Historic, Archive Document Do not assume content reflects current scientific knowledge, policies, or practices. r&>// tates ent of Forest Service November 1991 A report for land managers on recent developments in forestry research at the four western Experiment Stations of the Forest Service, U.S. Department of Agriculture. In This Issue page Acid test for New Perspectives 1 Small clearcuts help regeneration 6 Spruce beetle pheromone research in Alaska 12 New from research 17 Cover A female spruce beetle deposits eggs on a white spruce. Scientists with the Pacific Northwest Station are conducting pheromone research in Alaska to develop strategies for reducing insect damage. Details begin on page12. To Order Publications Single copies of publications referred to in this magazine are available without charge from the issuing station unless another source is indicated. See page 23 for ordering cards. Each station compiles periodic lists of new publications. To get on the mailing list, write to the director at each station. Western Forest Experiment Stations Pacific Northwest Research Station (PNW) P.O. Box 3890 Portland, Oregon 97208 Pacific Southwest Research Station (PSW) P.O. Box 245 Berkeley, California 94701 To change address, notify the magazine as early as possible. Send mailing label from this magazine and new address. Don’t forget to include your Zip Code. Permission to reprint articles is not required, but credit should be given to the Forest Service, U.S.D.A. Mention of commercial products is for information only. No endorse¬ ment by the U.S.D.A. is implied. Intermountain Research Station (INT) 324 25th Street Ogden, Utah 84401 Rocky Mountain Forest and Range Experiment Station (RM) 240 West Prospect Street Fort Collins, Colorado 80526-2098 D Acid test for New Perspectives by David Tippets Intermountain Station Scientists Norb DeByle (left) and Jim Brown observed the effects of different fire intensities on aspen . At the current rate of decline, half of all quaking aspen will be gone from western landscapes within 400 years. The other half will re¬ main in a climatic equilibrium, dominated by old trees, without a range of age classes important to wildlife. Although traditionally thought of by foresters as a weed species, no tree enhances wildlife habitat values more than aspen— the only wide-spread deciduous tree to create mosiacs of mixed forest with western evergreens. Will “New Perspectives,” an evolv¬ ing Forest Service management philosophy that emphasizes bio¬ diversity, sustainability, and ecosystem management, bring about management changes to preserve quaking aspen on western landscapes? Keeping aspen on the land may prove to be a tougher test than keeping the spotted owl in the forest. For aspen to thrive over its 7 million acres scattered across the West, fire must return to its natural histor¬ ical frequency, and grazing use must be controlled until young aspen grow tall enough to survive browsing. “Long-term “benign neglect’ has made the need for a greatly ex¬ panded recycling effort critically important on many areas,” Utah State University Range/wildlife Professor Phil Urness told a Socie¬ ty of American Foresters audience in 1985, building a case for why forests should include a diverse mosaic of plant communities. He pointed out that by eliminating the natural fire cycle that regenerates aspen, succession to less complex coniferous forests will not only reduce food for grazers and browsers, but will eliminate habitat for species that thrive in the more biologically complex mixed forest. Plant Ecologist Walt Mueggler sampled 713 aspen stands in Utah, Idaho, and Wyoming and determined that 95 percent were mature or overmature. Since the oldest known aspen tree is only 222 years old, its easy to picture a rapid deterioration of most aspen communities in the intermountain area. Sick, barren, and elderly A hundred years of fire suppres¬ sion and livestock grazing created a sanctuary for sick and barren elderly aspen, rotting in the shade of taller spruce, fir, and pine. Aspen compete on the same sites suitable for conifers but maintain a competitive advantage when fire stimulates prolific suckering. In areas with a 20-40 year natural cycle for wildfire, aspen has domi¬ nated conifers for the last several thousand years. But stomp out the fires and roughly half of all aspen communities succeed to conifers. 1 The understory of a Manning Basin aspen stand one week after the prescribed fire, and the same view one year later. The increased grazing pressure that accompanied white settlement compounded the problem. Aspen thrive in productive areas that have been valued for summer grazing since pioneer times. Some aspen stands with tall forb under¬ stories can produce over 4,000 pounds per acre of forage, making them some of the most productive of all western range types. Not only do cattle and sheep graze off many of the tender young aspen suckers needed to regenerate the stands, they remove much of the fine fuel, often making it impossi¬ ble for wildfire to burn through the stands. In extreme cases, grazing pressure has induced changes in understory vegetation to exotics such as Kentucky bluegrass and annual forbs that don’t produce enough fuel to burn the stands. In some areas of the West, ex¬ panding elk herds have made regeneration of aspen on winter range impossible, illustrating that maintaining aspen on the land¬ scape may require the ability to control all ungulate grazing and not just domestic livestock. The Forest Service’s first range ecologist Arthur W. Sampson recognized the dilemma soon after initiating his first research at the Great Basin Station, and by 1918 published management recom¬ mendations to promote aspen regeneration. He learned that even where aspen suckering occurred, intense domestic grazing killed the new growth and prevented regeneration. He further observed that suckers grow to a height above where livestock browse off the meristem tissue in 3-to-5 years; 2 he recommended protection from grazing for these periods to insure survival. Sampson’s recommenda¬ tions were both simple and cor¬ rect, but managers have faced a complex social and political en¬ vironment in which to apply the recommendations. After 72 years, the first useful aspen management research remains largely unap¬ plied as aspen continues to decline. The Intermountain Research Sta¬ tion, heir to Sampson’s Great Ba¬ sin research, continued the quest for answers to aspen problems through the Aspen and Fire Effects Research Work Units in Logan and Missoula. “The ground has been thoroughly plowed,” Urness said, referring to aspen research. By reviewing the literature that sprouted from that thoroughly plowed ground, one can see why preserving aspen forests may be¬ come New Perspectives acid test. Burning the decadent