Transferring Knowledge of Shrub Ecology and Management to Promote Integrated Vegetation Management on Powerline Corridors

Christopher A. Nowak, Ph.D.
The Research Foundation of State University of New York, for and in conjunction with, State University of New York, College of Environmental Science and Forestry
220 Marshall Hall
1 Forestry Dr
Syracuse, NY 13210
315-470-6575
315-470-6956 (fax)
canowak@esf.edu

Executive Summary

Knowledge of Integrated Vegetation Management (IVM) has grown in New York State. Key to our growing knowledge is the philosophy and principles for culturing desirable plant communities that minimize the presence of undesirable plants, in our case—trees. To meet this end, shrub communities are most commonly featured as the desirable plants. We are just now finalizing important steps in our learning about the ecology and management of shrubs. Through 20 years of practice and research, knowledge of shrubs and other aspects of management have been woven into the IVM approach.

Application of IVM for powerline corridors leads to ecological control of undesirable tree populations. Stable, diverse, short stature shrub communities are fostered to minimize the development of tall growing trees. As undesirable tree populations are minimized using IVM, the need for various treatments, especially chemical, are also minimized, as are the associated risks. This approach has worked in New York for over 20 years. Herbicide use has been reduced by at least half over that time.

In our project, we propose to develop a knowledge transfer package that captures what the electric utilities and research communities in New York State have learned about IVM. Specifically, we propose to reduce herbicide use and associated risk on powerline corridors across the U.S. by: (1) developing a training manual for practitioners covering the topics of IVM, focusing on shrub ecology and management; (2) creating a website on IVM; (3) conducting a two-day short course on IVM and shrub ecology and management; and (4) producing a final report that documents practitioner responses to the training manual, short course and website, includes a final, revised version of the manual, and presents the "how to" for using the training manual and conducting a related short course.

Objectives

Herbicide use and associated risk on powerline corridors across the U.S. will be reduced by:

developing a training manual for practitioners covering the topics of Integrated Vegetation Management, focusing on shrub ecology and management;
creating an IVM website which will serve as a source of accurate knowledge/information for the general public and professionals alike;
conducting a two-day short course on Integrated Vegetation Management and shrub ecology and management using a combination of classroom lecture and field demonstration, featuring the use of the training manual developed for Objective No. 1; and
producing a final report that documents practitioner responses to the training manual and short course, includes a final, revised version of the manual, and presents the "how to" for using the training manual and conducting a related short course.

Justification

Integrated Vegetation Management (IVM) follows the well-established principles and practices of Integrated Pest Management (Wagner 1994; McLoughlin 1997). In IVM, the pest is recognized as some form of vegetation. On powerline corridors, the pests are tall growing trees that can interfere with the safe and reliable transmission of electricity.

Over the past 20 years, the utilities in New York State have developed a system of IVM that has led to the progressive reduction in herbicide use (Finch and Shupe 1997). Trees are selectively removed from powerline corridor plant populations using a combination of chemical and mechanical methods, and desirable, low growing plants—mainly shrubs—are fostered to a level of dominance (Nowak et al. 1992a; Ballard et al. in press (b)). While trees do invade shrub dominated communities (Nowak et al. in press(a)), they do so relatively infrequently and grow more slowly than in an area without shrubs, which allows for subsequent management efforts to be reduced, including a reduction in herbicide use (Nowak and Abrahamson 1993).

For the objectives listed in Part II above, the potential outcome in terms of reducing negative environmental impacts, human health effects, and pesticide risk and use, collectively contribute to the project goal—to reduce the use and associated risks of herbicides on powerline corridors across the U.S.—by providing information and developing knowledge on IVM and shrub ecology and management for use by practitioners and managers and educating the general public (e.g., via the website). Much information has been published over the past two decades on powerline corridor vegetation management and IVM, most of this from research and monitoring in New York State. Shrub ecology and management is under continued investigation, from field identification to directing population dynamics. Yet, IVM and shrub management is not conducted on most powerline corridors across the U.S. Transfer of knowledge gained in New York should lead to more sophisticated vegetation management on powerline corridors across the U.S., with a corresponding, significant reduction in the use of herbicides to manage vegetation.

