Visiting the Med Bow
Students of UW’s Environment and Natural Resource Capstone Class have been broken into teams to begin developing an environmental assessment on a real-world problem, a Forest Service proposal to harvest and turn beetle kill trees into biofuel. The teams are focusing on a range of topics related to studying bark beetle kill trees in the Medicine Bow National Forest. The study topics range from forest products to plants and wildlife – from cultural resources and recreation to economics.
Last week, the students and their faculty mentors took a field trip to several sites in the Medicine Bow to see first-hand the impacts of the bark beetle on the forest ecosystem, and most noteworthy, on lodgepole pine, one of the species susceptible to bark beetles in the Medicine Bow because it dominates the landscape. This field trip presented students with an important opportunity to engage with faculty mentors, ask questions, and to see first-hand, in the “classroom” of the Medicine Bow, the devastating impacts of bark beetles on the forest landscape. The students visited Dry Park, Cinnabar Park, and Centennial Valley, and at each site faculty mentors shared their insights on the site-specific management needs and challenges.
One of the things the students observed up-close while hiking in a large forested area impacted by bark beetles and now totally red instead of green were the effects of the infestation both inside and on the outside of the trees. The faculty mentors showed the students several trees in which you could see on the outside what are called “pitch tubes,” which are masses of resin that the trees produce as a defense mechanism in their attempt to rid their trunks of the beetle infestation. Beetles kill trees by boring through the bark into the tree in which they then feed and lay their eggs in what are called beetle galleries, channelized areas of the cambial layer of the tree where the beetles lay their eggs and deposit what is called the blue-stain fungi, which, once established, will block the tree resin response. Faculty mentors pointed out that within about two weeks of the attack, the trees starve to death and their tree layers are damaged enough to cut off the flow of water and nutrients. The students asked a lot of good questions, including what trees are the must susceptible? The mentors said that during the early stages of an outbreak, attacks are limited largely to trees under stress from injury, poor site conditions, fire damage, overcrowding, root disease, or old age. As beetle populations increase, the beetles attack the largest trees in the outbreak area. (For some basic information on the mountain pine beetle, including signs and symptoms, life history and prevention, click here. LINK).
The students also hiked in an area where the Forest Service had removed a large swath of dead trees and the students asked the faculty experts about the Forest Service’s management efforts and harvesting objectives for other areas impacted. The faculty mentors described a variety of management tools for dealing with the beetle kill outbreak, including everything from a total clear cut of the area to a hands-off management scenario.
Students and faculty also discussed some of the suggestions generated by the scientists and forest managers who participated in the Ruckelshaus Institute’s Bark Beetle Workshop, held this month at the UW Conference Center. LINK . The Ruckelshaus Institute is in the process of developing a report on this workshop that will include statements and recommendations made during the breakout groups. Managers can use the resource as a guide for future management decisions and how best to utilize the beetle kill timber.
One thing noted on the tour was that the greatest challenge for forest managers is dealing with the sheer size of the bark beetle outbreak and how to reach desired forest conditions in the future. As the students work toward developing an environmental assessment, they are learning about the interrelated topics which frame the bark beetle epidemic and how these topics will then inform forest management practices. Our faculty mentors discussed the relationship between scales of time and space and a tree’s ability to resist bark beetle infestation (the larger the spatial scale of the forest, the more complex are the challenges posed by implementing forest management protocols).
The nature of fire regimes in the Medicine Bow forest is also of signal importance in the public debate regarding whether or not the continued presence of beetle-kill timber in the Medicine Bow will contribute to an increase in the fire risk. The fire regime in the Medicine Bow is characterized by high-intensity crown fires. Because of this historical pattern, whether timber is healthy and vital or whether it is deadkill as a result of bark beetle infestation is not as material to the management debate as one might think.
