1. Western Larch The Secrets of Success Inland Empire Paper Company Dennis Parent Forest Operations Manager

2. Summary • Review silvics of larch • Review larch silvicultural treatments • My “Secrets” of growing larch

3. Silvics of Western Larch • Western Larch: a “deciduous conifer in an evergreen world”

4. Silvics of Western Larch • Silvics of North America Available on the Internet: “Silvics of North American Trees”

5. Silvics of Western Larch Silvics of Western Larch Silvics of Western Larch • 10 species total • Three species in U.S. • Western larch • (Larix occidentalis) • Subalpine larch • (Larix lyallii) • Eastern larch • (Larix laricina) • The tallest and the largest of the world’s larches • A seral species

6. Comparative Shade Tolerance of Northwestern Conifers

7. Silvics of Western Larch • Growth • Fastest growing species in Inland Northwest • Diameter growth very sensitive to stand density • Develops into even-aged stands • Height growth both predetermined and free

8. Silvics of Western Larch • Fire resistant • Wind firm • Tolerates root rot • Tolerates soils with poor nutrition • Wood is hard, strong, and dense.

9. Silvics of Western Larch Insects, Diseases, Etc.

10. Insects & Diseases Mistletoe

11. Insects & Diseases Larch casebearer

12. Insects & Diseases Needle cast

13. Insects & Diseases Bears

14. Insects & Diseases Spruce budworm Heart rot Beetles, a recent phenomenon

15. Silvics of Western Larch • Cones & seed • Flowers very early • One of the best seed producers in northwest Montana • One of the worst seed producers in northern Idaho

16. Silvics of Western Larch • Genetics • Seed transfer is relatively broad • Adaptability intermediate between white pine and ponderosa pine

17. Silvics of Western Larch • Larch nutrition • Little information • High nitrogen use efficiency • Effectively translocates nitrogen

18. Silvics of Western Larch • Water use • Less efficient than other conifers • Avoids winter desiccation

19. Silvics of Western Larch • Carbon fixation • Efficient crown architecture • Small, short branches • Photosynthetic rate similar on a leaf area basis • Photosynthetic rate greater on leaf weight basis • Result: Larch fixes the same amount of carbon as other conifers

20. Silvics of Western Larch • Watershed values • Little snow interception • Higher water yield • Higher melt rates from ROS

21. Silvics of Western Larch • Aesthetics • Color diversity • Beautiful landscapes

22. Special Problems of Western Larch • Needs adequate site preparation • Losses crown quickly if overtopped • Susceptible to herbicides • Poor seed yields • Foresters and loggers!

23. Special Strengths of Western Larch • Fire resistant • Favored by wildfire

24. Fire Resistance of Inland Species

25. Special Strengths of Western Larch • Fire resistant • Favored by wildfire • Resistant to root rot

26. Relative Susceptibility of Inland Northwest Conifers to Root Disease

27. Special Strengths of Western Larch • Fire resistant • Favored by wildfire • Resistant to root rot • Genetic adaptability

28. Potential for Genetic Improvement of Inland Species • Genetic Characteristics of Western Larch • Highest potential gain in volume through genetic improvement: 20-40 percent • Higher value species • Fastest growth • Poor natural seed yields • Easy to graft • Seed transfer is relatively broad • Responds to intensive management

29. Special Strengths of Western Larch • Fire resistant • Favored by wildfire • Resistant to root rot • Genetic adaptability • Strong wood

30. Specific Gravity of Inland Northwest Woods

31. Special Strengths of Western Larch • Fire resistant • Favored by wildfire • Resistant to root rot • Genetic adaptability • Strong wood • Fast juvenile growth • Wind firm • Resists snow and ice loading • Good long-lived snag species • Arabinogalactan

32. Silvicultural Treatments • Natural Regeneration • Good site preparation

33. Silvicultural Treatments • Natural Regeneration • Predict cone crop

34. Silvicultural Treatments • Natural Regeneration • Enhance seed production by girdling

35. Silvicultural Treatments • Artificial Regeneration • Good site preparation = good survival

36. Silvicultural Treatments • Artificial Regeneration • Plant seedlings as large as you can afford.

37. Silvicultural Treatments • Artificial Regeneration • Spring vs. fall plant

38. Silvicultural Treatments • Vegetation control • Do it before planting!

39. For this Instead of this

40. Silvicultural Treatments • Vegetation control • Oust herbicide may work

41. Silvicultural Treatments • Density control • Principles of thinning • Concentrate growth on fewer stems • Decrease total stand growth • Increase merchantable stand yield • Total stand cubic foot yields are not increased.

42. Silvicultural Treatments • Precommercial thinning • Watch out for: • High costs = poor investment

43. Silvicultural Treatments • Density control

44. Silvicultural Treatments • Density control • Precommercial thin but watch for: • High costs = poor investment • Trees getting too big • Thinning too late => crown loss

45. Silvicultural Treatments • Density control • PCT conclusions • Thin early • Thin from below • Select spacing carefully

46. Silvicultural Treatments • Density control • Commercial thinning – some problems • Opens up stand to brush competition • Stand growth loss • Larger trees are not worth more money today.

47. Silvicultural Treatments • Density control • Other objectives for commercial thinning • Growing large diameter trees • Structural and vegetation diversity • Aesthetics • Earlier income generation • Perpetuate culmination of MAI

48. Silvicultural Treatments • Density control • Affect of thinning on wood strength • Not ring width, but summerwood/springwood ratio • Thinning can increase summerwood/springwood ratio • Thinning does not decrease wood strength • Young, managed larch has similar wood density levels as those found in natural stands. • This is not true for other western conifers!

49. Silvicultural Treatments • Pruning • Not necessary and probably a waste of money • Natural self-pruning • Epicormic branching • Dimension lumber; 1-2” knots acceptable

50. Silvicultural Treatments • Nutrition & fertilization • Little information available • Castille, 1983: Two-year growth • Filip and Oester, 2002: Ten-year growth • Graham, 1986: Effect on cone and seed production • IFTNC: Field trials on Boise Cascade lands • No firm conclusions for larch