Invasive Species

Invasive species are nonnative species that have the potential to spread and proliferate to an extent that they disrupt native ecosystems, or pose a danger to human health or the economy. Compared to other areas of New York State and the country, the Adirondacks remain relatively free of invasive species. Private landowners can play an important role in protecting the Adirondacks from the negative impacts of invasive species by not planting them on their property, and quickly controlling infestations if they occur.

Keeping your property free of invasive species is not only good for the environment, but might also be good for the health of you and your family. Tick-borne diseases have emerged as a major health threat, and it has been found that areas dominated by invasive shrub species such as Japanese barberry and honeysuckle have higher numbers of disease-bearing ticks (Williams 2010, Allan 2010).

Currently, the Adirondacks are not a suitable environment for many invasive species. Winters are still too cold for many such as the hemlock wooly adelgid (Paradis 2008), and shorter growing seasons makes things difficult for species present such Phragmites, which has trouble reproducing from its abundant, wind-borne seed (Brisson 2008). Calcium levels of many lakes are too low to support zebra mussels. Large tracts of unfragmented forest reduce the amount of edge habitat where invasive species often become established. However, some of these advantages are likely to diminish over the coming years as the climate changes and species adapt. Eliminating invasive species infestations now and establishing procedures to prevent their spread is critical to the long-term health of the region.

Mitigating the threats posed by invasive species is the sole focus of the Adirondack Park Invasive Plant Program (APIPP), and its partner organizations. The Adirondack Watershed Institute administers an aquatic invasive species prevention program by deploying boat launch stewards and boat wash stations throughout the region. Many other groups, such as the Adirondack Lakes Alliance, the Lake George Association, the Adirondack Landowners Association and others have initiatives focused on invasive species prevention, management, education and outreach. Many of these initiatives are funded though the invasive species line of New York State’s Environmental Protection Fund.

Stewardship Actions

The ability to deploy best prevention and management practices, and minimize potential sources of invasive species introduction are how private landowners can keep their properties free of invasive species. If invasive species are discovered early, before they become widely established, private landowners can move quickly to eradicate them. 

PreventING the spread of aquatic invasive species

Landowners can prevent invasive species from being introduced onto their property by taking a few simple steps. The old adage 'an ounce of prevention is worth a pound of cure' holds true, particularly when it comes to aquatic invasive species, which are difficult, if not impossible to eradicate once established.

If possible, keep aquatic gear such as boats, fishing equipment, waders and the like on the property and use only in your lake, pond or river. A number of large landowners prohibit the use of boats and other gear such as fishing equipment that have been used in other waters.  This greatly reduces the risk of aquatic invasive species being introduced. This is an exceptional advantage and opportunity that private landowners have, especially those that own the entire shoreline of an individual lake or pond. Aquatic invasive species are very difficult to eradicate once established. Some, such as spiny water flea, and zebra mussel veligers are so small that even gear which appears clean to the naked eye, may in fact be contaminated.

Clean, drain, dry, and/or decontaminate aquatic gear - if storing and using boating and/or fishing equipment at the water body where it will be used is not an option, the first and most basic preventative action you can take is to practice "clean, drain and dry." Under a new regulation boaters are required to take reasonable precautions to prevent aquatic invasive species by Cleaning, Draining and Drying their watercraft before launching into New York waters. First, inspect all areas of your watercraft and remove any visible plant or animal material that you find. Dispose of these materials in a garbage receptacle or in an upland area away from the water. Next, again in an upland area, drain any standing water from the boat's motor, bilge, live/bait wells, etc. Lastly, make sure any microscopic plant or animal material is killed between outings by allowing your boat to dry completely (usually for 5 days depending on weather conditions) or have your boat washed with hot water.

Free boat washing stations are now available throughout the Adirondack region making it easier than ever to prevent the spread of aquatic invasive species. To find your nearest free and complementary boat washing station visit adkcleanboats.com. In 15 minutes or less staff will have your boat Cleaned, Drained, Treated and ready to launch.

If you have a lower risk watercraft such as a canoe and can't make it to a washing station, or have other items you'd like to decontaminate such as wet suits, waders, fishing gear, and other small items, the most effective option is to let items thoroughly dry for 5 days. 

If letting items dry for 5 days is not an possible, here are some additional decontamination options:

Fantastik or Formula 409. These two household cleaners contain a quaternary ammonium compound that is a very effective disinfectant. They are available at any grocery or hardware store, in ready to go spray bottles. These would be good cleaning canoes, kayaks, paddles and other hard-surfaced items. 

