Cascade Range
Total Page：16
File Type：pdf, Size：1020Kb
United States bepartment of Agriculture Herbicide Forest Service Pacific Northwest Forest and Range and Conifer Experiment Station Research Paper PNW-292 Options for Reforesting October, 1981 Upper Slopes in the Cascade Range Edward J. Dimock II ROCKY Mof 'NTATN STATION This publication reports research involving pesticides. It does not contain recommendations for their use, nor does it imply that the uses discussed have been registered. All uses of pesticides must be registered by appropriate State and/or Federal agencies before they can be recommended. CAUTION: Pesticides can be injurious to humans, domestic animals, desirable Author plants, and fish or other wildlife -- if they I~ m w ~llmml are not handled or applied properly. Use EDWARD J. DIMOCK II is principal all pesticides selectively and carefully. silviculturist, Forestry Sciences Follow recommended practices for the Laboratory, 3200 Jefferson Way, disposal of surplus pesticides and Corvallis, Oregon 97331. pesticide containers. Abstract Summary Dimock, Edward J. I1. Herbicide and Nine herbicides (asulam, atrazine, Similar survival increases were also conifer options for reforesting upper bromacil, cyanazine, dalapon, consistently achieved with atrazine + slopes in the Cascade Range. Res. glyphosate, hexazinone, pronamide, and dalapon mixtures. Most successful Pap. PNW-292. Portland, OR: U.S. terbacil) were evaluated for control of applications of mixture produced 3-year Department of Agriculture, Forest sedge (Carex spp.) and beargrass survival of 62, 77, and 14 percent for white Service, Pacific Northwest Forest (Xerophyllum tenax [Pursh] Nutt.) to aid pine at the same three localities above. and Range Experiment Station; establishment of newly planted seedlings Survival of other conifers resulting from 1981.14 p. of western white pine (Pinus monticola best atrazine + dalapon treatments was: Dougl. ex D. Don), noble fir (Abies 33 percent for noble fir, 46 percent for Nine herbicides were compared for aiding procera Rehd.), Engelmann spruce Engelmann spruce, and 14 percent for establishment of four conifer species on (Picea engelmannii Parry ex Engelm.), Shasta red fir. upper-slope forest sites dominated by and Shasta red fir (Abies magnifica Murr. sedge and beargrass. Both glyphosate var. shastensis Lemm.). All trials were Preplanting sprays of glyphosate and and a mixture of atrazine + dalapon conducted on upper-slope sites ranging atrazine + dalapon proved generally, but produced substantial and consistent from 3300 to 4600 ft (1000 to 1400 m) in not always, superior to postplanting gains in survival of all four conifers after the Cascade Range. Various rates and sprays for enhancing survival of conifers. 3 years. mixtures of herbicide were compared as both preplanting and postplanting sprays Keywords: Herbicides (-regeneration, site in three independent studies. preparation (-regeneration, herbicide formulations, regeneration (stands), After 3 years, greatest gains in conifer western white pine, Engelmann spruce, survival were associated with glyphosate noble fir, Shasta red fir. sprays. In three widely separated local- ities, survival of white pine associated with best glyphosate treatments was 80, 77, and 30 percent compared to 40, 34, and 4 percent for untreated checks, respectively. Among other conifers, corresponding contrasts in survival between glyphosate treatment and untreated checks were: 56 versus 12 percent for noble fir, 30 versus 14 percent for Engelmann spruce, and 14 versus 0 percent for Shasta red fir. Introduction Study Areas Upper-slope coniferous forests occupy an A separate study was conducted on each annual precipitation near the study areas irregular belt paralleling the crest of the of three ranger districts: Mount Adams is: 100 in (254 cm) at Mount Adams, Cascade Range. These subalpine forests (Gifford Pinchot National Forest), 70 in (179 cm) at McKenzie, and 42 in closely conform to the cool, moist McKenzie (Willamette National Forest), (107 cm) at Prospect. Mean precipitation transition zone separating lower- and Prospect (Rogue River National during June through August for the same elevation temperate forests to the west Forest). The northernmost and locations is: 4.7 in (11.9 cm) at Mount and more arid forest types eastward intermediate locations (Mount Adams and Adams, 4.2 in (10.6 cm) at McKenzie, and (Franklin and Dyrness 1973). Reforesting McKenzie) fall within the Abies amabifis 2.5 in (6.4 cm) at Prospect. upper slopes concurrent with orderly zone as described by Franklin and timber harvest presents new challenges, Dyrness (1973); the southern most Site elevations of individual study blocks and silvicultural practices adapted to location (Prospect) falls within the Abies (three per