The Invasives Strike Force Crew and a group of dedicated volunteers combined forces to remove invasive species at the Great Swamp in Dutchess County, N.Y.  Photo credit: Christian Cifuentes.

What an incredible start to the 2021 volunteer field season! Thus far, 336 volunteers have dedicated over 2,400 hours to preserving our region's natural areas through our Ecological Stewardship programs. Volunteers working with our Conservation Corps Crews and Conservation Dogs teams have not only been removing invasive species but installing boot brush stations to prevent further spread of invasive species into other parts of our region's trail system. Habitat Helpers volunteers are not only helping to maintain existing native gardens at Trail Conference headquarters but are also growing native plants for future introduction into selected natural areas. Finally, Invasives Strike Force survey assignments have been sent out to all active volunteers as they embark upon their mission to detect and report invasive species throughout our region's trail system. Keep reading for more details on these programs, including how to get involved in upcoming volunteer opportunities!

The crew worked with staff members of the Mianus River Gorge Preserve to survey the river for aquatic invasives. They found water chestnut and curly-leaf pondweed while wading in water up to their chests! Photo by: Jean-Luc Plante

The Aquatic Invasives Strike Force crew has been hard at work across the Lower Hudson Valley during the month of June. The crew has surveyed nine lakes since the month started, spanning 400+ acres. From these surveys, the crew recorded 326 observations of presence, absence, and density of aquatic plants and invertebrates. Notable invasive species found include curly-leaf pondweed, water chestnut, Eurasian watermilfoil, fanwort, banded mystery snail, and Chinese mystery snail. The crew also expanded their efforts to include several rivers this year, including the Harlem River and Mianus River Gorge!

Looking forward, the month of July is going to be jam-packed with water chestnut removals! Water chestnut is arguably one of the most recognizable aquatic invasive species in this region, with its triangular, serrate, floating leaves arranged in rosettes with 4-horned sharp-barbed nutlets. Although water chestnut is listed as a Tier 3, or established, species, young individual populations may have the potential for eradication or suppression, which is where the Aquatic Invasives Strike Force crew comes into play. We will be performing water chestnut removals in several locations during the next month, many of which are welcoming volunteers! These include Rockland Lake in Rockland Lake State Park and Chodikee Lake in Ulster County. In addition, we’ve teamed up with PRISM Partners Audubon NY and Westchester Parks Foundation to co-host water chestnut removals in Constitution Marsh, Blue Mountain Reservation, and Tibbetts Brook Park. We’re also excited to return for the third year to Putnam County Veteran’s Memorial Park to see how our water chestnut mangement efforts in 2020 have impacted the infestation.

Members of the ISF Crew joined with a group of volunteers to remove invasive plants and to install a boot brush station at a trailhead at Black Rock Forest. Photo: Ryan Goolic.

Now that our crew members are fully trained, the field season is in full swing! June was full of exciting projects for the ISF crew. We started off the month at Black Rock Forest for National Trails Day where we were joined by 13 dedicated volunteers to remove multiple types of invasive plants that are widespread throughout the Lower Hudson region, but not as common in this less-invaded forest system. We also helped to install a boot brush station at Black Rock Forest in partnership with PlayCleanGo, a national invasive species education and outreach campaign, to further prevent the spread of invasive seeds into the forest! We celebrated Invasive Species Awareness Week (ISAW, June 6-12) by hosting two volunteer events. The first of these volunteer workdays was at a restoration site in Harriman State Park targeting Scotch broom and the second workday focused on removing some more common invasive plants at the Great Swamp in Dutchess County, N.Y. to help protect critical New England cottontail habitat. Following these ISAW events, the Crew took up the battle against sticky sage. This project is of extremely high priority because there are very few reported populations of sticky sage in the United States. The Appalachian Trail runs through this particular infestation in Dover, N.Y. and thus acts as a potential vector for spread to other sites. The crew will spend two more weeks on this project. We finished the month of June by focusing on giant hogweed management. This dangerous plant can cause burns upon contact and exposure to sunlight, so the crew was suited up head to toe with Tyvek suits! Thus far, the ISF Crew and volunteers have surveyed 24.8 acres, treated 8.6 acres, and managed 7,028 plants. Coming up in July, the ISF crew will be tackling many projects, including another week of sticky sage management, a week of sapphireberry management near Pound Ridge, N.Y. and castor aralia at Vassar College.

A partial map of the Blockbuster survey grids available for surveying west of the Hudson River. If you are interested in learning more about Blockbuster or potentially taking on a square, read the last paragraph of the survey update section below and then contact us!

The survey season is now officially underway! Thus far, 113 trail sections across northern New Jersey and the lower Hudson Valley have gone out for assignment to 132 volunteers, with another 25 surveyors currently in training. We expect to have an informative report about survey completion rates, what plants our volunteers are finding and in what locations in our next newsletter after our surveyors have had a full month of surveying under their belt. It's just amazing the level of commitment and passion our survey volunteers so readily demonstrate for not only learning about the diversity of life inhabiting our region's natural areas but in taking action to protect those open spaces. If you are interested in learning how to ID and report invasive species along our region's trail system, it's not too late to join our ISF Plant Survey team. Simply visit this ISF Survey volunteer opportunity webpage to learn more and fill out a volunteer interest form.

