2021 Corps Invasives Strike Force Blog

The Invasives Strike Force (ISF) crew, as part of the Trail Conference Conservation Corps and funded through the Lower Hudson PRISM, is a conservation-based crew devoted to eradicate, contain and prevent the establishment of emerging terrestrial invasive species within the Lower Hudson Valley in order to protect our high-value habitat through the use of skilled labor within the region.

Learn more about the program.

Table of Contents

April 2021

By Kassidy Robinson

In April 2021, the Invasives Strike Force prepared for the beginning of the field season. The new ISF Crew Leader, Kassidy, was thrilled to step into her first leadership role and assist with pre-season planning at the (virtual) office. She participated in activities such as creating management plans for emerging invasive species, emergency response plans, project reports, and received training in GIS and data collection, leadership, and invasive species identification, removal, and treatment. Kassidy learned a lot about what goes into both project management and invasive species management, and is very excited to begin working with the new ISF crew members in May!

The ISF crew visited two sites in the Bronx to remove incised fumewort, Corydalis incisa. They removed 3,223 incised fumewort at Bronx River Parkway Reservation, Mt. Vernon, N.Y., and with the help of volunteers removed 351 incised fumewort at the Nature Study Woods. The volunteers at Nature Study Woods became skilled in identifying and removing incised fumewort, and even returned later in April to remove another 936 incised fumewort!

The crew also scouted out several sites in Dover, N.Y., for the presence of sticky sage, Salvia glutinosa. While in Dover, the crew observed several uncommon and unique in the area that reinforce the necessity of invasive species management in the area. Some unique species observed were blue cohosh, toothwort, morel mushrooms, bloodroot, red columbine, and red eft newts. Further, part of the sticky sage infestation surrounds the Appalachian Trail. If left unmanaged, this infestation could have catastrophic consequences in acting as a pathway for the spread of sticky stage further along the Appalachian Trail. The crew is looking forward to tackling this important task later in the season.

Overall, the Invasives Strike Force is excited to gear up for the season! They had several successful invasive species removal days and gained useful intel through their scouting efforts. Upcoming events to read about in next months’ update include I Love My Parks Day, management at Old Croton Aqueduct and Croton Point, and the start of the season for ISF crew members!

May 2021

ISF Welcomes the Crew by Kassidy Robinson

This past month four new crew members joined the Invasives Strike Force to make a full team of five. They eagerly got to work learning and fighting invasives! Their enthusiasm and passion for the environment shined through and resulted in the team taking down 5,343 invasive plants in May. To start the season, the crew was trained in various subjects necessary to the invasive species work. They took their herbicide class, got certified in wilderness first aid and CPR, and received training in plant ID, manual removal, and data entry and report writing. Now they can confidently navigate in a field setting and combat invasive plants across the Lower Hudson region!

In the first project, the team focused on cutting Siebold’s viburnum with volunteers at Old Croton Aqueduct. The crew plus volunteers dedicated 144 total hours towards removing 1226 invasive plants, including 919 Siebold’s viburnum, 126 black jetbead, along with some widespread invasives. This site required not only hard work to fell the large tree-like viburnum shrubs, but also precision and detail. There were several stands of the spring ephemeral flower, bluebell, within the Siebold’s viburnum site. The ISF crew and volunteers took special care to keep vegetative waste away from the flagged bluebell patches. In one case, Loren and Kassidy cut down a sizable Siebold’s viburnum within a bluebell patch and had to tag-team with Christian to guide its fall away from the bluebells, all the while not letting the giant shrub touch the ground. Much of the work at OCA involved tiptoeing around the bluebells, but it is all worth it to protect native species such as this one whose habitat we seek to improve by removing invasives.

Croton Point Park was next and featured several interesting conservation targets. The crew worked on removing a total of 705 paper mulberry, sycamore maple, and Chinese bushclover - all tier two emerging invasive species. Their removal is critical to protecting other areas from becoming infested and spreading throughout the Lower Hudson region. This area is also of local concern for conservation for several reasons. The endangered northern bumblebee and the grasshopper sparrow - two very unique and threatened species - make their home at this park. The Audubon Society has also deemed this park an important bird area. The ISF’s work not only focused on eradicating the tier two species for regional conservation goals, but for the local conservation of these unique species. The crew also made friends with an adorable family of raccoons sleeping in a standing dead tree.

On Iona Island, the crew worked on eliminating both tier two and widespread invasive species to protect a unique habitat for species like the native prickly pear. They removed/treated 1,523 plants including 13 Chinese bushclover, 594 cutleaf blackberry, 159 multiflora rose, and 666 devils walking sticks. The crew especially enjoyed working in such a scenic part of Bear Mountain and observing the work the park managers put into fighting invasives and restoring the wetland. Overall, the crew had an excellent season kickoff and can’t wait to continue fighting invasives this season!

June 2021

ISF is Heating Up by Kassidy Robinson

As summer kicked into full gear, so did the ISF. In the month of June, the ISF worked on some very important and exciting projects, and took out a total of 18,837 invasives over 71 acres they surveyed!

