Low-elevation foothill fuelwood plantation

z zy zyxwvutsr zyxwvut zyxw zyxwvuts Two eucalyptus selections yielded 23 cords of firewood per acre over a 43-month period. Low-elevation foothill fuelwood plantation Janine K. Hasey P Richard B.Standiford o J. M. (Mike) Connor o I n March 1984,we established a test planting of selected eucalyptus and poplar species and clones in the Yuba County foothills. The main objectiveswere to evaluate survival and growth characteristics over a six-year period and to determine optimum harvest time of intensively managed hardwood trees grown as energy crops under foothill conditions. The species, clones, and seed sources of the trees in this study (table 1) were chosen for their cold tolerance, fast growth, or both, based on previous research at the University of California Sierra Foothill Range Field Station and elsewhere in the state. This report summarizes the results after 3.5 years of growth. Roy M. Sachs applied ranged from 40 to 65 gallons per tree per week. Herbicides and hand weeding were needed for successful weed control during the first year. Simazineat 0.5 pound active ingredient ( a i ) per acre) and Surflan (oryzalin) at 4 pounds a.i. per acre were applied in late May to control summer annuals. Even at this low rate of simazine, some herbicide injury occurred, especially to Eucalyptus uirninalis (manna gum). Subsequent hand hoeing was required two or three times on most plots. Bermudagrass and bindweed were successfully controlled by spot-spraying with 1.5% glyphosate in late August and September. Surflan (4 pounds a.i. per acre) was applied in November 1984. In the summer of Methods 1985, the canopy had mostly closed and no Eucalyptus seedlings 6 to 10 inches tall, further weed control has been necessary. rooted eucalyptus cuttings, and poplar Grasshopper damage was limited the cuttings were planted in Auburn-Las first summer after planting by two appliPosas-Argonaut rocky loam soils with 7 cations of malathion spray and Sevin (carpercent slope at a 575-foot elevation at the baryl) bait. Light deer browsing occurred Sierra Foothill Range Field Station. on several Eucalyptus species, but was exPreplant preparation consisted of tensive on many of the poplars during the spraying with 1 percent Roundup first season and, to a lesser extent, the sec(glyphosate)two weeks before planting to ond year. Two commercial deer repellents kill native annual grasses and forbs. Trees were used in 1984. Their effectivenesswas were sprinkler-irrigated during the first of short duration, possibly because of the growing season, beginning within two sprinkler irrigation. Although early weeks of planting and continuing until growth may have been slowed, the popmid-September. A drip irrigation system lars survived the browse damage and, by was installed in 1985. Since then, trees the end of the second summer, all had have been drip-irrigated weekly from grown too tall for deer to reach. May through September at the rate of 80 No fertilizer was used in 1984. Since percent of pan evaporation. Actual water 1985, a total of 75 pounds of nitrogen per acre as urea has been applied in equal monthly applications through the drip system from June through September. Trees were planted in a randomized complete block design with four replications on a 6- by 6-foot spacing (1,210 stems per acre). Diameter at breast height (DBH) and total height were measured yearly in October after 1985. Diameter was also measured along the stem in 1986 and 1987 to calculate stem taper and volume. Only the interior nine trees of each 49-tree plot were measured to avoid an edge effect. ResuIts Over the three years compared, E. globulus (blue gum) consistently had the greatest average height and diameter, and the zyxw zyxwvutsrq TABLE 1. Species or clones studied Species or clone (and common name) Eucalyptus globulus (blue gum) E. camaldulensis (river red gum) E. camaldulensis. C-1 clone E. camaldulensis. C-2 clone E. viminalis (manna gum) E. dalrympleana (mountain gum) Populus deltoides X niwa (wplar) Seed source Barnback, Australia Lake Albacutya, Australia Unknown - random selection Improved Spanish seed South coast, New South Wales, Australia, 200-ft elevation, Australia, longitude unknown, latitude 35 S, 800-ft elevation 'Giacometti' hybrid clone CALIFORNIA AGRICULTURE,NOVEMBER-DECEMBER 1988 21 zyxwvutsrqpo zyxwvu zyxwvutsr zyxwvu zyxwvutsrqponmlkji zyxwvutsrqponml zyxwvutsrqponmlkjih zyxwvutsrqpon TABLE 3. Stand characteristics at two ages TABLE 2. Comparison of tree characteristic at various ages Average DBH' Species/clone 19 mo 31 mo Average height' 43 mo 19 mo 31 mo 43 mo . . . . . . . . . . . . . . . inches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . feet . . . . . . . . . . . . . . . E. globulus E. camaldulensis E. camaldulensis C-2 clone Poplar clone E. dalrympleana E. virninalis E. carnaldulensis C-1 clone * 2.45 a 2.21 a 3.22 a 3.14 ab 