Household Vinegar. Soaking items in undiluted white vinegar for 20 minutes will kill most invasive species.

Steam cleaners. Steam cleaners are another DIY decontamination option, but are much more expensive than the others.

DO NOT rely on salt water or bleach treatments, which are frequently recommended as decontamination options, as they are ineffective on the Spiny Water Flea, which is spreading through the Adirondacks.  

You can read more about decontamination options in the NOAA document Preventing Invasive Species: Cleaning Watercraft and Equipment, the NYS DEC page Disinfection Techniques for Fishing and Boating Equipment, and the General Prevention Procedures for Stopping Aquatic Hitchhikers of the Protect Your Waters site. 

Don't forget the dog. Avoid the temptation to let your dog out for a swim on the way to the Adirondacks. Your dog's feet and fur are ideal places for many invasive species to hitchhike to the lake, and for obvious reasons the decontamination options above shouldn't be used on Fido. Large lakes with the easiest access such as Lake Champlain, Lake George and Great Sacandaga Lake also are infested with insidious species such as Spiny Water Flea. (Lake George Association, Maryland DNR, Lake Whatcom Boat Inspections)

Buy certified bait. Minnows or crawfish trapped in one waterbody should never be used in another. If live bait is used, ideally it should be caught in the same waterbody that it will be used in. If minnows or other bait is purchased, be sure that it from certified distributor and that you keep your receipt in case checked by environmental police.

PREVENTING THE SPREAD OF TERRESTRIAL INVASIVE SPECIES

Clean your vehicles, boots and any additional gear of mud and debris before bringing it onto your property. Mud and other debris can contain invasive weed seeds, plant fragments, or other material that can lead to an infestation. Stipulate in any contracts that all equipment must be cleaned before being brought onto the property.

Plant non-invasive species. Garden and landscape ornamental plantings can serve as the source for invasive plant infestations in natural or managed areas. If you do choose to garden and landscape in the Adirondacks use a native or non-invasive species and adhere to the following guidelines:

• Never transplant garden plants from outside the region to the Adirondacks. The soil from your downstate garden may contain invasive plant seeds, invasive earthworms, or other unwanted hitchchikers.
• Avoid non-native species. It often takes several years for the invasiveness of a non-native species to become evident. For example, butterfly bush and Miscanthus grasses, which became very popular in recent decades, are now regarded as invasive.
• Evaluate the areas surrounding historic invasive species plantings. That Japanese barberry, burning bush or honeysuckle plant removed from your landscaping long ago may still result in an invasion of the species in your area due to the longevity of these species seed bank.

Buy and use local firewood, ideally cut on your own property. Invasive insect species such as emerald ash borer and Asian longhorned beetle can be spread long distances via firewood. It is illegal in NYS to move firewood more than 50 miles from its source. Visit the NYS DEC page Firewood and Invasive Insects for more information.

Worms are invasive species (!). A worm trailing a Lake Clear Wabbler is a classic Adirondack pond trout rig. Although worms are commonly perceived as beneficial (Seidl 2011), they are non-native and invasive in many circumstances, and can have severe, negative impacts to forest ecosystems. While the generally acidic soils of the Adirondacks make them less vulnerable, areas with higher pHs such as those that support high proportions of Sugar Maple are at risk. In addition, as the Adirondacks continue to recover from the effects of acid rain, they will become more conducive to earthworm invasion. Liming, which is used to help forests recover from acid rain, also appears to have the unintended consequence of increasing invasive nightcrawler populations (Homan 2016).  If fishing with worms, treat them as invasive species and put any extras in the trash instead of adding to your compost pile.

Use clean fill and mulch. Transportation of gravel, fill and mulch is one of the primary pathways for the introduction and spread of invasive plants such as Japanese knotweed and Phragmites. Both of these species are able to re-sprout from small fragments of their stem and root material and numerous other invasive plants can be spread through the seed contained in “dirty” fill. Be sure to use clean, local sources of fill and mulch.

Learn the Species of Concern 

Even if you implement all the measures above to significantly reduce the likelihood of invasive species being introduced to your property by people, the risk cannot be completely eliminated. Some species, like bush honeysuckle, can be spread by natural vectors such as birds, while others such as swallow-wort species can be spread a long distance by wind. Therefore, it is important to learn the species of concern to your area, and to keep an eye out for them. The objective is to detect new introductions early in the invasion curve and rapidly respond while the infestation is small and control is feasible. 