stands to regenerate them ranges from difficult to impossible under typical constraints for prescribed fire. Recognize opportunity The key is recognizing good op¬ portunities,” Fire Effects Project Leader Jim Brown said recently, explaining that his project’s research has provided managers with information about which com¬ munity types are the best candi¬ dates for treatment. If managers don’t carefully select stands based on probability of success, burning conditions are even more critical. Without good stand data and good planning, hit¬ ting the window of opportunity resembles shooting a small run¬ ning target with a rifle. And then getting a chance to shoot only after having to wait for years for the window to open for just a cou¬ ple of days. “Its the managers dilemma,” past aspen researcher Norb DeByle said, during a recent interview. “The window may not open for a decade.” “Careful planning and diligent preparation are critical,” Brown said. “The Prescription isn’t as for¬ giving as it is in sagebrush . . . you have to be ready at a day’s notice.” Aspen researcher Norb DeByle illustrated the height and rapid growth of aspen suckers after the old trees are killed by fire. 3 Brown suggests that where only small areas of aspen are included with sagebrush or conifer en¬ croachment burns, that managers write prescriptions for the aspen rather than the sagebrush or conifers. If you target the aspen you will have a high probability of success in the other communities, but not the other way around. Getting the right weather and fuel conditions to burn is tough enough. But add grazing policies that limit managers to occasional rest years or periods of non use, and the odds of maintaining aspen with fire look worse than a crap shoot. Sampson’s research showed that to maximize sucker survival, managers should rest burned areas on sheep allotments for three years, and five years on cattle allotments— advice that that’s pretty tough to follow on ac¬ tive grazing allotments. Prioritize diversity over production But New Perspectives allows a broader definition of success based on sustaining all biological productivity with a greater empha¬ sis on landscape management and biodiversity, rather than the traditional forestry philosophy that emphasized maximizing fiber production. Brown explains that maximizing suckering may not be needed to prevent succession to conifers and maintaining an aspen mosaic on the landscape. He ex¬ plains that if you know and under¬ stand aspen habitat types and livestock behavior you can identify some stands that can be burned and regenerated without resting from livestock grazing. “You have to evaluate preburn grazing in the community,” Brown insists, indicating another strata of resource inventory data that is im¬ portant to vegetation management. To successfully manage aspen on the landscape, a resource inven¬ tory needs to include as much data on non-commercial aspen stands as has traditionally been collected only for commercial stands. Aspen-ecosystem-land¬ scape management demands an integrated resource inventory with compatible strata of timber, fuels, wildlife, and range. Clearcutting or mechanical treat¬ ments can be substituted for fire, often providing more effective and economical alternatives. But these methods alone can't address all concerns for ecologically based landscape management. The eco¬ logical influences of natural fire are too fundamental for managers to overlook. The role of fire in eco¬ system health extends far beyond aspen regeneration alone. “Fire treats the entire vegetative community and not just the trees,” Brown emphasized. “Biodiversity is made up of a diverse landscape and a large number of species,” he said, explaining that the histori¬ cal role of fire seems woven through the heart of New Perspec¬ tives concerns. Historically, the same natural fire that maintained aspen on the landscape, also created the mosaic of other kinds and ages of vegetation essential to the survival of many species. Scientists used tame elk to study elk diet preferences after fire. “You can tolerate light grazing,” Brown said, adding that communi¬ ties with a light conifer overstory are unlikely to be heavily grazed before or immediately after burn¬ ing. One year rest and one year deferment might be adequate for many stands. Suckers will respond to grazing by producing lateral shoots and can survive as long as they aren’t cropped off “year after year.” 4 Jim Brown monitoring the highly successful Manning Basin prescribed fire on the Caribou National Forest in Idaho. From Sampson’s first research, through the work of DeByle, Mueggler, and others, to the cur¬ rent work of Brown’s Fire Effects research unit, Intermountain Sta¬ tion scientists have given man¬ agers the basic knowledge they need to preserve aspen. More research will help reduce the risks of prescribed fire and make aspen management easier. Application of research information will help change the odds in the manager’s favor. But the greatest limitations are neither climatic, biological, or lack of scientific knowledge. The biggest problem “The biggest problem is logistics and manpower ... the way we plan, budget, and set targets,” Brown said, explaining why aspen continues to decline in the face of knowledge of how to reverse the trend. Even seemingly little things like the changing of the fiscal year during the peak burning season for aspen can have a dramatic ef¬ fect on whether or not burning prescriptions are implemented. If New Perspectives’ commitment and enthusiasm can clear the path of internal stumbling blocks, the scientific foundation is already laid for aspen management. Appraising Fuels and Flammability in Western Aspen: A Prescribed Fire Guide, by Brown and Dennis G. Simmerman, is the best infor¬ mation available for fire managers who want to write quality prescrip¬ tions to successfully regenerate aspen. Brown and Simmerman paint a good picture of the “small moving target of burning” window, telling managers when and where they can burn to expect success within acceptable limits of risk. The publication, General Technical Report INT-205, should be on the bookshelf of every land manager and resource specialist charged with maintaining landscape and biodiversity in the interior west. Brown and Simmerman show color photographs of different aspen community types with differ¬ ent fuel loadings, and rate the probability of a successful prescribed fire. At first glance numerous charts and graphs make the report appear like a typi¬ cal research publication, but closer inspection reveals that these fire scientists have done an excep¬ tional job of simplifying research results to make the information easy for managers to understand and apply. Aspen’s acid test for New Perspec¬ tives will be to apply research in¬ formation and preserve aspen within the political, social, and economic environments that con¬ strain prescribed fire and limit the control of both wild ungulate and domestic livestock grazing. 