Consistency of Bud Bursting in Douglas-Fir William G

Eepr-inted from JOull.NA:t. OF FORESTRY, "\7oL. 55, No. 3, March 1957 Purchased by the Forest Service for Official Use

Consistency of Bud Bursting in Douglas-Fir William G. Morris, R.. R.. Silen and H. lrgens-Moller1

POSSIBILITY OF STRONG genetic con their progeny can be planted to ad Study Areas and Early trol over time of bud bursting in vantage in areas where late spring Observations Douglas-fir has been suggested by frosts are likely to occur. Observa In 1915, plantations were estab recorded observations extending tions in the early 1930's showed lished at Wind River, Washington, over a period of 22 years. If more that tardiness in beginning annual at an elevation of 1,100 feet, and detailed studies now under way growth apparently does not lessen near Mt. Hood, Oregon, at eleva bear out these observations, the a tree's chance of making the same tions of 2,800 and 4,600 feet (Fig. knowledge will have important ap height growth as one having an 1). Seed for these plantations came plication in selecting seed for early start. from 120 parent trees at 13 differ- planting forest lands in the Doug las-fir region of the Pacific North west. Records taken since 1933 on ; three plantations in Oregon and Washington indicate that relative order of vegetative bud bursting is constant between progenies from widely separated seed sources growing in the same plantation. This relationship apparently holds true regardless of altitude of plan tation, date when growing season • began, or stand age. Repeated ob servations of individual wild trees have further shown that naturally seeded trees growing side by side burst their buds at different dates but in about the same order year after year. " Growth of a Douglas-fir tree both in height and in branch elongation is resumed each spring from the dormant buds formed the previous growing season. If freezing tem peratures occur when the buds are in the tender, freshly opened stage, they are usually damaged and no ' growth occurs that year. Late bud bursting protects a tree against this damage. Time of bud bursting in relation to spring frosts is therefore impor

., nr tant to tree growth. If late-bud '" "' 121• bursting trees transmit this charac LEGEND teristic to succeediilg genertions, Principal range of Pacific coast form of Douglas fir in Oregon and Washington 1Morris and Silen are research forest 0 Plantations ers, Pacific Northwest Forest and Range Expt. Sta., Forest Service, U. S. Dept. x Seed sources Agrie., Portland, Ore. Irgens-Moller is a graduate student, Oregon State College, FIG. 1.-Locations and elevations 'bf seed sources and test plantations on which Corvallis, Ore. Douglas-:fir bud bursting was observed. 208 MA.Bea 1957 209

ent localities west of the Cascade drainage resulted in warm spring again used at Wind River for sam Range, from Darrington in north days and cold sprnig nights. (5) ples of three to six trees from each ern Washington to Benton near Time of bud bursting (early or seed source. Due to the lateness of Corvallis, Oregon, 250 miles south. late) had no apparent relation to sampling on the lower Mt. Hood Seed source elevations ranged from annual height growth. plantation, however, terminal shoot 100 to 3,850 feet. Plantation lay elongation in inches was estimated out was identical in that progenies Seed Source Ranking for ten branches in the upper from each parent tree were planted crown. Ten trees from each seed Progenies from the 13 seed in the same relative position at the source were used as a sample. On sources have been rated at various three locations. This was

TABLE !.-THIRTEEN SEED SOURCES OF DOUGLAS-FIR RANKED ACCORDING TO STAGE OF BUD BURSTING OF PROGENIES ON GIVEN DATES IN THREE PLANTATIONS 1933 1955 (June 9) (June 30) (June 29) 1934 1936 (June 23) (July 7) (July 7) Lower2 Upper8 (May 3) (May 21) Lower' Upper Wind River Mt.Hood Mt. Hood Wind River Wind River Wind River Mt.Hood Mt.Hood Rank' (1,100 feet) (2,800 feet) ( 4,600 feet) (1,100 feet) (1,100 feet) (1,100 feet) (2,800 feet) (4,600 feet)

1 Portland (Portland Carson Portland Carson Carson Lakeview 2 Carson and Carson Portland Carson Portland Portland Portland 3 Lakeview burst Lakeview Lakeview Granite Falls Race Track Carson 4 Gates earliest.) Gates Gates Lakeview Wind River Palmer 5 Santiam Santiam Santiam Race Track Gates Santiam 6 Race Track Race Track Race Track Gates Santiam Darrington 7 Palmer Palmer Palmer Palmer Lakeview Race Track 8 Wind River (Granite Falls, Wind River Wind River Darrington Pahfier Gates

9 Granite Falls _ Darrington, Granite Falls Granite Falls Santiam Darrington Wind River 10 Benton Benton, Fortson -Darrington Benton Wind River Hazel Granite Falls 11 Darrington andHazel burst Benton Darrington Benton Granite Falls Hazel 12 Fortson latest.) Fortson Fortson Hazel Benton Benton 13 Hazel Hazel Hazel Fortson Fortson Fortson

11 is most advanced; 13, least. s:Examined when bursting was too far advanced to permit ranking other than by two broad groups. 8E:xamined when bursting was not sufficiently advanced to permit ranking other than by two broad gr-oups. 'Exa.mined when bursting was too far advanced to accurately recognize differences between the earlier bursting seed sources. 210 JOURNAL OF FORESTRY remains co11Sistent through the TABLE 2.-SELECTED BuD-BURSTING DATES OP' Two DOUGLAS-FI& TREES OBSERVED NEAR PORTLAND, OREGON/ DURING THE PERIOD. 1942-55 years. For 14 years, two trees less than 200 feet apart have, on the Bud-bursting date Iriterval 1 2 average, burst tl;teir buds 7.8 days Item Year Tree Tree (days) apart. This is statistically signif Greatest interval 1952 April 29 May 11 12 1943 4 6 2 icant at the 1 percent level, with Least interval May May Earliest season 1947 April 14 April 24 10 standard error of ± 1.07. Tree 1 Latest season 1955 May 18 May 27 9 invariably burst its buds before lg50 feet elevation. Tree 2 (Table 2). The narrow range in interval between bud 3 to 15 years, show the same con from more detailed studies. How bursting dates, regardless of ex sistency. ever, the observations do strength tremes in climatic variation during All the above-cited observatio11S en the longheld view that Douglas this time, is remarkable. Pheno suggest a strong genetic control fir planting stock should be matched logical records irom nine other over time of bud bursting in Doug closely in growth period to the area trees, observed over periods of from las-fir. Proof must of course come to be planted.