Literature Review

Integrated Vegetation Management on Powerline Corridors

Powerline corridors are important technical and ecological features of the landscape. Tens of thousands of miles of such corridors traverse North America. Electricity is carried over metal conductors from generation facilities, through substation processing centers, to distribution facilities. Vegetation on corridors under these conductors is managed for low growing plant communities to: (1) provide for the safe and reliable transmission of electricity, (2) facilitate access for repair or construction activities, and (3) potentially provide other values (e.g., wildlife habitat, recreation). Tall growing plants, mostly trees, that grow into the conductor security zone (a zone of air space around each conductor) can cause electricity to arc through the tree to the ground, causing a ground fault that disrupts service and makes for unsafe conditions on the ground.

Vegetation management on powerline corridors in New York favors the long-term presence of herbs, shrubs and low-growing trees. These short stature species reduce the presence of undesirable tree populations through competition and other ecological mechanisms, and allow for safe and reliable transmission of electricity by maintaining a security zone around the conductors. Most all species of shrubs and short trees are considered to be desirable components of ROWs, yet we are just now learning about their ecology and management.

Integrated Vegetation Management is used across New York State to sustainably produce desired vegetation conditions and associated values. Vegetation is managed with a blend of physical, chemical, cultural, and biological treatments for suppressing pest plant populations (tall growing trees) to tolerable levels (McLoughlin 1997). In IVM for powerline corridors, the integrated application of these treatments leads to ecological control of pest tree populations, whereby stable, diverse, short stature plant communities are fostered to minimize the development of tall growing trees. As pest tree populations are minimized, the need for various treatments, especially chemical, are also minimized. This ecological control of vegetation is a key product of IVM, and a key to reducing risk from using herbicides.

Ongoing IVM Research at SUNY-ESF Related to Shrub Ecology and Management

A large research program in IVM has been conducted at the State University of New York College of Environmental Science and Forestry (SUNY-ESF) since the late 1980s. Currently, we have 15 ongoing studies and our research budget over the last decade has totaled nearly $1,000,000. Primary funding agencies have been the New York utilities, but also includes the Electric Power Research Institute as a co-funder on shrub research. The New York State Public Service Commission, which has regulatory control of the utility industry, has been a staunch supporter of the program (D. Morrell, pers. comm.).

Vegetation communities have been long studied on powerline ROWs in the eastern U.S., particularly in New York State (ESEERCO 1977, 1985a,b; Nowak and Abrahamson 1993; Nowak 1993; Canham et al. 1995). Most past research has focused on undesirable plants—tall growing trees. This makes practical sense, since the focus of management is primarily on controlling undesirable components that can jeopardize safe and reliable transmission of electricity. Control of trees is accomplished directly through cultural treatment and indirectly by establishment of desirable plant cover that can effectively interfere with the trees. Shrub communities are generally viewed as the most effective desirable plant community. Egler (1953) promoted the culture of shrubs on powerline corridors for both pragmatic and non-tangible values. Niering and Goodwin (1974) demonstrated that shrubs could be dominant, stable communities on corridors. In general, while shrubs have been recognized as important desirable plants, little is know about shrub community dynamics.

Understanding how the distribution, composition, and abundance of herb/shrub communities found on ROWs vary as a function of physiographic (site) conditions, past land use, treatment history, adjacent land use, and age of the ROW, and how shrubs respond to specific treatments (e.g., mowing) will improve our ability to predict the future condition of vegetation on a ROW. Management of herb/shrub communities can be adjusted to meet management objectives based on an understanding of the factors that influence shrub dynamics. A large portion of our ongoing work focuses on understanding and managing shrub communities, highlighted in the following five ongoing studies. These studies are all nearly complete, and will be able to provide much new information on shrub ecology and management for inclusion in the training manual and short course.

Study 1 - Competitive hierarchies of desirable plant communities

Plant communities found on powerline corridors are known to vary in their ability to inhibit undesirable tree seedling establishment, survival, and growth (Hill et al. 1995). Our study is confirming this notion for common plant communities found on powerline corridors in New York State, including four important shrub communities and two herbaceous communities. Two approaches are being employed: 1) stem analysis (static life-history tables) and 2) seedling demography of trees growing in each community type. Site-specific understanding of which communities are better at interfering with trees will enhance manager's abilities to foster stable, desirable plant cover.

Study 2 - Select shrub life histories: An annotated bibliography

The objective of this study was to develop an annotated bibliography that contained references important to the vegetation manager in understanding the life histories (e.g., reproduction, growth, and longevity) of common shrubs (Cornus spp., Rubus spp., and Viburnum spp.) in the northeastern United States. The annotated bibliography includes summaries of 77 articles. The completed document is being published by EPRI (Ballard et al., in press (a)).

