Cost Comparison of Right-of-Way Treatment Methods

Pretreatment

Pretreatment baseline data collection covers: existing conditions on study ROWs and their treatment units; density/height classes found; similarity of capable species found throughout New York; desirable non-target plant communities found; boundaries of pretreatment edge; soil compaction conditions; visual conditions; wildlife habitat evaluation for selected species; conditions on study ROWs to be treated with girdling and herbicide injection treatment methods; statistical relationships of various factors at the 95 percent significance level; and cost data and treatment quality for all treatment methods applied.

Site selection

Selection of study ROWs was critical because the cost of applying a treatment method is directly related to accessibility to the ROW and the density and height of tall-growing (capable) species. Eighteen of the 50 candidate ROWs submitted by ESEERCO qualified as study ROWs. A study ROW contained at least three of New York State’s five prevalent capable species: white ash, red maple, red oak, black cherry, and quaking aspen. Height and density were divided into six classes. Study ROWs and at least 2.3 miles of mesic habitat (moist but well-drained sites) and traversed a Northern Hardwoods forest type or one of its variants found in New York. Each ROW had a documented treatment history and was reasonably accessible. Study ROWs were divided into seven treatment units (1,760 feet long) aggregating 126 treatment units on 18 ROWs.

Capable species

Trees capable of growing to over 20 feet endanger safe and reliable energy transmission and are responsible for most maintenance problems in New York State. A prime goal of the study is comparing the costs of treatment of capable species. A species-area curve determined the optimum plot size for vegetation sampling in each density class. The density and height of capable species were evaluated by the analysis of variance. Forty-six capable species were found on study ROWs throughout the state. Sorensen’s Quotient of Similarity was used to calculate the similarity of species composition.

Desirable non-target species

Over 550 plant species were identified on study ROWs. Desirable nontarget species were evaluated by abundance and sociability data. Herbaceous cover generally increased with decreasing tree and shrub cover. Total herbaceous cover was high on ROWs and low in adjoining woods (due in part to forest competition reducing light infiltration).

ROW edge

ROW edges were studied to identify the boundaries of the ecotone (transition area between two or more biotic communities). Data were collected by the line transect technique. Data indicated a definite edge effect. The influence of the forest edge extends into the ROW area and affects vegetation composition. Also apparent is the influence of ROW clearing on composition and density of understory vegetation in immediately adjoining woods.

Surface soil properties were evaluated on ROWs and off-ROW sites for bulk density, penetrometer resistance, and thickness of surface organic layers at the A1 horizon.

Analysis of the visual impacts data related them to the magnitudes of each of the six basic components: form, line, color, value, intensity, and texture. Results included measuring change in variable values correlated to the change in magnitude of each visual component and provided a value indicating the significance of that change.

Wildlife

Effects of vegetation treatment methods on ROW wildlife habitat were assessed by a habitat evaluation procedure that concentrates on a species’ food and cover requirements, and provides a general rating useful in comparing ROW habitats. Species selected for study included rufous-sided towhee, gray catbird, ruffed grouse, meadow vole, and white-tailed deer. The habitat for each of these species was assessed on all treatment units in medium density (1,500 to 2,900 stems per acre) and high height (over 6 feet high) ROWs, and will be compared to habitat ratings derived from 1982 field data (posttreatment) to assess the effects of seven different treatment methods on wildlife habitat.

Treatments

Treatment methods were applied in the following sequence:

Treatment-cost coordinators collected data relating to the cost effectiveness of each treatment method. These data will be used to develop:

1. Cost comparison of treatments in relation to density and height of target vegetation, adjusted for terrain conditions that affect accessibility.

2. Effects on cost due to terrain conditions that limit or restrict accessibility or treatability.

3. Recommended ROW maintenance in relation to density and height of capable vegetation and terrain conditions.

The entire study will be completed in June, 1983. The analysis of data will provide a comparison of costs and environmental effects of treating capable species at various density/height classes on ROW conditions found in New York State.

Specific results will include a report of changes in density and height of capable species, abundance and sociability of desirable non-target species, soil compaction due to treatments, and changes in wildlife habitat.