producer Defined 0.0 1.223755407 perc_shadeintol percentage of total seedlings that are classified as shade intolerant. Producer Defined 0.0 100.0 perc_shadetol percentage of total seedlings that are classified as shade tolerant. Producer Defined 0.0 100.0 Madison M. Laughlin School of Environmental and Forest Sciences PhD Student mailing address

School of Environmental and Forest Sciences, University of Washington, 4000 15th Ave NE

Seattle WA 98195 United States (206) 616-1879 laughmad@uw.edu Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness, no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Digital Data https://zenodo.org/doi/10.5281/zenodo.10595208 None 20240208 Madison M. Laughlin School of Environmental and Forest Sciences PhD Student mailing

School of Environmental and Forest Sciences, University of Washington, 4000 15th Ave NE

Seattle Washington 98195 United States of America (206) 616-1879 laughmad@uw.edu FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999