A triage approach to invasive species is the most sensible one, allowing attention and efforts to be focused on species threats that are most detrimental to the property or ecosystem. Early detection is essential for successful eradication. Therefore, teaching your family and others who use the property on how to identify the species that are most likely to be introduced, and pose the greatest threat is encouraged. 

The New York Invasive Species Information website provides a list of ranked invasive species by their potential or realized impacts to New York’s native species and natural ecosystems. APIPP uses these state ranking assessments to evaluate risk and set monitoring and management priorities for invasive species located in, or approaching, the Adirondack PRISM. For the lists of APIPP’s target and watched in invasive species visit adkinvasives.com. The species that you should be most concerned of will depend on the habitats available on your property. In wetlands, common reed and purple loosestrife are two of the top threats. Knotweed is most likely to invade riverbanks. In the uplands, bush honeysuckles, barberry, and garlic mustard are a few species to keep an eye out for. If you happen to have open grasslands on your property, such as old fields or historically burned areas, species of lesser concern elsewhere in the Adirondacks such as spotted knapweed, wild parsnip and mugwort may be things you want to keep an eye out for. 

APIPP maintains databases on the distribution and management status of target terrestrial and aquatic invasive species in the Adirondack PRISM. The program also provides an interactive map for anyone to easily access this information. This tool is very helpful for knowing what's in your area. 

Terrestrial Invasive Species

Here are several high priority terrestrial invasive plant species that are spreading across the Adirondacks. Some are spread primarily through human activity, while others are spread by natural vectors such as birds and other wildlife. The invasiveness of these species is readily observable outside of the Adirondacks in areas that have been invaded for longer periods of time. You should contact APIPP if you discover any of these on your property and are interested in learning how to manage them. 

In contrast to aquatic invasive species, which are difficult or impossible to eliminate once introduced, infestations of terrestrial invasive species can sometimes be completely eradicated if identified early and managed appropriately. Therefore, vigilance and quick action by Adirondack landowners can make a significant difference in whether invasive plants are able to establish in an area.

Knotweed. Knotweed species are one of the top threats to riparian zones in the Adirondacks. There are a number of different Knotweed species, and as a group they have an invasiveness ranking of 97.94 out of 100 in NYS. As of 2015, APIPP has documented 767 occurrences of knotweed in the Adirondacks. Knotweed thrives in disturbed areas, such as roadsides and stream banks. Identification. Knotweed is distinctive year-round, forming dense thickets that people often mistake as "bamboo." In the spring, thick reddish shoots emerge amidst the previous year's dead stems. During the summer, distinguishing features include heart-shaped leaves, hollow, jointed stems and white billowy flowers. During winter, the large, dead, hollow, brown stems are easily spotted. Spread. Knotweed is most commonly spread vegetatively when root or plant fragments are transported from one location to another. This can occur through human activities such as road maintenance and use of contaminated fill. Once established along a stream, knotweed can easily spread through high water events such as floods that wash fragments downstream. If you discover knotweed in a stream corridor, be sure to search upstream and downstream for other colonies and contact APIPP.  When to Observe. Distinctive year-round. Peak flower usually occurs in August. Control. Call APIPP at (518) 576-2082. Mechanical control of knotweed is generally impractical, as the entire root system must be removed. Fragments from mowing or cutting can also worsen or spread an infestation to new locations. Knotweed is most effectively controlled with a glyphosate based herbicide. Links. APIPP Profile. APIPP Risk Assessment. Google Knotweed Images. Inter-agency Guidelines. APIPP Management Guide.

Common reed (Phragmites). Phragmites is one of the top threats to wetlands throughout the Adirondacks, with an invasiveness ranking of 92. Once established, it forms dense colonies that choke out native vegetation, an impact that can be observed along roadsides and in wetlands throughout New York. As of 2015 APIPP has documented 925 occurrences of common reed in the Adirondacks. Identification. Common reed is very distinctive, with alternating bluish-green leaves coming off a stiff, tall central stem. The plant can reach heights in excess of 15 feet and typically produces a large, feathery plume of seeds in July or August. If you keep an eye out while driving outside the Park, you'll surely see many examples. Spread. In colder parts of its range such as the Adirondacks, Phragmites is primarily spread vegetatively, when segments of its root system or stem are moved through road maintenance activities, movement of contaminated fill,orwhen fragments wash or float to another area. However, there are some examples of reproduction from seed in Canada (Brisson 2008), and anecdotal accounts of it occurring in the Adirondacks. In addition, it is thought that more viable seed is produced when it can cross-pollinate. When to Observe. Distinctive year-round.  Control. Call APIPP at (518) 576-2082. Common reed is most effectively controlled using herbicides. Common Reed is almost always found in wetlands, and using herbicides in wetlands requires an APA permit.  Links. APIPP Profile. APIPP Risk Assessment. NYIS Profile. USDA Forest Service Profile. Inter-agency Guidelines. APIPP Management Guide.

