Long term effects of electrical right-of-way vegetation management on floral and faunal communities

2018-2021, Carolyn G. Mahan, PhD, Pennsylvania State University

I propose to continue, replicate, and expand the research and outreach efforts on the effects of right-of-way maintenance on floral and faunal communities. In particular, the research will focus on understanding wildlife response through a treatment cycle. In general, rights-of-way are treated every 4-6 years. Data from our 2018-2020 field seasons indicates that wildlife communities (plants, bird, snakes, and ground beetle abundance and species richness) and processes (nest predation rates) differ within a field season ( e.g, May versus August) as well as through the vegetation treatment cycle. In addition, we note that IVM supports native wildlife communities on narrow transmission lines (SGL 103) as well as on wider transmission lines (SGLE 33, GLR&D). During 2021-2024, my research team will continue to evaluate floral and faunal response to ROW management at our 3 study sites: SGL 33, GLR&D, and SGL 103. We will continue to monitor native vegetation and breeding birds and complete our survey of ground beetles. We believe we may have one of the longest continuous data sets on breeding birds (abundance and productivity) in the Appalachians. We will add an examination of Lepidopteran diversity (using developed and tested sampling techniques) to our research design at all three research locations. This Lepidopteran work will build upon work first conducted by Yahner in 1998 (see Yahner 2004) and will expand to include moths and a voucher collection for better estimates of species diversity at all study sites. All research will be conducted in cooperation with the Center for Pollinator Research and the Frost Entomological
Museum at The Pennsylvania State University. We will continue to work with The Pennsylvania State University to revise, update, and review our website
(https://sites.psu.edu/transmissionlineecology/). Finally, we will work with WPSU to script, film, edit, and produce video content for distribution that promotes our research approach, partnerships, and findings.

 

Final Report Findings:

Due to COVID pandemic, all goals and timelines presented in the 2020 proposal were NOT met during the past 12 months.  The goals for this time period included:  Year 3 (May 1, 2020-April 30, 2021):  1) implement a ground beetle protocol at SGL 33 and GLR&D sites, 2) identify and summarize findings of ground beetle surveys in cooperation with the Center for Pollinator Research and the Frost Entomological Museum.  Species of conservation concern will be highlighted and implications for ecosystem services will be discussed, 3) continue website management and outreach activity, including presenting preliminary results of research at academic meetings and journals.  Presentations will be coordinated with research partners throughout the year.

The goal that was NOT met was the ground beetle survey at GLR&D (Green Lane Research and Demonstration site).  The ground beetle survey was not conducted because of travel restrictions by both the Commonwealth of Pennsylvania and The Pennsylvania State University due to the on-going COVID pandemic.  However, upon discussion with the research partners, we conducted a thorough snake inventory at SGL 33 and SGL 103 in Centre County and worked with partners to reclaim a road that was inadvertently (and unexpectedly) placed through several of our research sites (including HC [handcut]-1).

Ground beetle surveys

From 5 June to 30 August 2020, we used pitfall traps to perform four 72-hr-duration ground beetle collections at seven plots at SGL33. Six pitfall traps were installed at each of the seven plots. By 30 August 2020, we had collected a total of 168 pitfall trap samples at SGL33.

Sample Processing

To process pitfall trap samples, each sample is emptied into a sorting tray. All invertebrates in the sample are removed and sorted into three categories:  1) pinnable beetles, 2) non-pinnable beetles (which are too small to pin), and 3) all other non-beetle invertebrates.

Of the 168 pitfall trap samples, 96 samples have been fully processed.

Specimen Identification

As of 3 May 2021, a total of 1,283 pinned and vialled specimens have been identified:

Carabidae: 78 specimens

Staphylinidae: 222 specimens

Other Beetles: 90 specimens

Non-beetles: 893 specimens

All beetles collected have been sorted, pinned, and will be curated at the Frost Entomological Museum at the University Park campus of Penn State.

Reptile (snake) surveys

Time constrained area searches were used to survey species richness and abundance of snakes in the wire-zone of the ROW at SGL 33 and SGL 103. The nine ROW sections were surveyed by two people for 60 minutes on clear days during June and again in July of 2020. Searches were performed between 7 A.M. and 11 A.M. when herpetofauna have the greatest chance of being under cover. Rocks, logs, and any other debris (> 8 inches) were flipped to reveal individual specimens. Clickers were used to keep track of the number of flips per substrate type on each ROW section; this was later used to calculate the average number of flips needed to detect individual specimens within each ROW section. These calculations were used to compare ROW sections of varying sizes and sections with varying amounts of debris.

We observed 8 species (77 individuals) of reptiles and amphibians during our surveys at SGL 33 and SGL 103.  This included one salamander, one toad, one frog, and five snake species. Seven specimens were observed in the open, one specimen was found under a log, and the remaining 68 specimens were found underneath rocks. Northern ring-necked snake and red-bellied snake were the most abundant species encountered. Mowing sites contained significantly fewer snakes than sites managed using IVM.  In addition, species abundance and richness varied between sites as amounts of cover (rocks, logs, etc.) differed. To compensate for the varying amounts of cover, results were standardized by calculating the proportion of herpetofauna specimen observations per rock flip in each site.

 

Year: 2018-2021

Funding Duration: 3 year

Grant Program: Sponsored Grant

Grant Title: Long term effects of electrical right-of-way vegetation management on floral and faunal communities

Researcher: Dr. Carolyn G. Mahan

 

 

For more information on this project, contact the researcher via TREE Fund at treefund@treefund.org.