An Assessment of Vegetation Growing on Natural Gas Pipelines in Northeastern Pennsylvania
Introduction
Over hundreds of years, humans have impacted native forests in Pennsylvania by urbanization, agriculture, energy development, strip mining and timbering (Fike 1999). In the recent past, the demand for natural gas has been on a steady increase. This has been coupled with advances in the technology of the extraction of natural gas due mainly to hydraulic fracturing and horizontal drilling techniques (Kargbo, et al. 2010). The wellpads developed to extract the gas impact areas of forests leaving square or rectangular patches that are typically 6-8 acres (Johnson et al, 2011). Getting that natural gas to market requires the construction and installation of new pipelines (Johnson et. al, 2011).
Pipelines represent a different type of disturbance from other utility corridors (e.g., power line rights of way-broad and short) because they are long and narrow. They have a large edge effect, and are corridors for some organisms and barriers for others. Edge effect occurs at the boundary of two habitats where the environment at the edges is disturbed. For example, by creating an open forest boundary, sunlight and wind penetrate to a much greater extent drying out the interior of the forest close to the edge. Pipelines have several impacts on natural environments, including wildlife, vegetation, soil and water (Miles 1979; Johnson 2012). Some of these impacts last for a considerable duration while others are short term (Galleher and Michael 2004).
The construction of pipeline corridors in northeastern United States has resulted in the clearing of vegetation in areas that range from 9 to 40m wide and many km long (Galleher, 2004). A concern is that PA is poised to add thousands of miles of pipeline corridor in the next decade. Pipeline corridors pose a threat to watercourses (streams and rivers) due to erosion where crossings occur. They serve as corridors for invasives, and alter feeding and habitat for various animals (Johnson et al 2010). Their construction also results in soil loss from a portion of the site resulting in the loss of up to 450 metric tons per year (Matthew, 2010). In addition, vegetation injury has been also observed in some parts of the corridor where the pipeline was constructed. All trees that were taller than 25.4 cm were observed and some of them showed symptoms of discoloration, and damage or loss of foliage (Matthew, 2010).
Pipeline construction can degrade the atmospheric qualities through dust release, acoustic disturbance through noise, and modify the terrain. It can also displace wildlife, and affect fossil resources (Liu, Xila and Alfredo 2014). Pipeline leaks and ruptures can also have direct negative impacts on the natural environmental (Galleher and Michael 2004). Also, construction can affect soils through erosion, compaction, mixing, contamination and removal (Mathew 2011). The vegetation can also be disturbed by the introduction of new species, change in the natural water flows, surface disturbance and the contamination of the air (Zhu 2012).
Within the past year, two teams of Wilkes University students examined the vegetation within a 1700’ length of the Transco pipeline in eastern Luzerne County. They found that the corridor was complex, including some areas with low-stature herbs and shrubs, and other areas with taller herbs. Nearly all of the species were native to PA, with aliens being relatively rare (Klemow, 2015)
Follow-up discussion with the company that operates the pipeline indicated that they were interested in developing a new seed mix dominated by low-stature species. Further research into the diversity of pipeline vegetation in different parts of the northeastern U.S. is also needed, as well as a study of the food web dynamics within the pipeline. In this study, we propose to design a vegetation mix, for natural gas pipeline rights of way, that will be dominated by species that are low growing, native, have good cover, offer good habitat, and food for animals. An approach is to look at existing corridors and assess the kinds of vegetation that are successful. We will select those plants that fit our criteria and reject those that do not. The study will be conducted by looking at existing vegetation and the seed bank.
The results of this study will be essential in evaluating environmental impacts that pipelines have on our environment by finding out the types of vegetation that grow after a pipeline has been constructed. It is also expected that the knowledge generated will form a valuable resource for industry and regulatory agencies to develop better practices when constructing pipelines and when having to replant vegetation on top of the right of ways.

