This document discusses growing healthy native trees in the Willamette Valley region. It provides information on the environmental needs and tolerances of common native conifer and broadleaf tree species. It also covers principles of tree health, such as genetic adaptation, site requirements, competition, and stress from weather events. Throughout it uses examples of native tree species like Douglas-fir, grand fir, ponderosa pine, bigleaf maple, and Oregon white oak to illustrate these concepts.

1. Growing Healthy Trees Rick Fletcher OSU Extension Service

2. Learning Objectives for Today Become familiar with locally grown native trees in local landscapes. Understand basic environmental needs of common native tree species. Learn symptoms of problems faced by trees in local landscapes.

3. Conifers Cone bearing Generally evergreen Leaves linear in shape Long lived & slow growing Tallest of all plants Woody stem utilized worldwide

4. What kinds of native trees grow locally? Douglas-fir Grand fir False cedars- incense, western red Western hemlock Ponderosa pine

5. Douglas-fir(Pseudotsuga menziesii) Not a true fir- false hemlock Very common in home landscapes. Shallow rooted.

6. Douglas-fir Oregon’s signature tree. Wood prized worldwide for structural building products.

7. Grand fir(Abies grandis) Shade tolerant true fir on moist sites, at lower elevations in Valley. Late successional species, but not long living (about 100 years). Tolerant of moist sites, but not of drought.

8. Western Redcedar(Thuja plicata) Shade tolerant, moisture loving tree. Willamette Valley is at the south end of its natural range- more common to north. Commonly found along streams or other riparian areas.

9. Incense-cedar(Calocedrus decurrens) Sun loving, aromatic conifer. Prefers, well drained sites. Willamette Valley is at north end of its range. More prominent in Southern Oregon and California.

10. Ponderosa pine(Pinus ponderosa)

11. Introduced Species- There are Many! Nordmann Fir- A Promising Christmas Tree Species

12. Broadleaf Species Also called hardwoods. Angiosperms- true flowering plants. Most are deciduous.

13. The Riparian Hardwood Forest

14. What kinds of native broadleaf trees grow locally? Oregon white oak Bigleaf maple Oregon ash Pacific madrone

15. Key Principle: Genetic Adaptation Local adaptation is very common in conifer species. Seed zones- were 36, now only 16 in Western Oregon. Protocol for moving stock between seed zones.

16. Key Principle: Site Requirements Shade tolerance Wetness of soils/Flooding Drought/Heat Frost/Cold Animal damage

17. Conifer Species Tolerances Tolerance** to: Growth* Low Light Browsing Animals Wet Soil Drought Frost Conifers SPECIES Douglas-fir 3-4 2 2 2 3 4 Ponderosa pine 2-3 1 4 5 5 5 Grand fir 3-4 4 4 3 2 3 Noble fir 2-3 3 4 2 2 2 W Redcedar 2-3 5 1 4 1 2 W. Hemlock 2-3 5 3 3 1 1 Incense-cedar 1-2 2 3 2 5 3

18. Hardwood Species Tolerances Tolerance** to: Growth* Low Light Browsing Animals Wet Soil Drought Frost O. White Oak ½ - 1 1 3 4 5 5 SPECIES Bigleaf Maple 2-3 4 1 4 3 5 Red Alder 3-4 1 2 4 1 2 White Alder 2-3 1 2 5 1 2 Cottonwood/Poplar 6-12 1 1 5 1 5 Oregon Ash 1-3 3 2 5 2 5 Chinkapin 1-3 3 5 3 4 5 Madrone 1-2 2 5 2 5 3

19. Shade Tolerance- What to Plant?

20. Tolerance to Wetness/Flooding*

22. Pine Replaces Douglas-fir on Wet Site

23. Key Principle- Competition Young trees need relief from weeds. Most trees do poorly in shade, even ones that are listed as shade tolerant. Moisture competition is severe in late summer.

24. Spacing Guidelines for Conifers

25. Tree Stress Stresses disrupt the normal growth and maintenance abilities of the tree.

26. Shedding Normal tree process. Leaves, branches, bark after they lose utility. Sick parts of the tree, or parts attacked by insects and disease that must be shed and/or walled off.

27. Subdivision Stress

28. Causes of Tree Stress Weather events interacting with physical damage, herbicide damage, old age or other factors.

29. Tree Stress Trees have long term memories. Symptoms can show up long after damage occurs. Stress can be gateway to other problems.

30. How do conifers grow? Dormancy Shoots versus roots

31. Willamette Valley Weather DATEEVENTSTRESS OCT 1962 COLUMBUS DAY STORM HIGH WINDS DEC 1964 25 INCHES OF RAIN FLODDING DEC 1968 SNOW – 18” PRECIP BREAKAGE DEC 1972 BELOW ZERO WEATHER FREEZING AUG 1977 108° F ON AUGUST 17 HEAT NOV 1985 EARLY HARD FREEZE FREEZING FEB 1989 STRONG, COLD WINDS DESICCATION OCT 1990 NO RAIN DROUGHT OCT 1991 ALL TIME HIGHS & LOWS ACCLIMATION

32. More Weather DATEEVENTSTRESS MAY 1992 29° F ON MAY 22 FREEZING JAN 1993 HEAVY SNOW BREAKAGE FEB 1996 12” OF RAIN IN 3 DAYS FLOODING 2001 RECORD LOW RAINFALL DROUGHT OCT 2002 15° F - ALL TIME LOW FREEZING JAN 2004 SNOW, ICE AND WIND BREAKAGE JAN 2006 RAIN, RAIN, RAIN FLOODING JULY 2007 101 ° ALL TIME HIGH HEAT DAMAGE Dec 2007 42 STRAIGHT RAINY DAYS SATURATED SOIL

33. Tolerance to Heat/Drought Tolerant- ponderosa pine, oak, madrone Moderate- Douglas-fir, incense-cedar, ash, maple Intolerant- Grand fir, noble fir, western white pine, hemlock, redcedar, alder

34. Cold Damage Best- ponderosa pine, hemlock, white pine, grand fir, oak, maple OK-Douglas-fir, redcedar, incense-cedar, madrone Damaged- alder, noble fir

36. Wind

37. How trees grow and defend themselves. Protective chemicals Shedding. Compartmentalization Alex Shigo Associates

38. Can I have a drink?

39. Resin flow Host response to invasion. Black stain root disease in Doug fir.

40. Natural Predators

41. Protective chemicals Pitching out Mt. Pine beetles. An example of host response to attack.

42. Fire in the Forest- Good or Bad?

43. Fire- An Important Cleansing Tool

44. No Tree Lives Forever!

45. Decay and Trees Alex Shigo Associates

46. Compartmentalization: COLOR CODES Red-Tree response (chemical protective reactions). Green-Position of pioneer microorganisms (can be bacteria, decay fungi, or nondecay fungi). Wood in this area is usually discolored; its cell contents are altered. Brown-Position of decayed wood; cell walls are digested. Alex Shigo Associates

48. Transplant shock.