5 Small/ clearcuts help regeneration by Rick Fletcher Rocky Mountain Station Southwestern mixed conifer forests are found on high-elevation sites, generally above 8,000 feet, throughout Arizona, New Mexico, and southwestern Colorado. These forests are important sources of commercial and noncommercial resources. Natural regeneration is satisfactory in most undisturbed stands. These contain adequate density and stocking of advance regeneration to replace trees lost by natural mortality or by moder¬ ate harvesting. However, natural regeneration has been poor in large openings that were created by harvesting or by natural dis¬ turbances, partially because seed- fall cannot reach sites in the interior of such openings. Scientists at the Rocky Mountain Station's Forestry Sciences Lab in Flagstaff, Arizona have been ex¬ perimenting with small clearcut openings of about one to two acres in an effort to increase natural regeneration. “For some time, the creation of such patch clearcuts have been advocated as a method of increasing water yields, as well as enhancing other resource values,” says Research Forester Gerald Gottfried. “We’re finding that such a prescription can also sustain forest productivi¬ ty.” Under this prescription, a por¬ tion of the watershed is patch clearcut periodically throughout the rotation. Once harvested, the openings regenerate naturally, and eventually contain sufficient timber to be harvested again at the end of a 120-year rotation. In addition to the greater availability of seed from the surrounding stand, small openings have a more moderate microclimate, as well as better moisture conditions than larger openings. Beginnings In 1978, the Rocky Mountain Forest and Range Experiment Sta¬ tion and the Apache-Sitgreaves National Forests designed a sil¬ vicultural prescription that included creating small dispersed openings by patch clearcutting and group selection methods, in conjunction with single-tree selection in the ad¬ jacent stand. A resource allocation evaluation indicated that this prescription would benefit the greatest mix of resources, such as water yields, herbage production, wildlife habitat, and tree and stand growth. Peter Ffolliott, a coopera¬ tor from the University of Arizona’s School of Renewable Natural Resources at Tucson, and Gott¬ fried designed an experiment to evaluate the amount, composition, and stocking of natural mixed conifer and aspen regeneration in small clearcuts and to compare it to regeneration in the surrounding partially harvested forest. New regeneration in a smalt clearcut. 6 TABLE 1 Opening number Area (acres) Basal area (ft2/acre) X + SE Mean tree height (ft) X + SE Most common species (percent by basal area per acre) 1 1.2 146± 29 64 ± 7 White fir (26%), ponderosa pine (23%) 2 0.8 156 + 20 94 ± 6 Douglas-fir (40%), white fir (15%) 3 1.1 148 ±22 90 ± 5 Douglas-fir (44%), white fir (13%) 4 1.1 158 + 22 59 + 6 Douglas-fir (54%), ponderosa pine (22%) 5 0.8 158 + 21 62 ± 7 Douglas-fir (59%), aspen (21%) 6 0.3 169 + 26 72 ±7 Douglas-fir (51%), Engelmann spruce (12%) 7 1.1 123 + 23 57 ±4 Engelmann spruce (32%), Douglas-fir (27%) 8 1.0 208 + 31 56 ±5 Aspen (34%), Douglas-fir (26%) 9 1.6 191 ±22 85 ±6 Douglas-fir (45%), white fir (45%) Total study area 1.0±0.1 162 ± 8 71 ± 5 Characteristics of the nine clearings and adjacent partially harvested stands . The research was conducted on the South Fork of Thomas Creek, a 562-acre watershed within the Apache-Sitgreaves National Forests of east central Arizona. The water¬ shed originally supported an old- growth, uneven-aged mixed conifer forest consisting of eight main tree species: Engelmann spruce, blue spruce, Douglas-fir, white fir, corkbark fir, ponderosa pine, southwestern white pine, and aspen. Douglas-fir is the most common species, while ponderosa pine is the most commercially valuable. The stand consisted of a mosaic of groups and patches of various sizes and species compo¬ sitions. Much of the watershed has been classified as belonging to the Picea engelmanrtii/Senecio cardamine habitat type, although other habitat types occur locally within the area. The plan The multiresource prescription was prepared for 422 acres in the up¬ per part of the South Fork watershed. The prescription called for group selection and single-tree selection on 233 acres, patch clearcutting and single-tree selec¬ tion on 159 acres, and single-tree selection on 28 acres adjacent to the stream channel. Two acres of meadow were left undisturbed. The harvest removed 34 percent of the stand basal area and created 63 dispersed openings throughout the stand. Prior to treatment in 1978, estab¬ lished mixed conifer seedlings and aspen suckers were measured in nine forested areas marked for patch clearcutting. These data provided an indication of pretreat¬ ment conditions on the study area. Following the harvest, nine of the harvested clearings were selected for intensive study. The charac¬ teristics of the nine sites and sur¬ rounding stands are shown in table 1 . Regeneration was moni¬ tored on permanent transects and plots within each opening and sur¬ rounding stand. Seedling meas¬ urements, including number of stems, species, and percent stock¬ ing, were made in 1982, 1983, 1986, and 1989, representing 4, 5, 8, and 11 years following treatment. 7 The preharvest inventory meas¬ ured approximately 1,746 seed¬ lings and suckers per acre less than one foot in height (table 2). Douglas-fir and white fir accounted for 67 percent of the trees and aspen accounted for 25 percent. “In 1982, the first year of posthar¬ vesting sampling, all of the nine openings and all of the partially harvested areas were satisfactorily regenerated, containing at least 325 seedlings or suckers per acre, the level considered to indicate satisfactory density for similar mixed conifer stands. In fact, the openings averaged 2,605 stems per acre and the forested areas averaged 4,184 stems per acre,” says Gottfried. Douglas-fir and white fir seedlings were the most common species in the openings and in the forest. In 1983, regeneration densities fell sharply in both forested and open sites; differences between 1982 and 1983 were highly significant. The 1983 inventory indicated that only six of the openings contained satisfactory numbers of seedlings and suckers. One opening which had over 1,000 stems per acre in 1982, contained no regeneration in 1983. All forested sites con¬ tained at least 325 stems per acre. The average clearing contained 1,082 trees per acre, while the average forested area contained 2,272 trees per acre. General conifer and aspen numbers were similar between the two cover types. 