Fróðskaparrit - 01.01.2006, Page 118

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DISTRIBUTION OF RAUNKIÆR’S LIFE-FORMS
ALONG ALTITUDINAL GRADIENTS IN THE FAROE ISLANDS
Major life-forms
Therophytes
Geophytes
Hemicryptophytes
Chamaephytes
Surviving buds
seed, annual plants
buried in the soil
soil surface
< 0.25 m above the
soil surface
Main distribution area
In relation to position of sur-
viving buds and generalize
distribution
Open areas, deserts and steppes,
decreases toward the poles
Dry climate, steppes.
Temperate and arctic climate
Temperate and arctic climate
Table 1. Definitions oflife-forms according to Raunkiær (1934), the surviwing buds are in black on the
drawings.
cryptophytes changes to favour increasing
numbers of chamaephytes in the arctic zone
(Raunkiær, 1934). Vegetational studies of
the Faroe Islands have indicated a shift from
temperate vegetation in the lowlands to arc-
tic vegetation in the highlands (Bocher,
1937; Hansen, 1972; Fosaa, 2004). Studies
have also shown a change in life-form abun-
dances along Faroese mountain slopes
(Raunkiær, 1936; Hansen, 1972). In this
study, we use quantitative methods to ver-
ify these results and to determine the alti-
tude shift in vegetation zones. We also test
the importance of climatic and non-climatic
parameters on the abundance variation of
life-forms.
Previous studies have given a general
overview of changes in life-forms with al-
titude. These studies have, however, largely
been qualitative and a number of questions
remain unanswered: How do life-form abun-
dances change with altitude in a quantitative
manner? Is the shift from tenrperate to arc-
tic vegetation abrupt or is there a broad tran-