Fróðskaparrit - 01.01.2006, Page 123

ÚTBREIÐSLAN AV LÍVSHÆTTUM RAUNKIÆRS
NIÐAN EFTIR FJALLASÍÐUM í FØROYUM
121
200 400 600 800
Altitude (m a.s.l.)
3. Relationship between abundance of life-forms on the five investigated mountains, in altitudinal
"'tervals. For abbreviations see Jig 2.
Phytes and chamaephytes are the most abun-
dant life-forms.
The cross-correlation of variables are
shown in Table 4. We find that botli total
Vegetation cover and LOI were negatively
correlated with altitude. All of the tempera-
ture-related parameters were also negatively
correlated with altitude, except for snow
cover. Using Table 4, and starting with alti-
tude, the following sequence of variables
would be slope, pH, cover, LOI, and the tem-
Pcrature-related variables. When fítting the
hfe-form abundances against these vari-
ahles, slope and pH did not yield signifícant
* 'ts, with one exception. Geophytes could be
represented as a quadratic function of pH
w,th a signifícance level p=0.025, but none
of the other life-forms could be fítted sig-
nificantly (p<0.05) to pH, and none could
be fítted to slope. In the further analysis, we
therefore use altitude, cover, LOI, and the
temperature-related variables.
Since the temperature variables are not
independent variables, we choose just one
of these parameters, annual mean tempera-
ture, for further analysis (Fig. 6).
The analysis of altitudinal variation (Fig.
4 a-d through 7 a-d) indicated that abun-
dance of all the life-forms, except for cha-
maephytes, varied linearly with altitude,
hemicryptophytes decreasing linearly, while
therophytes and geophytes increased with
altitude. Chamaephytes had minimum abun-
dance around 400-500 m a.s.l.