1986 data By 1986, seedling densities ap¬ peared to be recovering, but the new levels still were below those of 1982; they were similar to 1983. Eight of the openings and all of the forested sites contained satis¬ factory numbers of seedlings and suckers. “However,” Ffolliott says, “the difference between the two cover conditions had become sig¬ nificant.” In 1986, Douglas-fir and white fir were between 50 percent and 60 percent of the regenera¬ tion in both conditions, while aspen made up 26 percent of the trees in the openings and 11 per¬ cent of those in the forest. Total regeneration density re¬ mained constant between 1986 and 1989 and continued to be be¬ low 1982 levels. The openings contained 1,014 trees per acre and the forested areas contained 3,092 trees per acre. The difference be¬ tween density in the openings and in the forest was still significant. Eight openings and all forested areas contained satisfactory seed¬ ling and sucker densities. Differ¬ ences were found between overall population of conifers; however, white fir was the only species to show a difference. Douglas-fir and white fir accounted for 53 percent of the regeneration in the forest and 47 percent of that in the clear¬ ings. The proportion of spruce in¬ creased from 11 percent to 32 percent in the forest and from 9 percent to 24 percent in the clear¬ ings between 1982 and 1989. The pretreatment inventory indi¬ cated that about 88 percent of the plots were stocked with at least one healthy seedling or aspen sucker. Stocking evaluations follow¬ ing treatment showed no statistical differences between forested and open areas over the study period. Stocking dropped significantly be¬ tween 1982 and 1983 and re¬ mained constant afterwards. Gottfried indicates that stocking, in 1989, ranged from 0 to 100 per¬ cent in the clearcut openings, with an average of 45 percent, and ranged from 20 percent to 92 per¬ cent in the forest, with an average of 61 percent. Most of the trees in the clearings were adjacent to the treeline; only two areas had trees in the center. 11 years later “This study showed that by 1989, 11 years after the timber harvest, eight of the nine monitored clear¬ ings had regenerated satisfactorily, with an average density of over 1,000 new seedlings and suckers per acre," states Gottfried. Al¬ though this was less than the density under the adjacent par¬ tially harvested forest, it was suffi¬ cient to regenerate the openings. Each of the eight stocked open¬ ings contained at least 325 trees per acre. Regeneration densities under the forest, which had been harvested according to the single¬ tree selection method, were also greater than that considered satis¬ factory and greater than that 8 measured before treatment. The stocking results for the clearings were less satisfactory; however, the center areas of the clearings should become stocked in the fu¬ ture as surrounding established seedlings grow and further modify the microclimate in the openings. Although each of the species has its own requirements for germina¬ tion and establishment, the conifer species generally have followed the same pattern of fluctuations as found for the total regeneration densities. Individual species popu¬ lation densities have remained similar within the partially harvest¬ ed stand and the openings throughout the study. Only white fir numbers were different for the two cover categories for each of the surveys. Gottfried explains that true firs and spruce can be at more of a disadvantage during drought than pines because of their shallow and slow-growing root systems. “More drought-hardy species have rapid-growing root systems, which can tap moisture from deeper soil layers where evaporation losses are less. Young seedlings in the clearings are sub- TABLE 2 Species 1978 1982 1983 1986 1989 Douglas-fir Forest 611+ 51 919 + 297 324 ± 116 712 ±270 376+ 126 Open 998 ± 592 189± 116 440 ± 169 335 ± 155 White fir Forest 555 + 88 2234 + 517 1239 + 303 1015 ±245 1275 ±348 Open 1081 ±823 273 ±111 1 18 ± 57 141 ± 65 Engelmann spruce Forest 44 ± 28 448+ 151 296 ± 203 932 + 389 974 ± 322 Open 224 ± 76 54 ± 28 133 ± 64 247 ± 1 73 Ponderosa pine Forest 32+ 20 18 ± 12 69 ± 33 28+ 20 28 ± 14 Open 57 ± 29 63 ± 46 126 ± 63 144 ± 73 Southwestern white pine Forest 68 ± 31 63 ± 18 18+ 12 0 56 ± 20 Open 41 ± 28 0 0 47 ± 31 Total conifers Forest 1311 ± 102 3682 ± 716 1947 ±414 2687 ± 698 2709 ± 559 Open 2400 ±91 6 579 ± 158 81 7 ±226 913 ±280 Aspen Forest 435 ± 86 502 ± 153 324 ± 89 321 ± 100 384 + 135 Open 205 ± 164 503 ± 382 281 ± 97 100 ± 69 TOTAL STUDY AREA Forest 1746 ±123 4184 ±817 2272 ± 453 3008 ± 701 3092 ± 623 Open 2605 ± 902 1082 ±466 1098 ±298 1014 ±266 1 Columns may not add up exactly because of rounding to integer values. Total, conifer, and Individual species regeneration density per acre 9 Average percent stocking was similar for both the openings (O) and forested areas (F) over the study. ject to greater environmental stresses than seedlings protected by the forest canopy.” he says. Solar radiation and temperature are higher in the openings during the day, although small openings have more moderate microclimates than larger clearings. Greater her¬ baceous cover in the openings could also impact tree germination and survival. Ideally, clearings can be created that will favor one species or group of species over other alter¬ natives. It was expected, for exam¬ ple, that openings might provide sufficient light to encourage regeneration of shade-intolerant ponderosa pine. Although, the four inventories did not show any differ¬ ences between densities in the forest and the openings for this pine, the relative importance of ponderosa pine within openings did appear to show an increase over time. Ffolliott indicates that aspen, another shade-intolerant species, should also have bene¬ fited from the clearings but that this species only made up 10 per¬ cent of the final total density. It is possible that the openings were too small to allow sufficient light to penetrate to the soil surface to stimulate abundant suckering. Poor aspen response could also be related to apical dominance of adjacent larger aspen trees which can suppress suckering activity, as well as to increased utilization of the openings by wildlife and live¬ stock. Larger openings should be more beneficial for these species, 10 but the best size has not been de¬ termined. The success of spruce in the clearings may indicate that the size, shape, or orientation of the openings was beneficial for this species. “Overall, regeneration was better in the small clearings than in the large clearcuts or in an adjacent heavily harvested diameter-limit area,” says Gottfried. “Better re¬ production resulted for a number of reasons. Small openings gener¬ ally receive sufficient seed because most of the regeneration