Physicochemical and biological variables measured in 110 national monitoring lakes between 1992 and 2022.
Physicochemical and biological data 110 national monitoring lakes for the years 1992 to 2022 were downloaded from the data host https://miljodata.slu.se/MVM/Opens in a new tab. Climate data were extracted from Climate Research Unit gridded Time Series dataset (version 4.06; Harris et al., 2020; https://crudata.uea.ac.uk/cru/data/hrg/Opens in a new tab) Eight data sets were compiled: 1. Physicochemical variables from surface water samples (10 variables): EU id Year Colour_absorbance_420nm Ca mg/l Conductivity_mS/m pH TOC mg/l C DIN_ µg/l_N TP_ µg/l_P Water_Temperature_°C. Lake physicochemical and climate data were log10(x + 1) transformed to approximate normal distribution prior to the analyses. 2. Climate data: annual mean air temperature (°C) and precipitation (mm per month for each lake in each year) extracted from the interpolated Climate Research Unit gridded Time Series dataset (version 4.06; Harris et al., 2020; https://crudata.uea.ac.uk/cru/data/hrg/Opens in a new tab) 3. Phytoplankton taxon abundances (biovolumes) for individual taxa collected in August (n = 780 taxa). Biovolumes were Hellinger transformed. 4. Phytoplankton metrics (n=5): number of taxa, taxon biovolumes, diversity (Hills N2), % cyanobacteria and between-year Euclidean distance*. 5. Littoral taxon abundances (numbers per unit effort) for samples collected in October/November (n=681 taxa). Abundances were Hellinger transformed. 6. Littoral metrics (n=4): number of taxa, total abundance, diversity (N2) and between-year Euclidean distance 7. Profundal taxa abundances (individual per m2) for samples collected in October/November (n=321 taxa). Abundances were Hellinger transformed. 8. Profundal metrics (n=4): number of taxa, total abundance, diversity (N2) and between-year Euclidean distance. * Between-year Euclidean distances were calculated using detrended correspondence analysis axes 1-3 as as d=√((x2 – x1)² + (y2 – y1)²) + (z2 – z1)²), where x1, y1, z1 represent DC axis scores one, two and three, respectively, at any year and x2, y2, z2 represent DC axis scores one, two and three, respectively, for the previous year.
Data files
Data files
Citation and access
Citation and access
Creator/Principal investigator(s):
Research principal:
Principal's reference number:
- SLU.ma.2025.IÄ-2
Data contains personal data:
No
Citation:
Data access level:
Language:
Method and outcome
Method and outcome
Time period(s) investigated:
Data format/data structure:
Species and taxons:
Data collection - Measurements and tests
Data collection - Measurements and tests
Mode of collection:
Measurements and tests
Description of the mode of collection:
Sampling and analyses of all abiotic and biological variables were based on standard protocols throughout the study period. These protocols are quality controlled and certified by the Swedish Board for Accreditation and Conformity Assessment (SWEDAC; https://www.swedac.se/). All physicochemical and biological analyses were performed at the Department of Aquatic Sciences and Assessment following international (ISO) or European (EN) standards (Fölster et al., 2014). Detailed information concerning methods and quality control can be found at https://www.slu.se/en/departments/aquatic-sciences-assessment/laboratories/vattenlabb2/. In brief, for physicochemical measurements mid-lake surface water samples (0.5 m) were taken annually during four sampling intervals (March to November) using a Plexiglas sampler. Phytoplankton was sampled quantitatively in late summer (August) with a tube sampler from the epilimnion in the open-water mid-lake area. Benthic macroinvertebrate samples were collected in autumn (mainly October/November) from littoral and profundal habitats. For littoral habitats, macroinvertebrates were collected using standardised kick sampling with a hand net (0.5 mm mesh). Five standardised kick samples (20-s duration, 1 m long, ca 0.5–1 m depth) were taken from stony, vegetation-free sites in each lake. For profundal macroinvertebrate collections consisted of five Ekman grab samples (247 cm2) taken within a 150 m x 150 m quadrate situated over the deepest area of the lake, washed through a 0.5 mm mesh and preserved in 70% ethanol (final concentration).
Time period(s) for data collection:
1992-03-01 - 2022-11-30
Data collector:
- Swedish University of Agricultural Sciences
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Geographic coverage
Geographic coverage
Geographic location:
Geographic description:
National lake monitoring data. The 110 study lakes cover broad geographic gradients in latitude (range 55.5 to 68.4 ºN) and longitude (range 11.6 to 23.4 ºE), and ecosystem sizes (median lake surface area = 0.56 km2).
Administrative information
Administrative information
Responsible department/unit:
Department of Aquatic Sciences and Assessment
Contributor(s):
Commissioning organisation:
- Swedish University of Agricultural Sciences
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Soil, Water, and Environmental Data:
Funding
Funding
Funding agency:
- Swedish Environmental Protection Agency and the Swedish Agency for Marine and Water Management.
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Funding information:
The Swedish Environmental Protection Agency and the Swedish Agency for Marine and Water Management financed these long-term monitoring programmes.
Funding agency:
- Swedish University of Agricultural Sciences
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Funding information:
Faculty support (professor)
Topic and keywords
Topic and keywords
INSPIRE topic categories:
Standard för svensk indelning av forskningsämnen 2025:
Relations
Relations
Is documented by:
Publications
Publications
Citation:
Johnson, R.K., Goedkoop, W., Lau, D. (2025). Multi-decadal trends in Northern lakes show contrasting responses of phytoplankton and benthic macroinvertebrates to climate change. Global Change Biology, http://dx.doi.org/10.1111/gcb.70274Opens in a new tab
Metadata
Metadata
