Isabella A. Oleksy Jill S. Baron 20210312 tabular digital data https://doi.org/10.5066/P9UR2K3E Isabella A. Oleksy Jill S. Baron Whitney S. Beck 20210212 publication n/a University of Chicago Press Oleksy, IA, Baron JS, Beck, WS. 2021. Nutrients and warming alter mountain lake benthic algal structure and function. Freshwater Sciences DOI:10.1086/713068. https://doi.org/10.1086/713068 The data include measurements of chlorophyll a and algal stoichiometry from benthic algae collected from Sky Pond, Rocky Mountain National Park, Colorado, in 2015-2017; results of nutrient diffusion experiments in Sky Pond including chlorophyll a and other pigments to identify chlorophytes, bacillariophytes, and myxomycetes, and results of a laboratory incubation using benthic chlorophytes to identify ecosystem responses (nitrogen uptake, net primary productivity, ecosystem respiration, net ecosystem productivity, and dissolved organic carbon production) under nutrient and temperature treatments. Benthic algae in historically unproductive mountain lakes are shifting from bacillariophyte-dominated to chlorophyte-dominated communities. These changes are taking place commensurate with increasing water temperatures and nutrient availability but the mechanisms promoting chlorophytes over bacillariophytes and the implications for ecosystem function are not well understood. These data were collected to test the effect of nutrient enrichment on the relative abundance of algal taxonomic groups in a field experiment and to test the interactive effects of nutrients and temperature on ecological function of chlorophyte-dominated benthic communities in a laboratory experiment. 20150701 20170901 observed Complete None planned -105.670624 -105.667191 40.279231 40.276644 Sky Pond, Rocky Mountain National Park, Colorado USGS Thesaurus algae benthic ecosystems nitrogen nutrient content (water) aquatic ecosystems periphyton USGS Metadata Identifier USGS:6048f8b0d34eb120311a962c None Rocky Mountain National Park Common geographic areas Colorado Rocky Mountain None. Please see 'Distribution Info' for details. None. Users are advised to read the data set's metadata thoroughly to understand appropriate use and data limitations. Jill S Baron U.S. Geological Survey, ROCKY MOUNTAIN REGION Research Ecologist mailing address

