An invasive species is defined as a species that is non-native to the ecosystem under consideration and causes or is likely to cause economic or environmental harm or harm to human health. Did you know that there are 146 invasive plant species that threaten the Lower Hudson Region’s ecosystems?
This season, NYBG hosted a citizen science training for the LHPRISM 2017 BlockBuster Survey that taught volunteers how to identify and monitor for 27 of the terrestrial plant species that have limited data in New York’s online mapping program called iMapInvasives and are regional candidates for eradication and containment. In one day, 22 volunteers learned how to identify each plant species, how to sample following the survey protocol, and use an app to collect the data. What makes this survey effort unique, is the extensive regional searching for presence and absence of each of the 27 terrestrial plant species. Each volunteer or team was assigned a three-mile by three-mile grid in which they have until mid September to search for the invasive species of interest.
Esther Jackson is the Public Services Librarian at NYBG’s LuEsther T. Mertz Library, where she manages Reference and Circulation services and oversees the Plant Information Office. She spends much of her time assisting researchers, providing instruction related to library resources, and collaborating with NYBG staff on various projects related to Garden initiatives and events.
In recent years, invasive species have been on the minds of many people and have been the focus of a variety of organizations working in ecology and biology, including The New York Botanical Garden. As Science Talk readers may know, the Botanical Garden hosted an invasive species summit in November 2015 to address the threat that invasive species represent to biodiversity worldwide. The summit featured discussion about conservation, including ecosystem management, and involved prominent speakers in the fields of invasion biology, restoration ecology, and not-for-profit land management. The New Wild is quite a topical book.
Robin Sleith, a Ph.D. candidate in the Commodore Matthew Perry Graduate Studies Program at The New York Botanical Garden, is researching algae under the direction of Kenneth G. Karol, Ph.D., Associate Curator in the Cullman Program for Molecular Systematics and the Botanical Garden’s specialist in algae.
The 400 lakes surveyed in the summer of 2014 Credit: Robin SleithThe star-shaped bulbil of Nitellopsis obtusa that gives rise to it common name, starry stonewort Credit: Robin Sleith
This summer, a team from The New York Botanical Garden will set out for the second year to document the diversity of green algae that live in hundreds of lakes in the northeastern United States and determine the distribution of an invasive freshwater alga species, Nitellopsis obtusa, or starry stonewort.
Starry stonewort, which is native to Europe and western Asia, is replacing native plant species and threatening the habitat and food sources of small fish and invertebrates in the lakes where it is found. Growing to a height of seven feet in water as deep as 30 feet, starry stonewort forms dense mats that out-compete native species.
First discovered in the St. Lawrence Seaway in 1978, it has spread at an alarming rate through the Great Lakes and into inland lakes in New York State. It is easily transported from lake to lake as plant debris caught in boat trailers.
Graduate student Robin Sleith with starry stonewort (Nitellopsis obtusa). Note the setting: this alga is often found in areas of high human traffic. Credit: Robert Stewart.
Last summer, we surveyed 400 lakes throughout New York State for starry stonewort and other green algae. Grappling hooks in hand, we traversed the state on week-long excursions, averaging 10 lakes per day. At each lake, we used the grappling hooks to gather algal specimens and also collected water-chemistry data and documented physical characteristics. There was no shortage of excitement on our journey, owing to multiple tornado warnings, many bear-sightings, and countless beautiful vistas.
We found starry stonewort in lakes across New York, from Jamestown to Potsdam, but did not find it within the boundaries of Adirondack Park. This is good news for the millions who visit the Park annually. The Adirondack region has a strong Watershed Stewardship Program, and we are partnering with this program to raise awareness about starry stonewort and the measures that can be taken—such as cleaning and fully drying boats and gear—to keep this invasive out of Adirondack lakes and ponds.
Now we are taking our grappling hooks to New England to conduct a similar survey of lakes, so stay tuned for more updates.
Scott A. Mori, Ph.D, is a Curator Emeritus associated with the Institute of Systematic Botany at The New York Botanical Garden. His research interests are the ecology, classification, and conservation of tropical rain forest trees.
If you have noticed a plant forming a green veil over utility poles or vegetation along roads and parkways in the New York metropolitan area, you probably thought that it was the notorious kudzu vine, a member of the pea family that has been well publicized as a fast-growing invasive plant.
Although kudzu has been reported in New York, it is not the invasive plant found along the Saw Mill River Parkway and other roadways. This plant is a member of the grape family (Vitaceae) and is called the porcelain berry (Ampelopsis brevipedunculata) because of its beautifully colored fruits. These two invasive plants can be distinguished from one another by the porcelain berry’s simple, lobed leaves; presence of delicate tendrils; small greenish flowers; and berry fruits. By contrast, kudzu has compound leaves (a leaf divided into separate leaflets); robust tendrils; larger, pea-like flowers; and legume fruits resembling peapods.
The porcelain berry, introduced from Asia as an ornamental plant, escaped from cultivation and has become one of the worst invasive plants in our area. The veil of green that it produces deprives all other plants of sunlight, water, and nutrients.
In early spring the porcelain berry appears as a massive tangle of stems, sprawling over low vegetation along the roadside and up into trees. The plant’s tendrils facilitate its climb into tree tops. The flowers produce abundant nectar that attracts swarms of small bees, wasps, and other insects, thereby facilitating the production of fruits.
The plant’s fruits are small, spherical berries with a pulp surrounding the seeds. They are multicolored, ranging from white to lavender to blue, with dark spots adorning their outer surfaces. The fruits are consumed by animals, especially birds, which disperse their seeds into new areas. Currently, the leaves have not yet flushed out, so it is possible to see that few, if any, other plants are able to compete with the porcelain berry.
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The accompanying images show the stages that the porcelain berry goes through during the year. The first image shows how the porcelain berry looks now. To limit this invasive from invading new habitats, do not cultivate it and pull out any young plants that you encounter! Once the porcelain berry becomes established, it is extremely difficult to eradicate.
For information about another invasive plant that is currently flushing new leaves, click on Japanese barberry.
A recent graduate from Pelham Memorial High School, Owen Robinson worked as a volunteer Forest Intern at the NYBG in the summer of 2012. He has since begun as a freshman at the University of Virginia, where he hopes to continue his pursuit of science research as a part of the Echols Scholar Program.
Norway maple leaf pack
In the summer of 2012 I conducted a project to determine whether or not invasive trees are negatively impacting aquatic macroinvertebrate populations. Aquatic macroinvertebrates are small, invertebrate insects that play essential roles in their ecosystems, acting as an energy bridge between outside plant life and the rest of their aquatic environment. They do this by breaking down tree leaves.
Invasive trees are an established and worsening problem in our region, one that impacts plant biodiversity as well as some mammalian and avian populations. As little research has been dedicated to my particular focus, I wanted to determine whether the leaves from these invasive trees were less beneficial to aquatic macroinvertebrate populations than the leaves of native trees. If this proved the case, there would be reason to work harder against the takeover of invasive plant species.