sites are within 198 feet of the forest edge. Small openings have more moder¬ ate microclimates than larger openings— there is more shade in small clearings from the surround¬ ing overstory, which tends to reduce soil and air temperatures; and there is less wind movement, which impacts air mixing and the pressure gradients that affect eva- potranspiration.” Ffolliott points out that small openings also enhance snow accumulations— greater snowpacks, remaining on the site longer, should result in more soil moisture for tree growth and survival. The implications from Ffolliott's and Gottfried’s study are clear: patch clearcutting or group selec¬ tion openings of similar sizes will result in satisfactory regeneration of forest tree species. The species mixes produced by the silvicultural methods appear consistent with those expected for the habitat type. Clearcutting should favor aspen and Douglas-fir. Douglas-fir was favored at Thomas Creek but aspen was less successful. Larger openings may stimulate more aspen regeneration but small openings appear to be less bene¬ ficial. This must be considered if aspen regeneration for wildlife is a prime objective. “A knowledge of the relationship between species and optimum clearing size for suc¬ cessful regeneration can give managers more flexibility to manipulate stands to obtain the species composition specified in the forest plans,” says Gottfried. The Thomas Creek Prescription is compatible with the integrated resource management philosophy, which recognizes that all natural resources are interrelated and that an interdisciplinary approach is necessary when designing projects. Satisfactory regeneration and increased growth of residual trees, coupled with the benefits of increased water yields and herba¬ ceous production for wildlife and livestock indicate the value of the experimental treatment at Thomas Creek. The findings also should be valid for similar old-growth stands, as well as for stands that have been lightly harvested in the past. “The bottom line to all of this,” explains Gottfried, “is that this type of prescription should be a valid consideration for multi¬ resource management within the mixed conifer forests of the South¬ west.” If you would like additional information on this and related studies, contact Gerald Gottfried at the Forestry Sciences Laboratory, 700 South Knoles Drive, Flagstaff, AZ 86001, (602) 527-7315, “ FTS-765-7315. In addition, a new report describ¬ ing research at Thomas creek is available from the Rocky Mountain Station. Request Mixed Conifer and Aspen Regeneration in Small Clearcuts Within a Partially Har¬ vested Arizona Mixed Conifer Forest , Research Paper RM-294. 11 by Sherri Richardson Pacific Northwest Station Spruce beetle pheromone research in Alaska Lindgren funnel trap used to trap bark beetles. The trap is baited with spruce beetle. As a boy growing up on a farm in a small Pennsylvania town, Richard “Skeeter” Werner would closely observe the habits of bees and hornets— he was fascinated by insect behavior. Today, Werner, a 30-year veteran in the field of entomology, is Supervisory Research Entomologist at the Pacific Northwest Research Sta¬ tion’s Institute of Northern Forestry in Fairbanks, Alaska. He is also lead scientist for a pheromone research project in cooperation with Region 10 Forest Pest Man¬ agement entomologists. The research is targeted to develop strategies to manipulate popula¬ tions of spruce beetles in order to reduce damage inflicted on thou¬ sands of spruce trees each year in south-central and interior Alaska. "The death of individual trees and entire stands represents large an¬ nual losses in forest productivity, recreation and esthetic values, and wildlife habitat,” Werner says. "An¬ other danger is that beetle-killed timber increases fuel loads within stands which, in turn, increases the risk of a catastrophic wildfire.” Pheromones are chemical sub¬ stances secreted by insects that influence the behavior of members of the same species. Pheromones are located in the digestive track of bark beetles. They are released in frass which is the woody boring material the beetle produces while eating. Synthetic bark beetle pheromone has an odor like tur¬ pentine. “Pheromones are used by insects as a sexual attractant for reproduc¬ tion, but they can also signify aggregation (gathering together) nor feeding,” Werner explains. “Our research seeks ways to use pheromones to manipulate the be¬ havior of the beetles, thereby sav¬ ing the trees. We are trying to find alternatives to insecticides. And, so far, pheromones seem to be the way to go.” 12 The spruce bark beetle is a major killer of spruce. The beetle attacks trees across Canada and from the southern Rocky Mountains to Alas¬ ka. During the last 15 years, more than 1 million acres of spruce in Alaska were infested. Since 1974, beetle populations have expanded throughout south-central Alaska from the Kenai Peninsula including the Chugach National Forest and Kenai National Wildlife Refuge. The beetles have also found their way to the west side of Cook Inlet in the Beluga-Tyonek area and north to Judd Lake. “Much of the loss has occurred in areas with high-value trees such as campgrounds, recreational areas, hiking trail systems, and ur¬ ban areas of small communities,” Werner says. Collaborating with Werner on the research are Edward Holsten, an Entomologist for Region 10 Forest Pest Management, State & Private Forestry; and Patrick Shea, Re¬ search Entomologist for the Pacific Southwest Forest and Range Ex¬ periment Station in Berkeley, California. The problem “Endemic levels of spruce beetles can be found in almost any spruce stand in Alaska,” Werner says. “The general progression for development of an outbreak would start with the attack of a few ‘focus’ trees.” Stressed, slow-growing trees are most likely to fall prey to the beetle attack. According to Werner, these trees then act as sites for popula¬ tion increases that allow the bee¬ tles to reach epidemic levels. A new brood of adult beetles emerges from the focus trees and attack the adjacent slower grow¬ ing, less vigorous trees. Stressed trees are the most preva¬ lent host for the spruce beetle. What factors contribute to stressed conditions? - Lack of silviculture management in over-stocked stands of slow- growing, mature, spruce trees. - Stress on residual stands in the fringe areas of wildfire areas partially burned or damaged by smoke. - Periodic flooding and deposition of silt on the forest floor. - Poor utilization of felled trees and accumulation of slash fol¬ lowing logging, rights-of-way construction, and windthrown trees. Three components of the research Werner’s pheromone research has three major goals: - Determine the role of bark beetle pheromones (from a vari¬ ety of species) in providing