Experiences and research on site preparation in Norway. Aksel Granhus Kjersti Holt Hanssen

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2 Aksel Granhus Kjersti Holt Hanssen

3 OBJECTIVES To provide a brief overview about site preparation in Norway Present use Current research and development Experiences with mechanized planting RegFor project ( ): Test of miniseedlings Scarification and planting in partially cut stands Development of equipment for cost-effective low-intensive scarification 3

4 Site preparation in Norway (ha per year) Seed years for spruce Since 1990: 12 20% of harvested areas treated Removal of subsidices Area in ha Year NORWEGIAN UNIVERSITY OF LIFE SCIENCES 4

5 WHAT ABOUT PLANTING AFTER SITE PREPARATION? Published data on the percentage of planted stands established after site preparation is lacking, but a rough estimate may be obtained by making some assumptions: 2002: A total of mill. seedlings were planted 8300 ha was scarified Assume 20 % of scarified area is planted: 8300 ha x 0.2 = 1660 ha planted Then: 1660 ha x 2000 plants/ha = 3.32 mill plants 12% of planted stands Sweden : 90 % of planted stands scarified 5

6 WHY LESS SCARIFICATION IN NORWAY - SOME LIKELY EXPLANATIONS Small forest properties Avareage farm forest is small (about 50 ha) Most regeneration areas are small (<1 ha) Lack of tradition and fairly good results with planting without site prep Terrain conditions Large regional variations (!) Hedmark county: Accounts for about 40% of the treated area Gentle terrain Many large forest properties 6

7 7 Testing mechanized planting in Norway Shortage of forestry workers for planting EcoPlanter 2000 tested from 1998 to 2001 in more than 80 plots Crane-mounted on single-grip harvesters Two individually operated rotors Magazine takes 240 plants M95 spruce seedlings used in most trials Photo: Finn Sønsteby

8 % survival mechanized planting : Year 1 Year 2 Year 3 Year 4 Spring Spring Fall Spring Fall Spring Pine weevil damage NORWEGIAN UNIVERSITY OF LIFE SCIENCES 8

9 Biological results mechanized planting no significant differences in survival or height growth between machine and manual planting after 2-4 years biological results (survival and vitality) depended on slope and amount of slash and stones 9 Photo: Finn Sønsteby

10 Economical results mechanized planting Performance was generally too low to justify the costs Critical factors: Reloading Spot preparation Length of planting season Logistics, planning Education 10 Conclusion: Machine planting is an alternative when manual planters are in want and should be concentrated to favourable sites Photo: Finn Sønsteby

11 Experiment with mini-seedlings (1) To gain experience with mini-seedlings, a field experiment has been established on a fertile site in 2004, with comparison of miniplants and conventional stock types 1. mini seedling (made in Norway) 2. M95 1 year 3. M95 2 year 4. M60 2 year 11 Photo: I. S. Fløistad

12 Experiment with mini-seedlings (2) - Scarification may be a prerequisite for planting mini-seedlings - The experiment combine seedling types (4) and site preparation method (patch + control) - Replicate blocks along a gradient of vegetation competition June Photo: I. S. Fløistad

13 Preliminary results: Low mortality first year One (1) miniseedling killed by pine weevil Frost heaving: affected miniseedlings only Scarified: 10% frost heaving first winter Unscarified: 3% frost heaving 13 May 2005 Photo: I.S. Fløistad

14 Good growth! But the weeds grow well too July 2005 Photo: I.S. Fløistad NORWEGIAN UNIVERSITY OF LIFE SCIENCES 14

15 ARTIFICIAL REGENERATION IN NEW STAND TYPES Is site preparation technically and biologically feasible within alternative silvicultural systems? Injuries to residual trees? Stand access? Survival and growth of seedlings? Uniform partial cutting Patch-cutting 35% 45% 55% 100%, 25 x 25 m UP I UP I UP I UP I UP I UP I UU PP I I U = Untreated P = Patch scar. I = Inverting Clear-cutting 100%, 50x50 m P P I I = Planted = Seeded/natural regen. 15 Untreated Patch scar. Inverting

