Lab members who contributed to the following research include: Greg Reardon (’15); Jacob Ammon (’17), Cassandra Cronin (’17), Jordan Fisk (’17), Emily Hamilton (’17), Adam Hammershoy (’17), Tracy Keza (’17), Eunice Kimm (’14), Sarah Messenger (’18), Jenna Wilborne (’15).
Update (Jan. 2016): We’re working on finalizing data analyses and manuscript preparations for this project, so stay tuned here for updates, or contact me (cameron.douglass@trincoll.edu) if you’re interested.
Methods
Overview: Data collection for this study took place at Knox Preserve, located in Stonington, Connecticut. The 16.7 acre site is adjacent to Quiambaug Cove on Long Island Sound, and is owned and managed by the Avalonia Land Conservancy. Within the preserve three distinct habitats are present: a meadow, a shrubland, and a transitional area between the two along an old stone wall. The transitional area along the stone wall has within the past decade become dominated by invasive vines that are common throughout the site, particularly black swallow-wort (Cynanchum louiseae), porcelainberry (Ampelopsis brevipendiculata), and Oriental bittersweet (Celastrus orbiculatus). Avalonia staff and volunteers began actively managing the invasive species in this portion of the site in 2012 with the assistance of staff from the Connecticut Department of Energy and the Environment (DEEP). In 2012, the invasive vines species abundant in this area were cut by hand and removed, the subsequently vigorous re-growth was treated with herbicides by DEEP staff in fall 2013. Annually since these initial treatments, Avalonia works with DEEP staff to continue these treatments as needed, and clears adjacent additional areas as possible each year. The purpose of our project was to monitor these ongoing integrated treatments to identify whether passive plant community recovery was desirable.
Survey Methods: Within the areas along the stone wall that were treated, we established 6 randomly located, nested, 25 meter square vegetation sampling plots in fall 2013. The following year (2014), we established additional sampling plots in adjacent areas that were being cleared mechanically, but not sprayed with herbicides, and also adjacent areas that were not being treated by any means. These two additional areas allowed us to actually compare the relative effect of integrated chemical + mechanical treatments versus mechanical only, and both of these treatments against a ‘negative control’ where the invasive-dominated plant community was left alone.
In each sampling plot (in the three treatment areas) we have sampled plant community richness and abundance (ground cover (%), stem densities (no. stems per meter square)) twice per growing season – early June, early September – since 2013/2014. Additionally, we are utilizing objective, quantitative measures of overall vegetative ground cover by photographing each meter squared sampling sub-plot and using ImageJ to digitally quantify the percentage of ground covered by green vegetation. Finally, in addition to assessments of taxonomic diversity in the sampling plots, we have collected specific leaf area data on target invasive vines and shrubs, along with native morphological analogues, to be used in functional diversity analyses. This last project is one that was spearheaded by Greg Reardon as his senior honors thesis research (available here soon).
Preliminary Results
Forthcoming …