Data from: Effects of advancing treelines and melting glaciers on alpine lake ecosystems: A mesocosm experiment
Data files
Jul 09, 2025 version files 34.89 KB
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gfomexp_radiometer.csv
1.83 KB
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gfomexp_tax.csv
4.88 KB
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gfomexp_water_pigment.csv
18.50 KB
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README.md
9.69 KB
Abstract
Climate warming promotes the upward advance of mountain treelines, thereby increasing allochthonous inputs of terrestrial organic matter into alpine lakes. Higher temperatures also accelerate glacial ablation, altering inputs of finely eroded rock particles, termed “glacial flour”. Organic matter (OM) and glacial flour (GF) both affect aquatic ecosystems; however, a knowledge gap exists concerning their combined impact. To test for the direct and interactive effects of OM and GF, we conducted a crossed two-factor outdoor mesocosm experiment. We hypothesized that GF sequesters OM through adsorption, thus reducing its effects on the abiotic environment and phytoplankton community. Addition of GF decreased underwater attenuation of ultraviolet radiation by the OM amendment (i.e., a GF-OM interaction), but not the pronounced positive effects of OM on nutrients and phytoplankton chlorophyll. GF did mediate the effect of OM on phytoplankton community composition by suppressing diatoms. These findings highlight the potential for future shifts in allochthonous inputs away from GF and towards OM to stimulate high-elevation lake ecosystems as glaciers ablate and treeline vegetation migrates to higher elevations under a warming climate.
https://doi.org/10.5061/dryad.hqbzkh1sj
Description of the data and file structure
Data collected for:
Effects of advancing treelines and melting glaciers on alpine lake ecosystems: A mesocosm experiment
Authors: Colleen Dawson, Janet M. Fischer, Mark H. Olson, Rolf D. Vinebrooke
Collection: 07/2023 to 08/2023 at Barrier Lake Field Station in Kananaskis, AB, Canada.
Files and variables
File: gfomexp_radiometer.csv
Description:
Underwater light attenuation data from the start and end of organic matter x glacial flour mesocosm experiment.
Missing values are indicated by n/a. Light attenuation coefficients were not calculated when shading effects resulted in weak fitting log-linear relationships.
Variables
- tank: Unique numerical identifier assigned to each mesocosm tank.
- treatment: Experimental treatment (Control, OM, GF, OM+GF).
- OM: Presence/absence of organic matter amendment.
- GF: Presence/absence of glacial flour amendment.
- day: Time period of experiment sampled (start/end).
- Kd305: Light attenuation coefficient of 305 nm calculated as the slope of the log-linear relationship between downwelling irradiance and depth radiometer measurements (m-1).
- Kd320: Light attenuation coefficient of 320 nm calculated as the slope of the log-linear relationship between downwelling irradiance and depth radiometer measurements (m-1).
- Kd380: Light attenuation coefficient of 380 nm calculated as the slope of the log-linear relationship between downwelling irradiance and depth radiometer measurements (m-1).
- KdPAR: Light attenuation coefficient of photosynthetically active radiation (PAR) calculated as the slope of the log-linear relationship between downwelling irradiance and depth radiometer measurements (m-1).
File: gfomexp_tax.csv
Description:
Algal taxonomic community data from the final day of organic matter x glacial flour mesocosm experiment.
Variables
- tank: Unique numerical identifier assigned to each mesocosm tank.
- treatment: Experimental treatment (Control, OM, GF, OM+GF).
- OM: Presence/absence of organic matter amendment.
- GF: Presence/absence of glacial flour amendment.
