Activities:
Time Period: June 1, 2004 - May 31, 2005
This research concerns interactions between below- and above- ground processes. Specifically, we are conducting long-term studies to test the hypothesis that tree mortality and gap formation occur by the following sequence: a) root herbivores and their associated fungi colonize roots of red pine trees, b) colonization by these organisms is not lethal, but rather compromises defenses against subcortical insect - fungal complexes that exploit the main stem; c) colonization by the latter group of bark beetles and fungi is lethal to trees; d) root fungi spread to adjacent trees through root grafts; e) trees continue to be killed in a progressively expanding gap.
We completed plot establishment at 31 sites throughout Wisconsin. They are arranged along a transect from southeastern to west central. We monitored populations of root insects, bark beetles, and predators throughout the summer of 2004. These species were sampled using funnel traps baited with racemic ipsdienol plus lanierone, funnel traps baited with ipsenol, pitfall traps baited with alpha pinene plus ethanol, and lower stem flight intercept traps baited with alpha pinene plus ethanol. We identified these insects to species during the winter. The total number of insects among treated and untreated plots was approximately 77,500. The major herbivores were the phloeophagous beetles Ips pini (47292) and Ips grandicollis (6516). The major root and lower stem feeding herbivores were in the genera Hylastes, Hylobius, and Dendroctonus. The predominant predators were Thanasimus dubius (Cleridae) (7312) and Platysoma (Histeridae) (2659). A total of 34 species were collected in this phase of the study. All of these data are online for use by all team members. It is at ; Study Sites & Data > Root Insect, Bark beetle & Predator Data.
During the summer and autumn of 2004, we completed spatial referencing of all trees in the study sites. The data are in Arc Info, and are ready for spatially explicit statistical analysis. The data maps are at the above web site via Study Sites & Data > Individual site maps. This portion of the project was done under the direction of co-PI Volker Radeloff. It was conducted by two undergraduate students, including one REU.
During the winter of 2004/2005, we evaluated all trees at each of the sites for insect and disease activity that occurred during the summer of 2004. Each tree was evaluated for the presence / absence of Dendroctonus, Ips, and Monochamus, as well as its overall condition. The roots of a subset of trees were sampled for Hylobius weevils. Data tabulation is complete. Data are uploaded at the above web site via Study Sites & Data > Tree Mortality & Insect Infest. This portion of the project was conducted in close collaboration with personnel from the Wisconsin Department of Natural Resources, under the direction of co-PI Jane Cummings-Carlson.
Stands were sampled for general beetle biodiversity throughout the summer of 2004, using unbaited pitfall traps, and for flying insects, using flight intercept traps. Identification and tabulation of these insects is partially complete. To date, 49 families are represented. These data are uploaded and are at the above web site via Study Sites & Data > Insect biodiversity. This portion of the work is under the direction of co-PI Dan Young, with assistance from director of the UW Insect Research Collection, Steve Krauth.
Co-PI’s Brian Aukema and Jun Zhu have begun statistical analyses of spatially explicit * temporal data from observations of insect colonization collected from 1986 - present. They have engaged in a new collaboration with Jesper Moller and his graduate student Jakob Rasmussen, both from Denmark. Prof. Moller is a world authority on modeling spatial / temporal processes. They are jointly developing discrete and continuous models. Prof. Moller presented a talk in the UK this spring on our long-term data set from. It is posted the above web site via Study Sites & Data > Each site with injury ratings each yr > Bakkens Pond 1986 - Present
We baited all of the funnel, pitfall, and lower-stem flight intercept traps for this year’s sampling by April 15, 2005. Sampling is underway and will continue until flights disappear, typically around late September - early October. These insects are being identified and tabulated as they arrive. We deployed all of the unbaited pitfall traps and flight intercept traps by mid - late May. These insects are being pinned and processed as they arrive.
We have used our LTREB network of field sites as a platform to attract additional scientists. In addition to Prof. Moller’s involvement in the spatial * temporal statistical portion, Enrico Bonello, OSU Dept. Plant Path, has joined our collaboration. He and his team will study tree physiology and chemistry. Prof. Bonello is an international authority on chemical communication between roots and stems in woody plants. He will use our sites as a platform for testing his mechanistically based model on how tree constitutive and inducible resistance may change with root stress. We have identified sites for Prof. Bonello and his postdoctoral associate.
We developed a web page to both foster team communication, and advertise NSF’s support of this work. It is at and is accessible through many links. Portions of it are public: Objectives, team members and links, research site locations, proposals, progress reports, publications & presentations, etc), and other portions are currently for team members only (intended to be depositories of data, including raw data that might need subsequent proofing), so that everyone in the team can gauge immediate progress, do preliminary analyses, estimate timetables, coordinate logistics, etc. We are sending the username and password to NSF by separate email. We have met often as subgroups, and have had two full-group meetings since our last progress report. These were on March 16, 2005, and June 10, 2005.
Immediate Goals
During the remainder of this year (June 2005 – May 2006), our primary goals are a) continued sampling of root insects, bark beetles, and predators, b) sampling arthropod biodiversity in each of the above stands, and in asymptomatic portions of symptomatic stands c) identification, tabulation, and data entry of insects, d) evaluation of insect colonization and tree mortality that occurs during 2005; e) continued development of procedures for statistical analyses of spatial * temporal data; f) preparation for launching predator-prey component of study during 2006 field season under the direction of co-PI John Reeve, and h) preparation for 2006 season (trap repair, site visits, ordering semiochemcials and supplies, etc).