com¬ petition for the spruce beetle in spruce trees in Alaska. - Determine the effectiveness of ground and aerial application of methycyclohexenol or MCH (a spruce beetle antiaggregation pheromone). - To develop a 5-year plan to study field testing of spruce beetle aggregation pheromone, and to produce applied technol¬ ogy for using pheromones. Use of bark beetle pheromones “Past outbreaks in south-central Alaska have been associated with warm, dry summers and an ac¬ cumulation of spruce debris from windthrown and felled trees that are highly productive breeding sites for spruce beetles,” Werner explains. “When beetle popula¬ tions increase and a sufficient sup¬ ply of breeding material is no longer available for colonization, beetles can infest nearby living trees, particularly in mature stands.” Stand manipulation or the use of chemical insecticides has been the standard way to control beetle in¬ festation. Werner and his col¬ leagues have been examining alternatives to insecticides. Other classic techniques for treatment of logging slash, felled, or wind- thrown green trees is the immedi¬ ate salvage of the trees. These trees are also disposed of by burning, chipping, or burying them. The use of Environmental Protection Agency (EPA) approved insecticides or pheromone-baited traps has also been successful in areas with high value stands. 13 An innovative technique used to combat the beetle infestations are the use of semiochemicals. Semi- ochemicals are used to manipulate bark beetle populations and in¬ clude synthetic host-produced chemicals and pheromones that prevent attack or reduce the attack density of bark beetles to a level below the threshold density re¬ quired for the development of brood trees. Werner says this technique has several advantages. “First, the use of insecticides would be minimal. Secondly, beetle resistance to treatment would be negligible since several different pheromones from competing species of bark beetles can usually be used," he says. “And finally, there would be little direct mortality to parasites and predators as occurs with in¬ secticide treatment.” "Field studies conducted in south- central and interior Alaska during the last 10 years were designed to determine the attractiveness of several scolytid (family name of all bark beetles) pheromones and host terpenes (chemicals in trees that attract bark beetles) to the spruce bark beetle,” Werner says. Werner and his colleagues dis¬ covered that seudenol + alpha pinene (host terpenes) dispersed from funnel or sticky traps at¬ tracted more beetles than frontalin + alpha pinene. But frontalin, when applied directly on uninfest¬ ed white and Lutz spruce trees, at¬ tracted more beetles than the seudenol-alpha pinene combination. "Host suitability is also a major factor in attracting spruce beetles to host material,” Werner adds. “When white spruce is infested with spruce beetle brood, more spruce beetles are produced than when Lutz or Sitka spruce are in¬ fested. In spite of host suitability differences, spruce beetle out¬ breaks have been more frequent and severe in Lutz spruce.” Application of MCH The use of MCFI is being studied to reduce tree mortality by spruce beetles in scuth-central Alaska. MCH is naturally derived from fe¬ male spruce beetles and is the primary antiaggregation phero¬ mone used by the insect (Rudinsy 1973). Several studies have been performed using MCH and a pilot test using ground and aerial appli¬ cations from a helicopter were done in 1991. 14 MCH was identified in 1974 as a major component of the spruce beetle pheromone. “Field tests have shown that granular formula¬ tion of MCH reduced attacks of spruce beetle on Engelmann spruce by 93 percent when trees were baited with MCH in Idaho,” Werner says. “The addition of MCH to sticky traps baited with the natural attractant as well as synthetic pheromones suppressed attacks by spruce beetles in Lutz spruce on the Kenai National Wild¬ life Refuge by 87 and 99 percent respectively,” A 5-year study plan “We’ve had a real problem with spruce beetle infestations in south- central Alaska since 1974,” Werner explains. “More that 1 million acres were infested. In 1986, out¬ break level populations were found along the Yukon and Kuskokwim Rivers in interior Alaska where 160,000 acres had been infested. It was conceivable that the entire commercial spruce stands in the Yukon, Kuskokwim, and Tanana River Valleys could be killed.” The Yukon River Spruce Beetle Management Council was recently formed to work out strategies and solutions to this problem. The interagency council is developing and coordinating a program to evaluate the present and future im¬ pact of the spruce beetle on the environment of the residents and ecosystems of the lower Yukon River. A primary objective of the council is the development and application of preventive and sup¬ pression methodologies. The 5-year project is a cooperative effort among FPM, Region 10, and the Institute of Northern Forestry in Fairbanks, Pacific Northwest Research Station. “The primary purpose of the spe¬ cial project is to develop opera¬ tional strategies for monitoring and manipulating spruce beetle popu¬ lations,” Werner says. “This will be accomplished by using semio- chemicals in traps and on baited trees in interior and south-central Alaska.” The project is part of a larger in¬ ternational project involving the Forestry Institute, Forest Pest Management (Region 10), Forestry Canada, the University of Calgary, Simon Fraser University, and Phero Tech Corporation (an insect pheromone manufacturer). Divided into two phases, the project addresses the develop¬ ment of new semiochemicals and the operational use of semi¬ ochemicals. “Phase one occurred in 1988-1990 and dealt with the de¬ velopment of an improved phero¬ mone blend for attracting spruce beetles. This phase included field tests on the effectiveness of the new formulations,” Werner says. “The tests were conducted in northern and southern Alberta, British Columbia, and south-central and interior Alaska. Phase two will be in operation from 1991-93 and will demonstrate the efficiency of pheromone methods with im¬ proved formulations for manipulat¬ ing spruce beetle populations in various management strategies.” The results of the first phase of the project resulted in several success¬ es. Efficacy field trials were done on a new formulation of spruce beetle lure in stands of white 15 spruce at Bonanza Creek Ex¬ perimental Forest in interior Alaska from 1988-89. “The lure was a ternary formulation which con¬ tained alpha pine, frontalin, and methylcyclohexenol (MCOL) com¬ pared to the current commercial lure produced by Phero Tech, which contains alpha pinene and frontalin," Werner explains. “The efficiency of this new lure was test¬ ed simultaneously against that of the