Species trials in the interior of northern Sweden
- Evaluation after 20 years
Johan Westin
8 species tested…
Abies lasiocarpa Abies sibiricaPinus sylvestris Picea glauca
Picea marianaPicea abies Pinus contortaLarix sibirica(L.sukaczewi)
Conclusions Good growth performance of
larch – the best? Survival can be improved
- better nursery management- other seed sources?
Stem straightness could become a future problem
Suitable soil types appear to be ”spruce” types
Background 70’s - a predicted future shortage of wood Need to utilize forests in the interior of
northern Sweden How to re-forestate?
- cold climate- low production
Sponsors Sveaskog Holmen SCA Norrbottens och Västerbottens
allmänningsskogar (=community forests) Swedish Forest Agency
Difficult to regenerate
Spring & autumn frosts Frost damages during the
growing period Variable climate -
Frequent occasions with ”destructive” weather
Flat sites, frost prone sites, frost ”pockets”
Vinter/Early spring damages
Short growing season
Long lasting snow coverage - 7-8 months
October 15 May 15
How to improve regeneration?
Fresch clear-cuts Site preparation Well adapted
provenances - growth rhythm
Planting material - seedling size, - planting time - seedlings in ”rest”
Field trials 21 survival trials 5 production
trials
Species & provenances; # per site, # total used
Picea abies (L.) Karst. 1-3 prov./site, 12 used Pinus sylvestris L. 2-3 6 Pinus contorta ssp. Latifolia 2 3 Abies sibirica Led. 1-2 2 Picea glauca (Moench) Voss 1-3 9 Picea mariana (Mill.) 2-4 8 Larix sibirica 2-4 7
(L.sukaczewi) (4 SO, 3 prov.) Abies lasiocarpa (Hook.) Nutt. 1-3 7
Field trial design (example)
Traits assessed on each tree Vitality 0-3 (Survival 1/0) Tree height, dm Stem straightness class, 0-2, Stem stability class, 0-3 Wood quality class, 0-4
Predicted future wood quality based on defects on the main stem. (stem stability considered separately).
Transfer effects Inoptimal seed sources
- three species Limitations on lat.transfer
but… ≥1 provenance/species & trial
Pinus sylvestris>1.1° southward transfer
Pinus contorta <5.1° northward transfer
Picea mariana <1.3° southward transfer Northward►
◄Southward
Good growth performance of Larch
Relatively low survival of Larch
Larch does not have straight stems
Larch stems have high stability
Intermediate stem wood quality
Site type effects Various variables tested
Spruce type?, Soil productivity, South facing?, Soiltype class,Texture class, Moisture class, Soilwater flow?, Slope-degrees?, Wind exposed?, Frostprone?
Larch survival+ spruce types (not pine),soil water flow, no frost sites - high productive soils
Larch height growth+ fine soils (silt, loam), wind exposure- high productive soils
Large variation in survival
Nursery related problems with Larch
Autumn frost damages in the nursery→Short day (SD) treatment
Grey mold (Botrytis cinerea)→plant density & humidity, removal of dead needles
Planting of seedlings in rest → cool room storage →freezer storage
Conclusions Good growth performance of
larch – the best? Survival can be improved
- better nursery management- other seed sources?
Stem straightness could become a future problem
Suitable soil types appear to be ”spruce” types
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