Island-mainland plant communities: effects of species pool, grazing and productivity on spatial components of diversity - verkefnislok

Fréttatilkynning verkefnisstjóra


Both management of natural resources and nature conservation depend on solid knowledge of the driving forces that shape patterns of biological diversity.

 The main focus of past research on diversity of biological communities has been on species diversity within communities (alpha diversity). However, how important driving forces, such as productivity, disturbances and species pool size, influence community differentiation and diversity among communities (beta) is poorly understood. In this project we aimed to disentangle the relative effects of these three driving forces on plant community diversity by investigating components of plant diversity at different spatial scales within Subarctic/Low Arctic regions with different species pool sizes. We surveyed vegetation at a variety of spatial scales within valleys of contrasting grazing regimes (sheep) in Iceland (island, relatively small species pool) and Norway (mainland, relatively large species pool) using a solid study design. The main emphasis was on vascular plant species, but alpha diversity of bryophyte communities was also assessed in the Iceland valleys. 

Heiti verkefnis: Fjölbreytni plöntusamfélaga: áhrif tegundaauðgi, beitarálgs og frjósemi á fjölbreytni í landslagi / Island-mainland plant communities:  effects of species pool, grazing and productivity on spatial components of diversity
Verkefnisstjóri: Ingibjörg Svala Jónsdóttir, Líffræðistofnun Háskóla Íslands
Tegund styrks. Verkefnisstyrkur
Styrkár: 2011-2013
Fjárhæð styrks: 18,95 millj. kr. alls
Tilvísunarnúmer Rannís: 11023502

Our main results were that vascular plant alpha diversity is similar in for both countries while beta diversity is greater in Norway (large species pool). Sheep grazing does not affect alpha diversity of vascular plants in any of these valleys, while grazing appears to increase alpha diversity of bryophyte communities in certain habitats. However, grazing shapes community differentiation (beta diversity) of vascular plant communities at certain spatial scales. In Iceland, grazing reduced beta diversity, but only at an intermediate, altitudinal landscape scale within the valleys. 

Our results contribute significant to theoretical understanding of how regional and local driving forces shape the patterns of alpha and beta diversity in general and particularly within Subarctic and Low Arctic rangelands. They may also provide guidance for management and conservation planning of these areas. Furthermore, our study has significant implications for improved sampling design of ecological studies. 

Information on how the results will be applied 

The results have been presented at several national and international conference and workshops. In addition, the results will be published in peer reviewed scientific journals and thus contribute to scientific knowledge in the field. The results will also provide guidance for practitioners to monitoring and management of plant diversity within northern tundra areas. 

A list of the projects output (reports, journal articles or manuscripts) 

Journal article

Mörsdorf, M.A., Ravolainen, V.T., Støvern, L.E., Yoccoz, N.G., Jónsdóttir, I.S: and Bråthen, K.A. Definition of sampling units begets conclusions in ecology: the case of habitats for plant communities. PeerJ, accepted. For pre-print: 

Manuscript soon to be submitted

Mörsdorf, M.A., Ravolainen, V.T., Yoccoz, N.G., Thórhallsdóttir, T.E. and Jónsdóttir, I.S. Effects of sheep grazing on vascular plant community structure, diversity and differentiation at various spatial scales in Iceland (working title). To be submitted to Ecosystems in January 2015. 

Manuscript in preparation

Mörsdorf, M.A., Ravolainen, V.T., Bråthen, K.A., Thórhallsdóttir, T.E. and Jónsdóttir, Impact of regional species pool size on vascular plant community diversity in relation to local driving forces. 

PhD thesis by Martin Mörsdorf is being prepared that builds on the above listed manuscripts.

Master's degree thesis is being prepared by Edwin C. Liebig, addressing bryophyte community diversity. 

Conference and workshop presentations

The students have presented parts of their projects on 12 different conferences and workshops.


Þetta vefsvæði byggir á Eplica