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Amy Rowe, Rutgers Cooperative Extension
With spring on the horizon, it’s time to think about invasive species.
First and Second Rounds: The Basics
An invasive species is one that is not native to an area that causes ecological and/or economic damage or harm to human health. Many people associate invasive species only with plants, but there are also invasive wildlife, insects, and diseases. The US Fish and Wildlife Service estimates that the economic damages associated with invasive species in the United States is approximately $120 billion/year (2012).
Invasive species are destructive for several reasons. Since they are not native to a particular ecosystem, there are no biological controls that have evolved over thousands of years to manage them such as natural predators and diseases. Without these controls, the invasives can outcompete the native species for resources and space.
Sweet Sixteen: How Do Invasive Species Move?
There are both natural and human-accelerated spread mechanisms.
- Animals can spread invasive species as birds disperse seeds and other plants and parasites can attach themselves to migrating wildlife.
- Deer play a role in spreading invasive plants because they do not eat them. Rather, they eat the native plants which allows invasive exotics the opportunity to spread.
- Natural disasters such as forest fires can also lead to the spread of invasive species.
- Humans have greatly increased the ease, speed, and movement of invasion.
- Some species have been introduced on purpose, as explorers found an interesting plant or animal and brought it back to their homeland.
- Other species have been introduced inadvertently via “hitchhiking” in shipping containers or on vehicles.
Elite Eight: Beating the Competition
How do invasive species outcompete native species so well? There are some common traits that make them more prolific (Kolar, 2001):
- Rapid reproduction
- Fast growth
- Tolerance of a variety of environmental conditions
- High dispersal ability – wind, animals, birds, etc.
- Association with humans – if humans placed them or cultivated them
Final Four: Some NJ Invasive Species
There are lots of invasive species that can be found in New Jersey, but here are a few examples:
- Japanese barberry – this popular landscape shrub is widespread and has invaded many of NJ’s forests. It has also been shown to harbor deer ticks, which are carriers of Lyme disease (Williams, et al., 2017).
- Spotted lanternfly – this plant hopper insect originally from Asia can feed on more than 70 plant species including cultivated and wild grapes, fruit trees, and hardwood trees common in woodlots and as landscape plantings (NJAES, 2019).
- European starling – this prolific bird was introduced in Central Park in the late 1890s and has flourished at the expense of native woodpeckers, great-crested flycatchers, common flickers, bluebirds and other cavity-nesting species (NJDEP, 2003).
- Snakehead fish – these adaptable were once imported live as an ornamental species and as food for people. They are voracious eaters and will feed on any fish that will fit in their disproportionately large mouths (NJDEP, 2016).
Championship: What Can We Do to Defeat Invasive Species?
A few suggestions for reducing invasive plant species from Michele Bakacs’ “Plant This, Not That” webinar:
- Support the New Jersey Invasive Species Strike Team and help control invasive species. (www.fohvos.info/invasive-species-strike-team/)
- Understand that invasive plants don’t know boundaries. They may behave on your property while quietly invading a nearby forest.
- Identify and remove invasive plants from your property. Don’t remove until you have a replacement.
- Choose natives plants and talk to your nursery about offering native plant selections.
- Support local ordinances and eventually statewide bans.
- Resources and further reading can be found after the Upcoming Events.
Resources and Further Reading
Bakacs, Michele. 2020. Plant This, Not That. (Video) rutgers.webex.com/rutgers/lsr.php?RCID=13b11be4969474066f1e67a12de40413 . Passcode: EarthDay2020.
Kolar, C.S. (2001). “Progress in invasion biology: predicting invaders”. Trends in Ecology & Evolution. 16 (4): 199–204.
New Jersey Agricultural Experiment Station (2019). njaes.rutgers.edu/spotted-lanternfly/
New Jersey Department of Environmental Protection (2004).
www.state.nj.us/dep/dsr/njcrp/starlings.pdf
New Jersey Department of Environmental Protection (2004). www.nj.gov/dep/njisc/pdf.htm
New Jersey Department of Environmental Protection (2016). www.state.nj.us/dep/fgw/aquatic_invasives.htm
New Jersey Invasive Species Strike Team. www.fohvos.info/invasive-species-strike-team/
U.S. Fish and Wildlife Service. 2012. The cost of invasive species. www.fws.gov/verobeach/PythonPDF/CostofInvasivesFactSheet.pdf
Williams, S.C., Linske, M.A., Ward, J.A. (2017). Long-Term Effects of Berberis thunbergii (Ranunculales: Berberidaceae) Management on Ixodes scapularis (Acari: Ixodidae) Abundance and Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) Prevalence in Connecticut, USA, Environmental Entomology, Volume 46, Issue 6, Pages 1329–1338, doi.org/10.1093/ee/nvx146