Purple Loosestrife. Purple loosestrife has an invasiveness ranking of 91 in NYS, and as of 2015 APIPP has documented 388 occurrences of the species in the Adirondacks. Like common reed, purple loosestrife invades wetlands. Identification. In addition to its distinctive magenta flowering spires, Purple Loosestrife has opposite or whorled leaves on a square or angular stem. Spread. Purple loosestrife spreads mainly through incredible amounts of seed - one mature plant can produce literally millions of seeds that are only 400 microns (.015 inches) long, and have a viability of 99% (Munger 2002). It is therefore extremely important to carefully clean your gear after you've been in wetlands with purple loosestrife. These seeds are easily spread along road corridors by highway maintenance practices and movement of contaminated fill. When to Observe. Purple loosestrife usually blooms in late July or early August. Isolated or immature plants can be tough to spot most of the year. Control. Call APIPP at (518) 576-2082. Individual purple loosestrife plants can be easily dug or pulled out by the roots. Herbicide treatments can also be effective. However, purple loosestrife is almost always found in wetlands, and using herbicides in wetlands requires an APA permit. A biocontrol agent (Galerucella calmariensis) is also available to release and feed on purple loosestrife. The beetles only feed on purple loosestrife and maintain self-sustaining populations once released. Links. APIPP Profile. APIPP Risk Assessment. USDA Forest Service Profile. Google Purple Loosestrife Images. Inter-agency Guidelines. APIPP Management Guide.

Japanese Barberry. Japanese barberry has an invasiveness ranking of 91.00, and is a threat to the forest understory as it is very shade tolerant. In addition, it poses a threat to human health by often harboring a disproportionate number of Lyme Disease bearing ticks than surrounding native vegetation. The species is widely distributed throughout the Adirondacks as a result of ornamental plantings. The spines on Japanese barberry deter browsing, giving ita competitive advantage over other native plants; especially where deer densities are high, such as Keene Valley and Old Forge. Identification. Japanese Barberry is dense shrub, typically 2-4 feet tall that has a single spine where the leaves meet the stem, oval red berries, and bright yellow inner bark and roots.  Spread. Japanese barberry is still a popular landscaping plant, although its sale was recently prohibited in NYS. Once planted in a landscape or garden, Japanese barberry is often spread by birds that eat the plant’s bright red berries. Once fruit producing bushes are in an area it can be distributed rapidly over long distances. Like most invasive species, its seeds typically germinate betterin disturbed areas such as roadsides. When to Observe. Early spring and late fall. Like a number of other invasive plants, Japanese barberry leafs out much sooner than native species, and holds onto its leaves later in the fall. In the fall, Japanese barberry’s leaves turn bright red or orange, making it easy to spot when other native plants have already dropped their leaves. Control. Call APIPP at (518) 576-2082. In most circumstances, landowners can and should manage Japanese barberry themselves by digging or pulling the plants out by the roots. Cutting then treating the stump with herbicide to prevent re-sprouting can also be effective. For extensive infestations like those shown, foliar spraying with herbicide may be the most practical method. Links. APIPP Profile. APIPP Risk Assessment. USDA Forest Service Profile. Google Japanese Barberry Images. Ornamental Japanese Barberry Images. Inter-agency Guidelines. APIPP Management Guide.

