Renee K. Takesue Leticia P. Hallas Amy E. East 20251211 comma-delimited text data release DOI: 10.5066/P13QWYFV Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/P13QWYFV Renee K. Takesue Leticia P. Hallas Pamela L. Campbell-Swarzenski Nancy G. Prouty Amy E. East 2025 data release DOI:10.5066/P13QWYFV Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey Suggested Citation: Takesue, R.K., Hallas, L.P., Campbell-Swarzenski, P.L., Prouty, N.G., and East, A.E., 2025, Compositions of ash, soil, sediment, water, and biota after the 2020 CZU Lightning Complex Wildfire, Santa Cruz Mountains, CA: U.S. Geological Survey data release, https://doi.org/10.5066/P13QWYFV https://doi.org/10.5066/P13QWYFV After the CZU Wildfire in August 2020, stream sediment (7 burned, 1 unburned drainages), airborne ash, in situ ash, and regolith were collected from August 2020 to August 2023 to characterize wildfire effects. Solid-phase parameters include sand-sized charcoal counts, total carbon (TC), total inorganic carbon (TIC), total organic carbon (TOC), bulk stable carbon 13/12 isotope ratios (d13C), bulk stable nitrogen 15/14 isotope ratios (d15N), and concentrations of 60 elements in the less than 63 micron fine fraction. Ash, soil, and sediment were collected and characterized immediately post-wildfire to quantify potential environmental and public hazards from wildfire-related chemicals. Repeated collections at regular intervals over three years showed temporal changes of in situ wildfire-related properties or changes related to transport of wildfire materials in coastal watersheds and streams. Airborne wildfire particulates were collected downwind in Santa Cruz up to one month post-fire. Sediment provenance in Scott Creek watershed and three of its tributaries was determined from geochemical fingerprinting of granitic rocks on Ben Lomond Mountain. In combination, these parameters show how the chemistry of hillslope soil and stream sediment of forested watersheds and streams were affected by wildfire and how recovery progressed over three years. Additional information about the field activity from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2020-638-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 20200911 20250313 Airborne ashes were collected up to one month post-fire. Stream sediments were collected after first flush, high flow, and low flow conditions for three years post-fire. In situ ashes were collected at 6-month intervals for three years post-fire. Complete None planned -122.3958 -122.0299 37.3259 35.4568 USGS Metadata Identifier USGS:7993238a-08e7-42f6-80b2-28a9556fff3a ISO 19115 Topic Category environment geoscientificInformation Data Categories for Marine Planning Substrate USGS Thesaurus geochemistry soil chemistry fires sediment transport metal elements rare earth elements Marine Realms Information Bank (MRIB) keywords stream watershed river discharge sediment geochemistry environmental chemistry mercury analysis stable isotope analysis None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Pacific Coastal and Marine Science Center PCMSC Geographic Names Information System (GNIS) Santa Cruz Mountains Ben Lomond Mountain San Gregorio Creek Pescadero Creek Butano Creek Gazos Creek Waddell Creek Scott Creek Big Creek Little Creek San Vicente Creek Santa Cruz No access constraints USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov pic_LittleCreek.JPG Left bank of Little Creek five months after the 2020 CZU Wildfire. JPEG Angela Tan analyzed total carbon, total inorganic carbon, and total organic carbon contents at the USGS Pacific Coastal and Marine Science Center Sediment and Carbon Laboratory. Ratios of stable isotopes of carbon 13/12, and of total carbon to total nitrogen were measured at the Washington State University Core Stable Isotope Lab. Elemental compositions were determined by the Analytical Chemistry Project of the USGS Geology, Geophysics, and Geochemistry Science Center (GGGSC). Geochemical data are tabulated in comma separated variable (CSV) format. For charcoal counts, relative standard deviations (RSD) of 31 field-based triplicate samples ranged from 6 to 115 percent with a mean RSD of 35 percent and a median RSD of 28 percent. For carbon contents, process duplicates were run for every sample and were within 15 