Already a trained plant surveyor that's looking for an extra challenge? ISF Blockbuster survey volunteers are needed for Orange and Ulster Counties. Blockbuster surveyors look for 27 invasive plants (many of which you already learned during ISF standard or intermediate training). The goal of the program is to cover the entire Lower Hudson area with surveys and cross off the block squares as we go (see photo above). You select places within your block for 3 short surveys using the same protocols as for your trail surveys. Please contact us at [email protected] if you’re interested in learning more.

Habitat Helpers volunteers are potting up native plants for future restoration efforts. Photo credit: Mei Wu

Our Habitat Helpers Program enables our volunteers to not only help hone their gardening skills and remove pesky weeds and invasive species from landscaped environments, but to be a part of growing and nurturing native plants and planning for native plant restoration efforts. Habitat Helpers Sunday morning workdays are now  posted for July and can be accessed by clicking on the green button below. The mid-week opportunity this month is Thursday, July 22. Bergen county Master Gardeners can count their hours by participating in our workdays and volunteering with our Habitat Helpers Crew. Please also note that we are offering a guided native plant garden tour at Trail Conference headquarters in Mahwah, N.J. on July 17. Come join us!

The Habitat Helpers Growers group has already grown over 800 plants for use in our restoration sites and our native gardens. We anticipate potting up many more seedlings over the next month.  If you’d like to help by taking care of a tray of plants until we are ready to plant them in the fall, you can either email Linda at [email protected] or sign up for a Habitat Helpers work day (click button below). Watch for the next potting up date to be posted for mid to late July.

Dia finds some sticky sage as soon as her paws hit the ground. Photo by Arden Blumenthal

Our summer season is starting out hot! Lucky for us, the dogs have been primarily working in forested areas with plenty of shade. We've been surveying some new locations in Westchester County for sticky sage and found a few small plants just beyond the known infestation area. The good news is that nothing else was found beyond that! This is one of the areas where the dogs really excel, finding the true borders of an infestation. Some field days have also been spent with New York-New Jersey Trail Conference volunteers in Harriman State Park. We cleared quite a number of Scotch broom plants from a known infestation area and now the site is ready and waiting for the dogs to discover what we may have missed during manual removals. We are very grateful for all of the help from the dedicated group of volunteers who came out to join us! After the holiday, we will continue our work with Scotch broom and start training on a new species, silver vine. If you are interested in attending a volunteer workday, please get in contact with Arden at [email protected]. We'd love to see you in the field!

We would like to thank our project partner, Stancy DuHamel, for housing the ISF Crew at her beautiful property during our sticky sage removal work. This property is within walking distance to the sticky sage infestation which makes for a very convenient commute to work and efficient day in the field! We’d also like to thank Jim Utter and the Friends of the Great Swamp for their volunteer contributions (and the snacks!) during our work removing invasive plants at the Great Swamp.

Thank you also goes out to Stephanie Clark, Tom Hobbick, M. Lisa Liu and Nancy Fezell for their efforts on data management and entry projects in the month of June. 

Comparison of invasive Japanese hop (cluster of 4 photos on right) versus American hop (cluster of 4 photos on left). Japanese hop leaves have 5 or more lobes (top row, third photo) with much sharper angles between the lobes (bottom row, third photo) than American hop leaves which typically have three lobes (top row, second photo) and more rounded/wider space between the lobes (bottom row, second photo). Note also that Japanese hop bracts, or modified leaf structures that cover the fruiting spikes, curve outward (top right) versus American hop bracts which tend to hug the fruiting spike in a more pinecone-like fashion (top left). Lastly, American hops have tiny oil producing glands along the primary leaf veins (bottom left) versus Japanese hops which do not (but also note that Japanese hops do have downward facing prickles but no soft oil glands). Photo credit: bplant.org 

Whether you are hiking along a wooded trail or hanging out near the shore of one of your favorite lakes, we've got something for you to be on the lookout for in this month's Hop to It! EcoQuest Challenge. Our first hop-themed species is Japanese hop, an annual climbing or trailing vine that can grow up to 35 feet in one season, smothering native vegetation in the process. This invasive vine can be distinguished  by its 5+ lobes on its leaves versus its beer-making native counterpart, American or common hop, which typically only has 3 lobes. Check out the other differences between these two hop species in the above photograph and caption. Please make sure to watch this Japanese hop field ID video created by Invasive Species Citizen Science Coordinator, Brent Boscarino, for further tips!

Hopping along to our next themed species, European frog-bit is a free-floating aquatic invasive plant that tends to grow well in slow-moving marshes, rivers, lake shorelines and sheltered bays. Frog-bit displays rapid vegetative spread forming dense mats that block sunlight from penetrating the water column and inhibit recreational use of waterways. This species' ID features and impacts are highlighted in the below photo and discussed in detail in this Statewide Species of Concern Webinar that was presented as part of New York Invasives Species Week. Simply hop to the frogbit portion which we have conveniently sectioned off starting at minute 39:52 of the webinar. European frog-bit is also a featured species of the 6th Annual New York Invasive Species Mapping Challenge with N.Y. iMapInvasives.     

Hoppy trails to you and good luck!

European frog-bit has small (0.5-2.5 inch) heart-shaped leaves with smooth margins. It also produces a small 3-petal slower with yellow center at this time of year in our region. New growth sprouts from trailing runners, or stolons, that form dense mats on the surface of the water as well from turions or buds that lie dormant over winter. Photo credit: vtfishandwildlife.com