Projects
Diversity of Swedish mires: models of mire regionality used to predict
the response of communities and ecosystems to environmental change
This project will start in 2006 and is in
cooperation with Prof.
Håkan Rydin, Dept of Plant Ecology,
Objectives
Over the last decade immense data sets have been accumulated that cover
the distribution of vegetation types and structural elements of peatlands.
Parallel to this, detailed knowledge has been accumulated on fine-scale
ecological processes in peatlands, such as methane emission, productivity and
carbon sequestration in different mire vegetation types. The distribution data
can be used to model the national mire type distribution, and can be used in
combination with the fine-scale ecological data to scale up the processes and
estimate their large-scale importance for carbon sequestering. The following
goals are set up for the project:
1. To model the distributions of mire types (with data from the Swedish
Wetland Inventory) in relation to gradients in latitude, altitude and climate
(temperature, precipitation and continentality). This model will be used to
predict future wetland type distributions under climatic warming scenarios.
2. To estimate the regional mire type scarcity and vulnerability to
environmental changes for assessment in the national mire type conservation
plan.
3. To use the distribution and areal extent of mire vegetation types and
mire structures in models to scale up ecological processes in peatlands, such
as carbon sequestration, peat accumulation rate, methane emission, biological
nitrogen fixation and changes in biodiversity.
4. To assess regional changes (e.g. along a nitrogen deposition gradient)
in the balance between Sphagnum (peat
mosses) and vascular plants, and the effect of the changes on peatland
biodiversity.
5. To investigate to what extent the current rate of peat accumulation is
environmentally controlled on ombrotrophic mires and how the accumulation rate
is differentiated among regions.
The project has importance for management and conservation of
biodiversity by providing data on mire type regionality, scarcity and degree of
human disturbance.
Genetic variation and population dynamics in Sphagnum fuscum over time
and space
S. fuscum and S.
austini from Store mosse,
This project started in 2004 and aims at to investigate if it is
possible to use peat cores as sources of ancient DNA.
Objectives
The following proposal suggests a study of
sub-fossil plant population dynamics. I intend to use the peat archives in
ombrotrophic bogs as a study system to extract Sphagnum fuscum debris
from the peat (2000-3000 years old). The specific aims are:
1. To investigate the rates of change
in allele frequencies and in genetic diversity over time in ancient populations
of Sphagnum fuscum collected from peat cores.
2. To compare the temporal genetic variation
extracted from peat profiles with the spatial variation in current Sphagnum
fuscum populations.
3. To examine the possible maximal age
of single individuals of Sphagnum fuscum.
Metapopulation and genetical structures in marginal populations of the
rare species, Sphagnum angermanicum
Sphagnum angermanicum from Flickran, Dalarna, Sweden. Photo
This project is in cooperation with Prof. Lars Söderström and Kristian Hassel
and started in summer 2001 during a post doc visit at NTNU,
Objectives
1. Under which ecological conditions
(pH, nutrient status, and disturbance regime) does S. angermanicum occur? (Gunnarsson 2004).
2. To investigate the pattern of
genetic structure and diversity of S.
angermanicum in Swedish populations. (Gunnarsson, Hassel & Söderström 2005, in press).
3. To investigate if Scandinavian
populations of S. angermanicum are
dispersal or habitat limited. (Ongoing experiment).
4. To compare the genetic structure
with other plats with different life history strategies (Gunnarsson &
Hassel, manuscript)
References:
- Gunnarsson,
U. 2004. Populations of Sphagnum
angermanicum in
- Hassel,
K. & Gunnarsson, U. 2003. The use of inter simple sequence repeats
(ISSR) in bryophyte population studies. Lindbergia 28: 152-157. (PDF)
- Gunnarsson,
U., Hassel, K. & Söderström L. 2005. Genetic variation in populations of the
rare peatmoss Sphagnum angermanicum
in
- Hassel,
K., Såstad, S., Gunnarsson, U., & Söderström L. 2005. Genetic variation and structure
in the expanding moss Pogonatum
detatum in its area of origin and in a recently colonised area.
American Journal of Botany. In press.
- Gunnarsson,
U. 2002. Swedish populations of Sphagnum angermanicum – genetic
structure and establishment. In: Såstad, S. & Rydin, H. (eds.) Third
international symposium on the biology of Sphagnum,
Retrospective studies of changes in wetlands the passed 40-50 years
Ombrotrophic parts of Store Mosse, Småland, Sweden. Photo Sept 2003,
Urban Gunnarsson.