percent. For stable isotope ratios, standard external reference materials and long-term internal reference materials were included in every run; 2-sigma uncertainties were 0.5 per mil. For elemental chemistry, GGGSC checked QA/QC for standard reference materials and long-term internal reference materials for every batch (job). The percent recoveries for elements were within 15 percent of reference values. No formal logical accuracy tests were conducted. Charcoal was counted only in stream sediment. Carbon contents and stable isotope ratios were not measured in regolith. A Garmin handheld GPS (model GPSmap 78sc) reported a horizontal accuracy of 3 meters. However, Garmin cites the actual accuracy as 5 to 15 meters. SAMPLE COLLECTION. Stream sediment was collected by hand from recently deposited fine-grained material on stream banks and stored in wire-top polyethylene bags. Charcoal samples were collected in duplicate or triplicate in sandy material on the stream bank using a one-quarter teaspoon scoop and stored in falcon vials. Ash, soil, and mixed samples were collected from undisturbed forest sites by hand, stored in combusted 500 milliliter glass jars, and sieved to remove particles greater than 2 mm in diameter. 20230816 CHARCOAL COUNTS. Sediment was gently agitated with bleach at room temperature for two hours without changing particle sizes. Stainless steel sieves were used to separate particles greater than or equal to 0.125 mm in diameter. The retained particles were rinsed in a water bath. Particles were transferred to a petri dish and dried completely at 45 degrees Celsius. Charcoal particles were counted under a stereo-microscope. 20220803 CARBON CONTENTS. Carbon analysis was performed at the PCMSC Carbon Laboratory by combustion, acidification, and coulometric detection using a UIC CM5015 Coulometer. Approximately 1 gram of sediment was dried overnight at 80 degrees Celsius and pulverized by hand in a mortar and pestle. 20 milligrams of sediment for total carbon (TC) were combusted at 950 degrees Celsius (UIC CM 5230 furnace) and quantified with a coulometric titration. 20 milligrams of sediment for total inorganic carbon (TIC) were digested with perchloric acid (UIC CM 5130 acid digester) and quantified with a coulometric titration. Total organic carbon (TOC) was calculated as the difference between TC and TIC. Average values of process duplicates are reported. 20250313 Angela Tan U.S. Geological Survey, Pacific Coastal and Marine Science Center Physical Scientist mailing and physical

2885 Mission Street

Santa Cruz CA 95060 831-460-7409 atan@usgs.gov STABLE ISOTOPE RATIOS OF CARBON 13/12 (d13C) and NITROGEN 15/14 (d15N). Bulk sedimentary d13C and d15N were determined at the Washington State University Stable Isotope Core Laboratory using an elemental analyzer (Costech Analytical) interfaced with a Delta PlusXP isotope ratio mass spectrometer using a Santrock correction (ThermoFinnegan). Ratios of d13C ratios were referenced to the Vienna PeeDeeBelemnite (VBPD) using NBS 19 and LSVEC as anchor points. Ratios of d15N were referenced to air. 20220105 Benjamin Harlow Washington State University School of Biological Sciences Manager, Stable Isotope Core Laboratory Mailing

367 Eastlick

Pullman WA 99165 509-335-6154 bharlow@wsu.edu ELEMENTAL CHEMISTRY. Bulk sediment was oven-dried at 60 degrees Celsius and disaggregated gently with a mortar and pestle to avoid changing grain sizes. Disaggregated sediment was dry-sieved through stainless steel sieves to obtain 2 grams of the less than 0.063 millimeter fine fraction. Fine sediments were sent to the Analytical Chemistry Project of the USGS Geology, Geophysics, and Geochemistry Science Center (GGGSC), which contracted AGAT and SGS Labs, both nationally accredited, for analyses of major, minor, and trace element contents using two methods: a near-total four-acid digestion (labeled multi-acid in the table of data) and a total digestion with a sodium peroxide fusion (labeled fusion in the table of data) for elements hosted in acid-resistant minerals. Quantification was performed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) for major and some minor elements and by inductively coupled plasma mass spectroscopy (ICP-MS) for some minor and all trace elements. 20250105 Jaime Azain USGS Geology, Geophysics, and Geochemistry Science Center Research Geologist mailing