16 SITE PREPARATION: Bucket with extension blade Photo: D. Fjeld Excavators (5-8 t) with boom reach 6-7 m Operated from striproads (spacing 24 m) + drove in gaps where possible NORWEGIAN UNIVERSITY OF LIFE SCIENCES 16

17 TECHNICAL FEASIBILITY OF SITE PREPARATION IN PARTALLY CUT STANDS Untreated Patch scar. Inverting Relative density Relative density of planting spots (Patch cut = 100) 0 35 % 45 % 55 % Patch cut Photo: D. Fjeld NORWEGIAN UNIVERSITY OF LIFE SCIENCES 17

18 ROOT INJURIES Stand averages Tretment-free zone 1.5 m 7.6% 2.0 m 2.0% Per cent of trees injured Injury risk for individual trees with scarification closer than 2.0 m 18 DBH DBH DBH <10 cm cm >20 cm Mean 7% 10% 78% 23% Photo: D. Fjeld

19 Operational efficiency of planting in partially cut stands Time studies were performed during the planting work in patch cuts and partially cut plots Time consumption for clearing + planting cmin / plant Untreated Patch scar. Inverting

20 MAIN TIME PER PLANT: Including preparation of planting spot, planting and walking: cmin plant Untreated Patch scar. Inverting Partial harvest plots Patch clear-cut plots 20 plants ha-1

21 BIOLOGICAL RESULTS: MORTALITY Mortality - 10 years after planting % 45 % 55 % Patch-cut 35 % 45 % 55 % Patch-cut Clear-cut 35 % 45 % 55 % Patch-cut % Clear-cut Unscarified Patch scar. Inverting NORWEGIAN UNIVERSITY OF LIFE SCIENCES 21

22 BIOLOGICAL RESULTS: GROWTH Diameter at stem base - 10 years after planting % 45 % 55 % Patch-cut 35 % 45 % 55 % Patch-cut Clear-cut 35 % 45 % 55 % Patch-cut mm Clear-cut Unscarified Patch scar. Inverting NORWEGIAN UNIVERSITY OF LIFE SCIENCES 22

23 DEVELOPMENT OF A NEW TRACTOR-BASED AGGREGATE (1) Traditional equipment have some drawbacks Expensive Environmental and aesthetic impacts May be harmful to ancient remains Development of aggregate in the RegFor project Should be suitable for small properties at low cost Moderate ground disturbance 23

24 DEVELOPMENT OF A NEW TRACTOR-BASED AGGREGATE (2) Mine-cleaning principle (chains on rotating drum) Photo: M. Nitteberg NORWEGIAN UNIVERSITY OF LIFE SCIENCES 24

25 DEVELOPMENT OF A NEW TRACTOR-BASED AGGREGATE (3) Ground disturbance can be regulated by varying the speed of the rotating drum Makes strips or patches size can be adjusted 25 Photo: P. H. Nygaard

26 The sice of each spot is controlled by lifting the aggregate hydraulically Photo: P. H. Nygaard NORWEGIAN UNIVERSITY OF LIFE SCIENCES 26

27 Experimental testing: Comparison with conventional equipment in seed seed-tree stands of pine (Trysil, Hedmark county) Field trial started 2004, artificial seeding New scarifier Conventional 27 Photo: P. H. Nygaard

28 DOES IT WORK? Results from the field trials are not ready yet, but the new scarifier seems to produce satisfacory results (personal communication, Per Holm Nygaard) Regrowth of vegetation in the scarified spots is likely to produce a shorter effective timespan for successful natural regeneration than with conventional methods Still at the prototype level, continous improvement as technical experience is gained Plans for development of a similar crane-based aggregate Scarification in shelterwoods 28

29 ACKNOWLEDGEMENTS: Inger Sundheim Fløistad (Bioforsk Plantehelse) Morten Nitteberg (Skogforsk) Per Holm Nygaard (Skogforsk) Kjetil Kohmann (Skogforsk) Finn Sønsteby (Mjøsen Forest Owner Association) Dag Fjeld (SLU, Umeå) 29