Table Of Content

Historic, Archive Document Do not assume content reflects current scientific knowledge, policies, or practices. - Qw^D \\ S United States * £ k? Department of -3- Agriculture Forest Service November 1994 — ':j6 CO oO •->j A report for land managers on Forest^ recent developments in forestry research at the four western Experiment Stations of the Forest Service, U S. Department of Agriculture. In This Issue To Order Western Forest page Publications Experiment Stations Mountain pine beetles Single copies of publications referred to in this magazine are may use “antifreeze” available without charge from the Pacific Northwest Research Station to survive the cold 1 issuing station unless another (PNW) 333 S.W. First Avenue source is indicated. See page 23 A view from the top: Portland, Oregon 97204 for ordering cards. canopy crane enhances ecosystem research 5 Each station compiles periodic Pacific Southwest Research lists of new publications. To get Station (PSW) Methods of cutting study has on the mailing list, write to the P.O. Box 245 unexpected benefits 9 director at each station. Berkeley, California 94701 Can Southwest aquatic To change address, notify the Intermountain Research Station habitats and fishes magazine as early as possible. (I NT) be sustained? 13 Send mailing label from this 324 25th Street magazine and new address. Don’t Ogden, Utah 84401 New from research 18 forget to include your Zip Code. Rocky Mountain Forest and Permission to reprint articles is not Range Experiment Station (RM) required, but credit should be 240 West Prospect Street Cover given to the Forest Service, Fort Collins, Colorado 80526-2098 U.S.D.A. Entomologist Barbara Bentz, Intermountain Station, collects Mention of commercial products is samples of mountain pine beetle for information only. No endorse¬ larvae from a lodgepole pine tree. ment by the U.S.D.A. is implied. Scientists are investigating how the tiny but devastating insect survives winter cold. Read about it beginning on page 1. MPB may use by Cindy Chojnacky Intermountain Station “antifreeze” to survive the cold The work has meant frozen fingers, long treks on snowshoes and four trips a month to three states to visit lodgepole pine stands infested with mountain pine beetle. But researchers at the Intermountain Station’s Logan Forestry Sciences Lab have gained new insights into how the tiny but devastating insect yearly survives winter cold, emerging each summer to attack and kill pine trees throughout the West. The research is part of a long¬ term project to model mountain pine beetle phenology — the beetle’s survival strategy or process it uses to synchronize its life cycle with environmental conditions. If researchers know how environment affects the To collect the sample, Logan inscribes a insect’s life cycle, they can As part of this assessment, circle, carefully removes the bark, and predict beetle population trends Entomologist Barbara Bentz is then collects beetle larvae from the — giving resource managers a phloem beneath. learning how temperature drives better handle on when and where mountain pine beetle beetle epidemics may occur. development. This is a key part of the tiny insect’s strategy in its Infrequent mountain pine beetle The mountain pine beetle continual war against the pine outbreaks can affect large land Dendroctonus ponderosae tree. The beetle infests green areas. For instance, more than 4 Hopkins is both an economically trees, constructs vertical egg million acres per year were serious pest and a critical galleries, and lays eggs in the infested in the West between component of western forest phloem, where its young will live 1979-1983, killing more than 15 ecosystems, according to and grow. The network of million trees a year. However, the Mountain Pine Beetle Project galleries ultimately girdle a tree, beetle is also a natural part of Leader Jesse Logan. killing it by cutting off flow of forest ecosystems and has nutrients and water from its roots. helped shape their scale and pattern. The mountain pine beetle The tree’s aim is to spit out the project is building on 32 years of invaders A vigorous tree will research to assess the insect in expel or “pitchout” beetles with a its broader ecological context. copious flow of resin. 1 A key weapon for the beetle is The cycle Somehow, the lifestages synchronous emergence — the synchronize development so that ability of adult beetles to emerge It usually starts in early August, by the time the brood has within a short time period, when mature adult beetles developed to the adult stage the following August, the mature regardless of when they started emerge from their host trees, fly, their life cycle the previous fall. attack live trees, and begin adults are ready to emerge within “This is crucial for the successful building new galleries and laying a 3-4 week time span. Bentz, Logan and past Project Leader attack by a small, weak predator eggs. At higher elevations, Gene Amman hypothesize that (beetle) on a large dangerous however, because of colder inherent temperature thresholds prey (pine trees),” says Logan. temperatures, the mountain pine in the different lifestages help in beetle life cycle can take up to this synchronization. Ongoing But how do they do it? 2 years. research is testing this Temperature seems to be the key hypothesis. factor driving phases of the Oviposition (egg-laying) of new beetle's life cycle. At lower brood may last as long as two Beetles progress through five elevations in the West, that cycle months, depending on the onset different stages: eggs, larvae, is a year long. of cooler