Denver Federal Center, Bldg 20

Denver CO 80225 303-236-9376 jsazain@usgs.gov Point Point 211 0.0001 0.0001 Decimal degrees D_WGS_1984 WGS84 6378137.0000 298.2572 CZUparticulates_charcoal_isotopes_elements_data.csv Table of data. -9999 indicates not determined Producer defined LabID Unique sample identifier for the CZU Wildfire Project (CZU) with sample type abbreviations: SED, stream sediment; RGTH, regolith; HVAC, intake vent filter on the roof of PCMSC; CONTROL, unburnt forest; ASH, wildfire ash; MIX, mixture of ash and soil; SOIL, soil below the ash layer. Producer defined Unique alphanumeric field sample identifier SiteID_Loc_Period Unique sample identifier assigned during field collection based on the Site (SiteID), location within the site (Loc) if relevant, and period of collection (Period). Abbreviations: VIC, San Vicente Creek; LIT, Little Creek; BIG, Big Creek; MIL, Mill Creek; SCO, Scott Creek; WAD, Waddell Creek; GAZ, Gazos Creek; BUT, Butano Creek; PESC, Pescadero Creek; GREG, San Gregorio Creek; LAST, Last Chance Creek; BERRY, Berry Creek; CLE, Clear Creek basin; JAM, Jamison Creek basin; LOCK, Lockheed gate; EAG, Eagle Mountain trail head; Y1, Year 1 from August 2020 to July 2021; Y2, Year 2 from August 2021 to July 2022; Y3, Year 3 from August 2022 to August 2023; PF, pre-flush; FF, first flush; HF, high flow; LF, low flow; AC, roof-top HVAC unit and number; AG, ash collected by Amy Gartman; RT, ash collected by Renee Takesue; mo, months.; DUP, duplicate. Producer defined Unique alphanumeric field sample identifier Date_collected Date the sample was collected, in mm/dd/yy Producer defined 08/19/20 08/16/23 mm/dd/yy 1 Latitude_WGS84 Latitude where the sample was collected relative to geodetic datum WGS84. Producer defined 35.4568 37.3259 decimal degrees 0.0001 Longitude_WGS84 Longitude where the sample was collected relative to geodetic datum WGS84. Producer defined -122.3958 -122.0299 decimal degrees 0.0001 Charcoal_count Number of charcoal particles greater than or equal to 0.125 mm in diameter per one-quarter teaspoon of stream sediment. -9999=not determined Producer defined 4 663 particle 1 Total_Carbon Total carbon (TC) content determined by coulometry. -9999=not determined Producer defined 0.32 14.16 percent by weight 0.01 Total_Inorganic_Carbon Total inorganic carbon (TIC) content determined by coulometry. -9999=not determined Producer defined 0.00 5.29 percent by weight 0.01 Total_Organic_Carbon Total organic carbon (TOC) content determined by subtraction of TIC from TOC. -9999=not determined Producer defined 0.29 12.14 percent by weight 0.01 d13C_bulk Ratio of carbon 13/12 stable isotopes in bulk sedimentary organic matter; -9999=not determined Producer defined -31.70 -24.81 standard per mil notation 0.01 d13C_TC Total carbon (TC) determined by elemental analyzer in the measurement of d13C. -9999=not determined Producer defined 0.32 38.76 percent 0.01 d15N_bulk Ratio of carbon 13/12 stable isotopes in bulk sedimentary organic matter; -9999=not determined Producer defined 0.07 5.21 standard per mil notation 0.01 d15N_TN Total nitrogen (TN) determined by elemental analyzer in the measurement of d15N. -9999=not determined Producer defined 0.02 0.92 percent 0.01 GGGSC_JobID Unique laboratory identifier assigned to a batch of samples by the GGGSC Analytical Chemistry Laboratory. -9999=not determined Producer defined Unique alphanumeric batch identifier GGGSC_SampleID Unique laboratory identifier assigned to each sample by the GGGSC Analytical Chemistry Laboratory. -9999=not determined Producer defined Unique alphanumeric batch identifier Hg_by_CVAA Total mercury (Hg) content analyzed by cold vapor atomic absorption (CVAA) in units of mg per kg; -9999=not determined Producer defined 0.012 0.710 milligrams per kilogram (mg per kg) 0.001 Al_by_fusion Aluminum (Al) content of fused, digested sediment; -9999=not determined Producer defined 1.45 12.20 weight percent 0.01 Ca_by_fusion Calcium (Ca) content of fused, digested sediment; -9999=not determined Producer defined 0.10 30.10 weight percent 0.01 Fe_by_fusion Iron (Fe) content of fused, digested sediment; -9999=not determined Producer defined 0.80 12.30 weight percent 0.01 K_by_fusion Potassium (K) content