Presentations and Publications
Raffa KF, Aukema BH, Erbilgin N, Klepzig KD, & Wallin, KF. 2005. Interactions among Conifer Terpenoids and Bark Beetles across Multiple Levels of Scale: An attempt to understand links between population patterns and physiological processes. Rec. Adv. Phyochem. 39: 80-118.
Canadian Forestry Service, and University of Quebec. April, 2005. Feedbacks between chemical signaling and population dynamics: A mechanistically based approach to understanding eruptive herbivores.
Univ. Northern British Columbia. Sept. 2004. Bark beetles in conifers: When do boring insects become dramatic?
Joint meeting of the International Society for Chemical Ecology & Phytochemcial Society North America. July, 2004. Ottawa, Canada. Interactions among conifer terpenoids and bark beetles across multiple levels of scale: An attempt to understand links between population patterns and physiological processes. K.F. Raffa
Workshop on Recent Advances in Modeling Spatio-Temporal Data, May 25-26, 2005, Southampton, UK. Møller, J., Zhu, J., Rasmussen, J.G., Aukema, B.H., and K.F. Raffa. "Spatio-temporal models for red pine decline."
Findings:
The total number of root and subcortical insects was approximately 77,500. The major herbivores were the phloeophagous beetles Ips pini (47292) and Ips grandicollis (6516). The major root feeding herbivores were in the genera Hylastes, Hylobius, and Dendroctonus. The predominant predators were Thanasimus dubius (7312) and Platysoma (2659). A total of 34 species were collected in this phase of the study. Forty-nine additional families of beetles were obtained in the biodiversity component.
A novel approach to spatial-temporal analysis of interactions between below-ground herbivory and above-ground processes such as gap formation was developed based on Markov Chain Monte Carlo simulations. It is applicable in both discrete and continuous time, and in conjunction with covariance data such as weather information.
Contributors
The following individuals have contributed to the above results. Their roles are listed by project objectives.
Insect Sampling & Identification:
Co-PI’s: Kenneth Raffa, Daniel Young
Curator, UW Insect Research Collection: Steve Krauth
Undergraduates: Robert Murphy, Matt O’Brien, Katrien Werner (REU), Robyn Vershay, Jason Jones
LTE’s: Renee Pinski, Stephanie Eastwood
Site Mapping:
Co-PI: Volker Radeloff
Undergraduates: Adam Ridley (REU), Joseph Lennart, Brian Milligan
Evaluation of Insect Colonization & Tree Injury
Co-PI’s: Kenneth Raffa, Jane Cummings Carlson
Wisconsin DNR: Sally Dahir, Kyoko Scanlon, Mark Guthmiller, Todd Lanigan
Undergraduates: Robert Murphy, Maggie Grosenick
Statistical Analyses:
Co-PI’s: Brian Aukema, Jun Zhu
Cooperators: Jesper Moller
Graduate Student: Jakob Rasmussen
Training
We have established training opportunities at several different levels. These students are from various disciplines, and so we feel this blending of talents is one of the most instructive aspects of this project for young scientists. Students are gaining an opportunity to work both independently and in teams. Five of the 11 undergraduates and LTE’s are women.
Undergraduate level:
We have hired 9 undergraduate students and established programs for three REU students. These students are conducting research within the framework of this overall study, but also have their independent portions. One is taking responsibility for the vegetation-mapping component. This individual is a Forest Ecology & Management major, and is under the direct supervision of Prof. Volker Radeloff. The other two REU students are assuming responsibility for the arthropod biodiversity component. They are entomologists, and are under the direct supervision of Prof. Daniel Young. The two REU students work largely as a team.
A Forest Ecology & Management major is engaging in this project to fulfill his “Professional Experience” requirement for his BS degree. This individual is assuming primary responsibility for coordinating activities between the University of Wisconsin and the Wisconsin Department of Natural Resources. A complete training program has been developed for this individual. In addition to salary, he will receive academic credit. In addition to his liaison capacity, he is involved in plot establishment and insect sampling.
Graduate level:
Prof. John Reeve has recruited a graduate student, who will conduct the portion of this project investigating the role of insect dispersal in tree mortality. Specifically, he will investigate movement by Ips pini and Thanasimus dubius.
We are mentoring a Danish student, Jakob Rasmussen. We are also mentoring 2 LTE’s.
Postdoctoral Level
Dr. Brian Aukema has been working on the spatial modeling components of this project, in conjunction with Prof. Jun Zhu and Prof. Murray Clayton. He has also been gaining experience in mentoring, assuming partial responsibility for one of the undergraduates involved (see above).
A visiting scientist from France, Auerlien Salle is focusing on how breeding density affects the host selection behavior of Ips pini.
Outreach
This project has had an extensive outreach component. Scientists from UW-Madison and the Wisconsin Department of Natural Resources have jointly engaged in the following:
- Wisconsin DNR and UW-Madison personnel jointly presented the rationale and description of this work to land-owners and forest managers across Wisconsin.
- Kenneth Raffa gave a presentation to the Wisconsin DNR in Jan. 2005.
- Kenneth Raffa (UW-Madison) and Jane Cummings Carlson (WI DNR) have incorporated this project into a presentation and field trip for the upcoming North Central Forest Pest Work Conference.