Bush Honeysuckles. Bush Honeysuckles have an invasiveness ranking of 84.50, and are widely distributed throughout the Adirondacks. In some areas of the Adirondacks, they have already proliferated to a damaging extent. Like with Japanese barberry, they provide an ideal microclimate for ticks, significantly raising the risk of tick-borne diseases (Allan 2010). Identification. There are a number of different invasive Bush Honeysuckle species. The USDA Forest Service has a very helpful fact sheet on the different types of invasive bush honeysuckles. Both invasive and native honeysuckles leaf out early, although the invasives tend to hold onto their leaves much later into the fall. Invasive honeysuckles have showy, fragrant flowers, followed by red or orange, fleshy fruit perched on top of the stem. The center or pith of invasive honeysuckle branches is hollow.  A native honeysuckle found in the Adirondacks,  American Fly Honeysuckle, Lonicera canadensis, has a sparser growth habit, and has flowers and fruit that hang below the stem. Mountain Fly Honeysuckle, Lonicera villosa, also leafs out and flowers early, but is unlikely to be confused with the invasive species, as it generally has a short and shrubby growth form. Spread. Originally introduced to New York in the ornamental plan trade, bush honeysuckles are predominantly spread by birds who eat and distribute the plant’s abundant berries. Invasive honeysuckles typically become established in disturbed areas with ample sunlight such as roadsides and abandoned fields. When to Observe. Like many invasive shrub species, invasive honeysuckles leaf out early, and hang onto their leaves late into the fall. Native honeysuckles also leaf out early, however, so you'll need to distinguish between the native and invasive species. During mid-spring, invasive honeysuckles produce abundant, fragrant flowers, and during the summers, bright red or orange berries.  Control. Call APIPP at (518) 576-2082. Large shrubs can be cut, with the stump immediately treated with glyphosate to prevent re-sprouting. When using mechanical management techniques, hang all plant material roots up to prevent vegetative regrowth. If herbicide is not applied to the cut stump, repeated cuttings will likely be required (Luken 1991). Seedlings and small shrubs can be pulled or dug out by the roots, but soil disturbance should be minimized. Infested areas will need to be monitored for several years after treatment to address any seedlings emerging from the seed bank.. Links. APIPP Profile. APIPP Risk Assessment. Forest Invasive Plants Resource Center Fact Sheet. Inter-agency Guidelines. APIPP Management Guide.

Garlic Mustard. Garlic Mustard has an invasiveness ranking of 84.00, and as of 2015 APIPP has documented 176 occurrences in the Adirondacks. Garlic Mustard is very shade tolerant, and is a threat to the forest understory. It is able to produce chemicals through its roots (allelopathy) that suppress the growth of other plants nearby; allowing it to spread further into the forest. Identification. Garlic Mustard is a biennial, meaning it grows without flowering the first year. It then flowers, goes to seed, and dies the second year. First year plants have kidney-shaped leaves with scalloped margins. The second year, it springs to life early in the spring, producing triangular, toothy leaves and a flower spike with small white flowers.  True to its name, when a leaf is crushed, it has a garlicky, mustardy odor. Spread. Garlic Mustard produces abundant, small seeds, which are easily transported in mud on boots, equipment and vehicles. When to Observe. Garlic Mustard is easiest to spot in the early spring when mature plants are in flower, but persists in the Adirondacks throughout the growing season. Look for it in disturbed woodland areas, such as trailheads, campgrounds, and hiking trails.  Control.Call APIPP at (518) 576-2082. Garlic mustard must be managed in the spring before it sets seed Small infestations of Garlic Mustard can be hand pulled, while a foliar spray of herbicide may be most practical for large patches. Seed remains viable in the soil for up to seven years, so long-term monitoring will be required.  Links. APIPP Profile. APIPP Risk Assessment. Forest Invasive Plants Resource Center Fact Sheet. Google Garlic Mustard Images. Inter-agency Guidelines. APIPP Management Guide.

Additional Terrestrial Invasive Plants of Concern. New potentially invasive species, are constantly being moved and introduced across the globe. In addition, species that historically haven’t created an issue, can become a problem due to changing environmental variables such as warming winters and increased deer populations. Below are a few other priority terrestrial invasive plants to be aware of according to APIPP. 

Black swallow-wort, which has an invasiveness ranking of 89.69, and is currently present in the eastern Adirondacks. Oriental Bittersweet, which has an invasiveness ranking of 86.67, and is well established in the Lake George and Lake Champlain area. Burning Bushisa very common landscaping shrub with an invasiveness ranking of 81.25, but has yet to get firmly established in the Adirondacks. Common Buckthorn, which has a ranking of 81.00, and is currently found throughout much of the Adirondacks. Autumn Olive, which has an invasiveness ranking of 94, is found in isolated pockets in various communities throughout the Park.  Hemlock Woolly Adelgid is not yet present in the Adirondacks, but warmer temperatures and cold adaptability makes its arrival inevitable. The video below provides a good overview of the threat, and what's being done to help save New York's hemlocks.

Aquatic Invasive Species

Once aquatic invasive species are established in your lake, they are very difficult, if not impossible, to eradicate. Only new, small and/or isolated infestations have much chance of being fully eradicated although larger populations can be significantly reduced through continued management. To reiterate, preventing the introduction of aquatic invasive species should be a priority for Adirondack landowners. If aquatic invasive species are introduced to your property, the management options available for individual landowners are very limited. If you think you might have aquatic invasive species in your waters, here are some of the species you are likely to see. In addition, you should check out the program’s aquatic invasive species distribution map to see what might be lurking in waters in your area or that you might visit. 

