Danish wetlands remained poor with plant species 17-years after restoration

Formorethantwodecades,wetlandrestorationhasbeensuccessfullyappliedinDenmarkasatooltoprotectwa- tercourses from elevated nutrient inputs from agriculture, but little is known about how the fl ora and fauna re-spond to restoration. The main objective of this study was therefore to: (1) examine plant community characteristics in 10 wetland sites in the River Odense Kratholm catchment, restored between 2001 and 2011 byre-meanderingthestreamanddisconnectingthetiledrains,and(2)explorewhethertheeffectsofrestoration on plant community characteristics change with the age of the restoration. Speci fi cally, we hypothesised that plant community composition, species richness and diversity would improve with the age of the restoration andeventuallyapproachthestateofnaturalwetlandvegetation.Wefoundthattheprevailingplantcommunities couldbecharacterisedashumidgrasslands,moistfallow fi eldsandimprovedgrasslands,whereastheabundance of natural wetland plant communities (e.g., rich fens, fen-sedge beds and humid grasslands) was lower in both the recently restored as well as in older restored wetlands. Additionally, species richness and diversity did not seem to improve with the age of the restoration. We suggest that the continued high nutrient input at the re- storedsitesincombinationwithrestricteddispersalofwetlandplantspeciesmayhampertherecoveryofnatural plant communities and that the sites therefore may stay botanically poor for many decades.

[1]  B. Kronvang,et al.  Multi-functional benefits from targeted set-aside land in a Danish catchment , 2020, Ambio.

[2]  T. Urich,et al.  From Understanding to Sustainable Use of Peatlands: The WETSCAPES Approach , 2020, Soil Systems.

[3]  D. Zak,et al.  Unraveling the Importance of Polyphenols for Microbial Carbon Mineralization in Rewetted Riparian Peatlands , 2019, Front. Environ. Sci..

[4]  J. Couwenberg,et al.  Prompt rewetting of drained peatlands reduces climate warming despite methane emissions , 2019, Nature Communications.

[5]  T. Heinken,et al.  Do dispersal traits of wetland plant species explain tolerance against isolation effects in naturally fragmented habitats? , 2019, Plant Ecology.

[6]  D. Zak,et al.  Nitrogen and phosphorus retention in Danish restored wetlands , 2019, Ambio.

[7]  H. H. Bruun,et al.  Vascular plant species richness and bioindication predict multi‐taxon species richness , 2018, Methods in Ecology and Evolution.

[8]  S. Caporn,et al.  An overview of the progress and challenges of peatland restoration in Western Europe , 2017 .

[9]  D. Cooper,et al.  An overview of peatland restoration in North America: where are we after 25 years? , 2017 .

[10]  C. Hoffmann,et al.  Documenting success stories of management of phosphorus emissions at catchment scale: an example from the pilot river Odense, Denmark. , 2016, Water science and technology : a journal of the International Association on Water Pollution Research.

[11]  G. Blicher-Mathiesen,et al.  Successful reduction of diffuse nitrogen emissions at catchment scale: example from the pilot River Odense, Denmark. , 2016, Water science and technology : a journal of the International Association on Water Pollution Research.

[12]  P. Poschlod,et al.  Functional characterizations of Ellenberg indicator values – a review on ecophysiological determinants , 2016 .

[13]  H. E. Andersen,et al.  Environmental controls of plant species richness in riparian wetlands: Implications for restoration , 2015 .

[14]  A. Timmermann,et al.  Structural and functional responses of floodplain vegetation to stream ecosystem restoration , 2015, Hydrobiologia.

[15]  A. Grootjans,et al.  Ecological restoration of rich fens in Europe and North America: from trial and error to an evidence‐based approach , 2015, Biological reviews of the Cambridge Philosophical Society.

[16]  D. Zak,et al.  Changes of the CO2 and CH4 production potential of rewetted fens in the perspective of temporal vegetation shifts , 2014 .

[17]  J. B. Poulsen,et al.  Seed germination from deposited sediments during high winter flow in riparian areas , 2014 .

[18]  S. Larsen,et al.  Groundwater nitrogen and the distribution of groundwater-dependent vegetation in riparian areas in agricultural catchments , 2014 .

[19]  A. Baattrup‐Pedersen,et al.  CATCHMENT CHARACTERISTICS AND PLANT RECRUITMENT FROM SEDIMENT IN STREAM AND MEADOW HABITATS , 2013 .

[20]  R. Ejrnæs,et al.  Cost‐effective assessment of conservation status of fens , 2013 .

[21]  B. Kronvang,et al.  Species Recruitment following Flooding, Sediment Deposition and Seed Addition in Restored Riparian Areas , 2013 .

[22]  S. Larsen,et al.  Effects of stream flooding on the distribution and diversity of groundwater‐dependent vegetation in riparian areas , 2013 .

[23]  Brian Kronvang,et al.  Diversity and distribution of riparian plant communities in relation to stream size and eutrophication. , 2012, Journal of environmental quality.