of fused, digested sediment; -9999=not determined Producer defined 0.90 5.93 weight percent 0.01 Mg_by_fusion Magnesium (Mg) content of fused, digested sediment; -9999=not determined Producer defined 0.14 3.55 weight percent 0.01 Na_by_multi-acid Sodium (Na) content of multi-acid digested sediment; -9999=not determined producer defined 0.09 2.25 weight percent 0.01 P_by_fusion Phosphorus (P) content of fused, digested sediment; -9999=not determined producer defined 0.03 1.26 weight percent 0.01 S_by_fusion Sulfur (S) content of fused, digested sediment; -9999=not determined producer defined 0.0 1.1 weight percent 0.1 Si_by_fusion Silica (Si) content of fused, digested sediment; -9999=not determined producer defined 6.9 38.0 weight percent 0.1 Ti_by_fusion Titanium (Ti) content of fused, digested sediment; -9999=not determined producer defined 0.12 1.24 weight percent 0.01 Ag_by_multi-acid Silver (Ag) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.01 1.62 milligrams per kilogram (mg per kg) 0.01 As_by_multi-acid Arsenic (As) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 2 50 milligrams per kilogram (mg per kg) 1 Ba_by_multi-acid Barium (Ba) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 274 2710 milligrams per kilogram (mg per kg) 1 Be_by_multi-acid Beryllium (Be) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.28 2.74 milligrams per kilogram (mg per kg) 0.01 Bi_by_multi-acid Bismuth (Bi) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.03 0.64 milligrams per kilogram (mg per kg) 0.01 Cd_by_multi-acid Cadmium (Cd) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.06 6.73 milligrams per kilogram (mg per kg) 0.01 Ce_by_fusion Cerium (Ce) content of fused, digested sediment in units of mg per kg; -9999=not determined producer defined 12.5 115.0 milligrams per kilogram (mg per kg) 0.1 Co_by_multi-acid Cobalt (Co) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 1.7 33.0 milligrams per kilogram (mg per kg) 0.1 Cr_by_fusion Chromium (Cr) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 3 754 milligrams per kilogram (mg per kg) 1 Cs_by_multi-acid Cesium (Cs) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 1.49 9.41 milligrams per kilogram (mg per kg) 0.01 Cu_by_multi-acid Copper (Cu) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 4.6 220.0 milligrams per kilogram (mg per kg) 0.1 Dy_by_fusion Dysprosium (Dy) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 1.09 10.70 milligrams per kilogram (mg per kg) 0.01 Er_by_fusion Erbium (Er) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 0.51 5.70 milligrams per kilogram (mg per kg) 0.01 Eu_by_fusion Europium (Eu) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 0.23 2.86 milligrams per kilogram (mg per kg) 0.01 Ga_by_multi-acid Gallium (Ga) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 3.8 31.9 milligrams per kilogram (mg per kg) 0.1 Gd_by_fusion Gadolinium (Gd) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 1.03 11.10 milligrams per kilogram (mg per kg) 0.01 Ge_by_fusion Germanium (Ge) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 1 7 milligrams per kilogram (mg per kg) 1 Hf_by_fusion Hafnium (Hf) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 2 71 milligrams per kilogram (mg per kg) 1 Ho_by_fusion Holmium (Ho) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 0.16 2.04 milligrams per kilogram (mg per kg) 0.01 In_by_multi-acid Indium (In) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.013 0.114 milligrams per kilogram (mg per kg) 0.001 La_by_fusion Lanthanum (La) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 6.5 63.3 milligrams per kilogram (mg per kg) 0.1 Li_by_multi-acid Lithium (Li) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 8.0 73.0 milligrams per kilogram (mg per kg) 0.1 Lu_by_fusion Lutetium (Lu) content of fused, digested sediment in units of mg per kg; -9999=not determined Producer defined 0.07 1.15 milligrams per kilogram (mg per kg) 0.01 Mn_by_multi-acid Manganese (Mn) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 31 8310 milligrams per kilogram (mg per kg) 1 Mo_by_multi-acid Molybdenum (Mo) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.83 14.60 milligrams per kilogram (mg per kg) 0.01 Nb_by_fusion Niobium (Nb) content of fused, digested sediment in units of mg per kg; -9999=not