district) averaged about 4000 Douglas-fir (Pseudotsuga menziesii magnifica shastensis zone. Most ft (1220 m), but ranged from as low as [Mirb.] Franco) at lower elevations apply prevalent soils at Mount Adams range 3300 ft (1000 m) at Mount Adams to as only generally. A wider array of from gravelly sandy Ioams to silt Ioams high as 4600 ft (1400 m) at Prospect management options and species derived from varying combinations of (fig. 1). History of forest disturbance choices is needed for upper slopes. pumice, basalt, and andesite. To the differed somewhat both within and southward occur increasing deposits of between district locations. At McKenzie, As elevations increase in subalpine pyroclastic rocks (tufts, breccias, and all three blocks were sited within 1/2 mile stands, Douglas-fir is replaced by other agglomerates) that weather to silty clay (0.8 km) of one another. Slash on each conifers. Typically, dominant species and silty clay Ioams mixed with stonier had been burned broadcast after clear- include Pacific silver fir (Abies amabilis and coarser soils derived from basaltic cutting about 8 years before study Dougl. ex Forbes), western hemlock and andesitic bedrock. Topography or] all initiation. Failing to regenerate naturally, (Tsuga heterophylla [Raf.] Sarg.), noble districts is bench-like or mountainous with each site supported a heavy cover of fir (Abiesprocera Rehd.), and Shasta red level to steeply sloping ground. Mean beargrass interspersed with sedge fir (A. magnifica Murr. var. shastensis (fig. 2). Up to 12 miles (19.2 km) Lemm.). When harvested, such stands separated different block sites at Mount may regenerate unsatisfactorily despite Adams and Prospect. Slash had been intensive reforestation efforts. To survive, burned broadcast after recent clear- newly planted conifers must withstand cutting on only one site at Mount Adams, extremes of temperature and also and had been piled and burned on all sites moisture stress, which is exacerbated by at Prospect. Sedge was well represented established plant competitors. Sites at all district locations, but beargrass was supporting dense cover of sedge (Carex sparse at Mount Adams and totally absent spp.)-- particularly long stolon sedge at Prospect. Only scattered advance (C. pensylvanica Lam.)-- and beargrass regeneration of conifers had occurred at (Xerophyllum tenax [Pursh] Nutt.) appear any location (fig. 3). Dominant species especially prone to unacceptable before harvest had been primarily noble seedling mortality and plantation failure. fir at McKenzie, Pacific silver and noble fir at Mount Adams, and Shasta red fir at Herbicides have proved useful for Prospect. preparing conifer reforestation sites in herbaceous cover. Most studies, however, have concerned conifer crop species either unadapted or only marginally adapted to upper-slope forests of the Cascade Range (Crouch 1979; Dimock and Collard 1981; Eckert 1979; Gratkowski et al. 1979; Heidmann 1969, 1970; Newton 1974; and Stewart and Beebe 1974). Moreover, weed species targeted for control in other studies have been chiefly grasses (Gramineae) and broad-leaved forbs. Little is known about control of either sedges (Cyperaceae) or beargrass (Liliaceae) in forestry applications. I describe three studies aimed at evaluating the potential of nine herbicides for use in planting-site preparation with four conifer species. All studies were begun in 1977 and monitored for 3 years. ....... .... I -.. | I l I I TON ! , ! - ~ ... ;.OU.T AOA.S m m m I m vs~ f 0 ro~ / I N. FK. OREGON I % ~ f I "-2" I "PROSPECT I I I I I I I ! mmJ ~ ~lim'mD~ ~'lie n ~ m ~ ~ m ~ ~il, ~ m mlmBm mm m ~ m'~ J Figure 1,--The nine study blocks. A Ii Figure 2.--(A) Canopy coverage of beargrass ranged up to 90 percent at McKenzie, (B) Gaps between beargrass clumps were dominated by a continuous mat of sedge, as shown in foreground. B Figure 3.--(A) The predominant sedge-beargrass community at McKenzie proliferated from plants established under the preharvest forest overstory. Only scattered shrubs and (B) occasional naturally regenerated conifers were present. Materials and Methods Experimental design was identical on white pine planting stock from a single active ingredient (ai) in water carriers at every district, and two conifer species source with general resistance to white volumes of 200 gal/acre (1870 liter"ha). were tested per study. Western white pine pine blister rust (Cronartium ribicola No attempt was made to protect tree (Pinus monticola Dougl. ex D. Don) was Fisch.). The USDA Forest Service seedlings from postplanting herbicide common to all three tests, but a different nursery at Wind River, Washington, sprays. second species was used in each: noble provided all other stock grown from fir at McKenzie; Engelmann spruce sources local to each study