[24]  S. Larsen,et al.  Phosphorus load to surface water from bank erosion in a Danish lowland river basin. , 2012, Journal of environmental quality.

[25]  M. Power,et al.  Structural and Functional Loss in Restored Wetland Ecosystems , 2012, PLoS biology.

[26]  T. Sparks,et al.  The Influence of Time on the Soil Seed Bank and Vegetation across a Landscape‐Scale Wetland Restoration Project , 2012 .

[27]  D. Zak,et al.  Preface: Restoration, biogeochemistry and ecological services of wetlands , 2011, Hydrobiologia.

[28]  J. Audet,et al.  Evaluation of nutrient retention in four restored Danish riparian wetlands , 2011, Hydrobiologia.

[29]  G. Du,et al.  Soil seed bank dynamics in alpine wetland succession on the Tibetan Plateau , 2011, Plant and Soil.

[30]  R. Bekker,et al.  Species trait shifts in vegetation and soil seed bank during fen degradation , 2010, Plant Ecology.

[31]  C. Nilsson,et al.  The role of hydrochory in structuring riparian and wetland vegetation , 2010, Biological reviews of the Cambridge Philosophical Society.

[32]  A. Grootjans,et al.  Prospects for fen meadow restoration on severely degraded fens , 2010 .

[33]  Ü. Mander,et al.  Ecosystem services of peatlands: Implications for restoration , 2010 .

[34]  D. Zak,et al.  Phosphorus mobilization in rewetted fens: the effect of altered peat properties and implications for their restoration. , 2009, Ecological applications : a publication of the Ecological Society of America.

[35]  Martin Hermy,et al.  The LEDA Traitbase: a database of life‐history traits of the Northwest European flora , 2008 .

[36]  H. Rydin,et al.  Long-term effects of drainage and initial effects of hydrological restoration on rich fen vegetation , 2008 .

[37]  A. Grootjans,et al.  Wet meadow restoration in Western Europe: A quantitative assessment of the effectiveness of several techniques , 2007 .

[38]  C. Hoffmann,et al.  Re-establishing freshwater wetlands in Denmark , 2007 .

[39]  J. M. Andersen,et al.  Restoration of Skjern River and its valley: Project description and general ecological changes in the project area , 2007 .

[40]  B. Arheimer,et al.  Regional and global concerns over wetlands and water quality. , 2006, Trends in ecology & evolution.

[41]  S. Güsewell,et al.  Nutrient limitation and botanical diversity in wetlands: can fertilisation raise species richness? , 2005 .

[42]  R. van Diggelen,et al.  Light as an environmental filter in fen vegetation , 2004 .

[43]  B. Middleton.  Soil seed banks and the potential restoration of forested wetlands after farming , 2003 .

[44]  P. D. Ruiter,et al.  SPECIES RICHNESS–PRODUCTIVITY PATTERNS DIFFER BETWEEN N‐, P‐, AND K‐LIMITED WETLANDS , 2003 .

[45]  E. Tuittila,et al.  Status and restoration of peatlands in northern Europe , 2003, Wetlands Ecology and Management.

[46]  J. Zedler,et al.  Progress in wetland restoration ecology. , 2000, Trends in ecology & evolution.

[47]  A. P. Schaffers,et al.  Reliability of Ellenberg indicator values for moisture, nitrogen and soil reaction: a comparison with field measurements , 2000 .

[48]  R. H. Økland.  Vegetation ecology: theory, methods and applications with reference to Fennoscandia , 1990 .

[49]  J. Braun-Blanquet,et al.  Plant Sociology: the Study of Plant Communities , 1983, Nature.

[50]  M. Lewandowska.  POTENTIAL FOR FURTHER WETLAND RESTORA- TION IN THE ODENSE RIVER CATCHMENT AND NITROGEN AND PHOSPHORUS RETENTION , 2020 .

[51]  Sam D. S. Bosanquet,et al.  MOSSES AND LIVERWORTS OF BRITAIN AND IRELAND: A FIELD GUIDE , 2010 .

[52]  COMMUNICATION FROM THE COMMISSION TO THE EUROPEAN PARLIAMENT, THE COUNCIL, THE EUROPEAN ECONOMIC AND SOCIAL COMMITTEE AND THE COMMITTEE OF THE REGIONS , 2009 .

[53]  H. Laudon,et al.  The importance of groundwater discharge for plant species number in riparian zones. , 2007, Ecology.

[54]  Dave Smith,et al.  What's New in SAS® 9.1.3 for Clinical Programmers , 2006 .

[55]  A. Baattrup‐Pedersen,et al.  Overvågning af Vandmiljøplan II - Vådområder 2005 , 2006 .

[56]  Sang Joon Kim,et al.  A Mathematical Theory of Communication , 2006 .

[57]  M. Diekmann.  Species indicator values as an important tool in applied plant ecology – a review , 2003 .

[58]  Ruprecht Düll,et al.  Zeigerwerte von Pflanzen in Mitteleuropa , 1992 .