By Melody Cerniglia
On May 6, 2024, the LIISMA team of Melody Cerniglia (EDRR Manager), Abby Marino (CA Manager), and Kassidy Robinson (EO Manager) set out on the first trip of the year to Staten Island to conduct emerging invasive species surveys of four natural areas. We had our work cut out for us – but that was not going to stop the team from getting ahead of the spread in the LIISMA region! The team ventured off to four different sites including the William T. Davis Wildlife Refuge, Wolfes Pond Bluebelt, Blue Heron Park Preserve, and Great Kills Park, in search of six emerging, high-priority EDRR species.
The first site was William T. Davis Wildlife Refuge, a subset of Freshkills Park. We sought to identify and confirm research-grade observations of a Tier 2 species, incised fumewort (Corydalis incisa). Much to our dismay, we confirmed the species to be widely present within this disturbed site, overtaking much of the understory landscape on both sides of the trail. The population began at the parking lot area at the intersection of Richmond Ave. and Travis Ave. on the southeast corner of the refuge. The incised fumewort was densely interspersed with native and non-native species, with some invasive species present. The team utilized binoculars to inspect the area across from the adjacent river and observed no presence of the species on the northwest side.
We were pleased to find ecologically valuable native species on site, including American elm (Ulmus americana), silver maple (Acer saccharinum), may apple (Podophyllum peltatum), sweetgum (Liquidambar styraciflua), shadbush (Amelanchier sp.), golden alexander (Zizia aurea), selfheal (Prunella vulgaris), willow oak (Quercus phellos), spicebush (Lindera benzoin), poison ivy (Toxicodendron radicans), American beech (Fagus grandifolia), stinging nettle (Urtica gracilis), river birch (Betula nigra), Virginia creeper (Parthenocissus quinquefolia), and yellow wood sorrel (Oxalis stricta).
Though nothing is ever perfect! Among these native species, we also detected many invasive species interspersed throughout the landscape, including Norway maple (Acer platanoides), English ivy (Hedera helix), knotweed (Reynoutria japonica), mugwort (Artemisia vulgaris), horse chestnut (Aesculus hippocastanum), phragmites (Phragmites australis), white mulberry (Morus alba), garlic mustard (Alliaria petiolata), lesser celandine (Ficaria verna), greater celandine (Chelidonium majus), mock strawberry (Potentilla indica), and daffodil (Narcissus sp.).
Currently, there is limited information available on the management of incised fumewort in the Mid-Atlantic region. Based on desktop research, we found that manual control may be successful if the plant is cut and mowed to ground level at least 4-5 times per year. This may result in interrupting the plant’s ability to photosynthesize. Other experimental control efforts include weed torching or herbicide application. However, due to the interspersed native species around the fumewort, herbicide applications of broadcast foliar spraying may indirectly harm native species within the understory. It would be best to explore other methods of chemical control, such as hand wiping with a treated glove, as this method may have fewer off-target impacts. The LIISMA team will contact NYC Parks staff responsible for maintaining this site at Richmond and Travis Avenues to collaborate with them on an effective management plan, in hopes of preventing this species from escaping this site. The site is heavily populated with fumewort and may require up to 5 to 10 years of management before the species is eradicated. It would be beneficial to continually reseed the disturbed areas with competitive native species in the fumewort’s place.
Our next stop included a secondary monitoring survey for Tier 3 species (management goal: containment) Italian arum (Arum italicum) at the Wolfe’s Pond Bluebelt to follow up on the progress of manual control efforts by the NYC Department of Environmental Protection (NYCDEP). The species has been managed there at least twice since 2020, according to NYCDEP and iNaturalist reports.
Also known as orange candleflower, Italian arum is identified by its arrowhead-shaped, long-petioled, glossy grayish-green leaves with pale green midribs. The plant resembles our native Jack-in-the-pulpit (Arisaema triphyllum), with the main difference being the bloom description, as the native Jack-in-the-pulpit has a greenish-purple bloom, and Italian arum has a yellowish-green to creamy-white bloom. Each flower of Italian arum consists of an erect, finger-like spadix covered with minute, creamy white flowers and a large, sheath-like, light green spathe which subtends and partially envelops the spadix like a hood. It should also be noted that Italian arum is a hazard to human health, as all parts of the plant are poisonous. Contact with this plant can cause skin irritation; eating any part of the plant can be fatal.
The team determined that the manual control efforts are having a positive effect on the management of this species, as there is a lesser abundance and dominance in the understory as opposed to previous years. The plant appears to be emerging in smaller clumps throughout the .38-acre area of the Wolfes Pond Bluebelt. Twenty or so immature plants were counted and visible within the site. Care should be taken to ensure more plants are not emerging in the coming months.
It was noted that several more mature plants residing alongside the small adjacent parking area (located at the dead end of Prall St.) may have bypassed control efforts. These plants should be dug up (including rhizomes) and removed if possible. We recommend that the plant and site continue to be monitored and annually managed 1-2 times per year, for several years until the species is no longer emerging at this site.
For our third stop, LIISMA visited the Blue Heron Park Nature Preserve to investigate and confirm casual grade observations of Tier 3 species, fuzzy deutzia (Deutzia scabra), and several research grade iNaturalist reports of Tier 3 species water hyacinth (Pontederia crassipes) within the preserve. The team confirmed the species was fuzzy deutzia due to arching branches, white star-shaped flowers, and rough, hairy stems. Five deutzia shrubs about 5 to 8 feet tall were observed growing on a medium slope at the entrance to the trailhead adjacent to the Blue Heron Pond Nature Center.
