Skógræktarritið - 15.05.2001, Blaðsíða 186

Table I. Some meteorologicai observations from the nearest local weather stations
to the experimental sites, Hæli (Mosfell) and Hallormsstaður (Höfði)
Cliinatic data* Hæll (Mosfell) Hallormsstaður (Höfði)
Mean precipitation, year (mm) 1148 757
Mean temperature, summer Jun. -Sept. (°C) 9,1 8,9
Mean max. temperature Jun. -Sept. (°C) 12,7 12,7
Mean number of days exc. +15°C 29 43
Mean number of days exc. +6°C 131 121
*Received from the lcelandic Meteorological Institute.
Table 2. Description of the regeneration methods used in the trials on the scari-
fied seed spots in Mosfell 1993 and Höfði 1996
Method Description*
Control Sown directly
Covered with gravel Seeds covered with approx. 27 cm^ of gravel, diameter from 0,3 - 0,8 cm
Covered with pumice Seeds covered witli approx. 27 cm^ of pumice having diameter from 0,1-1 cm
Plastic cone "Cercon" cone, 80 min high, bottom diam. 59 mm and top diam. 17 mm
Pyramidal indentation Tool consisting of 10 pyramids, turned upside down, with base 4x4 cm and height 2cm, put together in two rows of 5 in.
Spring planting Planting containerised forest tree seedlings, using planting dibble.
Alttumn nlantim’ Planting conlainerised foresl Iree seedlings. using nlanting dihhle.
Autumn planting Planting containerised forest tree seedlings, using planting dibble.
Table 3. Description of the seeding methods used in the trials on TTS disc-scari-
fied ground in Mosfell and Höfði 1997
Method Description
Control Sown directly
plastic cone "Cercon" cone 80 mm high, bottom diam. 59 mm and top diam. 17 mm
Bio-pack* Fertiliser-kit, 10 gr. Biodegradable bag including coated, slow release fertiliser (N16, P6, K8, S2.7, Fe0.7, Mn 0.15, Zn 0.54)
Cluster-pack* Direct seeding-kit. Biodegradable bag including seeds, Sphagnum moss, water storinu oolvmers. bio-stimulants and mvcorrhizae inoculum.
* Products of Reforestation Technologies International Inc.
Both locations are within the
areas considered best suited for
afforestation in lceland.
At Mosfell, the terrain is flat
and exposed to winds from all
directions. The soils on the
experimental site are freely
drained palagonite loesses. The
vegetation is a hummock-heath,
dominated by Rachomitrium spp.,
Empetrum nigrum and other dwarf
shrubs.
At Höfði, the trials were placed
out on two different sites, a
Kobresia-Empetrum-heath and
moorland dominated by Betula
Nana. The soils here are similar
to those at Mosfell, with the
Kobresia-heath somewhat dryer
than the Betula nana moor.
Three different trials
On each site, various forest
regeneration methods have been
compared. In all trials, the direc-
tions concerning seed stratifica-
tion, exact counting and sowing
performance given in |ón Geir
Pétursson (1995) have been fol-
lowed. The most commonly used
forest tree seedlings and planti-
ng method were used for com-
parison.
Trials from 1993 at Mosfell
These trials were put out using
sitka spruce, lodegpole pine and
Siberian larch, comparing vari-
ous regeneration methods. The
main research questions in these
trials were:
- Does imported coniferous seed
germinate in the cold Icelandic
climate?
- Which species/methods are the
most useful?
- Do the seedlings establish and
grow properly?
- Are some of the direct seeding
methods comparable to plant-
ing forest seedlings?
Descriptions of these trials and
detailed results have been pre-
sented by the authors on various
occasions (|ón Geir Pétursson,
1995; Jón Geir Pétursson and
Aðalsteinn Sigurgeirsson, 1997).
Trials from 1996 at Höfði
Here, similar trials as in Mosfell
1993 were put out in a location in
E- lceland, although Sitka spruce
was not used. The aim of the
1996 trials, additional to the
ones in the 1993 trials, was main-
ly to compare different micro-
sites and locations in Iceland.
The trials were placed out in
lune, following the same procee-
dures as in the 1993 trials.
Trials from 1997 at Höfði and
Mosfell
These trials were placed out on
both sites, using lodgepole pine
and Siberian larch in Höfði and
lodgepole pine, Sitka spruce,
Siberian larch and native downy
birch {Betula pubescens) in Mosfell.
The main research questions
here were:
- Is it possible to improve the
results of direct seeding by
using „seeding kits", including
fertilisers (Table 3)?
- Can satisfactory results be ob-
tained from direct seeding on
sites prepared by the most
commonly used mechinised
scarification equipment?
The trials have been measured
regularly. Statistical analyses
(ANOVA) were performed using
SPSS. All data were arcsine trans-
formed to meet assumptions of
normality and variance homo-
geneity.
184
SKÓGRÆKTARRITIÐ 2001 l.tbl.