- Cymbella: Final day density of algal taxa Cymbella identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Fragilaria: Final day density of algal taxa Fragilaria identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Gomphonema: Final day density of algal taxa Gomphonema identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Naviculoid: Final day density of algal taxa naviculoid symmetrical biraphid diatoms identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Pennate: Final day density of algal taxa pennate diatoms identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Diatom Sp: Final day density of algal diatoms identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Ankistrodesmus: Final day density of algal taxa Ankistrodesmus identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Carteria: Final day density of algal taxa Carteria identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Chlamydomonas: Final day density of algal taxa Chlamydomonas identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Crucigenia: Final day density of algal taxa Crucigenia identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Haematococcus: Final day density of algal taxa Haematococcus identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Oedogonium: Final day density of algal taxa Oedogonium identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Oocystis: Final day density of algal taxa Oocystis identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Pandorina: Final day density of algal taxa Pandorina identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Aphanocapsa: Final day density of algal taxa Aphanocapsa identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Gloeocapsa: Final day density of algal taxa Gloeocapsa identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Oscillatoria: Final day density of algal taxa Oscillatoria identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Pseudanabaena: Final day density of algal taxa Pseudanabaena identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Rhabdoderma: Final day density of algal taxa Rhabdoderma identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Chrysamoeba: Final day density of algal taxa Chrysamoeba identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Chrysococcus: Final day density of algal taxa Chrysococcus identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Chrysphearella: Final day density of algal taxa Chrysphearella identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Mallomonas: Final day density of algal taxa Mallomonas identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Pseudokephyrion: Final day density of algal taxa Pseudokephyrion identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- Cryptomonas: Final day density of algal taxa Cryptomonas identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
- I (colonial green): Final day density of unknown colonial green algal taxa “I” identified using an advanced digitalized flow cytometer and light microscopy (cells/L)
File: gfomexp_water_pigment.csv
Description:
Physicochemical and algal pigment data from weekly sampling of organic matter x glacial flour mesocosm experiment.
Missing values where data collection was incomplete are indicated by n/a.
Variables
- ID: Sample ID. Includes treatment, tank number, and day sampled.
- tank: Unique numerical identifier assigned to each mesocosm tank.
- treatment: Experimental treatment (Control, OM, GF, OM+GF).
- OM: Presence/absence of organic matter amendment.
- GF: Presence/absence of glacial flour amendment.
- day: Day sample was taken of 28-day experimental period.
- TP: Total phosphorus concentration sampled from water column of mesocosm tank and analyzed by Biogeochemical Analytical Service Laboratory (µg/L)
- TDP: Total dissolved phosphorus concentration sampled from water column of mesocosm tank and analyzed by Biogeochemical Analytical Service Laboratory (µg/L)
- NO2NO3: Nitrite + nitrate concentration sampled from water column of mesocosm tank and analyzed by Biogeochemical Analytical Service Laboratory (µg/L)
- TN: Total nitrogen concentration sampled from water column of mesocosm tank and analyzed by Biogeochemical Analytical Service Laboratory (µg/L)
- TDN: Total dissolved nitrogen concentration sampled from water column of mesocosm tank and analyzed by Biogeochemical Analytical Service Laboratory (µg/L)
- DOC: Dissolved organic carbon concentration sampled from water column of mesocosm tank and analyzed by Biogeochemical Analytical Service Laboratory (mg/L)
- DO: Dissolved oxygen measured from water column of mesocosm tank using a YSI EXO2 sonde (% saturation)
- spcond: Specific conductivity measured from water column of mesocosm tank using a YSI EXO2 sonde (µS/cm)
- pH: pH measured from water column of mesocosm tank using a YSI EXO2 sonde
- temp: Temperature measured from water column of mesocosm tank using a YSI EXO2 sonde (°C)
- turbidity: Turbidity measured from water column of mesocosm tank using a YSI EXO2 sonde (FNU)
- a320: Absorption coefficient at 320 nm (m-1) of water sampled from water column of mesocosm tank as a measure of chromophoric dissolved organic matter (CDOM).
- fuco: Fucoxanthin concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- neo: Neoxanthin concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- viola: Violaxanthin concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- diadino: Diadinoxanthin concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- myxo: Myxoxanthophyll concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- diato: Diatoxanthin concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- lutzea: Lutein + zeaxanthin concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- cantha: Canthaxanthin concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- chlb: Chlorophyll b concentration quantified using high performance liquid chromatography for algal pigments (µg/L).
- chla: Chlorophyll a concentration quantified using high performance liquid chromatography for algal pigments (µg/L).