fall temperatures. pupae, brood adult and parent adult. Larvae hatch in fall and further develop from September- June through four stages called instars. The length of time spent in each instar is dependent upon temperature. Bentz’ dissertation work involved developing a computer simulation model to predict the temperature- development relationship. The winter surveys are part of work to validate the model by comparing larval development to temperatures in its environment. The project started in July 1992. Four sites close to beetle-infested lodgepole where chosen near Victor, Idaho; two sites in the Sawtooth National Recreation Area in Idaho; and one in Logan Barbara Bentz, entomologist with the Logan Forestry Sciences Laboratory Canyon, Utah. Five to ten trees Mountain Pine Beetle Project, huddles in were baited with a synthetic the snow as she records mountain pine pheromone that attracts beetles. beetle data. 2 After beetle flight, the researchers Success at last Detailed studies to help monitored beetle colonization of understand this process are the trees and placed temperature planned for this fall. David Gray, But the cold has been worth it. probes in the phloem on the a scientist at Virginia Polytechnic Bentz has discovered how pine north and south side of each Institute and State University beetle larvae and adults winter tree. The probes provide hourly (VPI&SU), cooperated with the over in the phloem of lodgepole temperature readings. “We researchers to build specialized trees, surviving temperatures as measure phloem temperatures, cold temperature cabinets. The low as -35 degrees Centigrade. the environment where the beetle cabinets will be used to test the lives, every hour for its entire life response of beetle lifestages to For insects, a common winter cycle,’’ says Bentz. This past year varying rates of temperature survival strategy is diapause - a new experiment was initiated change, intensity, and duration, kind of a mini-hibernation on the Dixie National Forest, and their ability to cold-harden. triggered by lower temperatures where mountain pine beetle infest Don Mullins, also at VPI&SU, is or shorter days (photo period). ponderosa pine. helping to identify the Other insects escape to warmer compounds used by the areas. The mountain pine beetle To monitor beetle development, mountain pine beetle to survive does not have a known diapause, Bentz has visited each site the long cold periods in western and Bentz has found the larvae, monthly to sample larvae over the lodgepole pine. which remain in the phloem, are past two years. Biological often in an environment as cold Technicians Lynn Rasmussen and “Conventionally, people have as the air temperature in the Jim Vandygriff usually help. At thought that mortality was highest stand. These beetles are times, even Project Leader Logan in the mid-winter," Bentz says. “I obviously not escaping the accompanies the crew and think more mortality occurs in the extremes of winters in the West. freezes his fingers, too. For each spring and fall when you have Instead, it seems the mountain sample, they cut out a circle of the most extensive phloem pine beetle's strategy is bark, extract the live eggs, temperature fluctuations, as high chemistry. “The insect produces a larvae, pupae and adults and as 30-40 degrees in a day.” chemical sort of like ‘antifreeze’ " place them in alcohol. Back at Sudden changes in temperature Bentz explains. Lowered the lab, insects are placed under do not give the beetles adequate temperatures apparently prompt a microscope and measured. time to metabolize the necessary the insect to synthesize a polyol “The only way you can determine chemicals. (e.g. glycerol) that keep its what larval instar they are in is to tissues from freezing at measure the width of the This information on when and temperatures well below 0 headcap which changes as they how mortality occurs will also be degrees C. This cold-hardening molt from one instar to the next,” added to Bentz' phenology process is complex and depends explains Bentz. model. on the rate, duration and intensity of exposure to cold temperatures. “Although many researchers have Temperature seems to be a studied the beetles, no one had driving force in pine beetle ever sampled them in their population responses year-round. natural environment in the middle The past 2 summers have been of winter before,” Bentz says. “It’s extremes, in terms of weather. hard to. Here you are, out in the Last year was cold and rainy, snow, your fingers freezing, while this year it is hot and dry. holding a knife and tweezers in your teeth, trying to scrape larvae into a vial. It’s a slow, cold process.” 3 The beetles have responded accordingly. They flew much later in 1993; this year, they flew early. “The beetles are responding to these extreme conditions and it’s exciting to be measuring their response," Bentz says. The phenology model has both management and research applications. For instance, managers could use such predictions in the Bridger-Teton National Forest in western Wyoming, where trees are beetle- infested in campgrounds along the Snake River. “Managers are wondering if they need to spray, but they don’t want to because the area is also eagle habitat. If the model predicts a lot of mortality, for instance, they may not need to spray. Or it may show where and when they need to spray. “Predicting actual population numbers may be unrealistic, but we hope to be able to predict trends — whether the population is going up or down,” adds Bentz. “Also, the phenology model is allowing us to test research hypotheses on the long term role of the mountain pine beetle in the forest ecosystem.” Bentz scales a ladder for the cold, arduous task of collecting larvae. 