To kick off the month, the crew and volunteers celebrated Invasives Species Awareness Week by removing widespread invasives at Black Rock Forest and at a restoration site in Harriman State Park. The ISF also installed a boot brush station at Black Rock Forest for hikers to use to limit the spread of invasive seeds on their boots! At the restoration site after removing invasives, crew and volunteers planted native wildflowers, boneset, grass-leaved goldenrod, and heath and New England asters. Many of these volunteers come back year after year to foster healthy recovery of the habitat towards increased biodiversity and look forward to seeing its progress in the future.

The crew also removed the emerging invasive, Scotch broom, at several sites in Harriman and Bear Mountain State Parks. Their climbing abilities were tested when they faced steep slopes covered in seemingly endless Scotch broom. This posed quite a challenge for the team as they scaled the slopes and inevitably slipped down a few times. The crew will continue to work hard towards eradication in the upcoming months.

Next was giant hogweed, a harmful invasive known for its sap that causes photosensitivity and burns. The crew kept safe in Tyvek suits, rubber gloves, and boots and accomplished management of 7,115 giant hogweed plants! They had some fun treating the dangerous plants by thinking of themselves as the ghostbusters of invasives! Check out the crew all suited up above!

At the Great Swamp, the ISF worked with the Friends of the Great Swamp, a volunteer group, to remove general invasives oriental bittersweet, autumn olive, honeysuckle, and privet. Here, everyone removed 823 plants to improve the protected habitat for the New England cottontail rabbit. Last but not least, the crew started their work on the 100+  acre sticky sage infestation in Dover, N.Y. Sticky sage is a very important project due to its limited range and location; it is only known to infest two locations in N.Y. and part of the infestation in Dover overlaps the Appalachian Trail (A.T.). The ISF prioritized treatment along the A.T. because if left untreated, the trail represents a significant pathway for the dispersal of sticky sage. By treating sticky sage near the Appalachian Trail diligently, the crew limited the spread of sticky sage on animals and hikers along the Northeast. The crew will be going back again in July and August for 8 more days to work towards full treatment and eradication.

July 2021

By Kassidy Robinson

In July, the ISF crew continued to work hard in the fight against invasives. They kicked off the month removing Scotch
broom at Harriman State Park and the Ralph E. Ogden Foundation and had some help from volunteers. The crew also worked on Chinese silvergrass, swallowworts, and small carpetgrass at High Tor State Park and Shrub Oak Memorial Park.

Next, the crew continued managing sticky sage at Dover, N.Y. The crew proudly finished managing all the sticky sage
found along the Appalachian Trail in this visit! It is essential to manage sticky sage along the trail to prevent the spread of this relatively new invasive to other regions in the Northeast. Overall, the crew is proud to say that they treated a total of 6,182 sticky sage along the A.T.! The crew will be returning to Dover one last time for the season in August to continue working on sticky sage management on private properties.

After sticky sage, the ISF worked on removing sapphireberry and linden viburnum from Sachs Park and Lawther Preserve in Pound Ridge, N.Y. Next was more sapphireberry at Vassar College, in addition to managing castor aralia and hardy kiwi here. As one of the hotspots for emerging invasive castor aralia in the Northeast, thorough management at Vassar was crucial. The crew enjoyed working alongside interns from Vassar who thoroughly mapped the infestations to aid the ISF’s work. Thanks, interns!

This month, the ISF participated in several career development activities. The crew worked on their public speaking and presenting skills when they shared their season’s progress over zoom with interns and Lower Hudson PRISM staff and got the chance to learn from some experts in the field at a career panel and workshop about environmental career paths. Some members were also trained and became certified in Leave No Trace principles. Now they can confidently minimize their outdoor footprint and share what they learned with others!

Lastly, the ISF got their feet wet with invasive spotted lanternfly management in Orangeburg, N.Y., working in conjunction with the Department of Agriculture and Markets. They removed over 900 individual spotted lanternflies, set traps, cleared vegetation for easier access, and marked trees in the area for future treatment. The ISF is thrilled to do its part on this important assignment and will continue working hard to support invasive spotted lanternfly management!

This August, the ISF looks forward to working on sticky sage in Dover, sapphireberry at Franklin Fels, and at Granite
Mountain on a variety of invasives, along with many other exciting projects! 

August 2021

The ISF had their last week of treating sticky sage in Dover, N.Y., and accomplished management of 29,449 plants on 55 acres! The crew collaborated with the Conservation Dogs team who helped scout and treat the areas with sparse sticky
sage. Stay tuned below for some puppy pics! ISF also wrapped up their work at Vassar College, managing castor aralia and sapphireberry. They treated a total of 345 castor aralias and sapphireberries this visit! Sapphireberry was also managed at Ruth Walgreen Franklin & Winifred Fels Memorial Sanctuary. The crew spent 3 days searching and treating 95 acres, and found the biggest infestation they’d ever seen: 21 acres of dense monoculture of sapphireberry! The crew braved thick brambles and thorns, but persisted in successful treatment of 11,132 sapphireberries over 2.5 acres! Much remains to be done, and the crew will be going back in October to continue the fight against sapphireberry.