The importance of maintaining biodiversity in species numbers and in the “suite” or range of species while managing forest ecosystems, and the need to encourage a diversity of timber harvest composition and forest management practices in order to address the epidemic now and in the future, both hinge on managers’ understanding of the sensitivity of key indicator species. As specialists, the way those species use the habitat as it is affected by both bark beetle infestation and the possible management actions being considered represents a key area of current and future observation and study. As opposed to the generalist species in the affected areas whose habitat needs are less site-specific, specialist species, known more specifically as indicator species, and their needs are critical in creating management plans that will focus on maintaining habitat conditions to support these species. The idea here is if they are “happy,” the other, more generalist species will also be healthy.
The current forest management plan for the Medicine Bow emphasizes silvicultural practices, which control the establishment, growth, and health of the forest (to support desired future conditions). The plan also focuses on how these conditions might include younger stands and increased species, which over time will support resistivity to bark beetle infestation.
Of particular interest to the students was the relationship between soil ecology and current forest structure in the Medicine Bow. They wanted to know more about the ways in which soil chemistry and composition have impacted the species diversity and numbers in the forest over time. As we stood near an open field on the edge of the forest near Cinnabar Park, students discussed and questioned how large openings like the one before them might be managed should logging (what is called a mechanical option) become a viable option for the removal of bark-beetle kill timber. Specifically, a discussion between the students emerged concerning the ethical debate which would arise should the open area be used as a landing area for logging machinery and equipment. They asked what the environmental and ethical implications of this shift in the space’s utility might be: ought the open areas and spaces that define the Medicine Bow as much as do its forests be considered ecological features themselves? And what might this consideration mean in terms of current forest managers’ approaches to forest management and conservation?
One of the highlights for me was visiting a site in Centennial Valley with its ecological features punctuated visually by the presence of large ponderosa pine trees impacted by the infestation. A faculty mentor estimated one of the fallen trees to be approximately 450 years old. They were like sentinels, stalwart in their ecological wisdom of growth rings spanning time as evidence of the distant echoes of the shifts in forest regimes of which they have been a part. They were reminiscent to me of the Galapagos Tortoises, who, like the sentinels of the Medicine Bow Forest, have stood as witnesses to the evolution of a complex and highly diverse ecosystem. To marvel at these species’ experience of geologic time finds a complement in the last line of the poem by James Galvin LINK, who ranches in Tie Siding: “Ponderosa: What were your thoughts, concerning history?” The students seem to be engaging in all manners of questions in their engagement with the work before them. They, like the speaker in Galvin’s poem, are also asking questions of the trees themselves through their intense study and field trip exercises like this one.
Suggested Reading
Context
This paper was written as a resource for managers, describing options to aid in the reduction of bark beetle impact in the intermountain West. Another goal of this paper is to help readers understand the relationship between bark beetle management, populations, fuels and fire hazard and behavior.
Synopsis
This paper discusses various fire regimes (fire risk, hazard and severity) among a variety of tree species, the ecology of various types of bark beetles, the impacts bark beetles have upon forest fuels, the relationship between fire behavior and stage of beetle infestation, strategies for managing bark beetle and the implications they carry for fuels and fire behavior, the implications management strategies have for bark beetles, and ideas for future research.
Context
The intent of the paper is to inform forest management in the face of fire and insect outbreak. The focus is primarily on ecological factors associated with fire and insect outbreak, rather than factors associated with economics, wildlife, recreation, aesthetics and other elements of forest management. The paper is organized around key questions about the ecology of insect outbreaks.
Synopsis
The authors argue that responses to insect outbreaks and fires must be consistent with the ecology of the affect forests. The paper addresses which insect species are prevalent in the outbreaks in Colorado forests, reasons for the intensity and geographic scope of the current outbreak, fire behavior and intensity over the last 100 years, how insect outbreaks and fire are related, and how water quality and flow are affected by insect outbreaks. The authors also synthesize several management options.
Links
Basic bark beetle info:
http://www.ext.colostate.edu/pubs/insect/05528.html
Bark beetle workshop:
Info on poet James Galvin:
Well done article but it’s a little annoying for an author to link to a paper (Jenkins et al.) that’s behind a paywall.