Spatial macrophyte data on biomass, traits and CN content from the Baltic Sea, southwestern Finland, 2023

Roel Lammerant, Jenna Hölttä, Janina Pykäri, Nishant Nishant, Anna Villnäs, Sofia Wikström, Alf Norkko, Camilla Gustafsson

The dataset contains macrophyte species composition, biomass, and trait data (morphological and biochemical) from southwestern Finland, the Baltic Sea, in August– ⁠September 2023.

The data were collected in order to assess the spatial dynamics of macrophyte community composition and biomass-bound carbon stocks.

The dataset is based on a spatial field survey, where macrophyte material was destructively harvested at 20 sites along a salinity (1-6 ppt) and exposure gradient in the Pojo-Hanko archipelago (50 km), southwestern Finland. The macrophytes were collected from soft sediment habitats at two different depths: 1 – ⁠2 m and 3 – ⁠4 m.

MarineBenthic ecologyMarine biodiversityFunctional traitsAquatic plantsIntra-specific trait variationExposureSalinityCarbon storageBenthic ecologySpatial campaign 2023CoastClim

Name

Version

Citation

References

Lammerant R, Hölttä J, Pykäri J, Nishant N, Villnäs A, Wikström S A, Norkko A, Gustafsson C (2025a) Environmental gradients strongly affect functional composition and biomass C stocks within aquatic plant meadows. Ecosphere 16:e70327. https://doi.org/10.1002/ecs2.70327

Lammerant R, Hölttä J, Pykäri J, Nishant N, Villnäs A, Wikström S A, Norkko A, Gustafsson C (2025b) Intraspecific trait variability is a key feature underlying the association between community-weighted mean and abiotic gradients. OIKOS. https://doi.org/10.1002/oik.11665

Data description

This dataset is used in the publications Lammerant et al. (2025a) and Lammerant et al. (2025b)

The data are provided in seven csv files. For each data file, there is a corresponding readme txt file with specific explanations.

Data files

• c-n.csv Carbon and nitrogen content in macrophyte species.
• site-environmental.csv Environmental data for the sampled sites.
• data-exposed.csv Macrophyte data at the exposed sites.
• data-semi.csv Macrophyte data at the semi exposed sites.
• data-sheltered.csv Macrophyte data at the sheltered sites.
• data-pojo.csv Macrophyte data at the sites in the most sheltered area with the lowest salinity.
• site-coordinates.csv Coordinates of the sampling sites.

File content

c-n.csv

Number of variables: 13
Number of cases/rows: 762
Missing data codes: NA
Delimiter: Comma
Encoding: UTF-8

Variables

• position Sample position on well plate
• abbr Abbreviation for samples in well plate with site, species and tissue information
• exposure Exposure categories: Exposed, Semi, Sheltered, Pojo
• organism Origin of macrophyte material: Algae, Plant
• species Six letter code of the species:
  • CALHER Callitriche hermafroditica
  • CERDEM Ceratophyllum demersum
  • LEMTRI Lemna trisulca
  • MYRSIB Myriophyllum sibiricum
  • MYRSPI Myriophyllum spicatum
  • NAJMAR Najas marina
  • NUPLUT Nuphar lutea
  • POTNIT Potamogeton nitens
  • POTOBT Potamogeton obtusifolius
  • POTPER Potamogeton perfoliatus
  • RANBAU Ranunculus baudotii
  • RANCIR Ranunculus circinatus
  • RUPCIR Ruppia cirrhosa
  • STUPEC Stuckenia pectinata
  • ZANMAJ Zannichellia major
  • ZOSMAR Zostera Marina
  • Fontinalis Fontinalis sp.
  • Sparganium Sparganium sp.
• tissue Tissue used for elemental analyses: Leaf, Rhizome, Root
• dwt Dry weight of the sample used for elemental analyses in mg
• Nmass Amount particulate organic nitrogen in µg
• 15N Nitrogen stable isotope measurement
• Cmass Amount particulate organic carbon in µg
• 13C Carbon stable isotope measurement
• Npercentage Amount particulate organic nitrogen per dry weight of sampled tissue in µg/mg
• Cpercentage Amount particulate organic carbon per dry weight of sampled tissue µg/mg

site-environmental.csv

Number of variables: 6
Number of cases/rows: 20
Missing data codes: none
Delimiter: Comma
Encoding: UTF-8

