09.06.2016
Doctoral Dissertation

17.6. M.Sc. Anna Oldén (Faculty of Mathematics and Science, Ecology and Evolutionary Biology)

Time:

17.6.2016 12:00 — 15:00


Location: Seminaarinmaki , S212, Vanha juhlasali
Release: Dissertation: 17.6. Plant biodiversity in boreal wood-pastures: lmpacts of grazing and abandonment (Oldén)
M.Sc. Anna Oldén defends her doctoral dissertation in Ecology and Evolutionary Biology "Plant biodiversity in boreal wood-pastures: lmpacts of grazing and abandonment". Opponent Professor Hans Henrik Bruun (University of Copenhagen) and custos Adjunct Professor Panu Halme (University of Jyväskylä). The doctoral dissertation is held in English.

Anna Oldén, photo: Markus DernjatinM.Sc. Anna Oldén defends her doctoral dissertation in Ecology and Evolutionary Biology "Plant biodiversity in boreal wood-pastures: lmpacts of grazing and abandonment". Opponent Professor Hans Henrik Bruun (University of Copenhagen) and custos Adjunct Professor Panu Halme (University of Jyväskylä). The doctoral dissertation is held in English.

Abstract

Wood-pastures are traditional rural biotopes that host high biodiversity due to the small-scale heterogeneity of grazer activities and the structural diversity of trees. However, wood-pastures and their biodiversity are threatened by intensification of agricultural and forestry practices as well as by abandonment (cessation of grazing). Here I studied the biodiversity of vascular plants and bryophytes in 24 boreal wood-pastures that are still grazed and in 24 wood-pastures that have been abandoned during the past decades. The grazed sites had higher species richness of vascular plants, as well as of bryophytes that grew on soil or on rocks. The grazers increased the diversity of microhabitats via the small-scale variation in defoliation, trampling and defecating. These disturbances created suitable microhabitats for subordinate species that disappeared due to increased competition after abandonment. Bryophyte richness on trees and decaying wood was limited in both grazed and abandoned sites by the scarcity of large deciduous trees and large logs. Rare species were observed in both grazed and abandoned sites and they were mostly dependent on moist or naturally fertile soil conditions, decaying wood or dung. Grazing hampered the regeneration of deciduous trees, while abandonment resulted in a high density of small deciduous trees and spruces. In the long term, spruces can become dominant in all kinds of wood-pastures, which is generally unwanted from the conservation point of view. Based on my results maintaining grazing management in various kinds of wood-pastures is of primary importance in the conservation of plant biodiversity, but attention should also be paid on the diversity of trees and decaying wood. Some of the abandoned sites host high conservation values as well. Finally, there is a need to create new wood-pasture habitats within the landscape.

More information

Anna Oldén

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anna.m.olden@jyu.fi