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Coastal grasslands – habitats on the move

Explore the dynamic landscape of coastal grasslands in this study by Sara Cousins, Department for Physical Geography. Discover the impact of changing habitats, potential meadow areas, plant diversity, and genetic richness over 4000 years of land uplift. Investigate the role of rotational grazing, seed banks, and environmental factors in maintaining local biodiversity. Gain insights into the interplay between landscape structure, dispersal mechanisms, and conservation strategies for species like Campanula rotundifolia. This research presents valuable findings on the importance of rotational grazing as a management tool for preserving plant diversity in coastal habitats. Learn about historical trends, current challenges, and future prospects in the context of environmental changes. Follow @SAOCousins for more updates.

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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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