Variables

• site Site number combined with exposure category
• exposure Exposure categories: Exposed, Semi, Sheltered, Pojo
• salinity Salinity of surface water in ppt
• loi Organic matter content as loss on ignition in the top 1 cm of sediment in %
• sand Sand content of the top 1 cm of sediment in %
• clay Clay content of the top 1 cm of sediment in %

data-exposed.csv

Number of variables: 37
Number of cases/rows: 136
Missing data codes: NA
Delimiter: Comma
Encoding: UTF-8

Variables

• site Site code from where macrophyte material was destructively harvested made up out of depth, site number and quadrat number
• depth Depth category: D deep, S shallow
• number Number of the sites, ranges from 1-5
• species Six letter code of the species:
  • CALHER Callitriche hermafroditica
  • CERDEM Ceratophyllum demersum
  • LEMTRI Lemna trisulca
  • MYRSIB Myriophyllum sibiricum
  • MYRSPI Myriophyllum spicatum
  • NAJMAR Najas marina
  • NUPLUT Nuphar lutea
  • POTNIT Potamogeton nitens
  • POTOBT Potamogeton obtusifolius
  • POTPER Potamogeton perfoliatus
  • RANBAU Ranunculus baudotii
  • RANCIR Ranunculus circinatus
  • RUPCIR Ruppia cirrhosa
  • STUPEC Stuckenia pectinata
  • ZANMAJ Zannichellia major
  • ZOSMAR Zostera Marina
  • Fontinalis Fontinalis sp.
  • Sparganium Sparganium sp.
• height Maximum height in cm
• count Number of individuals in the destructively harvested plant material
• LA_1 Leaf area 1 in cm²
• LP_1 Leaf perimeter 1 in cm
• LA_2 Leaf area 2 in cm²
• LP_2 Leaf perimeter 2 in cm
• leaf_dwt_1 Dry mass weight of leaf 1 used for trait measurements in mg
• leaf_dwt_2 Dry mass weight of leaf 2 used for trait measurements in mg
• leaf_dwt_epp Dry mass weight of the leaves used for elemental analysis in mg
• stem_volume Stem volume in cm³
• stem_dwt Drymass weight of stem tissue used for trait measurements in mg
• rhi_length Rhizome length in cm
• rhi_dwt_trait Drymass weight of rhizome tissue used for trait measurements in mg
• rhi_dwt Drymass weight of rhizome tissue in the collected quadrat, which was not used for trait measurements in mg
• rhi_dwt_epp Dry mass weight of the rhizome used for elemental analysis in mg
• root_depth Maximum rooting depth in cm
• root_dwt Drymass weight of root tissue in the collected quadrat, which was not used for elemental measurements in mg
• root_dwt_epp Drymass weight of root tissue used for elemental measurements in mg
• above_dwt Drymass weight of aboveground tissue in the collected quadrat, which was not used for trait measurements in mg
• detritus_dwt Drymass weight of detritus present in the collected quadrat in mg
• tolypella Drymass weight of Tolypella (Algae) present in the collected quadrat in mg
• chorda Drymass weight of Chorda (Algae) present in the collected quadrat in mg
• notes Notes for the collected samples
• above_dwt_all Dry mass weight of all aboveground biomass present in the quadrat in mg
• below_dwt_all Dry mass weight of all belowground biomass present in the quadrat in mg
• rhi_dwt_all Dry mass weight of all rhizome biomass present in the quadrat in mg
• root_dwt_all Dry mass weight of all root biomass present in the quadrat in mg
• dwt_all Dry mass weight of all biomass present in the quadrat in mg
• algae_dwt_all Dry mass weight of all algae biomass present in the quadrat in mg
• SLA_1 The ratio of leaf area 1 to dry mass of the leaf in cm²/mg
• SLA_2 The ratio of leaf area 2 to dry mass of the leaf in cm²/mg
• LAP_1 The ratio of leaf area to perimeter of leaf 1 in %
• LAP_2 The ratio of leaf area to perimeter of leaf 2 in %
• SRhiL The ratio of rhizome length to dry mass of the root rhizome in cm/mg

data-semi.csv

Number of variables: 38
Number of cases/rows: 118
Missing data codes: NA
Delimiter: Comma
Encoding: UTF-8