Study 3 - Factors influencing the distribution and abundance of shrubs on ROWs in New York State: An observational study

The objective of this study is to determine what factors have influenced the distribution and abundance of shrubs on powerline corridors across New York. Distribution, composition, and abundance of shrub/herb communities found on corridors are expected to be a function of physiographic (site) conditions, past land use, treatment history, adjacent land use, and age of the corridor.

Study 4 - Assessment of cultural treatments to increase and maintain the presence of desirable shrub communities: A manipulative field experiment

While shrub communities are generally viewed as the most effective desirable plant community at minimizing colonization by undesirable, tall-growing trees, there is much to learn about shrub community dynamics. Of specific interest is understanding how various shrub species are affected by specific ROW treatments.

The objective of the study is to determine how shrubs respond to coppicing (i.e., handcutting with brush saws) to improve our understanding of the growth strategies that allow shrubs to increase or maintain their status in the early successional plant communities on ROWs. This study focuses on the response of individual shrub clumps of two species—arrowwood (Viburnum dentatum var. lucidum Aiton) and gray dogwood (Cornus racemosa Lam.)—to coppicing on a range of mesic site conditions.

Study No. 5 - Common shrubs and short trees in New York State: Identification and management on powerline corridors.

There are at least 75 species of shrubs and short trees (< 6 m tall at maturity) in New York State. Some of these plants are nonindigenous and invasive. We are developing a field guide for practitioners so that shrubs can be readily, correctly identified in the field. The first step in managing a plant community is to be able to correctly identify the plants, particularly when choices need to be made on what plants to remove, and what plants to keep. Shrubs need to be identifiable in relation to trees and for shrub-specific treatment (e.g., removal of non-indigenous invasives). The field guide is due for a first printing in December 2002.

Approach and Methods

Training Manual

A training manual will be constructed that describes IVM using the following steps as a framework (adapted from Witter and Stoyenoff 1996; Nowak et al. in press (b)):

Understanding pest and ecosystem dynamics
Setting management objectives and tolerance levels
Compiling treatment options
Accounting for economic and ecological effects of treatments
Site-specific implementation of treatments
Adaptive management and monitoring

Each step will have teaching material developed for a 30 minute lecture, including at least 30 powerpoint images to support each lecture, an accompanying script, and a listing of at least 10 refereed articles on the subject. The context of the lectures and literature review will be on powerline corridor IVM, but references and implications will be drawn from, and can be drawn to, other disciplines as well (e.g., forestry). We expect that one-third to one-half of the computer images will be original field photos from our ongoing research.

The section on Step 1—Understanding pest and ecosystem dynamics—will be expanded by adding sections on shrub ecology and management to cover the following:

Species identification
Common life history traits (e.g., reproduction, growth, and longevity)
Community ecology
Resource valuation (e.g., wildlife habitat)
Non-indigenous and invasive species
Cultural treatments for directing shrub dynamics

Shrubs common to the northeastern U.S. will be highlighted (e.g., gray dogwood and arrowwood). While this approach may seem parochial, we believe the deliverables (manual, course, website, report) could serve as a model and be readily tailored for use in other regions. Also, the training manual should be directly applicable throughout the northeastern U.S., from Pennsylvania to Maine.

Our training manual will be made available by CD and by website (see Final Report section below).

Website

An IVM website will be created in the SUNY-ESF domain that features downloadable files of the training manual and related products produced in this study. Links to other information will be included. The site will serve as a source of reliable information on IVM, including herbicide use on powerline corridors and shrub ecology and management, for use by vegetation managers, other professionals, students, and the general public. Comments and suggestions for improvement on the presented materials will be asked for as part of the website. The website will be maintained for at least one-year post project.

Short Course

A two-day short course is planned in Tully, New York, in September 2003, to be sponsored by EPA, EPRI, and SUNY-ESF, to provide vegetation managers, other practitioners, regulators and students practical and conceptual information and knowledge on IVM and shrub ecology and management. The agenda for the short course will follow the training manual format. About one half of course time will be spent in the field demonstrating and exploring topics and concepts learned in class.

SUNY-ESF's Office of Continuing Education and Public Service will manage the course with support from the Faculty of Forest and Natural Resources Management. Management duties will include: brochure/flyer printing, mailings, registration, hotel arrangements, meeting room arrangements (on campus), lunch, refreshments and reception, audiovisuals, lecture notes and other course materials.