The crew also began working on Japanese spiraea at Three Arrows Cooperative society with volunteers and community members at the cooperative, and at Cary Institute. At Three Arrows, the crew enjoyed collaborating with volunteers and
was able to manage over 2,000 spiraea! At Cary, the crew explored the beautiful hiking trails at the facility while they worked. There, they managed a total of 689 Japanese spiraea, chocolate vine, and Japanese angelica tree. Next, the crew managed a variety of species at Granite Mountain including yellow archangel, linden viburnum, and Japanese angelica tree. This project was important because of the Tier 2 emerging invasive: yellow archangel. This emerging invasive is an herbaceous plant in the mint family. It is not found in many locations in the Lower Hudson Valley so its management is crucial to prevent the spread of their seeds into more natural areas. The crew also worked at Pine Croft Meadow and Preserve. They enjoyed the opportunity to emerge from the forest and take a trip into a scenic meadow for a change. Here they managed 551 cutleaf blackberry and bamboo plants. In the upcoming month, ISF is looking forward to working on a variety of projects including managing viburnums, general invasives with volunteers at Joppenbergh Mountain, hardy kiwi in Bedford, and participating in a day of service with MEVO, a volunteer organization in Mahwah, N.J.

September 2021

The ISF welcomed in fall and enjoyed their cool weather field work! The crew kicked off the month with a volunteer day at Joppenbergh Mountain removing barberry, wineberry, and huge Asiatic bittersweet vines that posed a threat to mature native trees. Together with 12 dedicated volunteers, the ISF managed 642 plants, freed the strangled trees, and cleared a quarter of an acre of invasive plants which can now be restored to native vegetation! The ISF also had the opportunity to treat their very first Tier 1: watch species, Chinese fountaingrass, at Edith G. Read Natural Park and Wildlife Sanctuary. The sanctuary is a favorite spot of birders, and the crew got to experience the sights and sounds of the sanctuary while they were hard at work! They heard red-tailed hawks squawking and saw cormorants on the Long Island Sound while they worked hard, and ultimately took out almost 200 clusters of invasive grass! At the end of September, the crew celebrated National Public Lands Day by collaborating with the Wild East Women’s group to remove Japanese barberry and plant native meadow plants in Harriman State Park. They removed 164 barberry and planted 181 native plants, including boneset, woolgrass, seaside and blue stem goldenrod, little bluestem grass, and silverrod.

The crew also worked on other emerging invasives in September including chocolate vine at North Salem, N.Y., Asiatic photinia at Teatown Lake Reservation, hardy kiwi at Brinton Brook Sanctuary and in Bedford, N.Y., and Scotch broom in
Harriman State Park. The crew took out a total of 7,200 plants in September and looks forward to exciting projects in October! As the end of the field season approaches, the crew will work on kudzu management, wrap up other projects such as hardy kiwi, and collaborate once more with volunteers at Three Arrows Cooperative Society to take out Japanese spiraea!

October 2021

The End of the 2021 Corps Season

In October, the crew unlaced their work boots and wrapped up the field season. As the month began, they worked on kudzu across the state for three days. Known as “the vine that ate the south”, the ISF worked to stop this emerging invasive from nibbling at New York! From Poughkeepsie to Yonkers, this vine smothers trees and forms thick mats, shading out native vegetation and altering habitats. The crew visited 13 sites to treat this harsh invader and did their part by taking out about half an acre of kudzu!

After kudzu, the crew had their last volunteer workday at Three Arrows Cooperative Society. Joining forces with returning volunteers and community members, the team dug and pulled out 853 spiraeas on almost an acre! The crew had a blast working with these amazing volunteers, and over the course of the season put a 2-acre dent in the large 6-acre infestation! On their very last day, the ISF crew brought their season full circle and planted natives at the Welch Trail Education Center, which is not only where they called home throughout the season, but where they had their first training and work-day together as a crew. The crew planted native boneset, buttonbush, musclewood, and woolgrass by the shore of Lower Twin Lake to replace the barberry they removed back in May. Both this work site and the crew have come a long way this season!

As the field season winded down, the crew geared up to finish report writing, data entry, and map-making for the last few weeks of their term. After their days at the office, the crew also stopped at spotted lanternfly infestation
sites to check on progress. After clearing paths, squashing bugs, and checking traps throughout the season, SLF were barely detectable at three sites across the region! Go “swat team,” go!

After crunching the numbers, the results are in! Over the course of the season, the crew managed 421 acres of land, treated 113 acres, and treated 101,590 plants! Over these 35 projects and 20 emerging invasive species managed, the members of the 2021 Invasives Strike Force are all very proud of the work they’ve accomplished this season in the Lower Hudson Valley! Thank you to all of you wonderful volunteers who came out with the crew this season -- they couldn’t have done this great work without you!