Fuzzy Deutzia is typically identified as a large deciduous shrub that grows erect, with an open crown and arching branches. The plant grows up to 6 to 10 feet tall and 4 to 8 feet wide. The bark exfoliates on mature shrubs in large sheets, and the stems and leaves have a rough and hairy texture. White star-shaped flowers appear in panicles from late spring to early summer. The shrub is a member of the Hydrangeaceae or hydrangea family.
Much to our relief, the team detected no presence of water hyacinth within the area. However, due to the species’ subtropical nature, it may be too early in the year for the plant to emerge. It would be beneficial if all water bodies on site were monitored periodically, especially in late summer to early fall for the emergence of this high-impact species.
We were happy to find a diverse collection of native species on site, including celandine poppy (Stylophorum diphyllum), eastern enchanter’s nightshade (Circaea canadensis), Virginia creeper (Parthenocissus quinquefolia), purple raspberry (Rubus idaeus ssp. strigosus × R. occidentalis = R. ×neglectus), spicebush (Lindera benzoin), sassafras (Sassafras albidum), American beech (Fagus grandifolia), red maple (Acer rubrum), common greenbriar (Smilax rotundifolia), and tuliptree (Liriodendron tulipifera).
The usual invasive suspects were present as well, including knotweed, honeysuckle (Lonicera japonica), porcelain berry (Ampelopsis brevipedunculata), bittersweet (Celastrus orbiculatus), garlic mustard, multiflora rose (Rosa multiflora), and angelica tree (Aralia elata). However, this nature preserve seemed to have an abundance of native species, which gives us hope in their ability to counteract the invasive ones. We even found some vernal ponds along the way, which was a wonderful treat!
The literature suggests hand-pulling young fuzzy deutzia seedlings when the soil is moist, and any mature plants can be cut or dug up. For chemical control, deutzia can be managed using a cut stump herbicide application of a general-use herbicide such as glyphosate or triclopyr.
The last stop on our Staten Island field adventure was Great Kills Park, where we tracked down casual-grade iNaturalist reports of slender spurge (Euphorbia virgata) and research-grade reports of Asiatic sand sedge (Carex kobomugi) along the shoreline area.
Slender spurge grows in a variety of climate environments. It displaces native vegetation in grassland habitats by shading and usurping available water and nutrients and through plant toxins that prevent the growth of other plants underneath. It is an aggressive invader and, once present, can completely overtake large areas of open land to form monocultures in a few short years. Slender spurge is known to form dense clumps that quickly colonize large areas and outcompete with other native species. Native forbs and grasses can become entirely displaced. Due to the plant’s extensive root system, ability to resprout from fragments, and seed dispersal ejection up to 15 feet from the parent plant, it is a serious threat to other existing vegetation. The species is toxic to animals and people.
Much to our relief, the casual-grade report of this species was misidentified as slender spurge, when it was another more widespread spurge species, cypress spurge (Euphorbia cyparissias). Though finding another more widespread spurge is not the best-case scenario, it is not the worst. Through slender spurge’s rhizomatic spread, the species may cause more impact to its environment than its spurge cousin if left untreated. We are glad that wasn’t the case here.
We continued our search along the shoreline to locate the sand sedge, and we found it. The species was densely populated along the shoreline for as far as the eye could see. According to nearby reports, the populations may go on for miles.
Originally from East Asia, the sand sedge was introduced accidentally to the US in the early-to-mid-1900s, possibly arriving through ballast water. Growing readily in coastal ecosystems, the plant was promoted for erosion control to stabilize dunes and planted over the East Coast. Populations now extend across the coast from Massachusetts to North Carolina. After Hurricane Sandy in 2012, fragments of the plants from New Jersey appear to have washed up on New York shores, allowing the plant to establish numerous populations in the Rockaways and Fire Island. It is a prohibited species in Connecticut, but not yet on the regulated species list in New York.
Asiatic sand sedge is characterized by its V-shaped leaves that are triangular in cross-section. Its leaves have a yellow-green color (compared to native beach grasses that have a bluish-green appearance). This sedge is relatively short, reaching 6 to 12 inches. They have small teeth along the edge of the leaf that can be felt or seen with magnification. Flowering and fruiting occur from April through June, as the plant sends up a short brown spike of either male or female flowers. While their seeds are salt-tolerant and able to float, they reproduce primarily through vegetative spread. They can form dense colonies via their underground stems, or rhizomes. Rhizome fragments transported over water can establish new colonies.
Growing to densities of up to 350 shoots per square meter, populations of this plant can outcompete native beach grasses and forbs. This can include American beach grass (Ammophila breviligulata) and seabeach amaranth (Amaranthus pumilus), a state and globally imperiled species. Their populations can also reduce the habitat available for the threatened piping plover (Charadrius melodus). While the plant does achieve the function of partially stabilizing dunes, native dune species are known to stabilize dunes just as well.
Managing sand sedge can be a balancing act between removing harmful invasive species while maintaining native plant populations and stable dunes. In any chosen management technique, it is important to limit the off-target impacts to maintain the ecosystem services that dunes provide. We plan to coordinate with NYC Parks and National Park Service staff to discuss the future of this high-impact species as it meets with Long Island’s ecologically valuable tidal shorelines. This concludes LIISMA’s fun-filled field day of EDRR surveying in Staten Island’s many differing ecological communities!