commercial spruce beetle lure and proved superior by a wide margin. It attracted spruce beetles in much greater numbers in all areas of the field test." Werner added that the new lure worked extremely well in Alaska in areas with endemic and epidemic beetle populations. “Trap captures as high as 1,500 per trap in 1 week were observed during peak flight in interior Alaska. The catches are attributed to the strong synergism for the components of the ternary bait," he adds. Final tests are be¬ ing conducted in 1991. For more information on phero¬ mone research, contact Richard Werner at the Pacific Northwest Research Station, Institute of Northern Forestry, 308 Tanana Drive, Fairbanks, AK 99775-5500. Diversion trapping using baited funnel traps to remove beetles from fringe area surrounding a recent prescribed burn. 16 New from research Small mammals in beaver ponds and adjacent riparian habitats The more dense and complex mesic habitat of beaver pond ecosystems produce two to three times greater small mammal densi¬ ty than adjacent riparian habitat, Dean Medin and Warren Clary, Intermountain Station, learned from research on Summit Creek in east- central Idaho. “We suggest that the dense and structurally more complex vegeta¬ tion of the beaver pond ecosystem produced the food and cover resources needed to support higher relative populations of small mammals,” they reported. This research strongly demon¬ strates that beaver are important regulators of aquatic and terrestrial ecosystems with pervasive effects far beyond their food and space requirements. Request Small Mammals of a Beaver Pond Ecosystem and Adja¬ cent Riparian Habitat In Idaho, Research Paper I NT-445, available from the Intermountain Station. United States Department erf Agriculture Forest Service Intermountain Research Station Research Paper SNT-445 June 1991 Small Mammals of a Beaver Pond Ecosystem and Adjacent Riparian Habitat in Idaho Dean E. Medin Warren P. Clary 17 Arboreal rodent populations Three arboreal rodents are sensi¬ tive indicators of forest ecosystem function in the Pacific Northwest: the northern flying squirrel, the red tree vole, and the Douglas’ squir¬ rel. This paper discusses methods for measuring populations of these and other rodents. Trapping with live traps is described as the most effective way to count northern flying squir¬ rels, Townsend’s chipmunks, and woodrats. Douglas’ squirrels can be studied by direct observation because they are diurnal and rapidly adjust to the presence of an observer. The red tree vole is very difficult to study. No reliable method has been developed for capture except by climbing a nest tree and grabbing the voles. £r- Methods for Measuring Populations of Arboreal Rodents — - Andrew B Carey. Bnan L Biswell and eg Joseph W Witt For a copy of Methods for Measur¬ ing Populations of Arboreal Ro¬ dents, request General Technical Report PNW-273 from the Pacific Northwest Research Station. Advancing toward closed forest ecosystem models In forest management, a dramatic shift is occurring in the United States toward management of forests as ecosystems rather than simply as commodity-oriented production systems. One issue of ecosystem management is that of climate change and the uncer¬ tainty about the role of forests in regulating the global atmospheric balance of C02, particularly in the northern hemisphere. An important aspect in learning how ecosystems function is the ability to simulate and measure the influx and outflux of carbon and other materials in forest ecosys¬ tems. Scientists attending a recent workshop on closed forest eco¬ system models concluded that a major gap exists in the modeling of the carbon cycle, particularly regarding carbon fixation by forest stands and the allocation of car¬ bon after it has been fixed. Cur¬ rent models on the carbon cycle are limited, and new closed sys¬ tem models must be researched. For a copy of this brief discussion on closed forest ecosystem models, request Advancing Toward Closed Forest Ecosystem Models: Report on a Workshop, General Technical Report RM-201 from the Rocky Mountain Station. 18 Fifty Years of Research Progress: A Historical ^“Document on the Starkey Experimental Forest and Range fulst Jon M Skovlin History of the Starkey Experimental Forest and Range In 1940, the Starkey Experimental Forest was established. Several years later, its name was change to Starkey Experimental Forest and Range. Today it remains the only forest and range experimental area in the United States. The ex¬ perimental area has been very im¬ portant for the science of range management; many research methods and techniques were de¬ veloped from theories tested there. This publication traces the history of the Starkey Experimental Forest and Range. The author describes how the historical process of com¬ munity development affected the evolution of forest, range, and wildlife exploitation. A list of publi¬ cations from research at the experimental forest and range be¬ tween 1942 and 1988 is included. For a copy of Fifty Years of Research Progress: A Historical Document on the Starkey Exper¬ imental Forest and Range , request General Technical Report PNW-266 from the Pacific North¬ west Research Station. 19 The value and harm of windbreak insects Windbreaks are unique “mini¬ forest ecosystems’’ which contain a variety of unique insects. Even though an abundance of informa¬ tion on insect pests of windbreaks is available, it was never brought together until the Conference of the Entomological Society of America was held in 1988. Atten¬ dees discussed the importance and management of tree insect pests in windbreaks, and the ef¬ fects of windbreaks on the survival and distribution of crop pests. The recently published proceed¬ ings of this conference consist of 9 articles written by scientists with extensive experience in windbreak entomology. Some of the subjects include the effects of windbreaks on the overwintering of boll weevils, the damage caused by pine borers, and the general problems caused by pests in windbreaks. For a copy of Insects of Windbreaks and Related Plant¬ ings: Distribution, Importance, and Management, request General Technical Report RM-204 from the Rocky Mountain Station. Juniper woodlands are valuable habitat for birds Native woodlands constitute only a small portion of the northern Great Plains, yet they provide a special¬ ized habitat for several species of birds. In a recent two-year study conducted in Rocky Mountain juniper woodlands, scientists found that there were consistently more birds, as well as more species of birds, in juniper stands than in neighboring grasslands. The study draws attention to the value of Rocky Mountain juniper stands— they provide food and thermal cover in the winter; migratory cor¬ ridors in the fall and spring; and