1231 East Drive

Fort Collins CO 80523 United States 970-491-1968 970-491-1965 jill_baron@usgs.gov Bailey scholarship, Rocky Mountain Nature Association, Colorado State University PC, excel spreadsheet Chemical analyses were conducted according to standard procedures for the Loch Vale program (https://www2.nrel.colostate.edu/projects/lvws/data.html). Standard procedures include 10% replicate and 10% blank (de-ionized water) sample collections in the field. In the laboratory standard Environmental Protection Agency quality assurance techniques include %ion difference between measured and calculate ionic strength, comparison of sum of anions and sum of cations. Values below detection limits are presented as one half the detection limit. Pigments were quantified with high performance liquid chromatography (HPLC) ultraviolet mass spectrometry. We developed calibration curves from pigment standards to convert ultraviolet areas to masses. To obtain sample pigment masses, ultraviolet intensity curves were integrated using Compass Hystar data software Gross Primary Production, and Ecosystem Respiration were conducted using standard methods in a three by four factorial experiment, so that each treatment had four replicates. Values fall within expected ranges. All data collected were included in this data set, which applies specifically to Sky Pond, Rocky Mountain National Park, Colorado. Alexander J. Reisinger Jennifer L. Tank Martha M. Dee 201606 publication n/a University of Chicago Press Reisinger, A. J., Tank, J. L., & Dee, M. M. (2016). Regional and seasonal variation in nutrient limitation of river biofilms. Freshwater Science, 35(2), 474–489. https://doi.org/10.1086/685829 https://doi.org/10.1086/685829 Digital and/or Hardcopy 20160101 publication date Reisinger, Tank, and Dee (2016) methods from primary research paper Jennifer L. Tank 2017 publication Tank, J.L., Reisinger, A.J. and Rosi, E.J., 2017. Nutrient limitation and uptake. In Methods in stream ecology (pp. 147-171). Academic Press. https://doi.org/10.1016/B978-0-12-813047-6.00009-7 Digital and/or Hardcopy 20170801 20170817 accessed 20210310 Tank, Reisinger, and Rosi (2017) Methods are described in this publication Water samples were collected for chemical analyses at the beginning and end of the experiment at the nutrient diffusion substrate (NDS) deployment site in the littoral zone as well as from the mixed layer of the epilimnion. Chemical analyses were conducted according to standard procedures for the Loch Vale program (https://www2.nrel.colostate.edu/projects/lvws/data.html). These data are found in NDS_master.csv 2017 We sampled mixed-community periphyton and chlorophyte-dominated periphyton in Sky Pond in summer 2017 to look at variation in carbon and nitrogen content. At six evenly distributed littoral sites around the lake, we sampled three patches of chlorophyte-dominated periphyton and three patches of mixed-community periphyton. We dislodged periphyton with a wire brush and used ambient lake water to rinse slurry into falcon tubes which were kept on ice until we returned to the laboratory, where samples were immediately frozen. Carbon and N were analyzed on hand-ground, lyophilized samples with a LECO True-Spec carbon and nitrogen analyzer. These data are found in fieldata_CN_periphyton_export.csv. 2017 Nutrient diffusing substrates (NDS) were built and deployed using methods outlined by Tank, Reisinger, and Rosi (2017). We filled 30 milliliter plastic vials with 4% agar solution and amended the treatments with no nutrients (control treatment, Ctrl), 0.5 M NaNO3 (nitrogen treatment, N), 0.031 M KH2PO4 (phosphorus treatment, P), or 0.5 M NaNO3 plus 0.031M KH2PO4 (nitrogen and phosphorus treatment, N & P). These data are found in NDS_master.csv. Tank, Reisinger, and Rosi (2017) 2017 Porous fritted glass disks were placed in Sky Pond in early July 2017. Tiles were retrieved after two weeks and transported on ice back to the laboratory where they were incubated in growth chambers in an 8ºC water bath containing filtered lake water and a 16:8 hour light dark cycle (approximately 100 µmol photons m-2 s-1 irradiance). After one week of equilibration, we manipulated temperature (8, 12, 16 degrees Centigrade) and nutrients (control, elevated N, P, and N&P) for eight days in a three by four factorial experiment. These data are found in incubation_master.csv. 2017 We conducted short term light-dark incubations on each of the fritted glass disks to estimate gross primary production (GPP) and ecosystem respiration (ER) following methods developed by Reisinger, Tank, and Dee (2016). These data are found in incubation_master.csv. Reisinger, Tank, and Dee (2016) 2017 incubation_master.csv Comma Separated Value (CSV) file containing data on nutrient and temperature treatments that produced measures of net ecosystem production, ecosystem respiration, gross primary production, and changes in nitrogen and carbon concentrations. Producer defined nutrient_trt Nutrient treatment, either control, nitrogen added, phosphorus added or N&P Producer defined C Control Producer defined NP Nitrogen and Phosphorus added Producer defined N Nitrogen added Producer defined P Phosphorus added Producer defined temperature_trt Temperature treatment Producer defined 8¡C 8 degrees Centigrade Producer defined 12¡C 12 degrees Centigrade Producer defined 16¡C 16 degrees Centigrade Producer defined NEP_ugcm2h net ecosystem production in micrograms per centimeter squared per hour Producer defined 7.2 65.9 micrograms per centimeter squared per hour ER_ugcm2h ecosystem respiration, in micrograms per centimeter squared per hour Producer defined -52.0 -3.1 micrograms per centimeter squared per hour GPP_ugcm2h gross primary productivity, in micrograms per centimeter squared per hour Producer defined 23.5 85.4 micrograms per centimeter squared per hour GPP_ER ratio of gross primary production to ecosystem respiration Producer defined 1.138461538 9.451612903 changeTDN_uM total dissolved nitrogen uptake, in micromoles N Producer defined 5.417 59.045 micromoles changeNO3_mgL total nitrate uptake, in milligrams per liter Producer defined 0.39 3.46 milligrams per liter changeDOC_mgL total dissolved organic carbon exudation, in milligrams per liter Producer defined 0.741 5.421 milligrams per liter percTDNuptake percent of total dissolved nitrogen assimilated Producer defined 15.37480303 88.60958956 percent percNO3uptake percent of nitrate assimilated Producer defined 42.17877095 99.1202346 percent NO3uptake_dailyrate daily nitrate uptake rate (micromoles of N per day) Producer defined 0.04875 0.4325 micromoles of N per day TDNuptake_dailyrate daily total dissolved nitrogen uptake (milligrams per day) Producer defined 0.677125 7.380625 milligrams per day diff_total_chla change in benthic chlorophyll a (micrograms per square centimeter) Producer defined -5.69 5.83 micrograms per square centimeter fieldata_CN_periphyton_export.csv Comma Separated Value (CSV) file containing data on percent carbon and nitrogen in algae. Producer defined sample_ID sample identification number Producer defined 1 26 type sample type (mixed periphyton or chlorophyte dominated periphyton, categorical/factor) Producer defined mixed community periphyton made up of chlorophytes, diatoms, and other algae Producer defined chlorophyte-dominated periphyton primarily composed of chlorophytes Producer defined perc_N percent nitrogen in sample Producer defined 0.206 5.727 percent perc_C percent carbon in sample Producer defined 2.69 46.957 percent CN carbon to nitrogen ratio Producer defined 7.313 13.085 NDS_master.csv Comma Separated Value (CSV) file containing data of algal pigments. Producer defined nutrient_trt nutrient treatment (categorical/factor) Producer defined C Control treatment Producer defined N nitrogen treatment Producer defined NP nitrogen plus phosphorus treatment Producer defined P phosphorus treatment Producer defined pigment_ID algal pigment (categorical/factor) Producer defined chla_total total chlorophyll a, measure of total algal productivity Producer defined chla_total total chlorophyll a (including pheophytin a, micrograms per square centimeter) Producer defined 0.122502618 1.483071553 micrograms per centimeter squared chlb_total total chlorophyll b (including pheophytin b, micrograms per square centimeter); measure of chlorophytes Producer defined 0.008853403 0.117898778 micrograms per centimeter squared fuco_total fucoxanthin (micrograms per square centimeter); measure of bacillarophytes Producer defined 0.005102792 0.06904014 micrograms per centimeter squared myxo_total myxoxanthophyll (micrograms per square centimeter); measure of cyanophytes Producer defined 0.004282723 0.049541012 micrograms per centimeter squared U.S. Geological Survey GS ScienceBase mailing address

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Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov 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. Digital Data https://doi.org/10.5066/P9UR2K3E None 20210312 FORT Metadata Specialist U.S. Geological Survey FORT Metadata Specialist mailing

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Fort Collins Colorado 80526 970-226-9100 970-226-9230 fortdatamanagement@usgs.gov FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata FGDC-STD-001.1-1999