If you do have aquatic invasive species in your waters and are interested in managing them, you should contact APIPP and get involved with the Adirondack Lakes Alliance, a group of lake associations with extensive experience in dealing with aquatic invasive species.

References AND RESOURCES

organizations and sites

Adirondack Park Invasive Plant Program. "The mission of the Adirondack Park Invasive Plant Program (APIPP) is to protect the Adirondack region from the negative impacts of invasive species... APIPP’s role is to serve as a clearinghouse of information, a coordinator of action, and a communicator of needs for invasive species issues affecting the Adirondack region." (Visit)

Adirondack Watershed Institute of Paul Smith's College. "The mission of the Adirondack Watershed Institute is to create scientifically-sound knowledge about terrestrial and aquatic ecosystems and human relationships with the environment, enhance the educational opportunities available for undergraduate students and to engage the Adirondack Community in ways that facilitate the stewardship of our natural resources." (Visit)

"Phragmites - Vectors and Dispersal." https://mnfi.anr.msu.edu/phragmites/vectors.cfm. Michigan State University Extension. 

Great Lakes Worm Watch - Natural Resources Research Institute. http://www.nrri.umn.edu/worms/. University of Minnesota.

Papers

Allan, Brian F., et al. "Invasive honeysuckle eradication reduces tick-borne disease risk by altering host dynamics." Proceedings of the National Academy of Sciences 107.43 (2010): 18523-18527. (PDF)

Bartuszevige, Anne M., and David L. Gorchov. "Avian seed dispersal of an invasive shrub." Biological Invasions 8.5 (2006): 1013-1022. (PDF)

Brisson, Jacques, Étienne Paradis, and Marie-Ève Bellavance. "Evidence of sexual reproduction in the invasive common reed (Phragmites australis subsp. australis; Poaceae) in eastern Canada: a possible consequence of global warming." Rhodora 110.942 (2008): 225-230. (PDF)

Groeneveld, Elisabeth, François Belzile, and Claude Lavoie. "Sexual reproduction of Japanese knotweed (Fallopia japonica sl) at its northern distribution limit: new evidence of the effect of climate warming on an invasive species." American journal of botany 101.3 (2014): 459-466. (PDF)

Gucker, Corey L. 2008. Phragmites australis. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2016, April 29]. (PDF)

Homan, Caitlin, et al. "Application of lime (CaCO 3) to promote forest recovery from severe acidification increases potential for earthworm invasion." Forest Ecology and Management 368 (2016): 39-44. (PDF)

Luken, James O., and Daniel T. Mattimiro. "Habitat-specific resilience of the invasive shrub Amur honeysuckle (Lonicera maackii) during repeated clipping." Ecological Applications (1991): 104-109. (PDF)

McCay, Timothy S., Deanna H. McCay, and Jessica L. Czajka. "Deposition of exotic bird-dispersed seeds into three habitats of a fragmented landscape in the northeastern United States." Plant Ecology 203.1 (2009): 59-67. (PDF)

Munger, Gregory T. 2002. Lythrum salicaria. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2016, April 4] (PDF)

Nuzzo, Victoria A., John C. Maerz, and Bernd Blossey. "Earthworm invasion as the driving force behind plant invasion and community change in northeastern North American forests." Conservation Biology 23.4 (2009): 966-974. (PDF)

Paradis, Annie, et al. "Role of winter temperature and climate change on the survival and future range expansion of the hemlock woolly adelgid (Adelges tsugae) in eastern North America." Mitigation and Adaptation Strategies for Global Change 13.5-6 (2008): 541-554. (PDF)

Seidl, Dara E., and Peter Klepeis. "Human dimensions of earthworm invasion in the Adirondack State Park." Human ecology 39.5 (2011): 641-655. (PDF)

Silander, John A., and Debra M. Klepeis. "The invasion ecology of Japanese barberry (Berberis thunbergii) in the New England landscape." Biological invasions 1.2-3 (1999): 189-201. (PDF)

Williams, Scott C., and Jeffrey S. Ward. "Effects of Japanese barberry (Ranunculales: Berberidaceae) removal and resulting microclimatic changes on Ixodes scapularis (Acari: Ixodidae) abundances in Connecticut, USA." Environmental entomology 39.6 (2010): 1911-1921. (PDF)