Ársrit Skógræktarfélags Íslands - 15.12.1990, Blaðsíða 20

Hákon Bjarnason og Einar G. Sæmundsen,
1949. Fræsöfnun, sáning og gróðursetning.
Ársrit Skógrœktarfélags íslands, bls. 53-79.
Kofoed-Hansen, 1934. Um stofnun skóglendis
og trjágarða. Ársrit Skógrœktarfélags íslands
1933-1934, bls. 10-19.
Sigurður H. Magnússon, 1989. Birki til land-
græðslu. Ráðunautafundur Búnaðarfélags
Islands og Rannsóknastofnunar landbúnaðar-
ins, bls. 99-108.
Sigurður H. Magnússon og Borgþór Magnússon,
1989. Pættir um vistfræði birkis og not þess í
landgræðslu. Grœðum ísland. Landgrœðslan
1988. Árbók II, bls. 97-108.
SUMMARY
Seeding of birch for land reclamation and wood-
land establishment
Birch (Betula pubescens) is the only native tree
in Iceland which forms natural forests. The settle-
ment of the country was followed by vast des-
truction of the birch forests and shrublands,
which have not regenerated. Conservation of the
existing birch forests, promoting their regenera-
tion and reintroduction of birch into cleared
areas is an important task of the present revegeta-
tion program in Iceland. Seedingof birch for land
reclamation and woodland establishment may be
feasible part of this program.
During the early part of this century, birch
seeding trials were carried out by the State Fores-
try Service, later resulting in the establishment of
small forest stands at a few farms in Iceland. The
birch was mainly seeded in grasslands following
removal of the sward and exposure of soil.
A research project on birch regeneration from
seeds was initiated at the Agricultural Research
Institute in 1987. In the project, the first stages of
birch colonization under natural and experiment-
al conditions have been investigated. The study
focuses mainly on the effect of sward and soil
conditions on seed germination and seedling sur-
vivorship, in five different vegetation types.
Some of the preliminary results are as follows:
- Sward conditions had marked effects on
seedling emergence. At sites with complete vegeta-
tion cover, emergence did not occur in a sward
thicker than 1 cm, except in a mire where the
seeds emerged in the moist moss layer. Seedling
emergence in the vegetation types studied, was
considerable after removal of the sward.
- Seeding in the autumn resulted in greater
total emergence during the following summer
and generally larger seedings at the end of the
first growing season, in comparison to spring
seeding.
- Seedling survival over winter was directly
related to seedling size in the first autumn.
- Seedling mortality was considerable at all
sites during the first winter, and was mainly
caused by frost heaving activity at sites with min-
eral soils but high water table at a mire site.
In the final part, a discussion and a general
advise on birch seeding under field conditions is
given in the paper.
18
ÁRSRIT SKÓGRÆKTARFÉLAGS ÍSLANDS 1990