Plant functional traits reveal strong effects of anoxia and nutrient limitation on species pool filtering in a riverine rich fen system

ABSTRACT

Background: In fens, plant species composition is predominantly controlled by two environmental factors: root anoxia and low nutrient availability.

Aims: We asked how these filters were reflected to the functional structure of plant communities in natural and drained rich fens.

Methods: We analysed traits related to species response to anoxia and nutrient availability, using single-trait and multi-trait approaches in fens of a river valley (Biebrza, Poland). We evaluated results concerning multi-trait indices using a null model consisting of simulated communities.

Results: Mycorrhizal status and specific leaf area (SLA) clearly distinguished the communities with different levels of anoxia and nutrient deficiency. Mean values, ranges and variance of canopy height showed the differences in the distribution of plant heights among analysed communities.

Conclusions: Functional traits distinguish plant communities of the most endangered mesotrophic fens from eutrophic and drained fens. We highlight the role of nutrient and oxygen deficiency in the assembly of fen vegetation and show the impact of the altered environment on the composition of communities in degraded habitats. We demonstrate that single-trait indices are suitable for identifying of environmental filtering in different types of fen communities. We suggest that caution is justified when using multi-trait indices to assess vegetation patterns.

KEYWORDS:

• Community assembly
• drainage
• fen meadow
• functional structure
• multi-trait index
• mycorrhizal association
• null-model
• nutrient availability
• single-trait index
• root anoxia

Acknowledgements

We would like to thank Albert Wiaderny, Katarzyna Kotowska, and Ewa Gutowska for sharing relevés. Part of this study was carried out at the Biological and Chemical Research Centre, University of Warsaw, established within a project co-financed by the EU European Regional Development Fund under the Innovative Economy Operational Programme 2007–2013. The study has also been supported by the TRY initiative on plant traits (http://www.try-db.org). The TRY initiative and database is hosted, developed and maintained by J. Kattge and G. Bönisch (Max Planck Institute for Biogeochemistry, Jena, Germany). TRY is currently supported by DIVERSITAS/Future Earth and the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig.

Authors’ contributions

KG, ŁK, TW, and WK conceived the ideas and designed the methodology; KG, MW, KB, FJ, EJ, HB, and WK collected the data; KG analysed the data; KG and WK wrote the manuscript; WK was project leader. All authors gave final approval for publication.

Data accessibility

Values of functional indices for all analysed sample plots have been deposited in the Dryad repository.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

The research leading to these results has received funding from the Polish-Norwegian Research Programme operated by the National Centre for Research and Development under the Norwegian Financial Mechanism 2009–2014 in the frame of Project Contract No Pol-Nor/199522/86/2013.

Notes on contributors

Klara Goldstein

Klara Goldstein is a quantitative ecologist with an interest in wetland ecology, functional structure of plant communities and functional niche modelling.

Łukasz Kozub

Łukasz Kozub is a plant ecologist with an interest in mire ecology, restoration and management, biodiversity and nature conservation.

Tomasz Wyszomirski

Tomasz Wyszomirski is a quantitative ecologist with an interest in simulation, individual-based models and, particularly, statistical uncertainties in biological research.

Mateusz Wilk

Mateusz Wilk is a mycologist with an interest in mycorrhiza, soil microbiology and the role of fungal communities on peatlands.

Kamila Brzezińska

Kamila Brzezińska is a botanist particularly interested in how agricultural management and agri-environmental programme affect the diversity of meadow plant communities.

Filip Jarzombkowski

Filip Jarzombkowski is a plant ecologist with an interest in wetland ecology and conservation, botany and soil science.

Ewa Jabłońska

Ewa Jabłońska is a plant ecologist with an interest in palaeobiology, mire ecology, ecohydrology and conservation.

Helena Bartoszuk

Helena Bartoszuk is a plant ecologist with an interest in phytosociology and nature management planning.

Wiktor Kotowski

Wiktor Kotowski is a wetland ecologist specialised in peatland ecosystems, their vegetation processes and ecological restoration.