Variables

• fucus Dry mass weight of Fucus vesiculosus (Algae) in the collected quadrat in mg

All other columns are the same as in the data-exposed.csv

data-sheltered.csv

Number of variables: 43
Number of cases/rows: 70
Missing data codes: NA
Delimiter: Comma
Encoding: UTF-8

Variables

• green_algae Drymass weight of Green algae present in the collected quadrat in mg
• vaucheria Drymass weight of Vaucheria (Algae) present in the collected quadrat in mg
• chara_glo Drymass weight of Chara globularis (Algae) present in the collected quadrat in mg
• chara_sp Drymass weight of Chara sp. (Algae) present in the collected quadrat in mg
• reed Drymass weight of dead reed biomass present in the collected quadrat in mg
• fucus Drymass weight of Fucus vesiculosus (Algae) present in the collected quadrat in mg

All other columns are the same as in the data-exposed.csv

data-pojo.csv

Number of variables: 41
Number of cases/rows: 131
Missing data codes: NA
Delimiter: Comma
Encoding: UTF-8

Variables

• detritus_algae Drymass weight of detritus interspersed with algae present in the collected quadrat in mg
• green_algae Drymass weight of Green algae present in the collected quadrat in mg
• chara_sp Drymass weight of Chara sp. (Algae) present in the collected quadrat in mg
• aeglin Drymass weight of Aegagropila linnaei (Algae) present in the collected quadrat in mg
• vaucheria_sp Drymass weight of Vaucheria sp. (Algae) present in the collected quadrat in mg

All other columns are the same as in the data-exposed.csv

site-coordinates.csv

Number of variables: 5
Number of cases/rows: 39
Missing data codes: none
Delimiter: Comma
Encoding: UTF-8

Variables

• exposure Exposure categories: Exposed, Semi, Sheltered and Pojo
• site Number of the sites, ranges from 1-5
• depth Depth category, D deep and S shallow
• north_coord North coordinates in decimal degrees using the WGS84 format
• east_coord East coordinates in decimal degrees using the WGS84 format

Comments

CoastClim

This is a contribution from the Centre for Coastal Ecosystem and Climate Change Research. CoastClim is a multidisciplinary strategic partnership between Stockholm University and the University of Helsinki, that evaluates the links between coastal biodiversity, carbon cycling, and climate feedbacks.

Funding

Walter and Andrée de Nottbeck Foundation (PhD grant R.L., J.P., N.N.), Jane and Aatos Erkko Foundation (A.N., C.G.), Research Council of Finland (project grant 354454 C.G.). This study used research infrastructure facilities at Tvärminne Zoological Station, University of Helsinki, as part of FINMARI (Finnish Marine Research Infrastructure Consortium).

Project

CoastClim

Publisher

Bolin Centre Database

License

Creative Commons Attribution 4.0 International License (CC BY 4.0)

First name

Roel

Last name or organisation

Lammerant

Email address

roel.lammerant@outlook.be

Address

Tvärminne Zoological Station; University of Helsinki

Postal code

10900

City

Hanko

Country

Finland

GCMD science keyword

Earth science > Biosphere > Aquatic ecosystems > Benthic habitat

GCMD location

Continent > Europe > Northern Europe > Scandinavia > Finland

Dataset language

English

Begin date

2023-08-15

End date

2023-09-08

DOI

Time

Versions

• 1 2026-04-20T08:17:44.92+00:00
• 1 2026-04-20T08:17:28.299+00:00