The floodplain meadows of Soomaa National Park, Estonia Vegetation – Dispersal – Regeneration Dissertation zur Erlangung des Doktorgrades (Dr. rer. nat.) der Naturwissenschaftlichen Fakultät III – Biologie und vorklinische Medizin – der Universität Regensburg vorgelegt von Jaan Palisaar aus Kiel Edertal, April 2006 Promotionsgesuch eingereicht am 10. April 2006 Tag der mündlichen Prüfung 26. Juli 2006 Die Arbeit wurde angeleitet von Prof. Dr. Peter Poschlod Prüfungsausschuß: Prof. Dr. Jürgen Heinze Prof. Dr. Peter Poschlod Prof. Dr. Karl-Georg Bernhardt Prof. Dr. Christoph Oberprieler Contents List of figures.........................................................................................................................III List of tables...........................................................................................................................VI Acknowledgments................................................................................................................IX A. Foreword.............................................................................................................................1 B. Study area............................................................................................................................3 1 Physical setting...............................................................................................................3 2 Land use...........................................................................................................................8 C. Vegetation types and habitat parameters.....................................................................11 1 Introduction...................................................................................................................11 2 Methods.........................................................................................................................15 2.1 Vegetation.............................................................................................................15 2.2 Habitat parameters..............................................................................................16 2.3 Statistical methods..............................................................................................17 3 Results and Discussion................................................................................................19 3.1 Species groups......................................................................................................19 3.2 Plant communities...............................................................................................21 3.2.1 Dry floodplain grasslands..........................................................................22 3.2.1.1 Nardus-Festuca ovina community....................................................22 3.2.1.2 Festuca ovina-Sesleria caerulea community....................................23 3.2.2 Moderately moist (mesic) floodplain grasslands....................................26 3.2.2.1 Festuca rubra-Deschampsia-community.........................................26 3.2.2.2 Alopecurus pratensis-Galium mollugo-community......................27 3.2.2.3 Alopecurus-Deschampsia-community.............................................28 3.2.3 Moist floodplain grasslands.......................................................................29 3.2.3.1 Sesleria-Deschampsia-community....................................................30 3.2.3.2 Melampyrum nemorosum-Deschampsia-community...................30 3.2.3.3 Carex cespitosa-Deschampsia-community......................................31 3.2.4 Wet floodplain grasslands with tall sedges.............................................32 3.2.4.1 Carex disticha-Juncus filiformis-community...................................32 3.2.4.2 Ranunculus flammula-Juncus filiformis-community.....................33 3.2.4.3 Potentilla palustris-Carex disticha-community..............................33 3.2.4.4 Carex acuta-community.....................................................................33 3.2.4.5 Carex elata-community.......................................................................34 3.2.5 Wet floodplain grasslands with tall grasses, reed-beds.........................34 3.2.5.1 Phalaris-Phragmites-community.......................................................34 3.2.5.2 Carex acuta-Schoenoplectus lacustris-community.........................34 3.3 Syntaxonomy........................................................................................................35 3.3.1 Nardetalia strictae........................................................................................36 3.3.2 Molinio-Arrhenatheretea............................................................................36 I 3.3.2.1 Arrhenatheretalia.................................................................................37 3.3.2.2 Molinietalia...........................................................................................39 3.3.3 Caricion nigrae.............................................................................................41 3.3.4 Phragmito-Caricetea....................................................................................42 3.4 Habitat and vegetation parameters...................................................................45 3.4.1 Soil..................................................................................................................45 3.4.2 Groundwater................................................................................................47 3.4.3 Biomass..........................................................................................................48 3.5 Synopsis of habitat – vegetation relations........................................................51 3.5.1 CCA................................................................................................................51 3.5.2 Ellenberg indicator values..........................................................................53 3.5.3 Vegetation profiles.......................................................................................56 3.6 Nature conservation and management.............................................................65 D. Dispersal, regeneration, and the role of plant traits...................................................71 1 Introduction...................................................................................................................71 1.1 Seed banks.............................................................................................................72 1.2 Seed dispersal.......................................................................................................73 1.3 Gap regeneration..................................................................................................75 1.4 Plant trait analysis................................................................................................76 1.5 Questions asked....................................................................................................78 2 Methods.........................................................................................................................81 2.1 Seed rain................................................................................................................81 2.2 Seed sowing experiment.....................................................................................84 2.3 Disturbance and regeneration............................................................................88 2.4 Plant traits.............................................................................................................90 3 Results............................................................................................................................95 3.1 Seed rain................................................................................................................95 3.1.1 Seed traps......................................................................................................95 3.1.2 Drift material..............................................................................................108 3.2 Seed sowing experiment...................................................................................109 3.2.1 General results............................................................................................109 3.2.2 Establishment.............................................................................................110 3.3 Disturbance and regeneration..........................................................................112 3.3.1 General results............................................................................................112 3.3.2 Comparison of species composition........................................................115 3.3.3 Species traits...............................................................................................116 3.4 Plant traits...........................................................................................................120 4 Discussion....................................................................................................................132 4.1 Methodological considerations........................................................................132 4.2 Seed rain..............................................................................................................133 4.3 Seed sowing experiment...................................................................................141