4 Canopy crane by Sherri Richardson Pacific Northwest Station enhances ecosystem research In February 1992, two scientists The visit to the rain forests also there with the birds and suddenly from the Pacific Northwest Station was the first step in the you are seeing things from their - Cathy Rose and Martin development by the Station and perspective. You see monkeys Raphael — spent 10 days with a the University of Washington of a and all kinds of wildlife you never team of researchers deep in the similar project in the old-growth see on the ground. Researchers hot, humid rain forests of Panama forests of the Northwest — in the tropics who were the first and Costa Rica to observe the making it the second of two such to go up in the trees were so operational aspects of several structures in the world. surprised about what they found canopy access systems. They — many species they had never were particularly interested in a When Forest Ecologist Rose first even known existed. It was as if crane installation used by the went up in the gondola of the people finally understood what Smithsonian Tropical Research crane high above the tree tops in the word biodiversity really Institute — a pioneer in the use the Panama City park where the meant." of construction cranes for canopy crane is located, she called it a research. sensory experience. “You are up Wildlife Biologist Raphael used the word “fantastic" to describe the first time he went up in the gondola. “The experience struck me as a marvelous way to view a canopy with minimal disturbance, basically, without touching anything. It was an unmatched opportunity." The 80-foot-high apparatus Rose and Raphael were referring to is patterned after a tower crane typically used in building construction. The crane has a gondola that scientists can work inside of that will lower them to almost any location in a 2-hectare arc of the forest. The researcher can then observe the uppermost branches of trees to study the broad variety of life that lives in the canopy. The scientist can be raised and lowered from within the gondola by signaling to an operations technician controlling the crane. Forest Canopy Crane. (A) tower, (B) load jib, (C) counter-balance jib. (D) operator's cab, (E) gondola. Illustration Robert Van Pelt. 5 Examining crane During the Costa Rica and Installation of canopy operations in Panama Panama trip Franklin participated crane in Pacific in, the team observed the pros and Costa Rica Northwest underway and cons of several canopy research systems used by The 1992 Trip that Rose and scientists in the tropical rain For the past 3 years, the Pacific Raphael participated in also forests. Northwest Research Station, in included Jerry Franklin, former partnership with the University of PNW researcher and now an • Fixed towers — employs Washington, has been working on ecologist at the University of scaffolding stairs; finding a site for a 300-foot-tall Washington and the prime mover disadvantage is that this steel and concrete crane for behind launching the $1 million allows observation from only research in the old-growth forests canopy crane project in the one point of the canopy of the Northwest. In June 1993, a Pacific Northwest; Gordon Smith, site was finally found in Skamania David Shaw, and Dean Berg of • Rope systems — employs County, Washington, in the Wind the Olympic Natural Resource climbing ropes installed at River Experimental Forest, which Center; and Robert Szaro, Forest fixed points; disadvantage is is part of the Gifford Pmchot Environment Research, Forest this causes disturbance to National Forest. Service, Washington Office. plants and other forms of life According to Project Coordinator Franklin first got the idea of using • Ladder systems — employs a John Henshaw, the site was a crane system in the Pacific ladder mounted on a tree; selected by scientists for its Northwest about 4 years ago disadvantage is ladder allows “excellent example of old-growth while attending a meeting in access to only one spot forests and the close power Denver on global climate change. supply at the Wind River Nursery Present at the meeting were The team also visited a canopy needed to operate the crane." scientists from the Smithsonian research site in Monteverde, Tropical Research Institute who Costa Rica, in which several The road to the recently signed shared information about the large trees had been installed memorandum of understanding project. “I was very excited about with the rope system. “We all among county officials, the using the crane here and took turns wearing climbing Station, and the University of immediately followed up on the harnesses and ascending ropes Washington was not a smooth idea by contacting several using specialized devices,” one, however. Two sites, Forks Congressmen who were equally Raphael explained. “I certainly and Quinault, Washington, also enthusiastic,” recalled Franklin. appreciated the advantages of were considered before the Wind “The crane will open up whole crane-based access after this River location was selected. new areas of research and any experience!" “Project planners changed their knowledge [about the forest] can minds about Forks because the only by helpful.” The crane will area was not thought to have the belong to the University of key elements the scientific Washington, and Franklin will be community believed were the principle investigator for the necessary to complete the research. project," Henshaw explained. 6