This project was a part of my PhD-thesis, with Prof. Håkan Rydin as my main
supervisor. The papers were prepared in cooperation with Prof. Em. Hugo Sjörs
and Prof. Em. Nils Malmer.
Objectives
- To
investigate changes in flora (vascular plants and bryophytes) and water
chemistry (pH and electric conductance) in ombrotrophic mires from two
parts of Sweden with high (Åkhultmyren, southern Sweden) and low
(Skattlösbergs Stormosse, central Sweden) amount of nitrogen and sulphur
deposition we did re-inventories of two well known mire area after 50 and
40 years of free development. (Gunnarsson, Rydin and Sjörs 2000,
Gunnarsson, Malmer & Rydin 2002, Sjörs & Gunnarsson 2002).
- To test
if the changes in water chemistry could be accompanied with similar
changes in the flora. (Gunnarsson,
Rydin and Sjörs 2000, Gunnarsson, Malmer & Rydin 2002)
- To
investigate if the number of trees have increased during the last 50 years
and to relate the survival of pines to the height above the groundwater
table. (Gunnarsson & Rydin 1998, Gunnarsson, Rydin and Sjörs 2000,
Gunnarsson, Malmer & Rydin 2002)
References:
- Sjörs,
H. & Gunnarsson, U. 2002. Calcium estimations and pH in northern and
central Swedish mire waters. Journal of Ecology 90: 650-657. (PDF)
- Gunnarsson,
U., Malmer, N. & Rydin, H. 2002. Dynamics or constancy on Sphagnum dominated mire ecosystems:
– a 40 year study.
- Gunnarsson,
U., Rydin, H & Sjörs, H. 2000. Diversity and pH changes after 50 years on
the boreal mire
- Gunnarsson,
U. & Rydin, H. 1998. Demography and recruitment of Scots pine on a
raised bog in eastern
- Falkengren-Grerup,U.,
Ericson, L., Gunnarsson, U., Nordin, A., & Rydin, H. 2000. Förändras
floran av kvävenedfallet? In: Bertills, U. & Näsholm, T. (eds.)
Effekter av kvävenedfall på skogsekosystem. Naturvårdsverket, Rapport 5066: 75-100. (Finns även i engelsk
översättning Naturvårdsverkets
Rapport 5067)
- Gunnarsson,
U. 2000. Vegetation changes on Swedish mires. Effects of raised
temperature and increased nitrogen and sulphur influx. Comprehensive Summaries of
Effects of nitrogen
deposition on ombrotrophic bogs and Sphagnum growth
This project was also a part of my PhD-thesis. In this project I had the
possibility to work together with researchers from SLU, Umeå, Sweden, (Gunnar
Granberg, Mats Nilsson and Annika Nordin), which was running a huge experiment
at Degerö Stormyr. Today this experiment has been running for almost ten years
and large effects on the vegetation have been observed, this will be analysed
together with researchers from
Objectives:
1. To investigate the effects of
nitrogen, sulphur and temperature on Sphagnum dominated communities in ombrotrophic bogs and poor fens. (Gunnarsson
& Rydin 2000, Gunnarsson, Granberg & Nilsson 2004).
2. To investigate the temporal changes
in the vegetation.
3. To measure the changes in nitrogen
and phosphorus concentrations after nitrogen treatments. (Gunnarsson &
Rydin 2000).
4. To investigate the effect of
increased nitrogen influx on the amino acid concentrations. (Nordin &
Gunnarsson).
5. To look for global patterns of Sphagnum
growth in relation to climate and look for productivity differences between
species. (Gunnarsson 2005).
References:
- Gunnarsson,
U., Granberg, G. & Nilsson, M. 2004. Growth, production and interspecific
competition in Sphagnum: effects
of temperature, nitrogen and sulphur treatments on a boreal mire. New Phytologist, 163: 349-359. (PDF)
- Nordin,
A. & Gunnarsson, U. 2000. Amino acid accumulation and growth of Sphagnum under different levels of
N deposition. Écoscience 7:
474-480.
- Gunnarsson,
U & Rydin, H. 2000. Nitrogen fertilisation reduces Sphagnum production in bog
communities. New Phytologist
147: 527-537. (PDF)
- Gunnarsson,
U. 2005. Global patterns of Sphagnum
productivity. Journal of Bryology. In press.