Fróðskaparrit - 01.01.2002, Side 130

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THE MYCORRRHIZAL STATUS
IN MOUNTAINOUS VEGETATION IN THE FAROE ISLANDS
Plant Mycorrhizal status Plant Mycorrhizal status cor- lation
Thymus praecox Normally AM Viola riviniana Normally AM 0.58
Calluna vulgaris Ericoid Potentilla erecta Normally AM 0.55
Empetrum nigrum Ericoid Vaccinium myrtillus Ericoid 0.54
Potentilla erecta Normally AM Nardus stricta Normally AM 0.53
Galium saxatile Normally AM Agrostis capillaris Normally AM 0.53
Empetrum nigrurn Ericoid Calluna vulgaris Ericoid 0.51
Viola palustris Normally AM Agrostis capillaris Normally AM 0.50
Sibbaldia procumbens Non-mycorrhizal Alchemilla alpina Occasionally AM 0.49
Nartliecium ossifragum AM Nardus stricta Normally AM 0.49
Empetrum nigrum Ericoid Nardus stricta Normaly AM 0.46
Narthecium ossifragum AM Calluna vulgaris Ericoid 0.39
Silene acaulis Occasionally AM Polygonum viviparum Ecto 0.39
Deschampsia flexuosa Normally AM Salix herbacea Eclo 0.38
Juncus squarrosus Occasionally AM Nardus stricta Normally AM 0.37
Juncus squarrosus Occasionally AM Calluna vulgaris Ericoid 0.32
Festuca vivipara Normally AM Polygonum viviparum Ecto 0.30
Polygonum viviparum Ecto Salix herbacea Ecto 0.27
Agrostis canina Normally AM Salis herbacea Ecto 0.24
Agrostis canina Normally AM Polygonum viviparum Ecto 0.21
Festuca rubra Normally AM Polygonum viviparum Ecto 0.21
Table 8. The most significant results of correlations performed directly on plants with afrequency of al least
100. All the results are significant. AM= Arbuscular Mycorrliizal. Ericoidplant species have a strong
correlation with some species, for example Potentilla erecta, Nardus stricta, Narthecium ossifragum and Juncus
squarrosus, while ectomycorrhizal plant species luive strong correlations to other plant species, such as Silene
acaulis, Deschampsia flexuosa, Festuca vivipara and Festuca rubra.
Salix herbacea (r = -0.1, p = 0.03) while
Thymus praecox seems not to be dependent
upon Calluna vulgaris (r = 0.04, p = 0.39).
In a study from 1981 Read and Hasel-
wandter found that Festuca rubra was ecto-
mycorrhizal as well as arbuscular mycor-
rhizal. This single record from 1981 is
mentioned in the mycorrhiza check-list
from Harley and Harley (1987), but is not
supported from any additional record in the
additional checklist from 1990 (Harley and
Harley, 1990).
Distribution
Some of the different types of mycorrhiza
co-occur in the same ecosystem, while oth-
er types seems to avoid each other.
One of the general findings is that ecto-
mycorrhizal plants does not coexist with
ericoid or orchid mycorrhizal plants.
Ectomycorrhizal plant species were nev-
er found in the same plots as orchids. This
is in contrast to findings suggesting a
mycelial link between orchids and ectomy-
corrhizal plant species, as proposed by
Smith and Read (1997). Instead orchids
and ericoid species do coexist (Table 7).
This could indicate that it is the fungus’
saprophytic abilities that are required.