Marie Jokerud Utrecht March 10

Transcription

Marie Jokerud Utrecht March 10
21/04/2011
BEGIN – Biodiversity of
European Grassland – the
impact of Atmospheric Nitrogen
Deposition
MARI JOKERUD
Ecological & Environmental Change Research Group
Department of Biology
University of Bergen
Stevens CJ, Dise NB, Moundford
JO, Gowing DJ (2004). Impact of
nitrogen deposition on the
specie richness of grasslands.
Science 303:1876–1879
Supervisor: VIGDIS VANDVIK
Is to determine whether N-deposition is impacting species richness and
species composition on ombrotrophic mires in Western Norway
Critical Load
Some vulnerable habitats
Europe – exceeded
Ombrotrophic mires
Norway – exceeded to some degree
Poor grasslands
Costal heatlands
Habitat
Mire
Vegetation type
mg N/m2/ yr
Effects
Ombrotrophic mire (D1
Raised and blanket bogs)
500-1000
Increase in vascular plants, change in moss
flora, nitrogen saturation in Sphagnum,
N-accumulation in peat and peat water
D2.2 Poor fens
1000-2000
Increase in Juncaceae, Cyperaceae and
vascular plants, negative effect on Sphagnum
D4.1 Rich fens
1500-3500
Increase in tall grasses, decrease in diversity
Adjusted after Achermann & Bobbink (2003) by Bruteig & Aarrestad (2004)
RESAMPLE STUDY
Resample two historical datasets on ombrotrophic mire community
composition in low-deposition (1965-68) and high-deposition (1978) areas.
Hypothesis:
Greater change in species richness and composition, high-deposition region
Increase in minerotrophic species in the high-deposition region.
GRADIENT STUDY
Sample 25 mires along a N-deposition gradient
Hypothesis:
Change in species richness and composition
Higher N-deposition → More minerotrophic species
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© Jutta Kapfer
© Jutta Kapfer
© Jutta Kapfer
© Jutta Kapfer
Hitra
1965-1968
150 plot
0.5 x 0.5 m plots
Hult-Sernander du Rietz
© Jutta Kapfer
© Jutta Kapfer
Austre Moland
1978
150 plot
0.5 x 0.5 m plots
Hult-Sernander du Rietz
Analyses
Compare dataset
Species richness
Species composition
Ellenberg values
Norwegian Institute for Air Research
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Norwegian mire reserve survey
1970 – 1980s
Western Norway: ca 500 localities
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Carex livida
Carex demissa
Viola palustris
Carex dioica
Sphagnum teres
Pedicularis palustris
Sphagnum warnstorfii
Rhynchospora fusca
Warnstorfia exannulata
Aneura pinguis
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Parnassia palustris
Bartsia alpina
Carex hostiana
Tofieldia pusilla
Carex pulicaris
Carex lepidocarpa
Campylum stellatum
Eriophorum latofolium
Juncus triglumis
Scorpidium scorpioides
Calliergon giganteum
Schoenus ferrugineus
Tomentypnum nitens
Calliergonella cuspidata
Fissidens adianthoides
Fremstad 1997
Average mm pr year
NR Locality
1 Botnemyr
2 Storemyr
3 Storslåtta
4 Bervamyr
5 N for Lundsmyr
6 Dyrlimyra
7 Ugjellsvannet
8 Hellemyra
9 Myrer V for Brattåsen
10 Vinddalen
11 Måmyra
12 Øyastøl
13 Fossastølen
14 Myr SV for Ringås
15 Skitdikane
16 Eikevolltjønnmyra
17 Dalemannsvege
18 Myr ved Kleppstølsvatn
19 Myr ved Dalesætrane
20 Myr ved Sætervatnet
21 Djupmyra
22 Myr ved Gjerstad
23 Myr V for Sørli
24 Myr V og N for Storelv
25 Havmyrene
Municipality
Froland
Åmli
Evje & Hornnes
Sirdal
Bjørnestølheia
Kvinesdal
Lista
Lista
Marnardal
Forsand
Hjelmeland
Hjelmeland
Etne
Lindås
Voss
Flora
Gaular
Naustdal
Bremanger
Bremanger
Vestnes
Surnadal
Averøy
Tustna
Hitra
Average C during growing season
Nitrogen zone Number of localities
County
Øst-Agder
Øst-Agder
Øst-Agder
Vest-Agder
Vest-Agder
Vest-Agder
Vest-Agder
Vest-Agder
Vest-Agder
Rogaland
Rogaland
Rogaland
Hordaland
Hordaland
Hordaland
Sogn & Fjordane
Sogn & Fjordane
Sogn & Fjordane
Sogn & Fjordane
Sogn & Fjordane
Møre & Romsdal
Møre & Romsdal
Møre & Romsdal
Møre & Romsdal
Sør-Trøndelag
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Norwegian Institute for Air Research
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25 Localities (5 in each nitrogen zone)
10 plot per locality
0.5 x 0.5 m plots
Estimate % cover
Total 250 plots
Analyses
Patterns along the N-deposition gradient
Species richness, species composition, nitrogen indicators
Compare to previous description and classification (1975)
– change in presence of species, increase in minerotrophic species
Critical load
Norwegian Institute for Air Research
Norwegian Institute for Air Research
[email protected]
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