As per Executive Order 13112 an "invasive species" is defined as a species that is:
- non-native (or alien) to the ecosystem under consideration and
- whose introduction causes or is likely to cause economic or environmental harm or harm to human health.
Control over invasive species can be thought of as having 3 levels:
- Prevention - The methods usually employs outreach or legistation. Examples include encouraging people to stop purchasing invasive landscape plants or banning the movement of firewood to prevent the spread of invasive insects.
- Early Detection/Rapid Response - The focus is on identifying invasions as they are emerging in order to prevent them from impacting native species. The goal is to fully eradicate target species.
- Control and Management - The focus is on the protection of sites with high conservation values and includes long-term control programs to reverse larger infestations of widespread species. The goal is restoration of the site.
Ultimately, we hope that regulatory actions banning the sale and movement of invasive plants and animals will be implemented at both the state and national levels. This would significantly improve our chances of halting the continuing introduction of new invasive species.
Deer & Invasive Plants
When addressing invasive plant species, there is a critical link between deer overabundance and proliferation of invasive species. Many native species are preferred deer forage, while invasive species are largely unimpacted. In order to gain control over invasive plants, this problem needs to be addressed through active deer management programs, aimed at reducing herd size. The long term goal is to establish ecological control where native plants are able to overcome and outcompete invasive plants, diminishing their ecologial impacts.
Defining the problem is simple..
For Invasive Plants: A relatively small number of nonindigenous species take up large amounts of space that would otherwise be occupied by a diversity of native species, leading to negative impacts on native plants and animals.
For Invasive Animals: Invasive animals, insect pests and pathogens, cause significant damage through the degredation of whole native systems or through competition and predation of native species.
(Source: NJ Strategic Management Plan for Invasive Species)
Climate Change and Invasive Species
Climate change -- with its increasing frequency of extreme weather events and its ability to alter critical components of natural systems such as temperature, precipitation, atmospheric composition and land cover -- can facilitate the spread of invasive species. When rivers overflow their banks, invasive plants and animals can be transported to new sites. When heavy winds topple trees in forests, invasive plants often outcompete natives for the sunlight streaming in through newly-opened gaps in the canopy. Higher average temperatures lengthen terrestrial growing seasons, enhance the winter survival rates of species that would otherwise suffer die-backs due to freezes, and expand aquatic habitats for invasive warm–water species while stressing populations of native cool-water species.
Diligent monitoring of vulnerable areas is required to spot and stop populations of invasives, whether they arise after events like Superstorm Sandy, slower moving impacts of climate change, or other factors (the inadvertent transport of aquatic hitch-hikers from one waterway to another on boats, waders and other fishing equipment, for example).
Climate change is opening doors to invasive species, but we do not have to have to stand idly by. We can arm ourselves with knowledge about the invasive species most likely to cross New Jersey's thresholds, be on the lookout for them and strike as soon as they are detected.
Download the list of invasive species threatening New Jersey here.
Learn more about the link between climate change and invasive species
- Climate Change 2014: Impacts, Adaptation, and Vulnerability (Intergovernmental Panel on Climate Change)
- National Climate Assessment (U.S. Global Change Research Program)
- Climate Change & Invasive Species: Many Questions, a Few Answers and Much to be Determined! (New Jersey Invasive Species Strike Team)
- Climate Change: Challenge of Invasive Species (USGS)
- Invasive Plants and Climate Change (U.S. Forest Service)
- Climate change and invasive alien species (CABI)
- Predicting Climate Change Impacts on Invasive Species in Pennsylvania (Pennsylvania Sea Grant)