Final Report

A final report will be written to document practitioner responses to the training manual, short course, and website, and present the "how to" for using the training manual and conducting a related short course. This report will be included in the frontispiece of the training manual. As part of the final reporting, changes will be made to the manual according to critical comments garnered over the project's life. A final training manual will be presented as part of the final report.

Impact Assessment

Impact assessment of an educational program is focused on the number of people educated, either through readership of educational material (e.g., the training manual, the website) or students in short courses. Impact of the latter will be assessed through course evaluations. We know, through our experiences over the past 20 years, that implementation of an IVM program on powerline corridors will lead to a reduction in herbicide use through the careful culture of shrubs and other desirable, low growing plants. The first, objective evidence of this reduction in herbicide use and associated risk became available to us only after one decade of research (Nowak and Abrahamson 1993; Nowak et al. 1992a; Ballard et al. in press (b)) and two decades of monitoring (Nowak et al. 1995; Finch and Shupe 1997). Such impacts in other areas of the country with newly established IVM programs can only be surmised in the short-term, and will need to be field monitored in the long-term.

Direct impact of the training manual and short course will be measured through student comments in course assessments and by the number of website visitors and their comments.

Literature Cited

Ballard, B.D., C.A. Nowak, H.L. Whittier, P.J. Donoso, J.C. Deegan, and J.W. Goodrich-Mahoney (compilers). In press (a). Life histories of common shrubs on utility rights-of-way in the northeastern United States: An annotated bibliography. Electric Power Research Institute, Palo Alto, CA.

Ballard, B.D., C.A. Nowak, L.P. Abrahamson, E.F. Neuhauser, and K.E. Finch. In press (b). Integrated vegetation management on electrical transmission rights-of-way using herbicides: Treatment effects over time. Paper to be published in the Proceedings of the 7th International Symposium on Environmental Concerns in Rights-of-way Management, held September 9-13, 2001, in Calgary, Canada.

Canham, C.D., J.D. Hill, A.R. Berkowitz, and R.S. Ostfeld. 1995. Ecological perspectives on tree invasion in rights-of-way: quantifying variation among communities in resistance to tree invasion. p. 81-86 In G.J. Doucet, C. Séguin, and M. Giguère (eds.) Proc. Fifth International Symp. on Environmental Concerns in Rights-of-way Management, Sept. 19-22, 1993, Montreal, Quebec, Canada, Hydro-Québec, Montreal, Quebec, Canada.

Egler, F.E. 1953. Vegetation management for rights-of-way and roadsides. P. 299-322 In Smithsonian Institution 1953 Annual Report, Smithsonian Institution, Washington, D.C.

ESEERCO. 1977. Environmental and economic aspects of contemporaneous electric transmission line right-of-way management techniques. Volumes 1, 2 and 3. Empire State Electric Energy Research Corporation, Schenectady, NY.

ESEERCO. 1985a. Long-term right-of-way effectiveness. Empire State Electric Energy Research Corporation, Schenectady, NY, Research Report EP 83-15.

ESEERCO. 1985b. Right-of-way treatment cycles. Empire State Electric Energy Research Corporation, Schenectady, NY, Research Report EP 84-26.

Finch, K.E., and S.D. Shupe. 1997. Nearly two decades of intergrated vegetation management on electric transmission rights-of-way. p. 67-75 In J.R. Williams, J.W. Goodrich-Mahoney, J.R. Wisniewski, and J. Wisniewski (eds.) Proceedings of the 6th International Symposium on Environmental Concerns in Rights-of-Way Management, February 24-26, 1997, New Orleans, Louisiana, Elsevier Science Ltd, New York.

Hill, J.D., C.D. Canham, and D.M. Wood. 1995. Patterns and causes of resistance to tree invasion in rights-of-way. Ecological Applications 5: 459-470.

McLoughlin, K.T. 1997. Application of integrated pest management to electric utility rights-of-way vegetation management in New York State. p. 118-126 In J.R. Williams, J.W. Goodrich-Mahoney, J.R. Wisniewski, and J. Wisniewski (eds.) Proceedings of the 6th International Symposium on Environmental Concerns in Rights-of-Way Management, February 24-26, 1997, New Orleans, Lousiana, Elsevier Science Ltd, New York.

Niering, W.A., and R.H. Goodwin. 1974. Creation of relatively stable shrublands with herbicides: Arresting "succession on rights-of-ways and pastureland. Ecology 55: 784-795.