feeding, nesting and perching sites in the summer. For a copy of Rocky Mountain Juniper Woodlands: Year-Round Avian Habitat, request Research Paper RM-296, available from the Rocky Mountain Station. RMM software helps determine the value of recreation A software program called Recrea¬ tion Market Model (RMM) has re¬ cently been developed to give a “quick and dirty” estimate of the value of recreation. The software was designed to simulate a short- run partial equilibrium market for visits to a single recreation site. It takes into account consumer de¬ mand and the cost of operations of a certain site, as well as travel cost and access fee. In addition, the program can esti¬ mate the supply and demand functions from data supplied by the user. It can even accept func¬ tions estimated externally by other means. If you are interested in ob¬ taining the user's manual for the RMM software, request General Technical Report RM-202, titled User’s Guide to RMM Software: A Short-Run Partial Equilibrium Model for Economic Valuation of Wildland Resource Benefits from the Rocky Mountain Station. 20 Questions and answers on the spotted owl controversy The authors wrote this publication to clarify A Conservation Strategy for the Northern Spotted Owl: Report of the Interagency Scientific Committee to Address the Conser¬ vation of the Northern Spotted Owl. The questions are from a May 1990 hearing of the U.S. Senate Committee on Energy and Natural Resources. Following are examples of ques¬ tions: Do the spotted owls use only old growth throughout their home range? Do you have an ac¬ curate inventory of how many spotted owls exist today in Oregon, Washington, and northern California? And, if the northern spotted owl depends on old- growth timber for essential habitat, why are managed, second-growth forests included in the proposed habitat conservation areas? For answers to these and 108 other questions about a conserva¬ tion strategy for the spotted owl, request Questions and Answers on A Conservation Strategy for the Northern Spotted Owl , Miscellane¬ ous Publication, from the PNW Research Station. United States Department ol Agriculture Forest Servtee Peptic Norttewi n—earcn Station February 1M1 Questions and Answers on A Conservation Strategy for the Northern Spotted Owl 21 Birds in grazed and ungrazed riparian habitat Grazing did not reduce bird pro¬ ductivity or diversity on the West Fork of Deer Creek in northeastern Nevada, Dean Medin and Warren Clary discovered in a study that compared breeding bird densities inside an ungrazed four hectre ex¬ closure with the grazed riparian area outside the exclosure. However, the Intermountain Station researchers did observe species differences between the grazed and ungrazed area. Empidonax flycatchers, warbling vireos, and MacGillivray’s warblers all had higher densities in the exclosure. House wrens and song sparrows preferred the grazed area. In general, insect foraging guilds preferred the grazed communities and herbivorous/granivorous forag¬ ing guilds preferred the ungrazed. Grazing in the study area had not seriously altered the structure be¬ tween the two compared commu¬ nities except in the case of seasonal grass utilization. Shrub biomass, canopy cover, and height were similar in the grazed and un¬ grazed areas. This information is another piece of the puzzle needed to under¬ stand riparian ecosystems, and has added value when combined with the other knowledge acquired by the Riparian Research Work Unit based at the Boise, Idaho Forestry Sciences Laboratory. Request Breeding Bird Populations In a Grazed and Ungrazed Ripari¬ an Habitat in Nevada, Research Paper I NT-441, available from the Intermountain Station. Fuel consumption by prescribed fire in logging slash For managers concerned about sustainability and long-term pro¬ ductivity of forest soils after log¬ ging and slash disposal, this publication provides them with tools to help plan slash fires to leave the desired amount of duff and other organic material on the site. Equations are presented for computing moisture contents for desired levels of consumption. The best slash fires balance be¬ tween adequate site preparation and reducing the fire hazard. The authors recommend levels of fuel loading that seem best for that compromise as well as for guard¬ ing site productivity. 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O ^ 00 CD O CD cn r'h f\3 03 f\D O CO 00 o CO CO CO DO 5 8 8- O d d o' TI O CD CO CD =3 Q. 30 CD d CO CD m X TO CD i' CD d > 3" T o g o' CD I t o' 13 CO g CO CT d O' 13 O 00 r\o cl * (Q CD CD IV) cn CO CD 00 CD 4^ ^ 4^ O d O 3 o c d cd 30 CD CO CD 03 O CO i t CD o d > “0 d g o' CD I < o' d CO g CO cr d o' d T o d =!l ■ d'. 33 Tl O 03 ^ o CD d Q_ o CD CQ o d CD -si rv> o 00 00 o X CO 00 CD o o CD CO 30 CD CO CD 03 O CO cd •• » o' d CO STAMP - STAMP Predicting the behavior and size of crown fires The 1988 fire season demon¬ strated that managers need more and better tools to predict the be¬ havior and size of crown fires, and specialty tools to deal with ex¬ treme fire behavior like that demonstrated during that record setting year. Research Paper, I NT-438, by Fire Behavior Project Leader Dick Rothermel meets part of that demand. Rothermel wrote the paper primar¬ ily for well-trained fire behavior analysts to use in the field when they don’t have computers to as¬ sess the characteristics of running crown fires. This paper provides analysts with new nomograms to help predict wind driven crown fires. Rothermel’s description of the crown fire phenomenon is interest¬ ing and informative for anyone from ground pounders to Regional Foresters who are called on to deal with extreme fire behavior. He explains the natural phenomenon that produced some of the most destructive and fatal fires. He explains the downburst phe¬ nomenon that can occur with plume-dominated fires, sudtr as occurred on the Shoshone Fire in Yellowstone on July 23, 1988, when trees were broken off or up¬ rooted along a 3 1/2 mile front. Plume-dominated fires often seem deceptively safe with strong con¬ vection currents drawing the fire inward. But the convection column can collapse as it did on the Dude fire killing six firefighters in Arizona in 1990. The paper describes indicators that warn firefighters of a soon to occur downburst. Request Predicting Behavior and Size of Crown Fires in the Nor¬ thern Rocky Mountains, Research Paper I NT-438, available from the Intermountain Station. United Stales De panmem of Agriculture Forest Servce Predicting Behavior and Size of Crown Fires in the Northern Rocky Mountains Richard C. Rothermel 25 5 o 2 35 S q: S: to \ ■— =*> CD O C ^ to 5 3' 3. ® £ to to to to 5 ® y* CO o o ti ro 0 £ 3. O 0$ o CD = to 3 '■* to "0 JP 3 « S3, a w-g ® to w w 0-0 o ® s 2. oS2 00 ® o ® cn — r\3 O) > to o' c ® FORESTRY RESEARCH WEST