Skógræktarritið - 15.05.2001, Page 189

There was a substantial differ-
ence in seedling mortality of the
various tree species between the
two locations. Direct seeding of
lodgepole pine, using the plastic
cones, provided equally good
results on both sites or about
80% of the seed spots with at
least one living seedling at the
end of the fourth growing sea-
son. However, the same method
for Siberian larch yielded a satis-
factory 80% of the spots with at
least one living seedling at
Höfði, but only 7,5% at Mosfell.
Very high mortality was found for
the Sitka spruce seedlings, giving
very poor results.
The seedlings show very poor
growth in all the trials. Seedling
stagnation is known from other
countries at northern latitudes
and is often traced to the leach-
ing of essential nutrients in the
soil. Another reason might been
undeveloped or no-existing
mycorriza, vital for the establish-
ment and growth of the seedling.
The trials put out in autumn 1997
were aimed at finding solutions
on this problem, but at the time
of the inventories, no significant
difference was fond between the
fertilised seedlings and the oth-
ers. There were however some
indications of positive effects
from the fertilizers. This effect
might become evident after a
longer time.
After seven years of studies,
the following inferences can be
made:
• The germination rate of Sitka
spruce, Siberian larch, and
lodgepole pine seed in lceland
is comparable to that which is
common in countries at similar
latitudes.
• Seed predation, by wood mice
and/or birds can be a serious
problem.
• Direct seeding of lodgepole
pine gave by far the best
results of the species tried,
both concerning germination
and seedling establishment. In
East lceland, direct seeding of
Siberian larch can be consid-
ered a viable alternative to
planting.
• Of the seeding methods tried,
the use of a plastic cone was
the most beneficial for all the
tree species and fully compara-
ble to planting as regards
establishment success.
Furthermore, problems owing
to seed predation can be
avoided through the use of the
seeding cone.
• Stagnated growth („check") of
seedlings was common in all
the trials. There are indica-
tions, however, that this can be
alleviated through the use of
slow-release fertilisers.
Publications by the authors
in the subject
Pétursson, ].G. 1995. Direct seeding
of Sitka spruce, lodgepole pine
and Siberian larch on scarified
seed spots in southern lceland,
using various methods. Report no
40, SLU, Department of Silvi-
culture, Umeá, 44pp.
|ón Geir Pétursson. 1996. Söfnun og
sáning barrtrjáfræs. (Collecting
and sowing coniferous seeds]
Gróandinn, 2:12, 1996. (in
lcelandic)
]ón Geir Pétursson. 1996. Beinar
sáningará barrtrjáfræi. (Direct
seeding of coniferous seeds)
Laufblaðið. árg, 2 tbl. 1996. (in
lcelandic)
Jón Geir Pétursson & Aðalsteinn
Sigurgeirsson. 1997. Beinar
sáningará barrtrjáfræi (Direct
seeding of coniferous seeds].
Skógræktarritið 1997: 75-87 (in
Icelandic, English summary.
|ón Geir Pétursson og Aðalsteinn
Sigurgeirsson. 1997. Ræktun
skóga með sáningu. I: Rannsókna-
og þróunarstarf í skógrækt, Rann-
sóknastöðin á Mógilsá 30 ára.
• Using mechanical site prepara-
tion, direct seeding of lodge-
pole pine can be an economi-
cally feasible alternative to
planting, especially given the
well-known stability problems
of planted lodgepole pine.
Acknowledgements
The work was supported by the
National Science Council of
Iceland (Rannís), the Foundation
for Agricultural Production in
lceland, the lcelandic Forestry
Association and the lceland
Forest Service and we are grate-
ful for their support. We also
wish to thank the staff at Herads-
skogar, Sudurlandsskogar, lce-
land Forest Service and lcelandic
Forestry Association for their
help in the fieldwork.
Ráðstefna haldin í húsi Ferða-
félags íslands, Mörkinni 6, 24. okt.
1997.
Pétursson, |.G. & Sigurgeirsson, A.
1998. Direct seeding of Sitka
spruce, lodgepole pine and
Siberian larch on freely drained
palagonite soils in S-lceland.
Fjölrit Rannsóknastöðvar Skóg-
ræktar ríkisins, Mógilsá, 13:1998.
)ón Geir Pétursson, Aðalsteinn
Sigurgeirsson og Vignir
Sigurðsson. 1998. Söfnun og
sáning barrtrjáfræs. Frækornið,
fræðslurit Skógræktarfélags
íslands 2:1998.
]ón Geir Pétursson, Aðalsteinn
Sigurgeirsson og Vignir Sigurðs-
son. 1999. Beinar sáningar á
barrtrjáfræi. í: Ráðstefnuriti
afmælisráðstefna Líffræðifélags-
ins, haldinn á Hótel Loftleiðum.
Pétursson, J.G. & Sigurgeirsson, A.
2001. Direct seeding of intro-
duced conifer species on freely
drained palagonite soils in
Southern lceland. (sent til birt-
ingar).
SKÓGRÆKTARRITIÐ 2001 l.tbl.
187