Fróðskaparrit - 01.01.2002, Síða 123

121
The Mycorrhizal Status in Mountainous
Vegetation in the Faroe Islands
Sopparót í Føroyskum Fjallavøkstri
Erla Olsen and Anna Maria Fosaa
Føroya Náttúrugripasavn, Faroese Museum of Natural History, Debesartrøð, FO-IOO Tórshavn, Faroe Islands
Emails: erla@ngs.fo - anmarfos@ngs.fo
Úrtak
Ein plantufrøðilig kanning á fimm Ijallasíðum í Føroy-
um, har m.a. hugt varð eftir vøkstrinum í ymsum hædd-
um, er nýtt sum grundarlag undireini meting av, hvussu
nær tengdar planturnar eru at teim gagnligu moldsopp-
unum (sopparót), sum m.a. kunnu veita teimum fleiri
føðsluevni og verja tær móti sjúkuelvandi moldsoppum.
Afturfyri fáa hesir gagnligu sopparnir sukurevni frá
plantunum. Tað vísir seg, at hóast nógvar plantur finn-
ast, sum ikki krevja sopparót, so er títtleikin hjá teimum
upp á seg væl minni enti hjá teimum plantum, sum helst
skulu hava sopparót. Fleiri sløg av soppum eru, sum
kunnu gera sopparót, men tað vísir seg sum um summir
teirra ikki trívast saman, t.d. er tað slagið av sopparót,
sum ger hunđalond, ikki vanligt á heiðalendi. Tað mest
vattliga slagið, arbuskul sopparót, tykist at vera saman
við øðrum sløgum av sopparót uttan stórvegis trupul-
leikar. Nøkur plantusløg eru, sum kunnu hava fleiri sløg
av sopparót, m.a. sera vanligar plantur so sum reyðving-
ul.
Abstract
A vegetation survey on five mountainslopes in the
Faroes, recording the vegetation at different altitudes, is
the basis for an estimate of how dependent the plants are
on the beneficial soil fungi (mycorrhiza), which are able
to provide the plants with nutrients and protect them
against pathogenic soil fungi. In return these beneficial
soil fungi require carbohydrates from the plants. Al-
though several plants are not able to or less dependent
upon mycorrhiza, they seem lo be less frequent than the
plant species, which normally are mycorrhizal. There
are different types of mycorrhiza, and some of them do
not coexist. For example mushroom-forming mycor-
rhiza is rare on heathland. The most common type, ar-
buscular mycorrhiza, seems to coexist witli other types
of mycorrhiza. The data presented in this paper indicate
that dual infection, where a planl is colonised by differ-
ent types of mycorrhiza could be of importance in the
Faroese mountainous vegetation.
Introduction
An ancient relationship exists between
plant roots and some soil l'ungi. It is be-
lieved to have evolved together with the
land plants approx. 400 mill. years ago
(Smith and Read, 1997). This symbiosis is
called mycorrhiza, which means fungus
root, and is beneficial for both species. The
plant achieves nutrients from the fungus,
which is much better adapted to explore the
soil due to its fine hyphae. ln return the fun-
gus gets carbohydrates.
There exist several types ol' mycorrhizas,
involving different fungi. Some are living
in symbiosis mainly with trees, and are vis-
ible because of the big mushrooms they
create for spore dispersal.
Mycorrhiza is known to have several
benefits for the plant. Apart from providing
nutrients, it is also thought to protect the
root against drought and pathogens (News-
ham et al., 1995).
Fróðskaparrit 50. bók 2002: 121-130