Nowak, C.A. 1993. Effectiveness and other practical considerations of electric transmission line rights-of-way vegetation management in New York State. Ph.D. Thesis, State University of New York College of Environmental Science and Forestry, Syracuse, NY.

Nowak, C.A., and L.P. Abrahamson. 1993. Vegetation management on electric transmission line rights-of-way in New York State: The stability approach to reducing herbicide use. p. 183-191 In D.H. Gjerstad (ed.) Proc.. International Conf. on Forest Vegetation Manage., Ecology, Practice and Policy, April 27-May 1, 1992, Auburn, AL, Auburn Univ. School of Forestry Report 1993:1.

Nowak, C.A., B.D. Ballard, and E. O'Neill. In press. Gray birch ecology on an electric powerline right-of-way in upstate New York. Paper to be published in the Proceedings of the 7th International Symposium on Environmental Concerns in Rights-of-way Management, held September 9-13, 2001, in Calgary, Canada.

Nowak, C.A., B.D. Ballard, and P.J. Appelt (Compilers). In press. Integrated vegetation management on gas line rights-of-way: Review of the literature. Environmental Consultants, Inc.: Gas Technical Institute, Chicago, IL, and Environmental Consultants, Inc., Downers Grove, IL.

Nowak, C.A., L.P. Abrahamson, E.F. Neuhauser, C.W. Foreback, H.D. Freed, S.B. Shaheen, and C.H. Stevens. 1992. Cost effective vegetation management on a recently cleared electric power right-of-way. Weed Technology 6:828-837.

Nowak, C.A., L.P. Abrahamson, and D.J. Raynal. 1992. Powerline corridor vegetation management trends in New York State: Has a post-herbicide era begun? Journal of Arboriculture 19:20-26.

Nowak, C.A., L.P. Abrahamson, D.J. Raynal, and D.J. Leopold. 1995. Selective vegetation management on powerline corridors in New York State: Tree density and species composition changes from 1975 to 1991. p. 153-158 In G.J. Doucet, C. Séguin, and M. Giguère (eds.) Proc. Fifth International Symp. on Environmental Concerns in Rights-of-way Management, Sept. 19-22, 1993, Montreal, Quebec, Canada, Hydro-Québec, Montreal, Quebec, Canada.

Wagner, R.G. 1994. Toward integrated forest vegetation management. Journal of Forestry 92: 26-30.

Witter, J.A., and J.L. Stoyenoff. 1996. Integrated pest management in urban and rural forests. p. 151-168 In S.K. Majumdar, E.W. Miller, and F.J. Brenner (eds.) Forests-A global perspective. The Pennsylvania Academy of Science, Easton, Pennsylvania.

Timetable

Objective No. 1: Develop a training manual August 1, 2002-July 31, 2003
Objective No. 2: Create and maintain a website January 1, 2003-December 31, 2004
Objective No. 3: Conduct a short-course (prepare, conduct, reflect) August 1, 2003-September 30, 2003
Objective No. 4: Complete the final report October 1, 2003-December 31, 2003

Major Participants

Christopher A. Nowak, PhD, Associate Professor
Faculty of Forest and Natural Resources Management
Role: Dr. Nowak will serve as the Principal Investigator for the project, which will entail overseeing all facets of work, participating in the writing and organization of all deliverables, and lecturing in the short course.

Lawrence P. Abrahamson, PhD, Senior Research Associate
Faculty of Forest and Natural Resources Management
Role: Dr. Abrahamson will serve as Co-principal Investigator for the project, and will have primary and secondary responsibility for overseeing all facets of work, participating in the writing and organization of all deliverables, and lecturing in the short course.

Benjamin D. Ballard, MS, MStat, Research Scientist
Faculty of Forest and Natural Resources Management
Role: Mr. Ballard will conduct much of the technical work of the project, along with an hourly research aid, under the guidance of Drs. Nowak and Abrahamson. Mr. Ballard, in addition to being a full time researcher, is also a PhD candidate. Much of the shrub work is related to his PhD program.

John W. Goodrich-Mahoney, Program Manager, Environment Department
Electric Power Research Institute
Role: Mr. Goodrich-Mahoney and the Electric Power Research Institute has agreed to co-this project for a total of $10,000 (see budget and attached letter of support).

Project Budget

Project Period: From: August 1, 2002 To: December 31, 2003

Funding Request
Funding Requested	Other Funding	Total Funding
$39,885	$10,013	$49,898