determined producer defined 2.8 27.0 milligrams per kilogram (mg per kg) 0.1 Nd_by_fusion Neodymium (Nd) content of fused, digested sediment in units of mg per kg Producer defined 5.2 55.9 milligrams per kilogram (mg per kg) 0.1 Ni_by_fusion Nickel (Ni) content of fused, digested sediment in units of mg per kg; -9999=not determined producer defined 5 182 milligrams per kilogram (mg per kg) 1 Pb_by_multi-acid Lead (Pb) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 7.1 780 milligrams per kilogram (mg per kg) 0.1 Pr_by_fusion Praseodymium (Pr) content of fused, digested sediment in units of mg per kg Producer defined 1.62 14.50 milligrams per kilogram (mg per kg) 0.01 Rb_by_multi-acid Rubidium (Rb) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 37.9 154.0 milligrams per kilogram (mg per kg) 0.1 Sb_by_multi-acid Antimony (Sb) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.21 8.35 milligrams per kilogram (mg per kg) 0.01 Sc_by_multi-acid Scandium (Sc) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 2.3 29.8 milligrams per kilogram (mg per kg) 0.1 Sm_by_fusion Samarium (Sm) content of fused, digested sediment in units of mg per kg Producer defined 1.2 12.0 milligrams per kilogram (mg per kg) 0.1 Sn_by_multi-acid Tin (Sn) content of multi-acid digested sediment in units of mg per kg; -9999=not determined Producer defined 1 43 milligrams per kilogram (mg per kg) 0.1 Sr_by_multi-acid Strontium (Sr) content of multi-acid digested sediment in units of mg per kg producer defined 55 2300 milligrams per kilogram (mg per kg) 1 Ta_by_multi-acid Tantalum (Ta) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.19 2.49 milligrams per kilogram (mg per kg) 0.01 Tb_by_fusion Terbium (Tb) content of fused, digested sediment in units of mg per kg Producer defined 0.15 1.85 milligrams per kilogram (mg per kg) 0.01 Te_by_multi-acid Tellurium (Te) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.01 1.77 milligrams per kilogram (mg per kg) 0.01 Th_by_fusion Thorium (Th) content of fused, digested sediment in units of mg per kg Producer defined 1.9 18.8 milligrams per kilogram (mg per kg) 0.1 Tl_by_multi-acid Thallium (Tl) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.17 1.79 milligrams per kilogram (mg per kg) 0.01 Tm_by_fusion Thulium (Tm) content of fused, digested sediment in units of mg per kg Producer defined 0.08 0.85 milligrams per kilogram (mg per kg) 0.01 U_by_fusion Uranium (U) content of fused, digested sediment in units of mg per kg Producer defined 1.12 15.00 milligrams per kilogram (mg per kg) 0.01 V_by_multi-acid Vanadium (V) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 22 188 milligrams per kilogram (mg per kg) 1 W_by_multi-acid Tungsten (W) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 0.2 5.3 milligrams per kilogram (mg per kg) 0.1 Y_by_fusion Yttrium (Y) content of fused digested sediment in units of mg per kg Producer defined 5.1 61.0 milligrams per kilogram (mg per kg) 0.1 Yb_by_fusion Ytterbium (Yb) content of fused digested sediment in units of mg per kg Producer defined 0.5 6.2 milligrams per kilogram (mg per kg) 0.1 Zn_by_multi-acid Zinc (Zn) content of multi-acid digested sediment in units of mg per kg; -9999=not determined producer defined 26 2540 milligrams per kilogram (mg per kg) 1 Zr_by_fusion Zirconium (Zr) content of the fused, digested sediment in units of weight percent (percent) Producer defined 58 2352 weight percent (percent) 1 The first line of the csv file is a header line. U.S. Geological Survey U.S. Geological Survey - CMGDS mailing and physical

2885 Mission Street

Santa Cruz CA 95060 1-831-427-4747 pcmsc_data@usgs.gov These data are available in csv format (CZUparticulates_charcoal_isotopes_elements_data.csv), accompanied by CSDGM FGDC compliant metadata and a map showing sample locations. 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 and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. comma-delimited text File contains the csv table and the associated metadata. No compression applied 0.0807 https://doi.org/10.5066/P13QWYFV Data and metadata can be downloaded using the Network_Resource_Name link and scrolling down to the Sampling Data section. None. These data can be viewed with any text reader. 20251211 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998