The role of Sphagnum in biodiversity switches
The unique biochemistry of peatmosses, Sphagnum, leads to acidification of the habitat and rapid accumulation of decay-resistant litter, processes that are the determinants of carbon sequestration of global importance. Sphagnum invasion triggers transitions from calcareous fen to acid fen to bog, plant species richness decreases markedly and peat storage increases. In this project we study the dynamics and mechanisms (dispersal, establishment, interactions) of biodiversity and community changes during Sphagnum invasion. Laboratory experiments and field transplants are used to elucidate the ability of different Sphagnum species to invade and modify the habitat.
Mire bryophytes as environmental indicators
Mire bryophytes grow in close contact with the peat substrate and are therefore sensitive indicators of the environment. In this project we assemble field and literature data on habitat requirements of peatland bryophytes and develop methods for their use in environmental monitoring. Such data can help to explain the reasons for recent changes in peatland vegetation and strengthen their use in monitoring programmes, and can also be used when in past changes are reconstructed from macrofossils in peat stratigraphy.
In the epiphyte project we apply spatial and metapopulation modelling to cover the whole chain of events determining the distribution of species: spore production, dispersal and survival. An example is the spatial pattern off the red-listed moss Neckera pennata and its dependence on host species. This is followed by the analysis of other bryophyte epiphytes in a metacommunity type of analysis. See papers with Per Johansson, Per Hazell, Tord Snäll, Karin Wiklund and Swantje Löbel as first author in the list below.
Rich fen restoration project
In a project starting 2002 we perform restoration experiments in previously drained rich fens and study dispersal and life history characteristics of rich fen bryophytes.
We have been involved in studies of nitrogen deposition and increased levels of carbon dioxide on mire ecosystems across Europe. With a mini-FACE technology (Free Air Carbon dioxide Enrichment) patches of mire vegetation were subjected to increased carbon dioxide levels (Berendse et al. 2001).
To study long-term dynamics in mire vegetation we re-analysed 40-50 year old detailed investigations of mires at locations in Sweden with different levels of air pollution. See papers with Urban Gunnarsson as first author in the list.
Another project on long-term dynamics covered the succession, island biogeography and seed bank development on small islands in Lake Hjälmaren which were created in 1886 when the water table of the lake was lowered. The floristic development has been followed with surveys in 1886, 1892, 1903, 1920s and in the 1980s (Rydin & Borgegård 1988 a, b, 1991)