3.93 a 3.48 c 25.6 a 19.5 cd 36.5 a 26.0 cd 46.5 a 31.9 c 2.16 a 1.82 b 1.80 b 1.79 b 2.99 abc 2.84 bcd 2.92 abcd 2.81 cd 3.90 ab 3.50 bc 3.56 abc 3.34 c 22.6 b 20.4 bc 17.6 de 17.9 de 34.5 a 29.7 b 27.1 bcd 27.4 bc 43.4 a 38.2 b 34.2 bc 34.1 bc 1.65 b 2.64 d 3.32 c 15.8 e 24.4 d 31.9 c Age Survival. Volume E. globulus mo 31 43 % 94 86 cu ft/ac cu ft/ac/yr 1.075.18 416.74 1.970.55 550.43 C-2 clone 31 43 100 100 1,040.57 1.969.88 403.32 550.25 E. dalrympleana 31 43 97 94 837.56 1.508.74 324.64 443.78 E. viminalis 31 43 83 83 770.41 1,449.27 301.71 404.82 E. camaldulensis 31 43 100 100 754.21 1,435.15 292.33 400.88 Poplar clone 31 43 100 100 659.43 1,286.25 255.59 359.29 C-1 clone 31 43 100 100 566.33 1.086.27 219.51 303.43 Treatments followed by the same letter are not significantly different. LSD (.05) E . camaldulensis (river red gum) C-1 clone was 15.5 percent and of the hybrid poplar had the lowest. At 3.5 years, the C-2 clone clone, 16 percent. In contrast, the CV for E. had reached an average diameter equal to globulus seedlings was 51 percent and for that of the E . globulus and was almost as E. viminalis, 76 percent. The large growth differences between tall (table 2). The largest yields per acre at 43 months the C-1 and C-2 clones point out the seedwere the same for E. globulus and the E. ling variability inherent within a species. camaldulensis C-2 clone (table 3). Both E. Both clones were selected from E . globulus and the C-2 clone yielded 23.2 camaldulensis seedlings. C-1, which has cords (1,972 cubic feet) per acre over the consistently performed poorly, was 43-month period (fig. 1). All mortality cloned from a random selection, whereas occurred within the first growing season the superior performing C-2 was cloned except for E. globulus and E. dalrympleana from trees from improved Spanish seed. All the Eucalyptus species have endured (mountain gum). Several small E. globulus trees died at 41 months, presumably from temperatures in the low 20s for several lack of sunlight and competition within consecutive days, with a minimum of 16"F, showing virtually no frost injury. the stand. The E . globirlus seedlings are fairly uni- Minor tip dieback has occurred on the C-1 form, and most trees have single, straight clone, E. viminalis, and E . globulus. The Cstems, a desirable characteristic for fuel- 1 clone has suffered branch dieback from wood trees. The C-2 clone is even more drought stress in the fall when the irrigauniform, as would be expected from a clo- tion system was off. nal population. It too has a very upright, Conclusions single stem. Early rates of growth during these 43 As an example of the lower variability in clonal populations, the coefficient of vari- months show that there is considerable ation (CV) for 1987 DBH of the C-2 clone promise for the production of large vol- Fig. 1 . Eucalyptus globulus and the E. camaldulensisC-2 clone produced the greatest volume at nearly 2000 cubic feet per acre at 3.5 years. 22 CALIFORNIA AGRICULTURE.NOVEMBER-DECEMBER1988 MAlt Specier/clone ' Survival of interior nine trees of each plot from which data were taken. t MA1 = mean annual increment.the average annual growth in cu ftlaclyr. umes of woody biomass from intensively managed plantations of exotic hardwood species on low elevation foothill rangeland sites. The high uniformity of the clonal blocks of both eucalyptus and hybrid poplars contrasts with the larger variability of the natural seedling stands. The uniformity of the clonal stands may be particularly useful in design of harvesting and processing technology. We will continue this study for at least another two years to determine the age at which biological growth reaches a maximum. Annual measurement of DBH, height, and per acre volume will continue. At final harvest, specific gravity and other wood properties will be sampled, and actual volumetric and weight yields will be determined. Superior individual trees will be identified from the seedling blocks, and cuttings from these maintained for future genetic improvement work. Janine K. Hasey is Farm Advisor, Cooperative Extension, Sutter-Yuba counties; Richard B. Standiford is Extension Natural Resources Specialist, Forestry, University of California, Berke1ey;Mike Connor is Superintendent, UC Sierra Foothill Range Field Station, Browns Valley; and Roy M . Sachs is Chair, Department of Environmental Horticulture, UC Davis. The authors are grateful to John Le Blanc, Staff Research Associate, Berkeley; Don Springsteen and staff at the Sierra Foothill Range Field Station; Doug McCreary, Natural Resource Specialist; Dean Donaldson, County Director, and Sherri Gallagher, Field Assistant, Napa County; Glen Forister, Jerry Ripperda, Vicki Keresztury, and Roy Woodward, Department of Environmental Horticulture, UC Davis, for field assistance; Zappettini Nursery, California Department of Forestry, and Agroforestry Associates for plant material.