Fróðskaparrit - 01.01.2002, Blaðsíða 126
124
THE MYCORRRHIZAL STATUS
IN MOUNTAINOUS VEGETATION IN THE FAROE ISLANDS
900 m
800 m
700 m
600 m
500 m
400 m
300 m
200 m
100 m
0 m
■ Nitrogen (%)
• Phosphorus (mg kg-1)
■ pH
J I I l I I
0 10 20 30 40 50 60
l I I 1
0 5 10 15 20 25 30
4,5 4,9. 5,3 5,7 6,1
Fig. 1. Humus, nitrogen and phosphorus decrease with increasing altitude, while pH values increase with
increasing altitude.
Apart from an increase of the non-myc-
orrhizal plant species in the summit region
- due to the annual Koenigia islandica - the
mycorrhizal rates are strikingly stable
(Table 5).
Soil pH and nutríents (Fig. 1).
Soil samples were analysed for Mg, Ca, Na,
K, H+, P, N, pH and humus according to the
Danish Plantdirectorat’s manual (Sørensen
and Biilow-Olsen, 1994)
The soil pH in the Faroes is relatively
Altitude (m) Non-myc. % Arbuscular % Ecto % Ericoid % Orchid % Max. myc. frequency % Min. myc. frequency %
> 800 15.0 65.8 15.5 2.2 0.5 84.2 68.9
> 750 9.5 69.3 15.5 5.3 0.1 90.3 76.8
> 700 5.2 78.4 9.2 7.0 0.1 94.7 74.6
> 650 9.8 75.2 10.5 4.2 0.0 89.9 73.3
> 550 6.9 74.4 9.3 8.3 l.l 93.1 76.1
2 500 6.7 72.1 11.4 9.3 0.3 93.1 73.4
> 450 6.1 72.5 13.1 8.1 0.0 93.8 70.3
> 400 9.1 68.9 18.3 2.5 0.3 90.0 74.2
> 350 3.9 75.7 13.5 6.3 0.3 95.8 71.8
> 300 4.9 72.6 18.6 3.6 0.0 94.8 76.9
> 250 3.5 73.0 12.2 10.7 0.2 96.1 73.4
> 150 5.7 73.0 11.6 9.1 0.5 94.2 76.4
Table 5. Tlie distribution of the differenl mycorrhizal categories with altitude.The estimated maximum
mycorrhizal frequency is based upon that all plants, that liave the ability to form mycorrhiza, actually do so.
Minimum mycorrhizal frequency is based upon, that the plant species tliat rarely or occasionally form
arbuscular mycorrhiza, in this case do not.