Specific Aims
Questions to be answered in this project are: (1) How do the plants in different pipeline corridors compare in species composition? (2) Do these plants represent primarily native or alien species? (3) Do these plants represent low-growing herbs and grasses, tall-growing herbs and grasses, shrubs, and trees? (4) How well correlated is the seed bank to the aboveground vegetation?

Methods
This study will include testing different samples of soils and vegetation. It will include the assessment of five different natural gas pipeline corridors in northeast PA. Soil samples and plugs of vegetation will be taken from various points on natural gas pipelines and will be grown to see what types of plants are present.
First, ten samples of vegetation communities will be collected from each of the five pipeline sites. These include the Transco pipeline right of way and four other sites that are to be determined. The vegetation communities will be collected by digging 1ft by 1ft squares. The squares will be placed in buckets to transport to Wilkes University, where they will be grown in the greenhouse and watered daily. The samples will be observed and the species composition will be recorded in a notebook.
Then, ten soil samples will be collected from each site by digging 1ft by 1ft and 3 inches deep and removing the top vegetation. The soil samples will be transported in plastic bags to Wilkes University where they will be spread on seed flats atop peat moss. They will then be watered daily and grown in the greenhouse. The growth and seed germination will be observed over time.
Once plants have grown to a recognizable state, each species will be identified and recorded into notebook and then will be constructed into a graph showing the quantity of each type of species. The vegetation and soil sample results will then be compared to one another for their species composition. By looking at the graphs, the most successful plants that fit the criteria of low-growing herbs and grasses can be determined, thus an appropriate seed mix for natural gas pipelines can be successfully achieved.
Literature Cited
Fike, J. 1999. Terrestrial and Palustrine Plant Communities of Pennsylvania. Pennsylvania Department of Conservation and Natural Resources. Harrisburg, PA.
Galleher, John J, and Michael T. Stift. Pipelines 2004: What’s on the Horizon? Proceedings of the Pipeline Division Specialty Conference: August 1-4, 2004, San Diego, California. Reston, VA: American Society of Civil Engineers, 2004. Print.

Johnson, N., T, Gagnolet, R, Ralls, and J, Stevens. Natural Gas Pipelines Excerpt from Report 2 of the Pennsylvania Energy Impacts Assessment. December 16, 2011. The Nature Conservancy – Pennsylvania Chapter.
Kargbo D.M., R.G. Wilhelm, D.J. Campbell DJ. 2010. Natural gas plays in the Marcellus Shale: challenges and potential opportunities. Environ Sci Technol 44: 5679–5684. Available: http://www.ncbi.nlm.nih.gov/pubmed/20518558. doi: 10.1021/es903811p PMID: 20518558
Klemow, Kenneth. Oral Communication, 2015.
Liu, Xila, and Alfredo H.-S. Ang. Sustainable Development of Critical Infrastructure: Proceedings of the 2014 International Conference on Sustainable Development of
Critical Infrastructure : May 16-18, 2014, Shanghai, China., 2014. Internet resource.
Mathew, Joseph. Engineering Asset Management and Infrastructure Sustainability: Proceedings
of the 5th World Congress on Engineering Asset Management (wceam 2010). London:
Springer, 2011. Print.
Miles, John. Vegetation Dynamics. London: Chapman and Hall, 1979. Print.
Zhu, Robert. Applied Mechanics and Civil Engineering: Selected, Peer Reviewed Papers from the 2011 Sree Workshop on Applied Mechanics and Civil Engineering (amce 2011), December 17-18, 2011, Macau, China. Durnten-Zurich: Trans Tech, 2012. Print.

Budget
Item Quantity Cost
Peat moss 5 bags $100.00
Shovels Razorback sharpshooter 4 $240.00
Seed flat trays 100 $300,00
Plastic buckets 80 $160.00
Plastic Ziploc bags 5 boxes $20.00
Measuring tape 1 $10.00
Transportation $300.00
Total $1130.00