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Coastal grasslands – habitats on the move

Coastal grasslands – habitats on the move. Sara Cousins Department for Physical Geography. @ SAOCousins. 1780. 1901. 96% Grasslands gone. 16 km. Cousins et al. 2015 AMBIO. Wild strawberries. Cock’s-foot. St. John’s wort. Wood anemone. Annual bluegrass. Dog violet.

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Coastal grasslands – habitats on the move

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  1. Coastal grasslands – habitats on the move Sara Cousins Department for PhysicalGeography @SAOCousins

  2. 1780 1901

  3. 96% Grasslands gone 16 km Cousins et al. 2015AMBIO

  4. Wildstrawberries Cock’s-foot St. John’swort Wood anemone Annualbluegrass Dog violet Silver cinquefoil Lady’s mantel Red sorrel Burnet-saxifrage Sheep’sfescue Yarrow Dactylorhizalati. Harebell Ribwortplantain White clover Hairywood-rush Timothy grass Buttercup Cowslip Bellflower Speedwell Sedge Mouse-earhawkweed Bitter vetch Lady’sbedstraw Sweet vernalgrass 0.25 m2

  5. www.kvarken.fi/varldsarvet/geologi/istiden/

  6. Landscape scale DTM 23000 km2 area Land upliftmodel ~ 4000 yearspotential meadow areas = slopesof 1-2 degrees Site scale Plant diversity in 10 managagedshoremeadows 10 unmanaged former shoremeadows

  7. 4000 yearsof landuplift (Upland and Södertörn) Norrtälje Stockholm

  8. Results Norrtälje 7900 km2 land emerged 2400-3400 km2potential meadow Potential meadow50-150 km2/100 yr Svartlöga

  9. X X Photo: S. Sternberg Photo: Cousins 2018 1920 45cm isostaticrebound in 100 years

  10. Historicalmap from 1901

  11. 2520151050 No of plant species (1m2) Relative age Auffret & Cousins 2018Proceedings B

  12. Plant functional connectivity defined as the effective dispersal of propagules or pollen among habitat patches in a landscape Depends on landscape structure interactions between plants, environment & dispersal vectors Auffret et al 2017 J Ecology

  13. Gällnö-Hjälmöarchipelago 50 km Photo: Cousins

  14. Questions Campanula rotundifolia • Does plant diversitydeclineifrotationalgrazing (spatial dispersal) ceases? • Canseed banks (temporal dispersal) maintainlocal plant diversity? • Does rotationalgrazinghavean effect on geneticdiversity?

  15. Vegetation samplingSeedbank Geneticdiversity 77 plots (14 islandswithrotationalgrazingnetworks/13 without)

  16. 1 cow=96000 seeds/season Photo: Brännäng

  17. Environmentalvariables • Presenceofrotationalgrazing • Grassland area • Island size • Distance to nearestgrassland and island • 160 yearsofchange

  18. Change in open habitat1850-2015 Habitat loss =80%Increase in isolation =20% Gain Loss 8 ha 0 8 ha 24 ha

  19. Results Campanula rotundifolia • 177 species: 147 fieldlayer,113 species (21082 emergentseedlings in the seed bank) • ~1/3 less species withoutrotationalgrazing • ~ Twice as manygrassland specialists withrotationalgrazing

  20. Fieldlayer Results Campanula rotundifolia Patchscalediversity • Rotationalgrazing + • Patchsize + • Increasingdistance – No rotationalgrazingRotationalgrazing

  21. Seed bank Results Campanula rotundifolia Patchscale (seed bank) • Rotationalgrazing + • Patchsize + • Increasingdistance – No rotationalgrazingRotationalgrazing

  22. Allelicrichness No rotationalgrazing Rotationalgrazing Population geneticdifferenciation No rotationalgrazing Rotationalgrazing Plue, Aavik & Cousins 2018Diversty & Distribution

  23. Landscape structure Present management 1850 Present Stationary Rotationalgrazing + Species diversity (15 sp) + Species diversity (14 sp) + + (area) Community diversity + (connectivity) + Genetic diversity

  24. Conclusions Campanula rotundifolia • Localdiversity(species and genes) declineswithoutrotationalgrazingbutseedbanks maybuffer (for a while) • Rotationalgrazingprovide a powerful management tool for conservation Plue & Cousins 2018OIKOS

  25. 0.3 km2managed shoremeadowtoday Last 100 years =80 km2 ”shore meadow”

  26. Today 0.3 km2managed shoremeadow 265 km2managed semi-naturalgrassland

  27. New challenges X X Photo: S. Sternberg Photo: Cousins 2018 1920 45 cm isostaticrebound in 100 years 67 cm sealevelrise in the next 80 years* *SMHI 2017 futuresealevelchange

  28. Conclusion and Future?

  29. Tack! @SAOCousins

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