Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme IV: POPULATION DYNAMICS AND ECOLOGY Posters
1056 - Does human impact influence the species
composition of epiphytic macrolichen communities?
S. Werth 1* , H. Tømmervik 2 & A. Elvebakk 3
1
Swiss Federal Research Institute WSL, Zürcherstrasse
2
111, 8903 Birmensdorf/ZH, Switzerland. - NINA,
Department for Arctic Ecology, Polarmiljøsenteret, N-9296
Tromsø, Norway. - 3 Ecological Botany, Institute of
Biology, University of Tromsø, N-9027 Tromsø, Norway. -
E-mail: silke.werth@wsl.ch
Epiphytic macrolichen communities were sampled on
lower stems (≤ 2 m) of deciduous trees in plots of size 400
m 2 along a regional macroclimatic gradient in Troms
county, northern Norway. Canonical Correspondence
Analysis (CCA) with variation partitioning revealed the
following key factors for macrolichen communities: 1.
Macroclimate was the primary factor controlling epiphytic
macrolichen communities, with strictly macroclimatic
variation accounting for 35% of total variation explained
(TVE). 2. Two other key factors were spatial variation and
tree substrate, amounting to 25.5% and 17% of TVE,
respectively. 3. Human impact explained little (5.2%),
forest fragmentation and natural patchiness none of the
variation in species composition. The largest amount of
shared variation was pooled between the sets of spatial and
climatic variables, while the set of human impact variables
shared no variation with other sets of explanatory variables.
The reliability of species groupings was confirmed by
DCA (Detrended Correspondence Analysis), showing an
ecologically sound aggregation of the species optima. DCA
revealed two main groups of species, characterised by
differing photobionts. Key factors controlling epiphytic
macrolichen communities are discussed in relation to
lichen ecology, physiology and distribution patterns.
1057 - Modelling colonies of fungi - a generic process
based approach
N.A. White * , R.E Falconer, J.L Bown & J.W Crawford
SIMBIOS, University of Abertay, Kydd Building, Dundee,
DD1 1HG, Scotland, U.K. - E-mail:
mltnaw@abertay.ac.uk
A fundamental challenge in ecology is to derive a
mechanistic understanding of biodiversity of natural
communites. This challenge is particularly difficult in
fungal communities since these systems are indeterminate
and demonstrate a high degree of plasticity in response to
both biotic and abiotic stimuli. The approach described
considers fungal communities in terms of constituent
colonies, and begins by identifying a generic, process
based description of individual colonies. An individualbased
model of fungal colony development is presented.
The model considers the spatio-temporal growth of mycelia
over heterogeneous substrates. The model is spatially
explicit where an individual colony is represented as a
number of interconnected cells. Communication among
cells is facilitated via fundamental ecological processes.
The processes of resource uptake, diffusion of internal
nutrients within the colony and conversion of resource
taken up into biomass are represented. In addition, the
directional translocation of nutrients over large distances is
supported. Colonies are characterised in terms of
physiological traits: different colony forms have different
traits; traits parameterise the model processes. Importantly,
processes within the model are amenable to quantitative
parameterisation from experiment. This model of
development of individual colonies serves as a platform for
investigations into fungal community dynamics through the
inclusion of interspecific interaction terms.
1058 - The widespread occurrence of dark septate
endophyte fungi in grassland communities
E.M. Wilberforce 1* , G.W. Griffith 1 , L. Boddy 2 & R.
Griffiths 3
1 Institute of Biological Sciences, University of Wales
Aberystwyth, Penglais, Aberystwyth, Ceredigion SY23
3DA, Wales, U.K. - 2 School of Biosciences, Cardiff
University, PO Box 915, Cardiff CF10 3TL, Wales, U.K. -
3 National Botanic Garden of Wales, Middleton Hall,
Llanarthne, Carmarthenshire, SA32 8HG, Wales, U.K. - Email:
emw96@aber.ac.uk
This study describes unexpectedly high levels of isolation
of dark septate endophytes (also known as mycelium
radicis atrovirens [MRA]) from surface-sterilised plant
roots from both undisturbed and agricultural mesotrophic
grasslands in Wales. We have also examined spatial and
temporal variables in their distribution. Most reports of
these fungi have previously related to subalpine and boreal
habitats. Their failure to sporulate in culture has hindered
further studies. Analysis of sequence and restriction
fragment polymorphism has been used to assess diversity
of these fungi. Preliminary data suggesting a potential
ecological role in these habitats is presented, based on
microcosm studies of their interactions with other fungi
isolated from the same site.
1059 - Cyanobiont specifity of lichens on Livingston
Island, maritime Antarctica
N. Wirtz 1* , H.T. Lumbsch 1 , B. Schroeter 2 , R. Türk 3 & L.G.
Sancho 4
1
Universitaet Essen, Fachbereich 9, Universitätsstr. 5,
2
45117 Essen, Germany. - Botanisches Institut,
Universitaet Kiel, Olshausenstr. 40, 24098 Kiel, Germany.
- 3 Universitaet Salzburg, Inst. f. Pflanzenphysiologie,
Hellbrunnerstraße 34, 5020 Salzburg, Austria. -
4
University Complutense, Depto.Biologia Vegetal II,
Fac.Farmacia, 28040 Madrid, Spain. - E-mail:
nora.wirtz@uni-essen.de
Book of Abstracts 319